Pulmonary Therapeutic Management

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Pulmonary Therapeutic Management

Kathleen M. Stacy

Objectives

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Be sure to check out the bonus material, including free self-assessment exercises, on the Evolve web site at evolve.elsevier.com/Urden/priorities/.

Oxygen Therapy

Normal cellular function depends on the delivery of an adequate supply of oxygen to the cells to meet their metabolic needs. The goal of oxygen therapy is to provide a sufficient concentration of inspired oxygen to permit full use of the oxygen-carrying capacity of the arterial blood; this ensures adequate cellular oxygenation, provided the cardiac output and hemoglobin concentration are adequate.1,2

Principles of Therapy

Oxygen is an atmospheric gas that must also be considered a drug, because—like most other drugs—it has detrimental and beneficial effects. Oxygen is one of the most commonly used and misused drugs. As a drug, it must be administered for good reason and in a proper, safe manner. Oxygen is usually ordered in liters per minute (L/min), as a concentration of oxygen expressed as a percentage, such as 40%, or as a fraction of inspired oxygen (FiO2), such as 0.4.

The primary indication for oxygen therapy is hypoxemia.3 The amount of oxygen administered depends on the pathophysiological mechanisms affecting the patient’s oxygenation status. In most cases, the amount required should provide an arterial partial pressure of oxygen (PaO2) of greater than 60 mm Hg or an arterial hemoglobin saturation (SaO2) of greater than 90% during rest and exercise.2 The concentration of oxygen given to an individual patient is a clinical judgment based on the many factors that influence oxygen transport, such as hemoglobin concentration, cardiac output, and arterial oxygen tension.1,2

After oxygen therapy has begun, the patient is continuously assessed for level of oxygenation and the factors affecting it. The patient’s oxygenation status is evaluated several times daily until the desired oxygen level has been reached and has stabilized. If the desired response to the amount of oxygen delivered is not achieved, the oxygen supplementation is adjusted, and the patient’s condition is re-evaluated. It is important to use this dose-response method so that the lowest possible level of oxygen is administered that will still achieve a satisfactory PaO2 or SaO2.2,3

Methods of Delivery

Oxygen therapy can be delivered by many different devices (Table 16-1). Common problems with these devices include system leaks and obstructions, device displacement, and skin irritation. These devices are classified as low-flow, reservoir, or high-flow systems.3

