Chapter 5, Advanced Cardiopulmonary Monitoring, contains discussions on preparation, care, and maintenance of central venous, arterial, and pulmonary artery lines. Review the chapter if needed.

Each hospital or physician may have a prescribed way that the catheter insertion procedure is performed. The general steps are listed here:

1. Inform the patient of the procedure and have the patient sign the medical release form if time permits.

2. Have a sedative or pain-relieving agent administered if needed.

3. If necessary, shave body hair from the insertion site.

4. Don a sterile mask, cap, gown, and gloves according to protocol.

5. Disinfect the insertion site with a Betadine (iodine) soaked sterile 4 × 4 inch gauze pad. Place the pad at the center of the insertion site, and move it in a widening spiral away from the center. This step should be repeated with a second gauze pad. Let the Betadine dry.

6. Protect the area around the insertion site with a sterile fenestrated surgical drape.

7. Prepare the sterile field where the catheter, scalpel, supplies, and so forth will be placed. Have a local anesthestic such as Xylocaine (lidocaine) available in a syringe with needle. The physician will inject this into the insertion site.

8. Assist the physician into his or her sterile mask, cap, gown, and gloves.

9. Obtain the properly sized catheter for the procedure or patient.

10. Assist the physician with the procedure as needed. This may include connecting the catheter to the tubing system, flushing the catheter and tubing system, and inflating the balloon on a pulmonary artery catheter.

11. Make any adjustments in the patient’s respiratory care equipment as needed.

12. Dispose of any used supplies and so forth after the procedure is completed.

13. Tend to the patient’s comfort.

3. Assist with ultrasound (ELE code: IIIJ9) [Difficulty: ELE: R]

The ultrasound (also called a sonogram or ultrasonography) procedure uses a transducer to send soundwaves through the soft tissues of the body. A lubricating gel is placed on the skin so that there is good sound transmission from the transducer into the patient. Depending on the density of the tissues and fluids, the soundwaves bounce off and are received back to the transducer. The sound energy is converted to electrical energy to produce a two-dimensional image of the various organs. Ultrasound can be very useful in the following areas of interest to respiratory therapists:

• Helps locate arteries and veins, visualize blood flow through the vessels, and determine blood pressure.

• Obstetric ultrasound will help to establish the number of fetuses and their size, the amount of amniotic fluid present, and the location of the placenta(s).

• Helps determine if a neonate has suffered a cerebral hemorrhage.

• Heart sonograms will provide information on cardiac structure and blood flow through the chambers and valves.

• Locates pleural fluid to help guide needle placement for a thoracentesis.

• Identifies the movement of the hemidiaphragms.

• A very small transducer can be placed via bronchoscopy into a bronchus. This procedure has been used to identify a bronchial wall tumor and affected local lymph nodes to help guide a biopsy procedure.

Note that the lungs themselves cannot be properly imaged with ultrasound because they are air-filled. The ultrasound procedure is noninvasive and safe with no patient side effects.

4. Assist with cardioversion (Code: IIIJ8) [Difficulty: ELE: R, Ap; WRE: An]

Cardioversion (or countershock) refers to deliberately sending a direct current (DC) electrical shock through the patient’s heart. Its purpose is to suppress an abnormal heartbeat so that the normal pacemaker at the sinoatrial (SA) node assumes control. This is accomplished if a great enough electrical current is sent through the chest wall to cause the depolarization of a critical mass of myocardial cells. After this, the SA node should take over as the pacemaker, provided that the heart muscle is oxygenated and not too acidotic. Two different types of cardioversion exist: defibrillation (also called unsynchronized cardioversion) and synchronized cardioversion. Both were introduced in Chapter 11 for the treatment of specific arrhythmias.

Defibrillation is performed in an emergency situation (see Figure 11-41). Patients who need to be defibrillated include those who have ventricular tachycardia or ventricular flutter (see Figures 11-38 and 11-39) when they are pulseless, unresponsive, or hypotensive or patients who have pulmonary edema and ventricular fibrillation (see Figure 11-40). Because the fastest possible action is needed, no attempt is made to synchronize the defibrillation shock with the heart’s rhythm. While cardiopulmonary resuscitation (CPR) is being performed, the defibrillator unit is prepared. The defibrillating paddles (large positive and negative electrodes) are placed on the patient’s right anterior and left lateral chest wall. The physician or other qualified person (respiratory therapist, registered nurse, or paramedic) performing the defibrillation should call out, “Stand clear.” All other medical personnel should stand back from the patient and the bed and not touch anything that is electrically grounded. When the buttons on the paddles are pushed, the shock is administered. If it is successful, the patient’s heartbeat returns to normal sinus rhythm. If the initial shock is unsuccessful, CPR is continued. The defibrillator is then recharged for another attempt as quickly as possible. Box 18-1 shows the sequence of increasingly more powerful countershocks that can be given.

BOX 18-1 Wattage Used in Synchronous Cardioversion and Defibrillation

SYNCHRONIZED CARDIOVERSION OF AN INFANT

0.5-1.0 J (watt-seconds) per kg

Stepwise increases in energy should be used if the initial shock fails to convert the rhythm.

SYNCHRONIZED CARDIOVERSION OF AN ADULT

Atrial flutter and paroxysmal atrial tachycardia: 50-100 J

Stepwise increases in energy should be used if the initial shock fails to convert the rhythm: 200, 300, 360 J.

ATRIAL FIBRILLATION

Stepwise increases in energy should be used if the initial shock fails to convert the rhythm: 200, 300, 360 J.

VENTRICULAR TACHYCARDIA WITH A REGULAR FORM AND RATE WITH OR WITHOUT A PULSE

100 J

Stepwise increases in energy should be used if the initial shock fails to convert the rhythm: 200, 300, 360 J.

VENTRICULAR TACHYCARDIA WITH AN IRREGULAR FORM AND RATE

200 J

Stepwise increases in energy should be used if the initial shock fails to convert the rhythm: 300, 360 J.

Synchronized cardioversion is similar in some ways to defibrillation. An electrical shock is sent by two paddles through the heart to suppress paroxysmal atrial tachycardia, atrial flutter, atrial fibrillation, or hemodynamically stable ventricular tachycardia (see Figures 11-25, 11-26, and 11-27) so that the SA node assumes control. Its major difference from defibrillation is that the electrical shock is administered automatically by the defibrillator after an R wave is recognized by the electrocardiogram (ECG) monitor (see Figure 11-5). The ECG electrodes must be in place and the best lead (often lead II) selected to show a clear, strong, upright R wave. The defibrillator unit is programmed for synchronized cardioversion. The physician holds the paddles on the patient’s right anterior and left lateral chest wall. When the discharge buttons are pushed on the paddles, the shock is sent after the next R wave is identified by the ECG monitor.

Cardioversion is not considered an emergency; however, it is performed as quickly as possible so that the patient does not stay in the abnormal rhythm any longer than necessary. Synchronized cardioversion is performed only if medical treatment with antiarrhythmia drugs or carotid artery massage has no effect. Because these patients are usually conscious, they should be sedated with diazepam (Valium), midazolam (Versed), or a similar medication. Patients who are hypotensive or already unconscious should not be sedated.

The respiratory therapist’s role in cardioversion may include the following:

• Making sure that the ECG electrodes are properly positioned for either monitoring or diagnosing the rhythm, as the physician requires

• Making sure that the ECG monitor and electrocardiograph are working properly

• Making sure that the ECG lead that results in a strong R wave is selected; usually the R wave is upright in lead II

• Charging the defibrillator to the power level ordered by the physician

• Adding the electrode cream to the electrode paddles to decrease the skin’s resistance to electricity

• Being prepared to keep a patent airway, manually ventilate the patient’s lungs, or begin chest compressions, if necessary

5. Bronchoscopy

Bronchoscopy is a procedure that involves looking directly into the patient’s tracheobronchial airways. The physician can perform a number of diagnostic and therapeutic tasks under direct vision. (See Box 18-2 for uses, limitations, and risks of bronchoscopy.)

