ASSESSMENT OF RESPIRATORY EFFORT BY MEANS OF STRAIN-GAUGES AND ESOPHAGEAL PRESSURE SWINGS - A COMPARATIVE-STUDY

We characterized apneas by a quantitative method (esophageal pressure measurements) and by a qualitative method (strain gauges) at the same time in 22 patients with sleep-related breathing disorders. Detection of respiratory effort by strain gauges significantly overestimated the total number of central apneas in each patient. Despite this overesti mation, none of the patients was wrongly diagnosed as having. pure cen tral sleep apnea syndrome. Strain gauges are sufficiently reliable for the characterization of apneas in most patients. When strain gauges r eveal that most apneas are central in origin, verification by esophage al pressure measurements is recommended.