Study design (if review, criteria of inclusion for studies)
Randomised, cross-over trial.
Participants
13 participants with CF with severe lung disease. Mean (SD) age 26 (5.9) years. Mean (SD) FEV1 % predicted, 31.7(10.6); awake PaO2 range 53-77 mmHg; PaCO2 ⥠45 mmHg; mean (SD) BMI 20 (3) kgm2.
Interventions
Order of intervention randomised. Night 1: Room air and low-level CPAP (4 - 5 cm H2O). Night 2: Oxygen (1.4 +/- 0.9L/min to maintain SaO2 ⥠90%) and low-level CPAP (4 - 5 cm H2O). Night 3: BVS +/- oxygen (0.7+/-0.9 L/min to maintain SaO2 ⥠90%). 3 nights within a 1-week period. Time between nights unclear.
During RA and LFO2 studies, patients wore a nasal mask with a baseline continuous positive airway pressure (CPAP) of 4 to 5 cm H2O. Minute ventilation (V I) was measured using a pneumotachograph in the circuit and was not different between wake and non-rapid eye movement (NREM) sleep on any night. However, V I was reduced on the RA and LFO2 nights from awake to rapid eye movement (REM) (p < 0.01) and from NREM to REM (p < 0.01). On the BVS night there was no significant difference in V I between NREM and REM sleep. Both BVS and LFO2 improved nocturnal SpO2, especially during REM sleep (p < 0.05). The rise in TcCO2 seen with REM sleep with both RA and LFO2 was attenuated with BVS (p < 0.05).
Authors' conclusions
BVS leads to improvements in alveolar ventilation during sleep in this patient group.
Keywords: Adult; Artificial Ventilation; non pharmacological intervention - devices OR physiotherapy; Oxygen; Ventilators; Sleep Disorders;