[Predictive value of nocturnal pulse oximetry in sleep apnea screening]

The monitoring of overnight oxygen saturation is widely used for sleep apnoea screening. The point of this screening has been questioned as a wide range of sensitivity has been reported in the literature. In a prospective study 70 subjects presenting with a possible sleep apnoea-hypopnoea syndrome had overnight oximetry followed by polysomnography 2 to 4 months later. Compared to polysomnography, the sensitivity of oximetry for sleep apnoea-hypopnoea was 85.2%, the specificity 77.8% and the predictive value positive 96.3%. When short, non-significant, repetitive desaturations have been declared pathologic, sensitivity increased to 91.8%. In the hands of an expert user, oximetry represents an excellent instrument for detecting patients with sleep apnoea-hypopnoea. Patients with pathological nocturnal oximetry are candidates for nCPAP treatment and therefore should undergo a sleep laboratory investigation.