BOX 18-2 Uses, Limitations, and Risks of Bronchoscopy

FIBEROPTIC BRONCHOSCOPY

Diagnostic Uses

Search for the origin of a positive sputum cytologic result

Evaluate lung lesions and perform transbronchial biopsy of lung tissue (should be done only under fluoroscopic control)

Stage lung cancer preoperatively

Investigate unexplained hemoptysis, unexplained cough, localized wheeze, or stridor

Search for the cause of unexplained paralysis of a vocal cord or hemidiaphragm

Search for the cause of superior vena cava syndrome, chylothorax, or unexplained pleural effusion

Assess airway patency and investigate suspected bronchial tear or other injury after thoracic trauma

Investigate a suspected tracheoesophageal fistula

Investigate problems related to an endotracheal tube such as tracheal damage, airway obstruction, or tube placement

Obtain mucus for identification of pathogens

Investigate suspected injury secondary to inhaled superheated gas and smoke from an enclosed fire

Investigate suspected injury secondary to the aspiration of gastric contents

Perform bronchoalveolar lavage

Therapeutic Uses

Remove secretions or mucous plugs that cannot be cleared by other methods

Remove small foreign bodies

Remove abnormal endobronchial tissue or foreign material by forceps or laser techniques

a. Recommend a diagnostic bronchoscopy procedure to evaluate hemoptysis or atelectasis (Code: IC3) [Difficulty: ELE: R, Ap; WRE: An]

Hemoptysis commonly is caused by blunt chest trauma or a bleeding bronchial tumor. Segmental or lobar atelectasis is commonly caused by an aspirated foreign body or a bronchial tumor. As listed in Box 18-2, bronchoscopy can be used to help diagnose and manage these problems.

b. Recommend a bronchoalveolar lavage (Code: IC5) [Difficulty: ELE: R, Ap; WRE: An]

A bronchoalveolar lavage (BAL) (also called bronchopulmonary lavage) is a diagnostic procedure most commonly performed if lung cancer or infection is suspected and expectorated sputum specimens are inconclusive. The BAL procedure involves introducing sterile saline through the open channel of a flexible fiberoptic bronchoscope into a specific segment or bronchus. The fluid and any loose alveolar cells or bacteria are then suctioned out through the bronchoscope. The removed materials are sent to the laboratory for cytologic and microbiologic studies.

c. Assist with the bronchoscopy procedure (Code: IIIJ2) [Difficulty: ELE: R, Ap; WRE: An]

Typical duties of the respiratory therapist during bronchoscopy may include the following:

1. Inform the patient of the procedure. Have the patient sign the medical release form if not already done. Ask the patient if he/she has eaten within the last 6 hours. (If the patient has recently eaten, the procedure will have to be rescheduled.)

2. Have a sedative such as midazolam (Versed) or diazepam (Valium) administered for conscious sedation, if needed.

3. Nebulize a topical anesthetic, such as 4% lidocaine (Xylocaine), to the airway.

4. Check the fiberoptic unit for proper function: working light source, working thumb control to flexible tip, working adjustable eyepiece focus, and patency of the suction and biopsy channel.

5. Check the functioning of the biopsy brush and forceps.

6. Set up and monitor the patient’s ECG.

7. Monitor the patient’s vital signs.

8. Place the pulse oximeter on the patient and monitor.

9. Administer oxygen via a nasal catheter or the suction and biopsy channel on the unit.

10. Collect all suctioned material or other specimens for culture and sensitivity.

11. Perform biopsies and brushings for cytology.

12. Operate any photographic equipment.

13. If the patient is being mechanically ventilated during fiberoptic bronchoscopy, perform the following:

• Place a bronchoscopy adapter between the endotracheal tube and Y of the circuit. This keeps a seal around the bronchoscopy tube to minimize any decrease in tidal volume.

• Place a bite block into the patient’s mouth so that the endotracheal tube and fiberoptic catheter cannot be bitten.

• Watch for an increase in the peak pressure from the increased resistance to airflow caused by the bronchoscopy tube.

• Be prepared to make adjustments in inspired oxygen, respiratory rate, flow, and set tidal volume if there is a leak.

• Be prepared to switch from conventional volume ventilation to high-frequency jet ventilation if needed.

14. Assess the patient after the procedure:

• Check vital signs and auscultate breath sounds every 15 minutes for 1 hour, then every 2 hours for 4 hours, then as ordered.

• Monitor cough for hemoptysis, especially after a biopsy procedure.

• Suction secretions if needed.

• Provide for pain relief if needed.

15. Use a glutaraldehyde disinfecting solution (Cidex) on the equipment between patient procedures.

Exam Hint 18-2 (WRE)

Usually one question on the examination asks about indications for bronchoscopy or hazards related to the procedure.

d. Manipulate a bronchoscope by order or protocol (Code: IIA27) [Difficulty: ELE: R; WRE: Ap, An]

1. Get a bronchoscope for the planned procedure

The rigid bronchoscope is a straight, hollow, stainless-steel tube (Figure 18-1). It has a distal light source so that the airway can be seen and a side port for providing oxygen or mechanical ventilation to the patient. The right and left mainstem bronchi can be observed by passing a mirror through the main channel. A hook or net can be passed through the main channel into the trachea or either bronchus to remove a foreign body. The rigid bronchoscope is preferred for the treatment of massive hemoptysis or to remove a foreign body.

Figure 18-1 A rigid tube bronchoscope being inserted into a patient’s trachea. Note how the head and neck must be hyperextended.

(From Simmons KF: Airway care. In Scanlan CL, Spearman CB, Sheldon RL, editors: Egan’s fundamentals of respiratory care, ed 5, St Louis, 1990, Mosby.)

Flexible fiberoptic bronchoscopy (FFB) uses a smaller diameter flexible tube with two sets of fiberoptic bundles that shine light into the airway and allow viewing of the airway. It has gained wide popularity because it is better tolerated by the patient and allows for better visualization and collection of specimens from smaller bronchi (Figures 18-2 and 18-3). The adult bronchoscopy tube is about 5- to 6-mm outer diameter (OD), and the pediatric tube is about 3-mm OD. The small diameter and ability to guide the catheter allow the operator to look into the bronchus to each lung segment (segmental bronchi). The fiberoptic bronchoscope is preferred over the rigid one when the patient is being mechanically ventilated or has disease or trauma to the skull, jaw, or cervical spine. As shown in Figure 18-2, a photo connection allows the assistant either to take still photographs of pulmonary anatomy or to videotape the entire procedure.

Figure 18-2 A flexible fiberoptic bronchoscope with its components and special features.

(From Wilkins RL, Stoller JK, Kacmarek RM: Egan’s fundamentals of respiratory care, ed 9, St Louis, 2009, Mosby.)

Figure 18-3 A flexible fiberoptic bronchoscopy procedure being performed on a patient.

(From Williams SF, Thompson JM: Respiratory disorders, St Louis, 1990, Mosby.)

A limitation of the pediatric unit is that there is no channel outlet for suctioning purposes. This is because of its small size. If a patient has an obstructing bronchial tumor, a special laser fiberoptic bronchoscope is used to burn part of the tumor. This enables the patient to breathe more easily, but this procedure is not a cure for the cancer.

2. Put the equipment together and make sure that it works properly

The fiberoptic bronchoscope is preassembled (see Figure 18-2 for its primary features). If photographing or videotaping is planned, the camera must be attached at the photo connection. Have a central or portable suctioning system set up with suction tubing. In addition, the following steps must be used to check for proper functioning:

1. Make sure the light source shines through to the distal end of the bronchoscope.

2. Look through the eyepiece. Point the distal end of the bronchoscope at a close object, and adjust the lens to bring it into focus.

3. Adjust the thumb control to bend the distal tip.

4. Pass biopsy forceps or brush through the channel port to the outlet.

5. Make sure the suction tubing connects to the channel port.

3. Troubleshoot any problems with the equipment

If the light source does not work, you must check the manufacturer’s equipment manual to help determine if the problem could be something simple such as a burned-out light bulb or a more serious problem. Similarly, problems with the camera equipment can be resolved by checking the manufacturer’s equipment manual.

Failure to pass a biopsy forceps or brush through the channel port probably means that an obstruction such as dried blood or tissue is present. Try applying suction through the channel port to clear out the debris. It also may be helpful to squirt sterile distilled water from a syringe through the channel. Try suctioning again or pushing the biopsy forceps through the channel. If alternating suction, instilling water, and pushing the forceps through the channel does not dislodge the debris, the unit cannot be used. Try soaking the bronchoscope in water to soften the debris before repeating these processes. If the channel cannot be cleared, the unit must be sent back to the manufacturer for repairs.

6. Thoracentesis

a. Recommend a thoracentesis to treat a pleural effusion (WRE code: IC14) [Difficulty: WRE: R, Ap, An]

Thoracentesis (also called thoracocentesis) is the surgical puncture of the chest wall and pleural space with a needle to aspirate pleural fluid for therapeutic or diagnostic purposes. Thoracentesis is performed as a therapeutic procedure to remove air or fluid that has accumulated in the pleural space and is causing the patient pain, dyspnea, hypoxemia, or a combination of these symptoms. Thoracentesis also is performed as a diagnostic procedure to obtain a fluid sample for analysis to diagnose the cause of a pleural effusion. Pleural fluid may be a transudate that results from congestive heart failure, cirrhosis, nephrotic syndrome, or hypoproteinemia. Pleural fluid may also be an exudate that results most often from inflammatory, infectious, or neoplastic diseases of the pleura or lung. Other causes of an exudate include pulmonary infarction, chest trauma, drug hypersensitivity, and collagen vascular disease.

b. Assist with a thoracentesis procedure (Code: IIIJ3) [Difficulty: ELE: R, Ap; WRE: An]

The respiratory therapist may be responsible for preparing the patient, disinfecting the puncture site, setting up the sterile field, and preparing the equipment and supplies. Each hospital or physician may have a prescribed way of doing this. If the patient had a previous thoracentesis procedure, review the patient’s chart for information on the nature of the removed fluid. Be prepared to compare the previously removed fluid with the fluid being removed at this time. The general steps listed here apply to a thoracentesis procedure and a percutaneous needle biopsy of the pleura and lung (described below):

1. Inform the patient of the procedure. Have him or her sign the medical release form if not already done.

2. Have a sedative or pain-relieving agent administered if needed.

3. Position the patient sitting on the side of the bed and leaning on the overbed table as shown in Figure 18-4. Alternatively, the patient may straddle a chair and rest his or her arms and head on the back of the chair. The patient who cannot sit up is positioned on his or her side with the unaffected lung down on the bed.

