borderline secondary right heart dysfunction should be evaluated with an electrocardiogram (EKG), CXR, and cardiology consultation for possible echocardiogram Rib fracture can occur secondary to osteopenia in patients with CF with poor nutrition, or secondary to overly aggressive chest percussion and postural drainage Superficial ecchymoses and point tenderness along the rib margin in the setting of malnutrition and scant subcutaneous fat tissue may suggest the diagnosis of rib fracture; diagnosis can be confirmed radiologically, although findings may not be apparent on CXRs Treatment is complicated by the need to at least temporarily limit airway clearance, which can lead to increasing airway obstruction History of fracture or suspicious behavior should also raise the question of child abuse in young children TABLE 99.5 CHEST PAIN IN CYSTIC FIBROSIS PATIENTS Common Uncommon Costochondritis Rib fracture Pleurisy/pleuritis Pulmonary embolism Pneumonia Pneumothorax Esophagitis/GERD Rare Cardiac disease Respiratory Failure Thickened airway secretions with bacterial infection, mucous hypersecretion, bronchoconstriction, mucosal edema, inflammation, and fibrosis contribute to respiratory muscle fatigue and can lead to the development of respiratory failure in CF The goal of treatment is to optimize gas exchange and acid–base balance, keeping in mind that these patients may have some degree of pulmonary hypertension and cor pulmonale Management includes maintaining adequate oxygenation and ventilation along with intensifying antibacterial treatment and airway clearance Supplemental oxygen should be introduced with caution in patients with chronic CO2 retention to avoid suppressing hypoxic ventilator drive Ventilation support may be necessary, and noninvasive means can be considered including CPAP or BiPAP The patient should also be evaluated for comorbidities (e.g., atypical infections, ABPA, pneumothorax), which can be precipitating events for acute or subacute decompensation