Cystic fibrosis (CF) is an autosomal recessive genetic disease of the epithelial cells in the body, especially those lining the intestinal tract and airways of the lungs. Normally, epithelial cells transport chloride through the cystic fibrosis transmembrane regulator (CFTR) with sodium and water following the ion flux. CF is the loss of the function of the CFTR with defective movement of Cl and water in the body. Thus, the secretions from the pancreas, hepatobiliary tree, reproductive tract, sweat glands, and the airways are thick and lead to obstruction with malfunction. This malfunction leads to organ system disease (Table 46-1).
TABLE 46-1Organ System Effects of Cystic Fibrosis |Favorite Table|Download (.pdf) TABLE 46-1Organ System Effects of Cystic Fibrosis
|Organ Obstruction ||Malfunction ||Clinical Effect |
|Pancreatic duct ||Duct obstruction ||Enzyme deficiency, maldigestion |
|Biliary duct ||Duct obstruction ||Cirrhosis, portal hypertension, esophageal varices |
|Intestines ||Viscous secretions ||Distal intestinal obstructive syndrome (DIOS) |
|Pulmonary ||Viscous secretions ||Obstruction, infection |
|Sweat glands ||Fail to reabsorb Na (“salty taste of skin”) ||Hyponatremia |
|Reproductive ||♂Obstruction epididymis, vas deferens, seminal vesicles ||Aspermia |
| ||♀Obstruction cervix ||Decreased fertility |
|Bone, joint ||Unknown ||Arthritis, osteopenia |
Clinical presentation of CF patients may vary in severity depending upon the genotype. However, all patients will develop a progressive deterioration in affected organ function from baseline as they age. Early disease is milder and later disease is advanced and severe. Early obstruction in the gastrointestinal system manifests as abdominal distention, pain, vomiting, and change in stool output. Early maldigestion, due to lipase deficiency, produces stools with high fat content known as steatorrhea. Steatorrhea is characterized by an increased number of foul-smelling, greasy stools. Late maldigestion leads to varying degrees of malnutrition. Late pancreatic disease can lead to cystic fibrosis–related diabetes (CFRD). CFRD can share components of both type I and type II diabetes. CF patients may experience insulin deficiency secondary to pancreatic obstruction, as well as the inability to utilize existing insulin in the body, which can be symptomatic or can present as untreated diabetes mellitus type 2. Late disease in the biliary tract leads to obstruction and liver failure (Table 46-2).
TABLE 46-2Early Versus Late Disease in CF Patients |Favorite Table|Download (.pdf) TABLE 46-2Early Versus Late Disease in CF Patients
|Organ Malfunction ||Early Disease ||Late Disease |
|Obstruction ||Distention, pain, nausea, and vomiting ||DIOS, liver failure, CFRD |
|Maldigestion ||Steatorrhea, malnutrition ||Severe malnutrition |
|Obstruction ||Cough, ↑sputum ||COPD, cor pulmonale |
|Infection ||Acute exacerbations ||Permanent ↓PFTs |
Pulmonary disease is also divided into early and late disease. Early obstruction in the pulmonary system leads to coughing, sputum production, wheezing, retractions, tachypnea, dyspnea, and cyanosis. Early pulmonary infection begins with a slow cycling pattern with well-being alternating with pulmonary deterioration ...