4. If necessary, shave the insertion site clear of body hair.

5. Put on a sterile mask, cap, gown, and gloves according to protocol.

6. Disinfect the insertion site with a Betadine (iodine) soaked sterile 4 × 4 inch gauze pad. Place the pad at the center of the insertion site, and move it in a widening spiral away from the center. This step should be repeated with a second gauze pad. Let the Betadine dry.

7. Protect around the insertion site with a sterile fenestrated surgical drape.

8. Prepare the sterile field with needed supplies such as 1% Xylocaine and a variety of needles and syringes. Note: A Curity Thoracentesis Tray or other prepackaged tray will contain the supplies that will most commonly be used.

9. Assist the physician into his or her sterile mask, cap, gown, and gloves.

10. Assist the physician with the procedure as described in the following steps.

11. Make any adjustments in the patient’s respiratory care equipment as needed.

12. Dispose of any used supplies and so forth after the procedure is completed.

13. Tend to the patient’s comfort.

Figure 18-4 Technique for thoracentesis. The patient sits up and leans on the overbed table. The pleural fluid is withdrawn through the needle by the syringe and then directed into the collection jar.

General steps in the removal of pleural fluid:

1. Check the patient’s chest x-ray for the location of the pleural fluid (or targeted tissue for a needle biopsy) and its relationship to the ribs and other tissues.

2. Inform the patient not to move or cough during the procedure so that accidental needle damage to the pleura or lung can be avoided.

3. The physician will anesthetize the thoracentesis site as shown in Figure 18-5, A and B.

4. The physician will insert a large-gauge needle (often 16 gauge) with attached 50-mL syringe into the pleural fluid (see Figure 18-5, C). (A cutting needle is used during a needle aspiration of pleural or lung tissue.)

5. The sample is then aspirated. If there is more than 50 mL of pleural fluid, the two-way valve or three-way stopcock, rubber hose, and collection tube are assembled to remove the fluid (see Figure 18-4).

6. The needle is removed and a bandage is placed over the puncture site.

7. Place the patient with the unaffected side down on the bed for 1 hour.

8. Observe the patient for dizziness and cyanosis. Frequently check the patient’s pulse oximeter valve. Assess the patient’s vital signs according to hospital policy. Auscultate frequently for diminished breath sounds over the affected lung as a sign of pneumothorax. The physician should order a chest x-ray to check for pneumothorax. (See Box 18-3 for the commonly seen complications of a thoracentesis or needle biopsy.)

9. Evaluate the gross appearance of the fluid that has been removed. A transudate is found when the fluid is clear, serous, or light yellow. It contains few cells of any kind. This is most commonly found in patients with congestive heart failure and pulmonary edema. A chylothorax is found when the fluid is opalescent or pearly white in color. Chyle is lymphatic fluid that drains into the pleural cavity when the thoracic duct is blocked. This could be caused by injury to the neck or a tumor that invades the thoracic duct. A hemothorax is found when the pleural fluid is bloody (sanguineous or serosanguineous). Chest wall injury or puncture is the usual cause. An empyema is found when the fluid is thick and puslike with a foul odor. The patient usually has a bacterial infection of the lung and/or pleura, and infected fluid has entered the pleural space. In all cases, the collected pleural fluid sample should be sent to the laboratory for detailed analysis.

10. Send the collected sample to the laboratory for analysis.

Figure 18-5 Anesthetizing the needle insertion site and performing a thoracentesis. A, A 25-gauge needle is used to inject Xylocaine into the thoracentesis puncture site until the skin is raised. B, A 22-gauge needle is used to inject Xylocaine into the periosteum of the rib and surrounding tissues. The properly anesthetized patient should feel no pain during the thoracentesis. C, A 22- or larger-gauge aspirating needle is pushed through the numbed tissues, over the top edge of the rib, and into the pleural space. The fluid sample can now be aspirated.

(From Martin L: Pulmonary physiology in clinical practice: the essentials for patient care and evaluation, St Louis, 1987, Mosby.)

c. Assist with percutaneous needle aspiration biopsies of the lung

Percutaneous aspiration of pleural tissue or lung tissue involves a cutting needle being inserted through the chest wall into the target tissue(s) and the tissue sample being removed. The general procedure for a needle aspiration is described in the preceding section with the thoracentesis procedure.

A pleural biopsy is indicated when exudative fluid is found during a thoracentesis procedure. The cause could be from an infection, including tuberculosis, or a lung tumor. Additionally, a pleural biopsy is indicated when a chest x-ray shows a pleural tumor or unexplained pleural thickening. A cutting needle is inserted into the parietal pleura to withdraw a specimen for analysis.

A lung biopsy is indicated when a chest x-ray or a computed tomography (CT) scan indicates pulmonary parenchymal disease. A tissue sample is needed to determine if the cause is lung cancer, granuloma, infection, or sarcoidosis. A cutting needle is inserted through the parietal and visceral pleura to withdraw a specimen of suspicious lung tissue for analysis.

7. Management of a pneumothorax

a. Treat a tension pneumothorax (Code: III I2) [Difficulty: ELE: R, Ap; WRE: An]

In an emergency when the patient has a tension pneumothorax and rapidly worsening vital signs, the trapped pleural air must be rapidly removed from the chest. This is done by inserting a large-bore needle (16 gauge or larger) through the second or third intercostal space in the midclavicular line of the affected lung. Place the needle over the top of the rib to avoid injury to the blood vessels and nerves below the ribs. The intrapleural air leaves the chest, allowing the lung to expand. A pleural chest tube is then inserted for a long-term solution to the problem. If necessary, review the discussion in Chapters 1 and 15 on the signs and symptoms of a pneumothorax.

b. Assist with chest tube insertion (Code: III J5) [Difficulty: ELE: R, Ap; WRE: An]

A chest tube (also called tube thoracostomy) may be inserted into either one or both pleural spaces around the lungs, the mediastinal space, or the pericardial space around the heart. This procedure is indicated when air or fluid, or both, in any of these spaces interferes with normal lung or heart function. Box 18-4 lists the indications for the insertion of a chest tube.

In addition to chest tube insertion, the patient is often given 100% oxygen by a nonrebreather mask for two reasons. The first is to treat the patient for hypoxemia. Second, if pure oxygen enters the pleural space through a tear in lung tissue, it will be quickly absorbed into the blood. This allows the lung to expand faster than if the patient was breathing a lower percentage of oxygen.

General steps in inserting a pleural chest tube follow:

1. Check the patient’s chest radiograph for the location of the air or fluid in the pleural space and its relation to the ribs and other tissues.

2. Prepare the patient as described in the thoracentesis procedure. The patient is usually positioned to lie on his or her back or with the lung of the unaffected side down on the bed.

3. The physician anesthetizes the tube insertion site as shown in Figure 18-5, A and B.

4. The physician creates an opening into the patient’s chest wall to place the chest tube (Figure 18-6). A tube to remove air is placed into one of two places and then advanced toward the apex of the lung. With a midclavicular approach, the tube is placed over the top edge of a rib into the second to fourth intercostal space. With a midaxillary approach (preferred site), the tube is placed over the top edge of a rib into the fourth to sixth intercostal space. A tube to remove fluid is placed over the top edge of the rib into the sixth to eighth intercostal space. It is inserted at the midaxillary line and advanced toward the posterior base of the lung. Mediastinal or pericardial tubes are placed via an opening below the xiphoid process and positioned posterior to the heart (Figure 18-7). This is most commonly done during open heart surgery.

5. The tube is secured by sutures and covered with a sterile 4 × 4 inch gauze pad and tape.

6. The other end of the tube is connected to the drainage system (discussed later).

7. Place the patient with his or her back against the bed or with the unaffected side down on the bed. The physician may want the head of the bed elevated or flat.

8. Observe the patient for dizziness, cyanosis, and changes in heart rate and respiratory rate. (See Box 18-4 for the most commonly seen complications.)

Figure 18-6 Technique for inserting a pleural chest tube. A, Anatomic landmarks. B, Dissecting through the tissues with a hemostat. C, Using a finger to widen the opening and ensure that the lung has not been punctured. D, Proper tube placement. Air is removed by a tube that is placed toward the apex of the lung. Fluid is removed by a tube placed toward the posterior base of the lung.

Figure 18-7 Pericardiocentesis procedure.

(From Black JM, Hawks JH: Medical-surgical nursing, clinical management for positive outcomes, ed 8, St Louis, 2009, Saunders.)

