Cystic Fibrosis

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Cystic Fibrosis

Chapter Objectives

After reading this chapter, you will be able to:

• List the anatomic alterations of the lungs associated with cystic fibrosis.

• Describe the causes and classifications of cystic fibrosis.

• List the cardiopulmonary clinical manifestations associated with cystic fibrosis.

• Describe the general management of cystic fibrosis.

• Describe the clinical strategies and rationales of the SOAPs presented in the case study.

• Define key terms and complete self-assessment questions at the end of the chapter and on Evolve.

Key Terms

Anatomic Alterations of the Lungs*

Although the lungs of patients with cystic fibrosis appear normal at birth, abnormal structural changes develop quickly. Initially, the patient has bronchial gland hypertrophy and metaplasia of goblet cells, which secrete large amounts of thick, tenacious mucus. Because the mucus is particularly tenacious, impairment of the normal mucociliary clearing mechanism ensues, and many small bronchi and bronchioles become partially or totally obstructed (mucous plugging). Partial obstruction leads to overdistention of the alveoli, and complete obstruction leads to patchy areas of atelectasis. The anatomic alterations of the lungs associated with cystic fibrosis may result in both restrictive and obstructive lung characteristics, but excessive bronchial secretions, bronchial obstruction, and hyperinflation of the lungs are the predominant features of cystic fibrosis in the advanced stages.

The abundance of stagnant mucus in the tracheobronchial tree also serves as an excellent culture medium for bacteria, particularly Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa. Some gram-negative bacteria are also commonly associated with cystic fibrosis, such as Stenotrophomonas maltophilia, Burkholderia cepacia, Burkholderia pickettii, and Burkholderia gladioli. The infection stimulates additional mucous production and further compromises the mucociliary transport system. This condition may lead to secondary bronchial smooth muscle constriction. Finally, as the disease progresses, the patient may develop signs and symptoms of recurrent pneumonia, chronic bronchitis, bronchiectasis, and lung abscesses (Figure 14-1).

image
FIGURE 14-1 Cystic fibrosis. AT, Atelectasis; HALV, hyperinflation of alveoli; MA, mucous accumulation; MP, mucous plug; PO, partial obstruction of the airways.

The major pathologic or structural changes associated with cystic fibrosis are as follows:

Etiology and Epidemiology

Cystic fibrosis is the most common inherited disorder in childhood. Cystic fibrosis is an autosomal recessive gene disorder caused by mutations in a pair of genes located on chromosome 7. Under normal conditions, every cell in the body (except the sex cells) has 46 chromosomes—23 pairs (one half inherited from father and the other half from mother). Over 1000 different mutations in the gene that encodes for the cystic fibrosis transmembrane conductance regulator (CFTR) have been described. One genetic defect linked to cystic fibrosis involves the absence of three base pairs in codon 508 (ΔF508) that codes for phenylalanine on chromosome 7 (band q31). Because of the loss of these three base pairs, the CFTR gene becomes dysfunctional. This is the most common genetic mutation associated with cystic fibrosis and accounts for 70% to 75% of the cystic fibrosis patients tested.

The abnormal expression of the CFTR results in abnormal transport of sodium and chloride across many types of epithelial surfaces, including those lining the bronchial airways, intestines, pancreas, liver ducts, sweat glands, and vas deferens. As a result, thick, viscous mucus accumulates in the lungs, and mucus blocks the passageways of the pancreas, preventing enzymes from the pancreas from reaching the intestines. This condition inhibits the digestion of protein and fat, which in turn leads to deficiencies of vitamins A, D, E, and K. In addition, diarrhea, malnutrition, and weight loss are also common. Some infants with cystic fibrosis develop a blockage of the intestine shortly after birth—a condition called meconium ileus. Most men with cystic fibrosis are infertile as a result of a missing or an underdeveloped vas deferens. Infertility is not common in women with cystic fibrosis.

