Proportional positive airway pressure: a new concept to treat obstructive sleep apnoea

Proportional positive airway pressure (PPAP) was designed to optimize airwa y pressure for the therapy of obstructive sleep apnoea (OSA). In a randomiz ed crossover prospective study, the clinical feasibility of PPAP and its im mediate effects on the breathing disorder and sleep in comparison with cont inuous positive airway pressure (CPAP) was evaluated. Twelve patients requi ring CPAP therapy underwent CPAP and PPAP titration in a random order. Obstructive and mixed respiratory events could be completely abolished with both forms of treatment. This efficacy could be achieved at a significantl y lower mean mask pressure during PPAP titration (8.45 +/-2.42 cmH(2)O) com pared to CPAP (9.96 +/-2.7 cmH(2)O) (p=0.002). The mean minimal arterial ox ygen saturation (Sa,O-2) (82.8 +/-6.5%) on the diagnostic night increased s ignificantly (p <0.001) to an average Sa,O-2 of 93.35 +/-1.71% and 93.19 +/ -2.9% during CPAP and PPAP titration. Total sleep time, slow wave sleep and rapid eye movement (REM) sleep increased significantly by the same amount during both CPAP and PPAP titration (p<0.001), while sleep stage nonrapid e ye movement (NREM) 1 and 2 decreased. Six patients preferred the PPAP titra tion night, four patients did not have a preference, and two patients prefe rred CPAP. The present data show that proportional positive airway pressure is as effe ctive as continuous positive airway pressure in eliminating obstructive eve nts and has the same immediate effect on sleep. The lower average mask pres sure during proportional positive airway pressure implies potential advanta ges compared to continuous positive airway pressure. Proportional positive airway pressure presents a new effective therapeutic approach to obstructiv e sleep apnoea.