Exam Hint 18-3 (ELE, WRE)

Every past examination has included at least one question that relates to identifying a patient having a tension pneumothorax, requiring the insertion of a large-bore needle or a pleural chest tube. Know the indications of a tension pneumothorax, including sudden deterioration of vital signs and hypoxemia, decreased breath sounds over the affected lung, decreased chest wall movement over the affected lung, hyperresonant percussion noted over the affected lung, and shift of the mediastinal structures away from the affected lung. See Figure 1-2 for a chest radiograph showing a pneumothorax.

c. Manipulate a pleural drainage system by order or protocol (ELE code: IIA21) [ELE difficulty: R, Ap, An]

1. Select a pleural drainage system

Modern drainage systems consist of either three or four chambers or sections designed to regulate the vacuum level, hold any drained fluids, prevent any outside air from entering the patient’s thorax, and act as a pressure-relief valve in case the vacuum regulator should fail. Argyle and Pleur-evac are two well-known manufacturers. The systems for draining the pleural space are discussed here, but the principles are the same for draining the mediastinal and pericardial spaces.

2. Assemble a pleural drainage system, ensure that it works properly, and identify any problems with it

Refer to Figure 18-8 for the assembly and operation of the three-chamber drainage system. The four-chamber drainage system is shown in Figure 18-9 and is discussed concurrently.

Figure 18-8 Three-chamber pleural drainage systems. A, Homemade three-chamber drainage system. The depth that the suction column tube is placed under water determines the level of vacuum that will be applied against the patient’s pleural space. B, Schematic drawing of a modern manufactured three-chamber drainage system.

(From Shapiro BA, Kacmarek RM, Cane RD et al: Clinical application of respiratory care, ed 4, St Louis, 1991, Mosby-Year Book. Used by permission.)

Figure 18-9 Four-chamber pleural drainage systems. Top, Homemade four-chamber drainage system. The depth that the suction column tube in chamber C is placed under water determines the level of vacuum that will be applied against the patient’s pleural space. Bottom, Schematic drawing of a modern manufactured four-chamber drainage system. The fourth chamber acts to vent high-pressure air if the vacuum should be turned off or malfunction.

(Modified from Pilbeam SP, Deshpande VM: Chest tubes and pleural drainage, Curr Rev Respir Ther 5:151, 1983. Used by permission.)

a. Vacuum level.

The operation of the wall or central vacuum systems was discussed in Chapter 13. It is common practice to set a partial vacuum of −15 to −20 cm H₂O pressure to the pleural space.

b. Suction control.

The suction control chamber is dry when the unit is unpacked. Follow the manufacturer’s instructions for adding the correct amount of water. The proper water level is generally 15 to 20 cm high and results in that level of vacuum being applied to the patient’s pleural space.

It is normal to have room air drawn into the opening on top and bubbling through the water column. This corresponds to bottle or chamber C in Figure 18-9. The constant air bubbling causes the water level to gradually decrease from evaporation. Water must be added occasionally.

c. Water seal.

The water-seal chamber, which corresponds to chamber B in Figure 18-9, is a safety feature. It is dry when unpacked. Follow the manufacturer’s directions regarding the amount of water to add. Typically, the water-seal tube should be filled with about 2 cm of water through which any patient air can bubble. As indicated by the arrows, it is designed to permit air to leave the patient’s chest cavity. (Air also will be seen bubbling when fluid enters the drainage collection chamber and displaces some of its air.) However, room air cannot be drawn “backward” through the water to enter the chest if the vacuum fails or is disconnected.

The water-seal chamber must be checked regularly to see if any air is bubbling through from the patient’s chest. If so, the patient has an active air leak. If the chest tube has been placed into the pleural space, it shows that the patient has an unhealed pneumothorax or bronchopleural fistula. If the chest tube has been placed into the mediastinum or pericardium, it indicates that air is leaking through a tear in the lung structures to these areas. When the air leak stops, it indicates that the tissues have healed over the tear.

d. Drainage collection.

The drainage collection chamber, which corresponds to bottle or chamber A in Figure 18-9, is designed to hold any fluid that is removed from the pleural space. It is divided into several sections that are demarcated for volume measurement. The volume that has accumulated in the chamber should be recorded each hour. A sudden, significant increase in the amount of drainage should be called to the physician’s attention. This is especially important if the patient is losing blood. Note the color of the drainage. Blood is obviously red, chyle is white, pus from an empyema is yellow or green, and pleural effusion fluid is a straw-yellow color. The whole drainage system must be replaced when the drainage collection chamber becomes filled.

e. Pressure-relief valve on the four-chamber system.

This additional chamber is a safety feature and is seen on four-chamber systems such as those shown in Figure 18-9, chamber D. Its purpose is to act as an escape route for any gas leaking from the patient if the vacuum system is accidentally turned off or disconnected. Without the relief valve, air pressure from a pneumothorax might increase to a dangerous level. Instead, the air and pressure are released. In three-chamber systems, the pressure has to build up to the point that water in the suction control chamber “geysers” out before the pressure is relieved.

3. Troubleshoot any problems with the pleural drainage system

A number of problems can occur with chest drainage systems. The practitioner must understand how the systems are designed to work and how to recognize and correct any problems. See Table 18-1 for examples of problems and their correction. Figure 18-10 lists important considerations when assessing the patient who is connected to a chest drainage system.

TABLE 18-1 Troubleshooting Problems with Chest Drainage Systems

Problem	Corrective Action
Drainage system is cracked open or drainage tubing is permanently disconnected from the drainage system	If the patient has a leaking pneumothorax:
	Leave the tube open to room air so the pleural air can be vented out.
	As quickly as possible, place the distal end of the tubing into a glass of water to create a water seal.
	If the patient does not have a leaking pneumothorax, clamp the distal end of the tube to prevent room air from being drawn into the pleural space.
	In either case, attach the tube to a new drainage system as soon as possible.
No bubbling through the suction control chamber	Increase the vacuum pressure.
No bubbling through the suction control chamber	Correct any leak in the system.
Water is spouting out of the suction control chamber (three-bottle system)	Turn on the vacuum.
	Remove obstruction inside tubing between vacuum and drainage system.
Air leak through the water-seal chamber	Check the patient for a pneumothorax; report a new air leak to the physician.
Air leak through the water-seal chamber	Check for a hole in the drainage tube, a loose connection between the tube and the drainage system, or if a fenestration in the tubing has pulled out of the chest wall.
Fluid has filled a dependent loop in the tubing	Drape the tubing so that are no loops or kinks
No change in drainage	Check for loops or kinks in tube.
	Carefully milk the tube to remove any clots.
	Do not rapidly strip the chest tube.
Drainage collection chamber is full	Prepare another unit, clamp the tube while making the exchange, and unclamp the tube after the new unit is functioning.

Figure 18-10 Assessing the patient’s chest drainage.

(From Erickson RA: Chest drainage, II, Nursing89 19[6]:47-49, 1989. Used by permission.)

Exam Hint 18-4 (ELE)

Remember that a pleural drainage system is operating properly when air leaking from a pneumothorax is seen bubbling through the water seal. Most examinations have a question concerning this or some other aspect of managing a patient with a pleural drainage system.

8. Assist with an intubation (Code: IIIJ1) [Difficulty: ELE: R, Ap; WRE: An]

The procedure for a therapist (or physician) performing oral endotracheal intubation was discussed in Chapter 12. The following discussions are limited to assisting an anesthesiologist or other trained physician in performing a nasal endotracheal intubation. Most commonly, the respiratory therapist is the assistant. This procedure is usually only carried out on spontaneously breathing patients. See Box 18-5 for indications and contraindications and Box 18-6 for complications of nasal endotracheal intubation. Two different procedures are used for passing an endotracheal tube by the nasal route: blind nasotracheal intubation and direct vision nasotracheal intubation.

a. Blind nasotracheal intubation

Be prepared to assist in blind nasotracheal intubation by positioning the patient properly in a sitting or supine position, providing supplemental oxygen or manual ventilation to the patient, selecting the proper endotracheal tube, making sure the cuff properly inflates and deflates, and securing the tube. Often, the physician orders spraying 1% phenylephrine or 0.25% racemic epinephrine into the patient’s nares. These medications constrict the blood vessels. This dilates the nasal passages, makes intubation easier, and also reduces the risk of bleeding. Often, 2% to 4% lidocaine (Xylocaine) is sprayed into the nares for its local anesthetic effect. The distal end of the endotracheal tube is usually also covered with a sterile, water-soluble lubricant for easier insertion (K-Y Brand Jelly), or lidocaine ointment can be used to lubricate the tube and numb the nasal passage.

This procedure is done without the aid of a laryngoscope and blade to visualize the patient’s anatomy and expose the trachea. However, other supplies will be needed. See Box 12-4 for a general list of equipment needed for intubation. The general steps in the procedure are listed here:

1. Place the patient in the sniffer’s position. Apply supplemental oxygen by mask and monitor the patient’s vital signs and pulse oximeter value.

2. Select the nasal passage that is the most open by feeling which one has the most airflow.

3. Select the proper endotracheal tube by size and style and check its cuff. See Table 12-1 for the proper tube size based on the age of the patient. It may be necessary to place a smaller than ideal size tube because the nasal passage is smaller than the oral passage. The tube should be very flexible and have a bevel that opens to the nasal septum of the selected naris. This is to minimize trauma as the tube is inserted.

4. Estimate the depth the tube will be advanced from the external naris to enter the larynx. In an adult male, this will be to about the 28-cm line on the tube. In adult females, this will be to about the 26-cm line on the tube. In other cases, this will be from the external naris to the earlobe.

