Cystic Fibrosis: Treatment

The cornerstones of treatment for CF patients are antibiotics, airway clearance, and nutritional support. A standard treatment regimen includes airway clearance and exercise, mucolytic agents, bronchodilators, anti-inflammatory agents, supplemental oxygen, and nutritional support. CF patients should be cared for at a comprehensive cystic fibrosis care center by a multidisciplinary health care team that includes a physician, nurse, respiratory therapist, dietitian, and social worker. A consensus statement detailing the current evidence-based approach to the care of these patients has recently been published.¹

Pulmonary

The pulmonary status of patients should be regularly monitored by an assessment of symptoms, a physical examination, and spirometry. Percent predicted forced expiratory volume in 1 second (FEV1) is accepted as the single most useful objective measure of pulmonary status. Oxygen saturation at rest, during exercise, and/or during sleep should be measured routinely in patients with moderate-to-severe pulmonary disease to assess the need for supplemental oxygen.

Antibiotics are used both for pulmonary exacerbations and chronic suppressive therapy. Azithromycin and inhaled tobramycin are both beneficial as part of a maintenance strategy. During exacerbations of infections, the choice of antibiotics depends on sputum culture and sensitivity. A complete microbiologic assessment of expectorated sputum, including antibiotic susceptibility testing, should be performed at least once a year. Over 80% of CF patients are chronically infected by P. aeruginosa by adulthood, and this represents the most significant cause of infection over the life of the patient.

Corticosteroids may reduce airway inflammation. They can be administered orally for short periods or as inhalations for long-term therapy.

Chest physiotherapy by manual percussion or a vibrating vest should be performed daily to assist with clearing mucus from the patient's airways. Recombinant human DNase (Pulmozyme) decreases the viscosity of CF sputum by degrading extracellular DNA into smaller pieces.

Nearly all CF patients will have a component of reactive airways disease, and bronchodilator strategies similar to those used in treating asthma are appropriate in CF as well (see Asthma Chapter).

Participation in regular exercise may help preserve pulmonary function. A review of exercise benefits indicated that over 3 years of physical training, the mean annual rate of decline in forced vital capacity was significantly greater in the control group, compared with the exercise group.² Both aerobic exercise and resistance exercise appear to benefit CF patients. Children who received aerobic training had significantly better peak aerobic capacity, whereas those who received resistance training had better weight gain, lung function, and leg strength than children who received aerobic training.³

In advanced disease, bilateral lung transplant is a viable option and should be considered in patients who are no longer responding to conventional therapies.

Pancreatic

Exogenous pancreatic enzyme replacement therapy allows for the digestion of lipids and prevents symptoms of steatorrhea.

A significant percentage of adults with the disease will develop CF-related diabetes mellitus (CFRD), which requires insulin treatment and individualized dietary advice.

Gastrointestinal

In the absence of steatorrhea, constipation can occur. This can be avoided and/or treated with an osmotic laxative, such as MiraLax or Golytely.

Cirrhosis due to biliary obstruction can be treated with ursodeoxycholic acid, which improves biliary excretion and bile acid composition.