Cystic fibrosis (CF) is a life-threatening genetic disease of the epithelial cells in the body, especially those lining the intestinal tract and 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 chloride and water in the body. Thus, the composition of fluid secreted by the pancreas, airways, and other organs is thick and leads to obstruction with malfunction. This malfunction eventually leads to widespread organ system disease (Table 47-1).
TABLE 47-1Organ System Effects of Cystic Fibrosis ||Download (.pdf) TABLE 47-1 Organ System Effects of Cystic Fibrosis
|Organ ||Malfunction ||Clinical Effect |
|Pancreatic duct ||Duct obstruction ||Pancreatic insufficiency (ie, enzyme deficiency), maldigestion, diabetes |
|Biliary duct ||Duct obstruction ||Cirrhosis, portal hypertension, esophageal varices |
|Intestines ||Viscous secretions ||Distal intestinal obstructive syndrome (DIOS) |
|Lungs ||Viscous secretions ||Obstruction, infection, inflammation |
|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 people with CF may be divided into signs and symptoms of early, mild disease with progression of disease severity later in life (Table 47-2). 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. Symptoms of steatorrhea are gas and stools with foul odor, bulkiness, greasiness, and more frequent in number. Late maldigestion leads to varying degrees of malnutrition. Late pancreatic disease leads to insulin inefficiency known as cystic fibrosis-related diabetes (CFRD). Late disease in the biliary tract leads to obstruction and liver failure.
TABLE 47-2Early Versus Late Disease in Cystic Fibrosis ||Download (.pdf) TABLE 47-2 Early Versus Late Disease in Cystic Fibrosis
|Organ ||Early Disease ||Late Disease |
|Obstruction ||Distention, abdominal pain, vomiting ||DIOS, liver failure, CFRD |
|Maldigestion ||Steatorrhea, malnutrition ||Severe malnutrition |
|Obstruction ||Mucus plug ||Bronchiectasis, Cor pulmonale |
|Infection ||Acute exacerbations ||Permanent FEV1 decline, bronchiectasis |
Pulmonary manifestations may also be divided into early and late disease. Early obstruction in the pulmonary system leads to coughing, sputum production, retractions, tachypnea, dyspnea, and cyanosis. Early pulmonary infection begins with a slow cycling pattern with well-being alternating with pulmonary deterioration known as acute pulmonary exacerbations (APE). Initial infection is primarily caused by methicillin-susceptible Staphylococcus aureus (MSSA) and non-typable Haemophilus influenzae; and subsequent, chronic infection is caused by Pseudomonas aeruginosa (Pa) and methicillin-resistant S. aureus (MRSA). Late pulmonary disease leads to increasing oxygen requirements, digital clubbing, increased anterior-posterior chest diameter, and flattened diaphragm. ...