Study objectives: Both oxygen therapy and nasal continuous positive airway pressure (CPAP) therapy have independently been shown to be effective in the treatment of Cheyne-Stokes respiration (CSR) in patients with congestive heart failure (CHF). The purpose of this study was to compare the short-term effects of oxygen therapy and nasal CPAP therapy on CSR in a group of stable patients with severe CHF.
Design: Prospective, randomized, controlled trial.
Setting: University hospital.
Patients: Twenty-five stable patients (mean [+/- SD] age, 56 +/- 9) with CHF and a mean left ventricular ejection fraction (LVEF) of 17 +/- 0.8%.
Interventions and measurements: All patients had a right heart catheterization prior to the study and an echocardiogram performed to measure LVEF. In addition, all patients had an initial sleep study to identify the presence of CSR. Sleep studies included continuous recordings of breathing pattern, pulse oximetry, and EEG. Those patients identified as having CSR were randomized to a night on oxygen therapy (2 L/min by nasal cannula) and another night on nasal CPAP therapy (9 +/- 0.3 cm H(2)O).
Results: Fourteen of the 25 patients (56%) studied had CSR (apnea hypopnea index [AHI], 36 +/- 7 events per hour) during their initial sleep study. Nine of the 14 patients with CSR completed the study. When compared with baseline measurements, both oxygen therapy and nasal CPAP therapy significantly decreased the AHI (from 44 +/- 9 to 18 +/- 5 and 15 +/- 8 events per hour, respectively; p < 0.05), with no significant difference between the two modalities. The mean oxygen saturation increased significantly and to a similar extent with oxygen therapy and nasal CPAP therapy (from 93 +/- 0.7% to 96 +/- 0.8% and 95 +/- 0. 7%, respectively; p < 0.05), as did the lowest oxygen saturation during the night (from 80 +/- 2% to 85 +/- 3% and 88 +/- 2%, respectively; p < 0.05). In addition, the mean percent time the oxygen saturation was < 90% also improved with both interventions (from a baseline of 17 +/- 5 to 6 +/- 3% with oxygen therapy and 5 +/- 2% with nasal CPAP therapy; p < 0.05). When compared with baseline measurements, the apnea-hypopnea length, cycle length, circulation time, and heart rate did not significantly change with either oxygen therapy or nasal CPAP therapy. Total sleep time and sleep efficiency decreased only with nasal CPAP therapy (from 324 +/- 20 to 257 +/- 14 min, and from 82 +/- 3 to 72 +/- 2%, respectively; p < 0.05). The arousal index, when compared with baseline, remained unchanged with both oxygen therapy and nasal CPAP therapy.
Conclusion: CSR occurs frequently in stable patients with severe CHF. In addition, oxygen therapy and nasal CPAP therapy are equally effective in decreasing the AHI in those CHF patients with CSR.