First results of a prospective study validating the method of ambulatory polysomnography using the POLY-MESAM unit.

Purpose: For some time, ambulatory diagnosis of respiratory disturbances during sleep has included the use of seven-channel recording units. One such unit is the POLY-MESAM (MAP, Martinsried, FRG). The present study prospectively investigated the operation of the unit by both physician and patient, the technical capacity of the unit, and the reliability of the automatic scoring of data by means of the accompanying software in comparison to scoring by hand.

Methods: Included in the study were 104 patients of both sexes with obstructive sleep apnoea of varying severity. The first 51 patients were fitted in the evening with the POLY-MESAM unit and instructed in its function by two physicians in the clinic. The second group of 53 patients were only instructed in the use of the POLY-MESAM unit in the afternoon; they attached the unit by themselves. The patients' status was monitored by means of a visual analogue scale. The automatic evaluation of the data was compared with the results of manual scoring.

Results: In all, results in 6% of cases were unusable. Patients' acceptance of the unit was very high. The correlation between automatic and manual scoring regarding the apnoeahypopnoea index (AHI) was surprisingly good.

Conclusions: The POLY-MESAM unit proved robust and user-friendly and was well suited as an ambulatory screening method for obstructive sleep respiratory disturbances which could be attached by the patients themselves. Validation using simultaneous polysomnography is the subject of ongoing studies.