TABLE 16-1

OXYGEN THERAPY SYSTEMS

CATEGORY DEVICE FLOW FiO2 RANGE (%) FiO2 STABILITY ADVANTAGES DISADVANTAGES BEST USE
Low-flow Nasal cannula 0.25-8 L/min (adults)
≤2 L/min (infants)
22-45 Variable Use on adults, children, infants; easy to apply; disposable, low cost; well tolerated Unstable, easily dislodged; high flows uncomfortable; can cause dryness/bleeding; polyps, deviated septum may block flow Stable patient needing low FiO2; home care patient requiring long-term therapy
Nasal catheter 0.25-8 L/min 22-45 Variable Use on adults, children, infants; good stability; disposable, low cost Difficult to insert; high flows increase back pressure; needs regular changing; polyps, deviated septum may block insertion; may provoke gagging, air swallowing, aspiration Procedures where cannula is difficult to use (bronchoscopy); long-term care for infants
Transtracheal catheter 0.25-4 L/min 22-35 Variable Lower O2 usage/cost; eliminates nasal/skin irritation; improved compliance; increased exercise tolerance; increased mobility; enhanced image High cost; surgical complications; infection; mucus plugging; lost tract Home care or ambulatory patients who need increased mobility or who do not accept nasal oxygen
Reservoir Reservoir cannula 0.25-4 L/min 22-35 Variable Lower O2 usage/cost; increased mobility; less discomfort because of lower flows Unattractive, cumbersome; poor compliance; must be regularly replaced; breathing pattern affects performance Home care or ambulatory patients who need increased mobility
Simple mask 5-12 L/min 35-50 Variable Use on adults, children, infants; quick, easy to apply; disposable, inexpensive Uncomfortable; must be removed for eating; prevents radiant heat loss; blocks vomitus in unconscious patients Emergencies, short-term therapy requiring moderate FiO2
Partial rebreathing mask 6-10 L/min (prevent bag collapse on inspiration) 35-60 Variable Same as simple mask; moderate to high FiO2 Same as simple mask; potential suffocation hazard Emergencies, short-term therapy requiring moderate to high FiO2
Nonrebreathing mask 6-10 L/min (prevent bag collapse on inspiration) 55-70 Variable Same as simple mask; high FiO2 Same as simple mask; potential suffocation hazard Emergencies, short-term therapy requiring high FiO2
Nonrebreathing circuit (closed) 3 × Ve (prevent bag collapse on inspiration) 21-100 Fixed Full range of FiO2 Potential suffocation hazard; requires 50 psi air/O2; blender failure common Patients requiring precise FiO2 at any level (21%-100%)
High-flow Air-entrainment mask (AEM) Varies; should provide output flow >60 L/min 24-50 Fixed Easy to apply; disposable, inexpensive; stable, precise Fio2 Limited to adult use; uncomfortable, noisy; must be removed for eating; FiO2 >0.40 not ensured; FiO2 varies with back-pressure Unstable patients requiring precise low FiO2
Air-entrainment nebulizer 10-15 L/min input; should provide output flow ≥60 L/min 28-100 Fixed Provides temperature control and extra humidification FiO2 <28% or >0.40 not ensured; FiO2 varies with back-pressure; high infection risk Patients with artificial airways requiring low to moderate FiO2

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VE, minute volume.

Modified from Wilkins RL, et al, editors: Egan’s fundamentals of respiratory care, ed 8, St Louis, 2003, Mosby.

Low-Flow Systems

A low-flow oxygen delivery system provides supplemental oxygen directly into the patient’s airway at a flow of 8 L/min or less. Because this flow is insufficient to meet the patient’s inspiratory volume requirements, it results in a variable FiO2 as the supplemental oxygen is mixed with room air. The patient’s ventilatory pattern affects the FiO2 of a low-flow system: as the ventilatory pattern changes, differing amounts of room air gas are mixed with the constant flow of oxygen. A nasal cannula is an example of a low-flow device.3

Reservoir Systems

A reservoir system incorporates some type of device to collect and store oxygen between breaths. When the patient’s inspiratory flow exceeds the oxygen flow of the oxygen delivery system, the patient is able to draw from the reservoir of oxygen to meet his or her inspiratory volume needs. There is less mixing of the inspired oxygen with room air than in a low-flow system. A reservoir oxygen delivery system can deliver a higher FiO2 than a low-flow system. Examples of reservoir systems are simple face masks, partial rebreathing masks, and nonrebreathing masks.3

High-Flow Systems

With a high-flow system, the oxygen flows out of the device and into the patient’s airways in an amount sufficient to meet all inspiratory volume requirements. This type of system is not affected by the patient’s ventilatory pattern. An air-entrainment mask is an example of a high-flow system.3

Complications of Oxygen Therapy

Oxygen, like most drugs, has adverse effects and complications resulting from its use. The adage “if a little is good, a lot is better” does not apply to oxygen. The lung is designed to handle a concentration of 21% oxygen, with some adaptability to higher concentrations, but adverse effects and oxygen toxicity can result if a high concentration is administered for too long.4

Oxygen Toxicity

The most detrimental effect of breathing a high concentration of oxygen is the development of oxygen toxicity. It can occur in any patient who breathes oxygen concentrations of greater than 50% for longer than 24 hours. Patients most likely to develop oxygen toxicity are those who require intubation, mechanical ventilation, and high oxygen concentrations for extended periods.3