5. As described previously, prepare the nasal passage and tube for the insertion.

6. Remove the supplemental oxygen and monitor the patient.

7. Gently advance the tube through the medial turbinate. The angle of approach may be adjusted but the tube should not be forced.

8. Advance the tube to less than the predetermined depth in step 4. With one ear positioned at the end of the tube, listen and feel for air movement on exhalation. On inspiration, carefully advance the tube through the oropharynx and into the larynx.

9. A cough with expiratory airflow through the tube usually confirms its placement into the trachea. The cuff needs to be past the vocal cords (see Figure 18-11). If there is no cough or airflow, the tube has likely entered the esophagus. Withdraw the tube until airflow can be heard and felt. Reposition the patient’s head and neck and advance the tube on inspiration again. Confirm the tube is properly placed into the trachea.

10. Inflate the cuff to a safe pressure. Apply supplemental oxygen to the endotracheal tube.

11. Auscultate for equal, bilateral breath sounds to confirm the tube is within the trachea. Secure the endotracheal tube. Check vital signs and the pulse oximeter reading.

12. Order a chest radiograph to confirm the position of the endotracheal tube.

Figure 18-11 An intubation guide stylet. The flexible tip can be guided by pulling or pushing on a ring attached to a wire running to the distal end. Once the end of the guide is directed into the trachea the endotracheal tube is slipped over it. After the intubation the guide is withdrawn.

(Modified from Heffner JE: Managing difficult intubations in critically ill patients, Respir Management 19[3], 1989.)

Because blind nasotracheal intubation can be challenging, several different devices can aid in this intubation procedure. The physician may choose to place a so-called trigger tube (see Figure 12-25) into the patient. This special endotracheal tube has a wire placed into it along the inside curve to the tip. The wire is pulled when the tube is near the larynx to bend the tip more anteriorly and aim it into the trachea. A flexible lighted stylet can be passed through the tube so that the light source is at the distal tip. The light shines through the skin over the larynx. When this is seen, the tube is advanced and the stylet is removed. A fiberoptic bronchoscope (Figure 12-31) can be placed through the tube and guided into the patient’s trachea. The tube is then advanced and the bronchoscope removed. Another choice is the intubation guide. This is a stylet with a flexible tip that can be bent through a proximal handle (performed by the physician) (Figure 18-11). The intubation guide is passed through and beyond the distal end of the endotracheal tube. When the guide is in the oropharynx, the tip can be bent in an anterior direction and directed into the trachea. The tube is then advanced over the guide and into the trachea. The guide is then removed.

b. Direct vision nasotracheal intubation

The respiratory therapist assists in direct vision nasotracheal intubation by positioning the patient properly, providing supplemental oxygen or manual ventilation to the patient, obtaining the endotracheal tube, ensuring that the cuff properly inflates and deflates, and securing the tube. Often 1% phenylephrine or 0.25% racemic epinephrine is sprayed into the nares. These medications constrict the blood vessels. This dilates the nasal passages, makes intubation easier, and also reduces the risk of bleeding. Often 2% to 4% lidocaine (Xylocaine) is sprayed into the nares for its local anesthetic effect. A sterile, water-soluble lubricant (K-Y Brand Jelly) is added to the distal end of the tube for easier insertion. Alternatively, lidocaine ointment can be used to lubricate the tube and numb the nasal passage.

This procedure is different from blind nasotracheal intubation in that intubation equipment is used to visualize the patient’s anatomy and see the glottis. See Box 12-4 for a general list of equipment needed for intubation. A Magill forceps is needed but a hard stylet is not. Prepare a laryngoscope handle and the physician’s choice of either a straight or a curved blade (see Figures 12-29 and 12-30). The general steps in the procedure are listed here:

1. Place the patient in the sniffer’s position. Apply supplemental oxygen by mask and monitor the patient’s vital signs and pulse oximeter value.

2. Select the nasal passage that is the most open by feeling which one has the most airflow. Select the proper endotracheal tube by size and style and check its cuff. See Table 12-1 for the proper tube size based on the age of the patient. It may be necessary to place a smaller than ideal size tube because the nasal passage is smaller than the oral passage. The tube should be very flexible and have a bevel that opens to the nasal septum of the selected naris. This is to minimize trauma as the tube is inserted.

3. Estimate the depth the tube will be advanced from the external naris to enter the larynx. In an adult male this will be approximately to the 28-cm line on the tube. In adult females this will be to about the 26-cm line on the tube. In other cases this will be from the external naris to the earlobe.

4. As described previously, prepare the nasal passage and tube for the insertion.

5. Remove the supplemental oxygen and monitor the patient.

6. Gently advance the tube through the medial turbinate. The angle of approach may be adjusted but the tube should not be forced.

7. Advance the tube to less than the predetermined depth in step 4. Look into the patient’s mouth for the tip of the tube in the oropharynx. If necessary, advance the tube so that the cuff is completely visible.

8. Grasp the laryngoscope handle with the left hand and carefully advance the laryngoscope blade along the right side of the patient’s mouth. Move the tongue to the left side (see Figure 12-34).

9. Advance the blade under the epiglottis and lift at a 45-degree angle toward the patient’s chest. To avoid injury to the patient’s front teeth, DO NOT pull back on the handle and blade.

10. Observe the patient’s open larynx (see Figure 12-36). Hold the Magill forceps with the right hand. Grasp the endotracheal tube proximal to the cuff to avoid damaging it (see Figure 18-12).

11. When the patient inhales, use the Magill forceps to pull the tip of the endotracheal tube between the vocal cords and into the larynx. The respiratory therapist may need to push on the end of the endotracheal tube to help advance it. The cuff needs to be inserted past the vocal cords (see Figure 18-13).

12. Carefully remove the laryngoscope blade and Magill forceps.

13. Inflate the cuff to a safe pressure. Apply supplemental oxygen to the endotracheal tube.

14. Auscultate for equal, bilateral breath sounds to confirm the tube is within the trachea. Secure the endotracheal tube. Check vital signs and pulse oximeter reading.

15. Order a chest radiograph to confirm the position of the endotracheal tube. See the complete discussion in Chapter 12 about confirming the location of the tube.

Figure 18-12 Direct vision nasotracheal intubation. Note that the Magill forceps and laryngoscope and blade are both used. The Magill forceps is used to grasp the tip of the endotracheal tube and pull it anterior into the trachea.

(From Shapiro BA, Harrison RA, Cane RD: Clinical application of respiratory care, ed 4, St Louis, 1991, Mosby.)

Figure 18-13 Properly placed nasotracheal tube.

(From Shapiro BA, Harrison RA, Cane RD: Clinical application of respiratory care, ed 4, St Louis, 1991, Mosby.)

Be aware that nasal intubation can be difficult in some patients. It may be necessary to perform oral intubation (discussed in Chapter 12) or perform a tracheostomy to ensure a safe airway.

9. Assist with a tracheostomy procedure (Code: IIIJ4) [Difficulty: ELE: R, Ap; WRE: An]

A tracheostomy is a surgical opening in the anterior tracheal wall. The opening is usually placed below the cricoid cartilage and through the second, third, or fourth ring of tracheal cartilage (Figure 18-14, A). The term tracheotomy is used to describe the surgical procedure itself (the two terms are often used interchangeably).

Figure 18-14 Anatomy of the larynx and insertion of a tracheostomy tube. A, Close-up of the larynx and the tracheostomy incision site. B, Anterior cut-away view of the tracheostomy tube after its insertion. C, Lateral cut-away view of the tracheostomy tube after its insertion.

(From Eubanks DH, Bone RC: Comprehensive respiratory care: a learning system, ed 2, St Louis, 1990, Mosby.)

Historically, most tracheostomy procedures were performed in the operating room under sterile conditions. When the respiratory therapist is called to assist at the bedside, it is usually because of a patient emergency. The emergency situation commonly involves an upper airway obstruction, such as that caused by facial trauma, or a surgical patient in which an endotracheal tube cannot be placed by either the oral or the nasal route. Because of time constraints, the full sterile technique may be bypassed in favor of a clean technique. The physician’s preference and the situation itself dictate how the procedure is performed. The respiratory therapist also may be called to assist in the procedure when the patient is already intubated. Usually this involves an unstable patient who requires long-term mechanical ventilation. Because of the patient’s critical condition, the physician makes the decision to perform the tracheostomy at the bedside rather than in the operating room. The respiratory therapist may be responsible for positioning the patient properly, providing supplemental oxygen or ventilation to the patient, monitoring the patient, obtaining the tracheostomy tube, ensuring that the cuff properly inflates and deflates, and securing the tube. In addition, the respiratory therapist or nurse will be responsible for preparing the patient, disinfecting the tracheostomy site, and setting up the sterile field around the site as well as the equipment and supplies needed for the procedure. Each hospital or physician may have a prescribed way that this is done. The general steps in the surgical tracheostomy procedure and the percutaneous dilational tracheostomy procedures are listed here:

1. Inform the patient of the procedure, and have him or her sign the medical release form.

2. Have a sedative or pain-relieving agent administered if needed.

3. If necessary, trim or shave the insertion site clear of body hair.

4. Put on a sterile mask, cap, gown, and gloves according to protocol.

5. Disinfect the insertion site with an iodine (Betadine) soaked sterile 4 × 4 inch gauze pad. Place the pad at the center of the insertion site, and move it in a widening spiral away from the center. This step should be repeated with a second sterile gauze pad. Let the iodine dry.

