[Analysis of Snoring in Patients with Obstructive Sleep Apnea (OSA) by Polysomnography and LEOSound].

INTRODUCTION

Snoring was monitored in patients with obstructive sleep apnea (OSA) using the LEOSound-Monitor and simultaneously polysomnographic (PSG) recording. In obstructive apneas snoring is normally apparent after apnea termination and the beginning of ventilation. We wanted to know how often obstructive apneas are terminated by ventilation in combination with snoring.

METHODS AND INTENTION

In 40 patients with OSA (AHI > 15/h) simultaneous polysomnographic recordings were performed amongst long-term respiratory sound monitoring using the LEOSound monitor. Patients' average age was 57±11 years. Average weight was 100±19 kg by a mean body mass index (BMI) of 33±7 kg/m. 12 out of 40 recordings had to be rejected for further analysis because of artifacts. Snoring recorded by polysomnography was compared with snoring monitored by LEOSound.

RESULTS

3778 obstructive apnea episodes were monitored. LEOSound identified snoring in 1921 (51,0%), polysomnography in 2229 (58,8%) obstructive apneas. Only in one patient there was a higher difference in snoring episodes between PSG and LEOSound.

DISCUSSION

In nearly 60% of obstructive apnea events we found snoring during apnea-terminating hyperpnoea. LEOSound is a good diagnostic tool to monitor snoring. It is necessary to clarify why only 60% of all obstructive events/hyperpnoea develop snoring. From a pathophysiological point of view opening of collapsed upper airway should lead in a very high percentage to turbulences in airstream and committed snoring.