Hyperoxia, or the administration of higher-than-normal oxygen concentrations, produces an overabundance of oxygen free radicals. These radicals are responsible for the initial damage to the alveolar-capillary membrane. Oxygen free radicals are toxic metabolites of oxygen metabolism. Normally, enzymes neutralize the radicals, preventing any damage from occurring. During the administration of high levels of oxygen, the large number of oxygen free radicals produced exhausts the supply of neutralizing enzymes. Damage to the lung parenchyma and vasculature occurs, resulting in the initiation of acute lung injury (ALI).2,4

A number of clinical manifestations are associated with oxygen toxicity. The first symptom is substernal chest pain that is exacerbated by deep breathing. A dry cough and tracheal irritation follow. Eventually, there is definite pleuritic pain on inhalation, followed by dyspnea. Upper airway changes may include a sensation of nasal stuffiness, sore throat, and eye and ear discomforts. Chest radiographs and pulmonary function tests show no abnormalities until symptoms are severe. Complete, rapid reversal of these symptoms occurs as soon as normal oxygen concentrations are restored.4

Carbon Dioxide Retention

In patients with severe chronic obstructive pulmonary disease (COPD), carbon dioxide (CO2) retention may occur as a result of administration of oxygen in high concentrations. A number of theories have been proposed for this phenomenon. One states that the normal stimulus to breathe (i.e., increasing CO2 levels) is muted in patients with COPD and that decreasing oxygen levels become the stimulus to breathe. If hypoxemia is corrected by the administration of oxygen, the stimulus to breathe is abolished; hypoventilation develops, resulting in a further increase in the arterial partial pressure of carbon dioxide (PaCO2).2,3 Another theory is that the administration of oxygen abolishes the compensatory response of hypoxic pulmonary vasoconstriction. This results in an increase in perfusion of underventilated alveoli and the development of dead space, producing ventilation/perfusion mismatching. As alveolar dead space increases, so does the retention of CO2.2,3,5 One further theory states that the rise in CO2 is related to the ratio of deoxygenated to oxygenated hemoglobin (Haldane effect). Deoxygenated hemoglobin carries more CO2 than oxygenated hemoglobin. Administration of oxygen increases the proportion of oxygenated hemoglobin, which causes increased release of CO2 at the lung level.5 Because of the risk of CO2 accumulation, all chronically hypercapnic patients require careful low-flow oxygen administration.3

Absorption Atelectasis

Another adverse effect of high concentrations of oxygen is absorption atelectasis. Breathing high concentrations of oxygen washes out the nitrogen that normally fills the alveoli and helps hold them open (residual volume). As oxygen replaces the nitrogen in the alveoli, the alveoli start to shrink and collapse. This occurs because oxygen is absorbed into the bloodstream faster than it can be replaced in the alveoli, particularly in areas of the lungs that are minimally ventilated.2,3

Nursing Management

Nursing priorities for the patient receiving oxygen focus on (1) ensuring the oxygen is being administered as ordered and (2) observing for complications of the therapy. Confirming that the O2 therapy device is properly positioned and replacing it after removal is important. During meals, an oxygen mask should be changed to a nasal cannula if the patient can tolerate one. The patient receiving O2 therapy should also be transported with the oxygen. In addition, SpO2 should be periodically monitored using a pulse oximeter.

Artificial Airways

Pharyngeal Airways

Pharyngeal airways are used to maintain airway patency by keeping the tongue from obstructing the upper airway. The two types of pharyngeal airways are oropharyngeal and nasopharyngeal. Complications of these airways include trauma to the oral or nasal cavity, obstruction of the airway, laryngospasm, gagging, and vomiting.6,7

Oropharyngeal Airway

An oropharyngeal airway is made of plastic and is available in various sizes. The proper size is selected by holding the airway against the side of the patient’s face and ensuring that it extends from the corner of the mouth to the angle of the jaw. If the airway is improperly sized, it will occlude the airway.6,7 An oral airway is placed by inserting a tongue depressor into the patient’s mouth to displace the tongue downward and then passing the airway into the patient’s mouth, slipping it over the patient’s tongue.7 When properly placed, the tip of the airway lies above the epiglottis at the base of the tongue. It should be used only in an unconscious patient who has an absent or diminished gag reflex.6,7