6. Protect the area around the insertion site with a sterile fenestrated surgical drape.

7. Prepare the sterile field with the tracheostomy tube, scalpel, supplies, and so forth. Have a local anesthetic such as lidocaine (Xylocaine) available in a syringe with needle. The physician injects this into the insertion site.

8. Assist the physician into his or her sterile mask, cap, gown, and gloves.

9. Get the proper size tracheostomy tube (see Table 12-1). Make sure the cuff inflates and deflates properly.

10. Assist the physician with the procedure as needed.

• Surgical procedure: If the patient is already intubated, withdraw the endotracheal tube after the tracheostomy opening has been created and the physician is ready to place the tracheostomy tube into the opening.

• Percutaneous dilational tracheostomy: If the patient is already intubated, withdraw the endotracheal tube but keep the tip within the larynx. Temporarily adjust the ventilator settings if there is a significant leak. The physician will insert a large-gauge needle between the first and second tracheal rings to create an opening into the trachea. The physician can then select from two methods to enlarge the initial opening. In the first, a guidewire is inserted through the needle into the trachea. The needle is removed and a series of rapidly increasing diameter dilators are passed over the guidewire. In the second method, a single dilator of gradually increasing diameter is slid over the guidewire into the trachea. (Examples of the single, tapered dilators are Ciaglia Blue Rhino, Balloon Ciaglia Blue Rhino, PercuTwist, and T-Dagger.) With either method, a stoma large enough to accept the tracheostomy tube has to be created.

11. Insert the tracheostomy tube into the tracheal opening. Inflate the cuff to a safe pressure. Make any adjustments in the patient’s respiratory care equipment as needed, such as modifying the oxygen percentage, changing the oxygen delivery apparatus, or adjusting the mechanical ventilator settings.

12. Auscultate for equal, bilateral breath sounds to confirm the tube is within the trachea. Secure the tracheostomy tube. Check vital signs and pulse oximeter reading.

13. Order a chest radiograph to confirm the position of the endotracheal tube.

14. Dispose of any used supplies and so forth after the procedure is completed.

15. Tend to the patient’s comfort. A pain-relieving medication may be needed.

See Chapter 12 for further discussion on the indications for the various airway routes and when to routinely change a tracheostomy tube. Table 18-2 lists the common complications of a tracheostomy.

TABLE 18-2 Common Complications of a Tracheostomy

Complication	Approximate Time of Onset
Bleeding	During and after surgery for up to 24 hr; if possible, do not replace the first tube for 2 to 3 days
Pneumothorax	During the procedure
Infection of the stoma or lungs	Usually seen after second day
Subcutaneous or mediastinal emphysema	May be seen during the procedure or at any later time

MODULE C

Exercise testing

1. Stress testing

a. Perform stress testing (e.g., ECG, pulse oximetry) (Code: IB9t) [Difficulty: ELE: R, Ap; WRE: An]

Stress testing is performed to determine a patient’s limits to exercise. The limiting factor(s) to exercise provide(s) much information about a patient’s medical condition. Box 18-7 lists the indications for stress testing. Before starting a stress test the patient’s chart should be reviewed for information on any previous stress testing. It is important to know the type of testing that was performed, how the patient tolerated it, and what caused the patient to stop the test. Review the physician’s evaluation of the test results and the patient’s diagnosis.

BOX 18-7 Indications for Exercise Testing

Evaluation of nonspecific dyspnea on exertion

Evaluation of the patient’s ventilatory response to increased work

Evaluation of the patient’s need for supplemental oxygen

Serial testing of the patient to help in evaluating the response to therapy, medication, smoking cessation, or a rehabilitation program

To determine the presence and/or nature of ventilatory limits to exercise, such as decreased flows, increased or decreased lung volumes, and/or decreased diffusing capacity

To determine the presence and/or nature of cardiovascular limits to exercise, such as heart rate, cardiac output, arrhythmias, blood pressure, and/or angina pectoris

To determine the presence and/or nature of muscular limits to exercise such as general deconditioning or decreased local perfusion

Preoperative assessment for a lung resection or transplantation

Assessment for the degree of impairment for disability evaluation

Assessment of an apparently healthy adult more than 40 years old before starting a vigorous exercise program

Stress testing is the intentional exercising of the patient to the point of exhaustion or physiologic deterioration, when the test must be stopped because the patient cannot continue. Because of this, the procedure is inherently risky to the patient. It is imperative that the patient be carefully evaluated before, during, and after the procedure. An informed consent statement must be signed by the patient before beginning the test. A physician should be present during the test along with the therapist and possibly a nurse.

Despite the risks involved in the procedure, a stress test is an important diagnostic or clinical evaluation tool for many patients (Table 18-3). Box 18-8 lists the steps in the patient work-up before testing can be safely performed. Box 18-9 lists the contraindications to exercise testing. Patients with any of these problems are too ill to be jeopardized by the procedure.

TABLE 18-3 Exercise Intolerance: Differentiating between Heart Disease, Lung Disease, and Deconditioned Muscles

BOX 18-9 Contraindications to Exercise Testing

ARTERIAL BLOOD GASES

Pao₂ less than 50 mm Hg when breathing room air

Spo₂ less than 85% when breathing room air

PULMONARY

Severe pulmonary hypertension

Recent pulmonary embolism

Untreated or unstable asthma

FEV_1.0 less than 30% of predicted

1. Commonly measured patient parameters specific to exercise testing metabolic equivalent of basal metabolic rate

A person who is sleeping or totally relaxed is consuming the minimum number of calories and the least amount of oxygen to stay alive. The minimum amount of carbon dioxide is being produced as a waste product of metabolism. He or she is said to be at basal metabolic rate (BMR). At BMR a person consumes about 3.5 mL of oxygen/kilogram of body weight/minute. Multiplying this value by the person’s body weight produces the metabolic equivalent of basal metabolic rate for oxygen, or MET, as it is abbreviated. The average adult at BMR consumes about 250 mL of oxygen/minute and produces about 200 mL of carbon dioxide/minute. Obviously, the more active a person is the more calories and oxygen are consumed and the more carbon dioxide is produced. Often a person’s exercise limit is quantified in terms of how many METs he or she can perform. For example, light household cleaning might be 2 METs of exercise while competitive swimming might be 8 to 10 METs of exercise.

2. Respiratory quotient and respiratory exchange ratio

Respiratory quotient (RQ) is the ratio, at the cellular level, of the amount of carbon dioxide produced in 1 minute to the amount of oxygen consumed in 1 minute. It must be readily apparent that it is impossible to directly measure the RQ because it studies cellular metabolism; however, the same gases can be easily measured in the lungs.

A metabolic study is performed to evaluate a patient’s oxygen consumption in 1 minute (Vo₂) and carbon dioxide production in one minute (Vco₂) for the assessment of a patient’s metabolism at rest or during exercise, or as part of a general nutritional assessment. The bedside testing procedure is called indirect calorimetry and involves collecting the patient’s exhaled gases to send them through a rapid O₂ analyzer and CO₂ analyzer. In a normal, healthy person the cellular metabolic processes, lung function, and cardiovascular function are working properly. As can be seen in Figure 18-15, this results in a cellular respiratory quotient (RQ) of 0.80 and a resulting respiratory exchange ratio (R) measured at the lung of 0.80. This indicates normal oxygen consumption and carbon dioxide production. The calculation is shown in the following equation.

Figure 18-15 Representation of the interconnected relationships between the pulmonary system, the cardiovascular system, and the tissues of the body to show the processes of oxygen delivery and consumption and carbon dioxide production and exhalation. Note how the relationship of oxygen consumption and carbon dioxide production in the mitochondria of the cells results in a respiratory quotient (RQ) of 0.80 and the intake of oxygen and exhalation of carbon dioxide by the lungs result in a matching respiratory exchange ratio (R) of 0.80. This allows indirect calorimetry to be used to evaluate a patient’s metabolism at rest and during exercise to assess the pulmonary system, cardiovascular system, and muscle function.

(From Madama VC: Pulmonary function testing and cardiopulmonary stress testing, ed 2, Albany, Delmar Publishers, 1998.)

Sick patients will often have an R value of greater than 0.80. This can be the result of the patient’s diet. However, in many sick patients, the high R value is because of the inability of the lungs to remove carbon dioxide (many COPD patients) or insufficient oxygen delivery to the tissues. Tissue hypoxia results in anaerobic metabolism with resulting lactic acid production. This lactic acid, in turn, converts to excessive carbon dioxide. Even a healthy person can have an increased R value during heavy exercise with a stress test.

