[Efficacies of continuous positive airway pressure on mixed sleep respiratory events in patients with sleep apnea]

To explore the efficacies of continuous positive airway pressure (CPAP) for mixed sleep apnea (MSA) events in patients with sleep apnea.A total of 21 patients with sleep apnea whose MSA events10 events/h on overnight polysomnography (PSG) were studied. They were selected from the Sleep Center, Guangzhou Institute of Respiratory Disease. Ten of them were diagnosed only by conventional polysomnography (PSG group) while the diagnosis of another 11 patients was further confirmed by diaphragm electromyogram (EMG) (EMG group). All of them were treated by CPAP titrated manually on PSG.Manual CPAP titrating pressure in PSG group was (8.1 ± 2.2) cmH2O (1 cmH2O = 0.098 kPa) and it was similar to that in EMG group ((8.9 ± 1.5) cmH2O). Apnea-hypopnea index (AHI) decreased significantly after CPAP in both PSG group (6.9 (3.5, 10.2) vs 62.2 (54.7, 71.4) events/h) and EMG group (1.5 (0.5, 5.5) vs 71.3 (59.5, 79.5) events/h) (both P0.01). CPAP could eliminate MSA diagnosed either by conventional PSG (0.1 (0.0, 0.4) vs 29.6 (19.6, 32.4) events/h) or by diaphragm EMG (0.0 (0.0, 0.2) vs 18.1 (9.1, 19.3) events/h) (both P0.01).CPAP can effectively treat MSA events in patients with sleep apnea.