Nasopharyngeal Airway

A nasopharyngeal airway is usually made of plastic or rubber and is available in various sizes. The proper size is selected by holding the airway against the side of the patient’s face and ensuring that it extends from the tip of the nose to the earlobe.6,7 A nasal airway is placed by lubricating the tube and inserting it midline along the floor of the naris into the posterior pharynx.7 When properly placed, the tip of the airway lies above the epiglottis at the base of the tongue.6,7

Endotracheal Tubes

An endotracheal tube (ETT) is the most commonly used artificial airway for providing short-term airway management. Indications for endotracheal intubation include maintenance of airway patency, protection of the airway from aspiration, application of positive-pressure ventilation, facilitation of pulmonary toilet, and use of high oxygen concentrations.8 An ETT may be placed through the orotracheal or the nasotracheal route.9,10 In most situations involving emergency placement, the orotracheal route is used, because it is simpler and allows the use of a larger-diameter ETT.10,11 Nasotracheal intubation provides greater patient comfort over time and is preferred in patients with a jaw fracture.9,11,12 The advantages of orotracheal and nasotracheal intubation are presented in Table 16-2.

ETTs are available in various sizes, based on the inner diameter of the tube, and have a radiopaque marker that runs the length of the tube. On one end of the tube is a cuff that is inflated with the use of the pilot balloon. Because of the high incidence of cuff-related problems, low-pressure, high-volume cuffs are preferred. On the other end of the tube is a 15-mm adaptor that facilitates connection of the tube to a manual resuscitation bag (MRB), T-tube, or ventilator (Figure 16-1).13

Intubation

Before intubation, the necessary equipment is gathered and organized to facilitate the procedure. Readily available equipment should include a suction system with catheters and tonsil suction, an MRB with a mask connected to 100% oxygen, a laryngoscope handle with assorted blades, a variety of sizes of ETTs, and a stylet. Before the procedure is initiated, all equipment is inspected to ensure that it is in working order. The patient should be prepared for the procedure, if possible, with an intravenous catheter in place, and should be monitored with a pulse oximeter. The patient is sedated before the procedure (as clinical condition allows), and a topical anesthetic is applied to facilitate placement of the tube. In some cases, a paralytic agent may be necessary if the patient is extremely agitated.9,11,14

The procedure is initiated by positioning the patient with the neck flexed and head slightly extended in the “sniff” position. The oral cavity and pharynx are suctioned, and any dental devices are removed. The patient is preoxygenated and ventilated using the MRB and mask with 100% oxygen. Each intubation attempt is limited to 30 seconds. After the ETT is inserted, the patient is assessed for bilateral breath sounds and chest movement. Absence of breath sounds is indicative of an esophageal intubation, whereas breath sounds heard over only one side is indicative of a main stem intubation. A disposable end-tidal CO2 detector is used to initially verify correct airway placement, after which the cuff of the tube is inflated and the tube is secured. Finally, a chest radiograph is obtained to confirm placement.911 The tip of the ETT should be approximately 3 to 4 cm above the carina when the patient’s head is in the neutral position.10 After final adjustment of the position is complete, the level of insertion (marked in centimeters on the side of the tube) at the teeth is noted.9,10,14

A number of complications can occur during the intubation procedure, including nasal and oral trauma, pharyngeal and hypopharyngeal trauma, vomiting with aspiration, and cardiac arrest.14 Hypoxemia and hypercapnia can also occur, resulting in bradycardia, tachycardia, dysrhythmias, hypertension, and hypotension.8,12,14