How the Cystic Fibrosis Gene Is Inherited

Because cystic fibrosis is a recessive gene disorder, the child must inherit two copies of the defective cystic fibrosis gene—one from each parent (cystic fibrosis carriers)—to have the disease. Even though the carrier of the cystic fibrosis gene may be identified through genetic testing, the carrier (heterozygote) does not demonstrate evidence of the disease. However, if both parents carry the cystic fibrosis gene, the possibility of their children having cystic fibrosis (regardless of gender) follows the standard Mendelian pattern: there is a 25% chance that each child will have cystic fibrosis, a 25% chance that each child will be completely normal (and not carry the gene), and a 50% chance that each child will be a carrier. Thus, when both patients have the cystic fibrosis gene, there is a one in four chance that the child will have cystic fibrosis (Figure 14-2). It is estimated that more than 10 million Americans are unknowing, symptomless carriers of the mutant cystic fibrosis gene.

image
FIGURE 14-2 Standard Mendelian pattern of inheritance of cystic fibrosis.

According to the Cystic Fibrosis Foundation, cystic fibrosis affects about 30,000 children and adults in the United States. About 1000 new cases of cystic fibrosis are diagnosed each year in the United States (70,000 worldwide). More than 70% of the patients are diagnosed by age 2. More than 40% of the cystic fibrosis patient population is age 18 or older.* Other researchers state that whites are most often affected (1 in 2500 to 3500). Cystic fibrosis is less common in Hispanics (1 in 9500) and African-Americans (1 in 17,000). Cystic fibrosis is rarely seen in Asians (1 in 31,000). The predicted median life expectancy is 37 years. Death usually is caused by pulmonary complications.

Screening and Diagnosis

The diagnosis of cystic fibrosis is based on clinical manifestations associated with cystic fibrosis, family history of cystic fibrosis, and laboratory findings. Box 14-1 provides common clinical indicators that justify evaluation for cystic fibrosis.

Box 14-1   Clinical Indicators Justifying the Initial Evaluation for Cystic Fibrosis

Pulmonary

The diagnosis of cystic fibrosis is based on results of one or more of the laboratory tests discussed in the following sections.

Sweat Test

The sweat test (sometimes called the sweat chlorine test) is the gold standard diagnostic test for cystic fibrosis. The sweat test is a reliable test for the identification of approximately 98% of patients with cystic fibrosis. This test measures the amount of sodium and chloride in the patient’s sweat. During the procedure a small amount of a colorless, odorless sweat-producing chemical called pilocarpine is applied to the patient’s arm or leg—usually the forearm. An electrode is attached to the chemically prepared area, and a mild electric current is applied to stimulate sweat production (Figure 14-3). To collect the sweat, the area is covered with a gauze pad or filter paper and wrapped in plastic. After about 30 minutes the plastic is removed, and the sweat collected in the pad or paper is sent to the laboratory for analysis. The test is usually done twice.

image
FIGURE 14-3 Sweat test. During the procedure a small amount of a colorless, odorless sweat-producing chemical called pilocarpine is applied to the patient’s arm or leg—usually the forearm. An electrode is attached to the chemically prepared area, and a mild electric current is applied to stimulate sweat production. Used with permission Wescor, Inc—an ELITech Group Company. Used with permission Wescor, Inc—ELITech Group Company.

Although the sweat glands of patients with cystic fibrosis are microscopically normal, the glands secrete up to four times the normal amount of sodium and chloride. The actual volume of sweat, however, is no greater than that produced by a normal individual. In children, a sweat chloride concentration greater than 60 mEq/L is considered to be a diagnostic sign of the disease. In adults, a sweat chloride concentration greater than 80 mEq/L usually is required to confirm the diagnosis. The sweat chloride level in the patient with cystic fibrosis may be up to five times greater than normal.

Immunoreactive Trypsinogen Test

An immunoreactive trypsinogen test (IRT) (also called trypsin-like immunoreactivity, serum trypsinogen, and serum trypsin) may be ordered as an initial test for (1) babies who are not creating enough sweat to perform a sweat test, or (2) infants with meconium ileus (no stools in the first 24 to 48 hours of life). The test may be particularly useful for small or malnourished infants in whom the sweat chloride test cannot be performed successfully. An IRT is also ordered for children and adults with signs and symptoms associated with cystic fibrosis and pancreatic dysfunction, such as persistent diarrhea; foul-smelling, bulky, greasy stools; malnutrition; and vitamin deficiency. During this procedure, a blood sample is analyzed twice for a specific protein called trypsinogen. Patients with cystic fibrosis have elevated blood levels of IRT. Two positive test results indicate cystic fibrosis, abnormal pancreatic enzyme production, pancreatitis, or pancreatic cancer. Elevated levels need to be followed with further testing, such as a cystic fibrosis gene mutation test.

