Pulmonary Complications of Cystic Fibrosis

Bryan Garcia, MD; Patrick A. Flume, MD


Semin Respir Crit Care Med. 2019;40(6):804-809. 

In This Article

Hypercapnic and Hypoxic Respiratory Failure

As previously described, CF lung disease pathogenesis is the result of the interplay between mucus stasis, chronic airway infection, and inflammation. This vicious cycle leads to airway remodeling with progressive bronchiectasis and obstructive lung disease. As a result of worsening bronchiectasis, ventilation-perfusion mismatching occurs and patients experience chronic respiratory failure marked by hypercapnia, hypoxia, or both.

There are no guidelines recommending screening for hypercapnia; however, symptoms including morning headaches, fatigue, and poor sleep quality should prompt a clinician to assess for hypercapnia with blood gas sampling. When present, patients may be candidates for nocturnal noninvasive positive pressure ventilation (NIPPV).[24] Recently, physicians have identified increased sleep disturbances among healthy CF patients, including the pediatric population. Routine screening with polysomnography has not been recommended and, at present, the initiation of NIPPV for hypercapnia related to worsening lung disease is based on expert opinion.[25,26] Furthermore, studies have not demonstrated survival benefit with the use of either nocturnal oxygen supplementation or NIPPV, but improvements in quality of life and functional status have been reported.[9,27,28]

Chronic hypoxic respiratory failure is associated with advanced lung disease and patients with FEV1 less than 40% predicted should be screened for resting and exertional hypoxia. Supplemental oxygen is indicated for anyone with desaturation below 88% during exercise testing and if present should be followed by oxygen titration.