Complications

Several complications can occur while the ETT is in place, including nasal and oral inflammation and ulceration, sinusitis and otitis, laryngeal and tracheal injuries, and tube obstruction and displacement. Other complications can occur days to weeks after the ETT is removed, including laryngeal and tracheal stenosis and a cricoid abscess (Table 16-3). Delayed complications usually require some form of surgical intervention.15

TABLE 16-3

COMPLICATIONS OF ENDOTRACHEAL TUBES

COMPLICATIONS CAUSES PREVENTION AND TREATMENT
Tube obstruction Patient biting tube
Tube kinking during repositioning
Cuff herniation
Dried secretions, blood, or lubricant
Tissue from tumor
Trauma
Foreign body
Prevention:

Treatment:

Tube displacement Movement of patient’s head
Movement of tube by patient’s tongue
Traction on tube from ventilator tubing
Self-extubation
Prevention:

Treatment:

Sinusitis and nasal injury Obstruction of the paranasal sinus drainage
Pressure necrosis of nares
Prevention:

Treatment:

Tracheoesophageal fistula Pressure necrosis of posterior tracheal wall, resulting from overinflated cuff and rigid nasogastric tube Prevention:

Treatment:

Mucosal lesions Pressure at tube and mucosal interface Prevention:

Treatment:

Laryngeal or tracheal stenosis Injury to area from end of tube or cuff, resulting in scar tissue formation and narrowing of airway Prevention:

Treatment:

Cricoid abscess Mucosal injury with bacterial invasion Prevention:

Treatment:

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PRN, as needed.

Tracheostomy Tubes

A tracheostomy tube is the preferred method of airway maintenance in the patient who requires long-term intubation. Although no ideal time to perform the procedure has been identified, it is commonly accepted that if a patient has been intubated or is anticipated to be intubated for longer than 7 to 10 days, a tracheostomy should be performed.16 A tracheostomy is also indicated in several other situations, such as the presence of an upper airway obstruction due to trauma, tumors, or swelling and the need to facilitate airway clearance due to spinal cord injury, neuromuscular disease, or severe debilitation.17

A tracheostomy tube provides the best route for long-term airway maintenance, because it avoids the oral, nasal, pharyngeal, and laryngeal complications associated with an ETT. The tube is shorter, of wider diameter, and less curved than an ETT; the resistance to air flow is less, and breathing is easier. Additional advantages of a tracheostomy tube include easier secretion removal, increased patient acceptance and comfort, capability of the patient to eat and talk if possible, and easier ventilator weaning.11,17 Table 16-2 presents a list of the advantages of a tracheostomy tube.

Tracheostomy tubes are made of plastic or metal and may have one or two lumens. Single-lumen tubes consist of the tube; a built-in cuff, which is connected to a pilot balloon for inflation purposes; and an obturator, which is used during tube insertion. The double-lumen tubes consist of the tube with the attached cuff, the obturator, and an inner cannula that can be removed for cleaning and then reinserted or, if disposable, replaced by a new sterile inner cannula. The inner cannula can quickly be removed if it becomes obstructed, making the system safer for patients with significant secretion problems. Single-lumen tubes provide a larger internal diameter for airflow, so airflow resistance is reduced, and the patient can ventilate through the tube with greater ease. Plastic tracheostomy tubes also have a 15-mm adaptor on the end (Figure 16-2).17,18

Tracheostomy

A tracheostomy tube is inserted by an open procedure or a percutaneous procedure. An open procedure is usually performed in the operating room, whereas a percutaneous procedure can be done at the patient’s bedside.18

A number of complications can occur during the tracheostomy procedure, including misplacement of the tracheal tube, hemorrhage, laryngeal nerve injury, pneumothorax, pneumomediastinum, and cardiac arrest.15,18

Complications

Several complications can occur while the tracheostomy tube is in place, including stomal infection, hemorrhage, tracheomalacia, tracheoesophageal fistula, tracheoinnominate artery fistula, and tube obstruction and displacement.18