Nasal Potential Difference

The impaired transport of sodium (Na+) and chloride (Cl−) across the epithelial cells lining the airways of the cystic fibrosis patient can be measured. As the Na+ and Cl− ions move across the epithelial cell membrane they general what is called an electrical potential difference—the amount of energy required to move an electrical charge from one point to another. In the nasal passages this electrical potential difference is called the nasal potential difference (NPD). The NPD can be measured with a surface electrode over the nasal epithelial cells lining the inferior turbinate. An increased (i.e., more negative) nasal potential difference strongly suggests cystic fibrosis. The NPD is recommended for patients with clinical features of cystic fibrosis who have borderline or normal sweat test values and nondiagnostic cystic fibrosis genotyping.

Genetic Testing

With a sample of the patient’s blood, a genetic test (also called a genotype test, gene mutation test, or mutation analysis) can be performed to analyze deoxyribonucleic acid (DNA) for the presence of CFTR gene mutations. From over 1000 different CFTR gene mutations, the most common gene alteration in cystic fibrosis is ΔF508. Although genetic testing for cystic fibrosis is considered a valuable diagnostic tool, it does have its limitations. For example, some individuals have CFTR mutations but demonstrate no typical clinical manifestations of cystic fibrosis. In addition, some patients may have CFTR mutations, but the mutations cannot be identified with our current gene analysis methods. It is estimated that genetic testing can confirm cystic fibrosis in about 80% to 85% of the patients tested. As a general rule, genetic testing is performed in patients who have negative sweat test results but still demonstrate a variety of clinical manifestations associated with cystic fibrosis (see following section).

Prenatal Testing

In women who are pregnant and who wish to make informed reproductive decisions, prenatal diagnosis may be performed by chorionic villus biopsy in the first trimester or by amniocentesis in the second or third trimester. Such testing is usually carried out in a family that has previously had a child with cystic fibrosis.

image OVERVIEW of the Cardiopulmonary Clinical Manifestations Associated with Cystic Fibrosis

The following clinical manifestations result from the pathophysiologic mechanisms caused (or activated) by Atelectasis (see Figure 9-8), Bronchospasm (see Figure 9-11), and Excessive Bronchial Secretions (see Figure 9-12)—the major anatomic alterations of the lungs associated with cystic fibrosis (CF) (see Figure 14-1).

CLINICAL DATA OBTAINED AT THE PATIENT’S BEDSIDE

The Physical Examination

CLINICAL DATA OBTAINED FROM LABORATORY TESTS AND SPECIAL PROCEDURES

Pulmonary Function Test Findings

Moderate to Severe Cystic Fibrosis (Obstructive Lung Pathophysiology)*

FORCED EXPIRATORY FLOW RATE FINDINGS

FVC FEVT FEV1/FVC ratio FEF25%-75%
↓ ↓ ↓ ↓
FEF50% FEF200-1200 PEFR MVV
↓ ↓ ↓ ↓

image

LUNG VOLUME AND CAPACITY FINDINGS

VT IRV ERV RV  
N or ↑ N or ↓ N or ↓ ↑  
VC IC FRC TLC RV/TLC ratio
↓ N or ↓ ↑ N or ↑ N or ↑

image

*Cystic fibrosis is primarily an obstructive lung disorder. However, when extensive total lung obstruction (from mucous plugging) and atelectasis is present throughout the lungs, restrictive pulmonary function testing values will likely appear.

Arterial Blood Gases

Oxygenation Indices*

Moderate to Severe Stages

*C(a-image)O2, Arterial-venous oxygen difference; DO2, total oxygen delivery; O2ER, oxygen extraction ratio; image, pulmonary shunt fraction; image, mixed venous oxygen saturation; , oxygen consumption.