The respiratory exchange ratio (R or RER) is the ratio, at the alveolar level, of the amount of carbon dioxide produced in 1 minute to the amount of oxygen consumed in 1 minute. The volume of these two gases is determined through indirect calorimetry, as discussed previously. Using the oxygen consumption and carbon dioxide volumes discussed earlier, the R (or RQ) of a resting adult would be calculated as:

The R value (and RQ) of 0.80 remains quite steady during light to moderate exercise (see Figure 18-15). A normal, healthy person can quite easily increase the amount of oxygen consumed and eliminate the extra carbon dioxide produced during exercise. This is what is seen during aerobic metabolism when all body systems are functioning smoothly. It is only during heavy exercise that the body has difficulty coping and must eventually stop.

(From Ruppel G: Manual of pulmonary function testing, ed 9, St Louis, 2009, Mosby.)

a. Treadmill.

The treadmill is a motorized continuously looped belt combined with a ramp. The belt’s speed may be adjusted from the stopped position to 1.5 to 10 miles per hour (great enough to exhaust a trained runner). The ramp may be adjusted from flat (0% grade) to sloped (30% grade) (great enough to require the patient to run to keep from falling off the back of the treadmill). There is a railing for the patient to hold if necessary. Commonly there is also an emergency button that the patient can hit to stop the unit. Adjunct equipment is nearby for monitoring the electrocardiogram, exhaled gases, and so forth (see Figure 18-17). The treadmill has an advantage over the bicycle ergometer in that it trains the patient’s muscles that are needed for walking. This is an important practical consideration for most patients. However, it is more difficult to quantitate the exercise test results from a treadmill compared to a bicycle because the patient’s stride and mechanics of walking vary as the speed increases.

Figure 18-17 Exercise equipment usually consists of a treadmill (left) and indirect calorimeter (also called a metabolic cart [right]) for analysis of exhaled oxygen and carbon dioxide. The operator can control the treadmill’s speed and angle of incline to vary the amount of work the patient performs. During the exercise test, the indirect calorimeter measures the patient’s respiratory rate, tidal volume, and exhaled gas concentrations.

(Courtesy Medical Graphics, Inc., St Paul, Minnesota. In: Ruppel G: Manual of pulmonary function testing, ed 5, St Louis, 1991, Mosby.)

b. Bicycle ergometer.

The bicycle ergometer is a stationary bicycle with seat, handle bars, and electronics for calculating distance, effort, and so forth. The electromechanical units as shown in Figure 18-18 have electronic brakes to increase the patient’s workload. Although less practical in training muscles for everyday tasks such as walking, the ergometer allows for easier workload adjustments and calculation of the exercise test results. Other exercise methods such as an arm ergometer or a rowing machine are rarely performed on patients.

Figure 18-18 An electromechanical bicycle ergometer with controls for electronic braking, pedaling resistance, test timer, meters for pedaling frequency in revolutions per minute (RPM), and external workload in watts.

(Courtesy Medical Graphics Inc., St Paul, Minn. In Ruppel G: Manual of pulmonary function testing, ed 5, St Louis, 1991, Mosby.)

7. Exercise protocols

There are a number of exercise protocols that may be followed. Basically they fall into one of the two following test categories and may be performed on either a treadmill or a bicycle ergometer.

a. Progressive multistage test.

This test is designed to examine the effects of rapidly increasing workloads on the cardiopulmonary system. A steady state may or may not be reached because the goals are to trend the measured exercise parameters and find the maximum workload. The following parameters are measured: maximum oxygen consumption, maximum carbon dioxide production, maximum minute ventilation, and maximum heart rate. This is a less exhausting test than the steady state and may be repeated if necessary. This test may be used for its own purposes or to establish maximum workloads before having the patient perform the steady-state test.

Patients with known or suspected cardiac disease use a version of the progressive multistage test called the Modified Bruce Protocol. Its goal is to rapidly increase the patient’s workload until a target heart rate of 85% of predicted is reached. To accomplish this, the speed and angle of the treadmill are increased every 3 minutes until the target heart rate is reached or the patient feels the need to stop.

b. Steady-state test.

This test is designed to measure cardiopulmonary parameters under steady metabolic conditions. Commonly these levels are 50% and 75% of the predicted maximum oxygen consumption. The following parameters are measured: oxygen consumption, carbon dioxide production, minute ventilation, and heart rate. This is a more exhausting test than the progressive multistage test because it takes longer. It usually is not repeated the same day.

8. General steps in the procedure

1. Explain the procedure to the patient. Answer any questions. Show the patient how to stop the test in case of an emergency. Develop a hand signal system so that the patient can approve an increase in workload (thumb up) or warn you of the need to stop the test (thumb down).

2. Set up the following monitoring equipment on the patient:

• Electrocardiogram with chest leads placed as usual and limb leads moved to the shoulder areas and lower abdominal areas

• Pulse oximetry monitor for Spo₂ or (rarely) arterial line for monitoring Pao₂, other blood gas values, and continuous blood pressure

• Arm cuff and sphygmomanometer for automatic or manual blood pressure monitoring if an arterial line is not inserted

• Mouthpiece with one-way valves or head hood to gather exhaled gases for analysis

3. Have the patient breathe normally through the system and take a set of baseline parameters. Tell the patient to warm up on the equipment by exercising at a low level (approximately 25% of Vo_2max). Take a set of parameters. Note: Steps 4, 5, and 6 are for the steady-state test. With the progressive multistage test, the patient will exercise at a given level for only a few minutes before moving to a higher work level.

4. Begin the test by having the patient exercise at a predetermined moderate level (approximately 50% of Vo_2max) for 5 to 8 minutes. Take a set of parameters in the last 1 to 2 minutes.

5. Increase the workload (approximately 75% of Vo_2max) and have the patient exercise at this level for 5 to 8 minutes. Take a set of parameters in the last 1 to 2 minutes. Alternatively, the patient may be given a short rest period or low exercise period between the steps of increased workload.

6. Repeat step 5, if necessary, at a higher workload until the patient is exhausted or cannot continue because of one of the conditions listed in Box 18-10.

7. Have the patient exercise at a low level for several minutes during a cool down/recovery period. It is important to monitor the patient during the recovery period because a sudden drop in blood pressure and fainting are known to occur if exercise should stop too quickly. Note how long it takes for the patient to return to baseline conditions.

BOX 18-10 Indications for Stopping an Exercise Test

ARTERIAL BLOOD GASES

Pao₂ decreasing to less than 55 mm Hg

Acidosis with or without a rise in the Paco₂ level

Spo₂ less than 83% or <4% less than the baseline value

PULMONARY

Exercise-induced bronchospasm

Severe dyspnea

EQUIPMENT

Monitoring equipment failure

Unavailability of CPR equipment and defibrillator

b. Interpret the results of stress testing (e.g., ECG, pulse oximetry) (Code: IB10t) [Difficulty: ELE: R, Ap; WRE: An]

1. In a healthy person the following physiologic changes can be expected

a. Tidal volume, respiratory rate, and minute volume.

All patients will find the combination of tidal volume and respiratory rate that allows the most efficient ventilation. Patients with normal, healthy lungs will increase their tidal volume to about 60% of their vital capacity. They will then increase the respiratory rate to produce the maximum ventilation possible. Patients with obstructive airways disease are flow-limited and cannot increase their respiratory rate adequately. They attempt to raise their tidal volume to increase their minute volume but must stop exercising earlier than predicted. Patients with restrictive lung disease cannot increase their tidal volume as expected. Instead, they increase their respiratory rate to raise their minute volume. They too must stop exercising earlier than predicted.

b. Heart rate, stroke volume, and cardiac output.

At low and moderate workloads the stroke volume increases from about 80 mL to 110 mL in healthy adults. Increases in heart rate account for the rest of the increase in cardiac output from low to heavy exercise. The heart rate increases are almost parallel with the increases in Vo₂ values (see Figure 18-19). A patient with a diseased left ventricle or heart block would be unable to increase cardiac output sufficiently when exercising and must stop earlier than predicted.

Figure 18-19 Exercise data showing 30-second averages from a normal, healthy adult subject. Heart rate increases linearly as workload is increased and is not the limiting factor in this exercise test. The other three graphic displays show that the anaerobic threshold (AT) occurs at 2 L/min of Vo₂. The following key points should be noted: (a) minute volume (V_E) increases sharply at AT; (b) end-tidal carbon dioxide (P_ETco₂) and the ventilatory equivalent for carbon dioxide (V_E/Vco₂) both decrease at the AT, which shows a disproportionate increase in CO₂ production secondary to lactic acid formation; and (c) end-tidal oxygen (P_ETo₂) and the ventilatory equivalent for oxygen (V_E/Vo₂) both increase at the AT.

(From Ruppel G: Manual of pulmonary function testing, ed 9, St Louis, 2009, Mosby.)

c. Oxygen consumption, carbon dioxide production, and respiratory quotient.

Both oxygen consumption and carbon dioxide production will increase linearly with low and moderate exercise. The respiratory quotient will remain at approximately 0.80 or increase slightly. As the subject exercises at levels closer and closer to the Vo_2max, the muscles are progressively starved for oxygen. This results in local anaerobic metabolism with lactic acid production. Lactic acid in turn converts to carbon dioxide. Because of this added CO₂, the respiratory center is stimulated to increase ventilation even more than expected. Eventually this fails to keep up with the increased production and the CO₂ level increases. The anaerobic threshold is identified when oxygen consumption equals carbon dioxide production and the respiratory quotient reaches 1.0.

d. Blood gases and pH.

