Predictive value of ventilatory steability in determining positive airway pressure efficacy in patients with obstructive sleep apnea / 中国耳鼻咽喉头颈外科

ABSTRACT

OBJECTIVE We hypothesized that unstable ventilatory control(high loop gain, LG) could predict the short-term efficacy of positive airway pressure therapy in patients with obstructive sleep apnea(OSA). METHODS 42 adult patients with OSA, M/F=39/3, were studied. The stability of the ventilatory control system(LG) was quantified by fitting a simplified mathematical model to the spontaneous ventilatory pattern obtained via polysomnography. LG, pulmonary function test results, and other PSG parameters were analyzed in patients who had post-treatment AHI≥10 events/hr(non-responders) using auto-positive airway pressure therapy. RESULTS The subjects aged(40±8) years, apnea-hypopnea index(AHI) were 68.2[42.9,81.0]events/hr). Nine patients(34.6％) were non-responders. Twenty pat ients(47.6％) had residual AHI＜5 events/hr. Loop gain and pre-treatment mixed apnea index were higher in the non-responders versus responders(0.74 [0.62, 0.82] vs 0.49[0.37, 0.77], P =0.035) and(11.0[4.3, 22.9] vs 2.0[0.2, 5.3], P =0.004). In the 26 patients with LG＞0.6, nine(34.9％) had posttreatment 5 events/hr≤AHI＜10 events/hr. And all of the non-responders had LG(n=9, 34.9％). The difference was signif icant between the LG＞0.6 a nd LG＜0.6 group(P =0.007). CONCLUSION Loop gain and mixed apnea index was higher in patients with residual AHI＞10 events/hr after short-term auto-PAP therapy. Ventilatory control stability evaluation might have predictive value for PAP treatment efficacy in OSA patients.