Hemodynamic Indices†

Moderate to Severe Stages

CVP RAP image PCWP CO SV
↑ ↑ ↑ N N N
SVI CI RVSWI LVSWI PVR SVR
N N ↑ N ↑ N

image

†CO, Cardiac output; CVP, central venous pressure; LVSWI, left ventricular stroke work index; image, mean pulmonary artery pressure; PCWP, pulmonary capillary wedge pressure; PVR, pulmonary vascular resistance; RAP, right atrial pressure; RVSWI, right ventricular stroke work index; SV, stroke volume; SVI, stroke volume index; SVR, systemic vascular resistance.

RADIOLOGIC FINDINGS

Chest Radiograph

During the late stages of CF, the alveoli become hyperinflated, which causes the residual volume and functional residual capacity to increase. Because this condition decreases the density of the lungs and therefore reduces the resistance to x-ray penetration, the chest radiograph appears darker. As the patient’s residual volume and functional residual capacity increase, the diaphragm moves downward and appears flattened or depressed on the radiograph (Figure 14-4).

image
FIGURE 14-4 Chest x-ray of a patient with cystic fibrosis. Note the lung overinflation, the diffuse infiltrates, and the large main pulmonary artery segment.

Figure 14-5 presents four serial chest radiographs of the progression of CF over 26 years. Because right ventricular enlargement and failure often develop as secondary problems during the advanced stages of CF, an enlarged heart may be identified on the radiograph. In some patients, areas of atelectasis, abscess formation, or a pneumothorax may be seen. Finally, computed tomography (CT) and positron emission tomography (PET) scans may be helpful when borderline radiographic findings are present.

image
FIGURE 14-5 Cystic fibrosis. Serial chest imaging over a 26-year period showing the progressive changes of cystic fibrosis. A, At 3 years of age, the patient had right middle lobe pneumonia. B, Mild hyperinflation and bronchial wall thickening (arrow) present at age 7 years. C, At age 15 years, the patient demonstrates progressive hyperinflation, bronchiectasis, and enlargement of the hila on the chest radiograph. D, Lateral chest radiograph at 29 years shows typical findings of end-stage cystic fibrosis. Note marked hyperinflation and “barrel chest” deformity, severe bronchiectasis, and tubular opacities consistent with mucous plugs. (From Hansell DM, Armstrong P, Lynch DA, McAdams HP: Imaging of diseases of the chest, ed 4, Philadelphia, 2005, Elsevier.)

COMMON NONRESPIRATORY CLINICAL MANIFESTATIONS

General Management of Cystic Fibrosis

The management of cystic fibrosis entails an interdisciplinary approach. The primary goals are to prevent pulmonary infections, reduce the amount of thick bronchial secretions, improve air flow, and provide adequate nutrition. The patient and the patient’s family should be instructed regarding the disease and the way it affects bodily functions. They should be taught home care therapies, the goals of these therapies, and the way to administer medications. Patients with severe cystic fibrosis commonly are best managed by a pulmonary rehabilitation team. Such teams include a respiratory care practitioner, a physical therapist, a respiratory nurse specialist, an occupational therapist, a dietitian, a social worker, and a psychologist. A pediatrician or an internist trained in respiratory rehabilitation outlines and orchestrates the patient’s therapeutic program.

Patients with cystic fibrosis should have regular medical checkups for comparative purposes to determine their general health, weight, height, pulmonary function abilities, and sputum culture results. In addition, oral time-released pancreatic enzymes, such as pancreatic lipase, are prescribed for patients with cystic fibrosis to aid food digestion. Patients also are encouraged to replace body salts either by heavily salting their food or by taking sodium supplements. Supplemental multivitamins and minerals also are important. To accomplish these objectives, the management of cystic fibrosis includes the protocols discussed in the following sections.

Respiratory Care Treatment Protocols

Oxygen Therapy Protocol

Oxygen therapy is used to treat hypoxemia, decrease the work of breathing, and decrease myocardial work. The hypoxemia that develops in cystic fibrosis is caused by the pulmonary shunting associated with the disorder. When the patient demonstrates chronic ventilatory failure during the advanced stages of cystic fibrosis, caution must be taken not to overoxygenate the patient (see Oxygen Therapy Protocol, Protocol 9-1).

