[Clinical experience with the Apnea Check System in screening for sleep apnea]

We examined 17 patients (3 female, 14 male) of 40 to 60 years of age suspected of suffering from sleep apnoea (SA) according to anamnesis and pulse oximetry, using the apnoea check system (AC) and by polysomnography (PS). AC measures the flow at the mouth and nose by means of thermistors and records the apnoea number, maximal duration of apnoea, and mean duration of apnoea (A mean). The PS-measured values: apnoea index (AI), maximal duration of apnoea (A max) and mean duration of apnoea (A mean) were taken to be equal to 100% and the AC-measured values were referred to these. AI (AC) was 76-577% of AI (PS). In 3 patients, AI (AC) was smaller than AI (PS), whereas in 14 patients it was greater. A max (AC) was 83-390% of A max (PS). In 11 patients A max (AC) was greater than A max (PS) and in 6 patients it was smaller. A mean (AC) was 56-223% of A mean (PS). In 9 patients A mean (AC) was greater and in 8 patients smaller than A mean (PS). PS had in 15 patients an AI > 10, in 2 patients < 10. In all patients, AC had an AI > 10. AC enabled identification of all patients suffering from sleep apnoea, and hence it appears to be suitable for screening. Further measurements in patients with AI < 10 will be necessary to examine the specificity.