A number of complications can occur days to weeks after the tracheostomy tube is removed, including tracheal stenosis and tracheocutaneous fistula (Table 16-4). Delayed complications usually require some form of surgical intervention.18

TABLE 16-4

COMPLICATIONS OF TRACHEOSTOMY TUBES

COMPLICATIONS CAUSES PREVENTION AND TREATMENT
Hemorrhage Vessel opening after surgery
Vessel erosion caused by tube
Prevention:

Treatment:

Wound infection Colonization of stoma with hospital flora Prevention:

Treatment:

Subcutaneous emphysema Positive-pressure ventilation
Coughing against a tight, occlusive dressing or sutured or packed wound
Prevention:

Treatment:

Tube obstruction Dried blood or secretions
False passage into soft tissues
Opening of cannula positioned against tracheal wall
Foreign body
Tissue from tumor
Prevention:

Treatment:

Tube displacement Patient movement
Coughing
Traction on ventilatory tubing
Prevention:

Treatment:

Tracheal stenosis Injury to area from end of tube or cuff, resulting in scar tissue formation and narrowing of airway Prevention:

Treatment:

Tracheoesophageal fistula Pressure necrosis of posterior tracheal wall, resulting from overinflated cuff and rigid nasogastric tube Prevention:

Treatment:

Tracheoinnominate artery fistula Direct pressure from the elbow of the cannula against the innominate artery
Placement of tracheal stoma below fourth tracheal ring
Downward migration of the tracheal stoma, resulting from traction on tube
High-lying innominate artery
Prevention:

Treatment:

Tracheocutaneous fistula Failure of stoma to close after removal of tube Treatment:

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PRN, as needed.

Nursing Management

The patient with an endotracheal or tracheostomy tube requires some additional measures to address the effects associated with tube placement on the respiratory and other body systems. Nursing priorities for the patient with an artificial airway focus on (1) providing humidification, (2) maintaining the cuff management, (3) suctioning, (4) establishing a method of communication, and (5) providing oral hygiene. Because the tube bypasses the upper airway system, warming and humidifying of air must be performed by external means. Because the cuff of the tube can cause damage to the walls of the trachea, proper cuff inflation and management is imperative. In addition, the normal defense mechanisms are impaired and secretions may accumulate; thus suctioning may be needed to promote secretion clearance. Because the tube does not allow air flow over the vocal cords, developing a method of communication is also very important. Last, observing the patient to ensure proper placement of the tube and patency of the airway is essential. Patient safety issues are addressed in the Patient Safety Priorities box on Artificial Airways.

imagePatient Safety Priorities

Artificial Airways

In the event of unintentional extubation or decannulation, the patient’s airway should be opened with the head tilt-chin lift maneuver and maintained with an oropharyngeal or nasopharyngeal airway. If the patient is not breathing, he or she should be manually ventilated with a manual resuscitation bag and face mask with 100% oxygen. In the case of a tracheostomy, the stoma should be covered to prevent air from escaping through it.

Humidification

Humidification of air normally is performed by the mucosal layer of the upper respiratory tract. When this area is bypassed, as occurs with ETT and tracheostomy tubes, or when supplemental oxygen is used, humidification by external means is necessary. Various humidification devices add water to inhaled gas to prevent drying and irritation of the respiratory tract, to prevent undue loss of body water, and to facilitate secretion removal.19,20 The humidification device should provide inspired gas conditioned (heated) to body temperature and saturated with water vapor.21

Cuff Management

Because the cuff of the ETT or tracheostomy tube is a major source of the complications associated with artificial airways, proper cuff management is essential. To prevent the complications associated with cuff design, only low-pressure, high-volume cuffed tubes are used in clinical practice.13,22 Even with these tubes, cuff pressures can be generated that are high enough to lead to tracheal ischemia and injury. Proper cuff inflation techniques and cuff pressure monitoring are critical components of the care of the patient with an artificial airway.10,22

