Acceptance of C-FLEX therapy in patients with obstructive sleep apnea who refused auto-continuous positive airway pressure.

C positive airway pressure (CPAP) is the standard treatment for obstructive sleep apnea (OSA).1 Different modalities of CPAP are available aiming to improve patients’ acceptance and compliance, including the conventional CPAP, auto-CPAP (APAP), bi-level positive airway pressure (bi-level PAP) and flexible CPAP or flexible pressure release CPAP (C-FLEX). Flexible pressure release CPAP is a new algorithm designed to reduce pressure during expiration to give the patient a feeling of comfort. Reducing pressure during exhalation while still providing adequate pneumatic splint may improve patients’ tolerance. This decrease in expiratory pressure depends on the expiratory flow, and it occurs at the beginning of expiration with the intention to relieve patient’s feeling of exhaling against high pressure. One of the major issues with CPAP is patients’ acceptance and compliance. The duration of nocturnal use has been estimated to be from 3.9 hour to 6.5 hour per night over the long-term.2 Among Saudi patients, a recent preliminary report showed that 27.5% of females and 9.1% of males with OSA refused to try CPAP titration in the Sleep Disorders Center (SDC) at the University Hospital due to the high air flow and pressure.3 The acceptance of the conventional CPAP seems to be less than the other newly modified CPAP. Konermann et al4 and Meurice et al5 showed that the duration of APAP usage increased by 0.8 hour and 1.4 hour respectively compared to the conventional CPAP.4,5 Nevertheless, we still face patients who refused titration trial in SDC due to high air flow. Very limited number of studies with small number of patients have explored the adherence to C-FLEX therapy in patients with OSA and had shown encouraging results.2,6-8 However, no study has explored the utility of C-FLEX therapy in patients who refused titration trials of APAP in the SDC. We report 6 patients (4 males and 2 females) with a mean age of 49 ± 5.8 years, body mass index of 32.6 ± 9.4 kg/m2 and Epworth sleepiness scale (ESS) of 13 ± 7.6. They were diagnosed to have severe OSA based on the attended polysomnography (PSG) in the SDC of King Khalid University Hospital between December 2006 and March 2007. The study was approved by the Ethical Committee.. The apnea-hypopnea index (AHI) was 52.6 ± 32 hour. All patients underwent a trial of APAP titration in the SDC under PSG monitoring. One patient terminated the titration trial as he could not exhale against the high expiratory pressure. The remaining 5 patients continued the trial but could not tolerate the pressure required to eliminate apneas and hypopneas. At the end of the titration, all 5 patients expressed that they will never use CPAP again, mostly due to the difficulty they experienced during exhalation against the machine. A daytime training for CPAP was given to all patients followed by 2 titration trials in 2 different nights. In a random order, APAP or APAP with C-FLEX (REM Star Auto, Respironics, Murrysville, PA, USA) was used for patients during the 2 follow up studies. The same titration protocol was used for both CPAP modalities and patients were blinded to the machine used. While the second APAP titration trial failed, all patients accepted C-FLEX and the optimal pressure that eliminated apneas and hypopneas was determined. Table 1 presents the PSG findings at baseline, on APAP and on C-FLEX. AHI, desaturation index and arousal index were significantly lower during C-FLEX compared to APAP. All the 6 patients preferred to use C-FLEX at home. These preliminary data demonstrate that the acceptance of C-FLEX therapy during titration could be better than APAP. Flexible pressure release CPAP therapy seems to be a good alternative in patients Brief Communication