STUDY OBJECTIVES: Based on studies of the impact of esophageal pressure on cardiovascular variables during sleep, this signal can be used to refine the severity level in the clinical diagnosis of @entity27 . We hypothesized that relative changes in diaphragmatic electromyogram (EMG) can reflect short-term changes in esophageal pressure durng obstructive @entity386 and @entity387 . DESIGN: Diaphragmatic EMG was sampled at 0.25 kHz; diaphragmatic EMG waveform was band-pass filtered and digitally converted; the electrocardiogram artifact was eliminated; using a gating procedure, the waveform was fast-Fourier transformed and digitally rectified; and a moving average of 200 milliseconds was calculated. For each inspiratory effort during @entity386 or @entity387 , we calculated maximum diaphragmatic EMG and esophageal pressure. Data were normalized calculating the percentage difference between the first obstructed and each subsequent inspiratory effort during the respiratory event. SETTING: @entity25 laboratory. @entity1 : 9 @entity1 with moderate @entity27 presenting with @entity27 . INTERVENTION: None. MEASUREMENTS AND RESULTS: 861 respiratory events were scored, and the evolution between esophageal pressure and diaphragmatic EMG were compared. Normalized data showed a good correlation between the 2 measures during @entity386 and @entity387 . There was a significant difference between the percentage increase in esophageal pressure and diaphragmatic EMG for @entity386 and @entity387 (esophageal pressure, @entity386 : 118.1% +/- 118.5%, @entity387 : 76.1% +/- 74.3%, P = .000; diaphragmatic EMG, 123.5% +/- 131.7%, @entity387 : 73.3% +/- 74.2%, P = .000). No significant differences for @entity386 or @entity387 were noted between the 2 measures under investigation. CONCLUSION: Diaphragmatic EMG may be clinically useful to describe relative changes in respiratory effort under conditions of @entity386 and @entity387 during sleep and to reliably dissociate central from obstructive events where esophageal pressure monitoring is not readily available.

Comparison of pleural pressure and transcutaneous diaphragmatic electromyogram in XXXX .

@entity1 :: ('9606', 'Species') :: ['patients', 'PATIENTS'] @entity387 :: ('MESH:D012891', 'Disease') :: ['hypopneas', 'hypopnea'] @entity27 :: ('MESH:D020181', 'Disease') :: ['apneas and hypopneas during sleep', 'obstructive sleep apnea syndrome'] @entity25 :: ('MESH:D012893', 'Disease') :: ['Sleep disorders'] @entity386 :: ('MESH:D001049', 'Disease') :: ['apnea', 'apneas']
@entity27 :: (MESH:D020181,Disease) :: ['obstructive sleep apnea syndrome']