Cuff Inflation Techniques

Two cuff inflation techniques are used: the minimal leak (ML) technique and the minimal occlusion volume (MOV) technique. The ML technique consists of injecting air into the cuff until no leak is heard and then withdrawing the air until a small leak is heard on inspiration. Problems with this technique include difficulty maintaining positive end-expiratory pressure (PEEP) and aspiration around the cuff. The MOV technique consists of injecting air into the cuff until no leak is heard at peak inspiration. This technique generates higher cuff pressures than does the ML technique. The selection of one technique over the other is determined by individual patient needs. If the patient needs a seal to provide adequate ventilation or is at high risk for aspiration, the MOV technique is used. If these are not concerns, usually the ML technique is used.10,11,22

Cuff Pressure Monitoring

Cuff pressures are monitored at least every shift with a cuff pressure manometer. Cuff pressures should be maintained at 20 to 25 mm Hg (24 to 30 cm H2O), because greater pressures decrease blood flow to the capillaries in the tracheal wall and lesser pressures increase the risk of aspiration. Pressures in excess of 25 mm Hg (30 cm H2O) should be reported to the physician. Cuffs are not routinely deflated, because this increases the risk of aspiration.10,22

Foam Cuff Tracheostomy Tubes

One tracheostomy tube on the market has a cuff made of foam that is self-inflating. It is deflated during insertion, after which the pilot port is opened to atmospheric pressure (room air), and the cuff self-inflates. After inflation, the foam cuff conforms to the size and shape of the patient’s trachea, thereby reducing the pressure against the tracheal wall. The pilot port can be left open to atmospheric pressure or attached to the mechanical ventilator tubing, allowing the cuff to inflate and deflate with the cycling of the ventilator. Routine maintenance of a foam cuff tracheostomy tube includes aspirating the pilot port every 8 hours to measure cuff volume, to remove any condensation from the cuff area, and to assess the integrity of the cuff. Removal is accomplished by deflating the cuff; this can be complicated if the plastic sheath covering the foam is perforated. If perforation occurs, the foam may not be deflatable because the air cannot be totally aspirated.23

Suctioning

Suctioning is often required to maintain a patent airway in the patient with an ETT or tracheostomy tube. Suctioning is a sterile procedure that is performed only when the patient needs it and not on a routine schedule.10,24 Indications for suctioning include coughing, secretions in the airway, respiratory distress, presence of rhonchi on auscultation, increased peak airway pressures on the ventilator, and decreasing oxygenation saturation.11 Complications associated with suctioning include hypoxemia, atelectasis, bronchospasms, dysrhythmias, increased intracranial pressure, and airway trauma.11,24

Complications

Hypoxemia can result because the oxygen source is disconnected from the patient or the oxygen is removed from the patient’s airways when the suction is applied. Atelectasis is thought to occur when the suction catheter is larger than one half of the diameter of the ETT. Excessive negative pressure occurs when suction is applied, promoting collapse of the distal airways. Bronchospasms are the result of stimulation of the airways with the suction catheter. Cardiac dysrhythmias, particularly bradycardias, are attributed to vagal stimulation. Airway trauma occurs with impaction of the catheter in the airways and excessive negative pressure applied to the catheter.10,11,24

Suctioning Protocol

A number of protocols regarding suctioning have been developed. Several practices have been found helpful in limiting the complications of suctioning. Hypoxemia can be minimized by giving the patient three hyperoxygenation breaths (breaths at 100% FiO2) with the ventilator before the procedure begins and again after each pass of the suction catheter.10,25 If the patient exhibits signs of desaturation, hyperinflation (breaths at 150% tidal volume) should be added to the procedure.10 Atelectasis can be avoided by using a suction catheter with an external diameter of less than one half of the internal diameter of the ETT.24 Using no greater than 120 mm Hg of suction decreases the chances of hypoxemia, atelectasis, and airway trauma.10 Limiting the duration of each suction pass to 10 to 15 seconds10,24 and the number of passes to a maximum of three also helps minimize hypoxemia, airway trauma, and cardiac dysrhythmias.26 The process of applying intermittent (instead of continuous) suction has been shown to be of no benefit.27 The instillation of normal saline to help remove secretions has not proved to be of any benefit24,28 and may actually contribute to the development of hypoxemia10,29 and lower airway colonization, resulting in hospital-acquired pneumonia (HAP).10,30