Pao₂, Paco₂, and pH will remain stable in the normal ranges during low and moderate exercise. The cardiopulmonary system is able to deliver adequate oxygen to the tissues and remove sufficient carbon dioxide to keep the body functioning properly. However, at high levels of work, a lactic acid buildup occurs and a progressive metabolic acidosis is seen. This forces the patient to decrease the exercise level. Some may need to stop. Patients with cardiopulmonary disease will not be able to exercise heavily because they can provide only very limited increases of oxygen to the muscles or eliminate the extra carbon dioxide produced during even moderate exercise. Figure 18-19 shows the parameter changes seen as a healthy individual exercises from a low to a maximal level.

c. Limitations caused by abnormal physiology

Patients who are forced to stop exercising at a lower than predicted workload will probably fall into one of the following three broad categories. Box 18-10 lists conditions that would require that the stress test be stopped. Table 18-3 lists parameters that will help in differentiating between deconditioned muscles, pulmonary limitations, or cardiac limitations as the reason that exercise had to be stopped.

1. Deconditioned muscles

Normal, healthy people are quite commonly seen in this category. They are deconditioned from lack of exercise. These people are able to do quite well in a training program if there are no underlying cardiopulmonary limitations.

2. Pulmonary limitations

As discussed earlier, patients with obstructive airways disease or restrictive lung disease have limited ventilatory reserve. This limits their exercise tolerance even if they have a normal cardiovascular system. If the limitation is due to bronchospasm, this may be treated by inhaling a bronchodilator before exercising. These patients may also be able to increase their exercise tolerance if given supplemental oxygen to prevent desaturation.

3. Cardiovascular limitations

Patients with a damaged or diseased left ventricle, heart block, exercise-induced angina because of coronary artery disease, hypertension, and so forth are unable to exercise to expected levels. Medical or surgical intervention may enable them to increase their work level.

2. Oxygen titration

a. Perform oxygen titration with exercise (Code: IB9i) [Difficulty: ELE: R, Ap; WRE: An]

Oxygen titration with exercise involves determining the amount of supplemental oxygen needed by a patient with cardiopulmonary disease to keep the Spo₂ value at no less than 93% during an exercise period. Many of the principle considerations for this procedure are the same as those discussed during the 6-minute walk exercise discussed in Chapter 17 and earlier in this module. See Box 18-7 for the patient indications for this procedure. Patient evaluation before testing is presented in Box 18-8 and contraindications to testing are listed in Box 18-9.

The patient’s history will indicate that he or she is hypoxemic at rest or becomes so during exercise. Therefore, the patient’s oxygen level must be monitored, along with the vital signs and electrocardiogram, during the oxygen titration with exercise procedure. Minimally, continuous pulse oximetry must be done. However, it is preferred to have arterial blood gas samples taken at rest and during peak exercise. While single samples can be taken, it is preferable to place an arterial catheter into the radial artery. The respiratory therapist’s duties will probably include monitoring the patient, changing the oxygen flow (likely by nasal cannula), and adjusting the exercise equipment.

The physician will determine the patient’s exercise workload at a given oxygen flow or percentage. It is preferable to measure the workload and heart rate (as a percentage of predicted) at each supplemental oxygen level. At each workload level, make note of the patient’s inspired oxygen flow or percentage, vital signs, and pulse oximeter reading. Ideally, obtain an arterial blood gas sample at the peak workload level. The overall goal of the procedure is to keep the patient’s Spo₂ <93% at an increased exercise level.

b. Interpret the results of oxygen titration with exercise (Code: IB10i) [Difficulty: ELE: R, Ap; WRE: An]

When the physician or patient decides to stop the procedure there must be a record of the workload level, inspired oxygen flow or percentage, vital signs, and pulse oximeter reading. An arterial blood gas sample should be taken to send to the laboratory for analysis. Note the reason that the test was stopped. See Box 18-10 for indications to stop an exercise test.

Based on the physician’s interpretation of the data, a plan will be developed so that the patient can safely exercise with a prescribed amount of supplemental oxygen. The patient will need to be instructed about the meaning of the test results, the exercise plan, and how to assess his or her response during exercise. This may be done as part of a pulmonary rehabilitation program.

MODULE D

Sleep-disordered breathing

1. Recommend sleep studies (Code: IC13) [Difficulty: ELE: R, Ap; WRE: An]

A sleep apnea study (cardiopulmonary sleep study or polysomnography) is performed to determine whether the patient has sleep-disordered breathing. Furthermore, it can help to determine the type of disorder and monitor the patient’s response to treatment. Box 18-11 lists the indications for a polysomnography sleep study.

BOX 18-11 Indications for a Cardiopulmonary Sleep Study

Patient with COPD whose awake Pao₂ is <55 torr but who has pulmonary hypertension, right heart failure (cor pulmonale), or polycythemia

Patient whose awake Pao₂ is <55 torr without continuous supplemental oxygen and who must have the proper oxygen flow rate set for sleeping at night; overnight sleep ear oximetry should be performed

Patient with restrictive ventilatory impairment secondary to chest wall or neuromuscular disturbances who also has chronic hypoventilation, polycythemia, pulmonary hypertension, disturbed sleep, morning headaches, or daytime somnolence and fatigue

Patient with awake Paco₂ <45 torr who also has polycythemia, pulmonary hypertension, disturbed sleep, morning headaches, or daytime somnolence and fatigue

Patient with snoring, obesity, and other symptoms indicating disturbed sleep pattern

Patient with excessive daytime sleepiness or sleep-maintenance insomnia

Patient with nocturnal cyclic bradytachyarrhythmias, atrioventricular conduction abnormalities while asleep, or increased abnormal ventricular beats compared with those when awake

2. Review data on sleep study results (e.g., diagnosis, treatment) (WRE code: IA10) [Difficulty: WRE: R, Ap]

The following procedures are usually performed before the sleep study:

1. History of the problem from the viewpoint of both the patient and the patient’s bed partner

2. Physical examination, including neck, upper airway, blood pressure, heart rate, and respiratory rate and pattern

3. Arterial blood gas (ABG) results or pulse oximetry results

4. Hemoglobin level

5. Thyroid function

6. Chest and upper airway radiograph examinations; may include a computed axial tomographic scan of the upper airway if obstructive sleep apnea is suspected

7. ECG

The following physiologic parameters are usually measured during a polysomnography sleep study:

• Pulse oximetry for O₂ saturation. An ear or bridge-of-nose oximetry probe is recommended. Finger oximetry is not recommended because the unit may fall off during patient movement.

• Sleep stages through an electroencephalographic (EEG) recording of brain wave activity and an electro-oculographic (EOG) recording of eye movements.

• Inspiratory and expiratory airflow by nasal thermistor, pneumotachograph, or end-tidal CO₂ analyzer.

• Inspiratory and expiratory effort by respiratory inductive plethysmography. (Some may prefer to have the patient swallow a transducer to measure esophageal pressure changes.) This is to look for paradoxical thoracoabdominal movements during obstructive apnea episodes.

• Body position related to normal and abnormal breathing patterns.

• Periodic arm and leg movements.

• ECG for monitoring heart rate and arrhythmias.

3. Initiate treatment for sleep disorders (e.g., CPAP) (WRE code: IIIK9) [Difficulty: WRE: Ap, An]

Apnea is the cessation of breathing for 10 seconds or longer. Sleep apnea is diagnosed when a patient experiences at least 30 apneic periods during 6 hours of sleep. In addition, the patient will likely have episodes of hypopnea. These harmful, and potentially fatal, problems that lead to repeated episodes of hypoxemia must be treated, as discussed in the following sections.

4. CPAP/BiPAP titration

a. Perform CPAP/BiPAP titration during sleep (Code: IB9v) [Difficulty: ELE: R, Ap; WRE: An]

b. Interpret the results of CPAP/BiPAP titration during sleep (Code: IB10v) [Difficulty: ELE: R, Ap; WRE: An]

During polysomnography, the EEG tracing should confirm that the apneic periods occur during both of the major sleep stages. The first stage is called non–rapid eye movement (non-REM) sleep and starts soon after the person loses consciousness. The second stage is called rapid eye movement (REM) sleep and follows the non-REM stage. Normally people cycle through both stages about every 1 to 1.5 hours during the night. This normal cycle of sleep is important for both mental and physical health. People with disturbed sleep do not dream as they should and are not physically rested when they awaken. Whether the patient was evaluated by overnight pulse oximetry (OPO) or polysomnography, the results lead to one of the following classifications for sleep apnea.

1. Obstructive sleep apnea

Obstructive sleep apnea (OSA) results when the patient’s upper airway is obstructed despite continued breathing efforts (Figures 18-20 and 18-21). Patients with this problem often exhibit the following symptoms: loud snoring (reported by the bed partner), morning headache, excessive daytime sleepiness, depression or other personality changes, decreased intellectual ability, sexual dysfunction, bed-wetting (nocturnal enuresis), or abnormal limb movements during sleep.