Bronchopulmonary Hygiene Therapy Protocol

Because of the excessive mucous production and accumulation associated with cystic fibrosis, a number of respiratory therapy modalities are used to enhance the mobilization of bronchial secretions. Aggressive and vigorous bronchial hygiene—especially chest physical therapy and postural drainage—should be performed regularly on patients both in the hospital and at home. Because many patients with cystic fibrosis require bronchial hygiene therapy at least twice a day for 20 to 30 minutes, a mechanical percussor or a high-frequency chest compression vest can be especially helpful in moving thick bronchial secretions (Figure 14-6) (see Bronchopulmonary Hygiene Therapy Protocol, Protocol 9-2).

image
FIGURE 14-6 An 18-month-old female cystic fibrosis patient wearing a high-frequency chest compression (HFCC) vest (the inCourage System). Today, HFCC is a commonly used bronchopulmonary hygiene treatment for airway clearance in patients with cystic fibrosis.

Medications and Special Procedures Prescribed by the Physician

Xanthines

Xanthines are occasionally used to enhance bronchial smooth muscle relaxation (see Appendix II, Xanthine Bronchodilators).

Lung or Heart-Lung Transplantation

Several large organ transplant centers currently are performing lung or heart-lung transplantations in selected patients with cystic fibrosis whose general body condition is good. According to the Cystic Fibrosis Foundation, approximately 900 lung transplants are performed each year in the United States. Since 1991, about 1600 cystic fibrosis patients have received lung transplants—120 to 150 patients per year. In 2003, 368 patients were accepted for the lung transplant procedure. The success of lung transplantation in patients with cystic fibrosis is as good as or better than in patients with other lung diseases (e.g., emphysema). As many as 90% of the patients with cystic fibrosis are alive 1 year after transplantation, and 50% are alive after 5 years.*

CASE STUDY

Cystic Fibrosis

Admitting History

A 27-year-old man has a long history of respiratory problems caused by cystic fibrosis. Even though his medical records are incomplete, he reported on admission that his parents told him that he had experienced several episodes of pneumonia during his early years. He is an adopted child and therefore does not know his biologic family history. His parents are actively involved in his general care, which entails the home care suggestions and therapeutic procedures presented by the pulmonary rehabilitation team. He takes supplemental multivitamins and timed-release oral pancreatic enzymes regularly, as prescribed by his doctor.

During his teens he had fewer respiratory symptoms than he has today and was able to lead a relatively normal life. During that time, he took up water-skiing and became proficient in the slalom event. He is known to most of his associates as a “wonder.” Although he qualifies for disability income because of his continual shortness of breath, he is able to do various small jobs, which always relate to water-skiing. He is well known throughout the water-skiing circuit as an excellent chief judge at national and regional tournaments. In addition, he is a certified driver for jump-trick and slalom events and recently has become involved in selling water-ski tournament ropes and handles, which provides him with a small additional income.

Over the past 3 years, his cough has become more persistent and increasingly productive, with about a cupful of sputum noted daily. Over the same period, he has noted intermittent hemoptysis and has become short of breath when climbing stairs. Even though the man has a normal appetite, he has lost a great deal of weight over the past 2 years. On admission, he reported a history of severe shortness of breath. He denied experiencing any recent changes in bowel habits, despite his weight loss, but said that he has noticed a tendency to pass rather pale stools. Much to the chagrin of his doctor, 3 years ago he began smoking about 10 cigarettes a day, his reason being that the cigarettes help him cough up the sputum.

Physical Examination

On examination the patient appeared pale, cyanotic, and thin. He had a barrel chest and was using his accessory muscles of respiration. Clubbing of the fingers was present. He demonstrated a frequent, productive cough. His sputum was sweet-smelling, thick, and yellow-green. His neck veins were distended, and he showed mild-to-moderate peripheral edema. He stated that he had not been this short of breath in a long time.

He had a blood pressure of 142/90, a heart rate of 108 bpm, and a respiratory rate of 28/min. He was afebrile. Palpation of the chest was unremarkable. Expiration was prolonged. Hyperresonant notes were elicited bilaterally during percussion. Auscultation revealed diminished breath sounds and heart sounds. Crackles and rhonchi were heard throughout both lung fields.