Closed Tracheal Suction System

One device to facilitate the suctioning of a patient on a ventilator is the closed tracheal suction system (CTSS) (Figure 16-3). This device consists of a suction catheter in a plastic sleeve that attaches directly to the ventilator tubing. It allows the patient to be suctioned while remaining on the ventilator. Advantages of the CTSS include maintenance of oxygenation and PEEP during suctioning, reduction of hypoxemia-related complications, and protection of staff members from the patient’s secretions. The CTSS is convenient to use, requiring only one person to perform the procedure.

Concerns related to the CTSS include autocontamination, inadequate removal of secretions, and increased risk of unintentional extubation resulting from the extra weight of the system on the ventilator tubing. Autocontamination has been shown not to be an issue if the catheter is cleaned properly after every use. Inadequate removal of secretions may or may not be a problem, and further investigation is required to settle this issue.11 Although recommendations for changing the catheter vary, one study indicated that the catheter could be changed on an as-needed basis without increasing the incidence of HAP.31

Communication

One of the major stressors for the patient with an artificial airway is impaired communication. This is related to the inability to speak, insufficient explanations from staff members, inadequate understanding, fear of being unable to communicate, and difficulty with communication methods.32 A number of interventions can facilitate communication in the patient with an ETT or tracheostomy tube. These include performing a complete assessment of the patient’s ability to communicate, teaching the patient how to communicate, using a variety of methods to communicate, and facilitating the patient’s ability to communicate by providing the patient with his or her eyeglasses or hearing aid.33

Methods to facilitate communication in this patient population include the use of verbal and nonverbal language and a variety of devices to assist the patient on short-term and long-term ventilator assistance. Nonverbal communication may include the use of sign language, gestures, lip-reading, pointing, facial expressions, or eye blinking. Simple devices available include pencil and paper; Magic Slates; magnetic boards with plastic letters; picture, alphabet, or symbol boards; and flash cards. More sophisticated devices include typewriters, computers, talking ETT and tracheostomy tubes, and external handheld vibrators. Regardless of the method selected, the patient must be taught how to use the device.10,33

Passy-Muir Valve

One device used to assist the mechanically ventilated patient with a tracheostomy to speak is the Passy-Muir valve. This one-way valve opens on inhalation, allowing air to enter the lungs through the tracheostomy tube, and closes on exhalation, forcing air over the vocal cords and out the mouth, permitting the patient to speak (Figure 16-4). Before the valve can be placed on a tracheostomy tube, the cuff must be deflated to allow air to pass around the tube, and the tidal volume of the ventilator must be increased to compensate for the air leak. In addition to aiding communication, the Passy-Muir valve can assist the ventilator-dependent patient with relearning normal breathing patterns. The valve is contraindicated in patients with laryngeal or pharyngeal dysfunction, excessive secretions, or poor lung compliance.34

Oral Hygiene

Patients with artificial airways are extremely susceptible to developing HAP due to microaspiration of subglottic secretions. Subglottic secretions are fluids from the oropharyngeal area that pool above the inflated cuff of the ETT or tracheostomy tube. These secretions are full of microorganisms from the patient’s mouth. Because the cuff of the artificial airway does not create a tight seal in the patient’s airway, these secretions seep around the cuff and into the patient’s lungs, promoting the development of HAP.35 Although bacteria are normally present in a patient’s mouth, in the critically ill patient there are increased amounts of bacteria and more resistant bacteria. Decreased salivary flow, poor mucosal status, and dental plaque all contribute to this problem.36

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