Sleep in Patients With Cystic Fibrosis

Background In patients with cystic fibrosis (CF), respiratory disease is characterised by a progressive and ineluctable decline in lung function. Sleep-disordered breathing may occur at an early stage of lung disease and may impair quality of life. Oxygen therapy or noninvasive positive pressure ventilation may improve nocturnal hypoxemia and hypercapnia.Risk factors for nocturnal hypercapnia or hypoxemia are not well identified in patients with CF.

Type of study : prospective, transversal, open

Methods :

During the annual check up, a sleep study will be performed with a nocturnal recording of a least 6 hours of pulse oximetry (SaO2) and transcutaneous carbon dioxide (PtcCO2) by the SENTEC device and wrist movements by means of actigraphy. The results of the sleep study will be correlated to·

• clinical scores which evaluate sleep quality (such as the PITTSBURG Sleep Quality Score).·
• respiratory function parameters : lung volumes, forced expiratory of the respiratory muscles: maximal inspiratory and expiratory pressures and the sniff nasal inspiratory pressure.·
• nutritional state with the body mass index z-score·
• the presence of arterial pulmonary hypertension on an echocardiography·
• infectious status (colonisation by Staphylococcus aureus or Pseudomonas aeruginosa) and the CFTR genotype.

Expected results This study should be able to document abnormal nocturnal gas exchange and sleep-disordered breathing in patients with CF in a stable state. The identification of parameters associated with nocturnal hypoventilation and/or poor sleep quality will help to screen those patients who will need a sleep study and treatment such as oxygen therapy or noninvasive positive pressure ventilation.

Inclusion criteria

• children > 8 years and adults with CF
• in a stable state (no acute respiratory exacerbation since one month or patient finishing an antibiotic course)
• able to perform reproducible forced expiratory flows
• having a forced expiratory volume in one second ≤ 60% predicted value
• who accepts to perform a sleep study in the hospital during one night
• written agreement to participate to the study

Exclusion criteria

• acute respiratory exacerbation in the previous month or patient who has not finished an antibiotic course
• Inability or impossibility to perform reproducible forced expiratory flows (pneumothorax during the previous year and/or without surgery)
• having a forced expiratory volume in one second > 60% predicted value
• refusal or impossibility to perform a sleep study in the hospital during one night
• patients receiving long term oxygen therapy or noninvasive positive pressure ventilation
• no social security
• impossibility of a medical examination