His chart showed that during his last medical checkup (about 10 months before this admission) a pulmonary function test (PFT) was conducted. Results revealed moderate-to-severe airway obstruction. No blood gases were analyzed.

His chest x-ray examination on this admission revealed hyperlucent lung fields, depressed hemidiaphragms, and mild cardiac enlargement (Figure 14-7). His arterial blood gas values (ABGs) on 1.5 L/min oxygen by nasal cannula were as follows: pH 7.51, Paco2 58 mm Hg, image 43, and Pao2 66 mm Hg. His hemoglobin oxygen saturation measured by pulse oximetry (Spo2) was 94%. On the basis of these clinical data, the following SOAP was documented.

image
FIGURE 14-7 Chest x-ray film from a 27-year-old man with cystic fibrosis.

Respiratory Assessment and Plan

S “I’ve not been this short of breath in a long time.”

O Skin: pale, cyanotic; barrel chest and use of accessory muscles of respiration; digital clubbing; cough frequent and productive; sputum: sweet-smelling, thick, yellow-green; distended neck veins and peripheral edema; vital signs: BP 142/90, HR 108, RR 28, T normal; bilateral hyperresonant percussion notes; diminished breath sounds; crackles and rhonchi; CXR: hyperlucency, flattened diaphragms, and mild cardiac enlargement; ABGs (1.5 L/min O2 by nasal cannula): pH 7.51, Paco2 58, image 43, Pao2 66; Spo2 94%

A 

P Bronchopulmonary Hygiene Therapy Protocol (cough and deep breathe Tx q4h), sputum culture). Oxygen Therapy Protocol (2 L/min by nasal cannula). Monitor possible impending ventilatory failure closely (pulse oximetry, vital signs, ABGs).

48 Hours after Admission

The respiratory therapist from the Consult Service noted that the patient was again in respiratory distress. The man stated that he could not get enough air to sleep even 10 minutes. He appeared cyanotic and was using his accessory muscles of respiration. His vital signs were as follows: blood pressure 147/95, heart rate 117 bpm, respiratory rate 32/min, and temperature 37° C (98.6° F).

He coughed frequently, and although his cough was weak, he produced large amounts of thick, green sputum. Hyperresonant notes were produced during percussion over both lung fields. On auscultation, breath sounds and heart sounds were diminished. Crackles, rhonchi, and wheezing were heard throughout both lung fields. No recent chest x-ray film was available. A sputum culture confirmed the presence of Pseudomonas aeruginosa. His Spo2 was 92% and his ABGs were as follows: pH 7.55, Paco2 54 mm Hg, image 45, and Pao2 57 mm Hg. On the basis of these clinical data, the following SOAP was documented.

Respiratory Assessment and Plan

S “I can’t get enough air to sleep 10 minutes!”

O Cyanosis and use of accessory muscles of respiration; vital signs: BP 147/95, HR 117, RR 32, T 37° C (98.6° F); cough: frequent, weak, and productive of large amounts of thick, green sputum; Pseudomonas aeruginosa cultured; bilateral hyperresonant notes and diminished breath sounds; crackles, rhonchi, and wheezes; Spo2 92%; ABGs: pH 7.55, Paco2 54, image 45, Pao2 57

A 

P Start Aerosolized Medication Protocol (0.5 cc albuterol in 2 cc rhDNase q4h). Up-regulate Bronchopulmonary Hygiene Therapy per protocol (CPT and PEP therapy q2h). Up-regulate Oxygen Therapy Protocol (HAFOE mask at Fio2 0.35). Continue to monitor possible impending ventilatory failure closely.

64 Hours after Admission

The respiratory care practitioner noted that the patient was in obvious respiratory distress. The patient said he could not find a position that allowed him to breathe comfortably. He appeared cyanotic and was using pursed-lip breathing, using his accessory muscles of respiration. His vital signs were as follows: blood pressure 145/90, heart rate 120 bpm, respiratory rate 22/min, and oral temperature 38° C (100.5° F). Palpation was normal, but bilateral hyperresonant percussion notes were elicited. Auscultation revealed crackles, rhonchi, and wheezing bilaterally. No recent chest x-ray film was available. His Spo2 was 65%, and his ABGs were as follows: pH 7.33, Paco2 79 mm Hg, image 41, and Pao2 37 mm Hg. On the basis of these clinical data, the following SOAP was entered in the patient’s chart.

Respiratory Assessment and Plan

S “I can’t get into a comfortable position to breathe.”

O Cyanosis; pursed-lip breathing and use of accessory muscles of respiration; vital signs: BP 145/90, HR 120, RR 22, T 38° C (100.5° F); bilateral hyperresonant percussion notes, crackles, rhonchi, and wheezing; Spo2 65%; ABGs: pH 7.33, Paco2 79, image 41, PaO2 37

A 

P Contact physician stat. Consider intubation and implementation of the Mechanical Ventilation Protocol. Continue Aerosolized Medication and Bronchial Hygiene Therapy Protocol (after patient has been placed on ventilator). Up-regulate Oxygen Therapy Protocol (initially, Fio2 0.50 on ventilator). Monitor closely.

Discussion

The science of respiratory care has advanced over the years, and the prognosis for patients with this multisystem genetic disorder has improved. In this patient’s lifetime, the following four therapeutic landmarks can be noted:

This patient had received at least three of these treatments and was in the hands of caring parents. His own stubborn nature and interest in athletics were clearly helpful in his prolonged survival. Important to note are the circumstances surrounding his admission, especially the fact that he had experienced hemoptysis, dyspnea, and weight loss during the several years preceding his admission. Note also that he had started smoking cigarettes.

In this case study, the patient’s chief complaints purposely have been buried in the admitting history. The reader should have discerned that the patient was coughing productively and had hemoptysis, dyspnea, and weight loss. The recommended therapeutic strategy arises from recognition of these four presenting complaints. Note also that on admission the patient had neck vein distention and peripheral edema, suggesting cor pulmonale. If the experience with chronic obstructive pulmonary disease can be translated to patients with cystic fibrosis, this is a bad prognostic sign and one that clearly calls for intensification of the therapeutic regimen.

Note that on the initial physical examination, the patient demonstrated excessive bronchial secretions and a productive cough; no baseline arterial blood gases existed with which to compare his current values (see Bronchospasm, Figure 9-11). Thus the observation of an elevated Paco2 should be taken very, very seriously, because (at least initially) whether this value is a “chronic” arterial blood gas value is unclear.

At the time of the second evaluation the patient clearly was not improving. The up-regulation of Bronchopulmonary Hygiene Therapy (see Protocol 9-2) and addition of the Aerosolized Medication Protocol at this point was appropriate—the increased chest physical therapy (along with PEP therapy) q2h, and Pulmozyme therapy. A repeat chest x-ray study would not be out of order at this time. We could argue that the Aerosolized Medication Protocol should have been started earlier.

The third assessment suggests that the patient clearly was deteriorating despite vigorous noninvasive therapy. At this point, the patient was placed on an Fio2 of 0.5, and the stat call to the physician regarding the acute ventilatory failure was clearly justified. The addition of intubation and mechanical ventilation at this time would prevent fatigue, allow deep nasal tracheal suctioning, and facilitate repeat therapeutic bronchoscopy if it were to become necessary.

Despite this initial downhill course, the patient was placed on a ventilator and slowly improved. Over the next 7 days, the patient was extubated. The therapist should note that despite all the “good” things the patient and family did to treat his illness, the patient’s initiation of smoking clearly could be a “last-straw” phenomenon. The patient should be placed on a smoking-cessation program. This step is as important for the long-term prognosis as is the skill of the practitioner caring for him during this bout of acute ventilatory failure.

*Cystic fibrosis does not affect the lungs exclusively. It also affects the function of exocrine glands in other parts of the body. In addition to being characterized by abnormally viscid secretions in the lungs, the disease is clinically manifested by pancreatic insufficiency and high sodium concentrations in the sweat.

*Cystic Fibrosis Foundation (www.cff.org).

*Cystic Fibrosis Foundation (www.cff.org).

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