title: [Assessment of neural respiratory drive in humans].
abstract: OBJECTIVE
  Assessment of neural respiratory drive is useful for diagnosis of dyspnea and respiratory failure with unknown causes. The purpose of the study was to compare the sensitivity of trandiaphragmatic pressure (Pdi) and diaphragm electromyogram (EMGdi) in assessment of neural respiratory drive.
  
  
  METHODS
  A combined catheter with 10 electrodes and 2 balloons was used to record EMGdi and Pdi during CO2 rebreathing. Three different inspiratory maneuvers-inspiration from functional residual capacity to total lung capacity (TLC), deep inspiration from functional residual capacity against closed airway (MIP), and short sharp inspiration through the nose (Sniff) were performed. Ten healthy subjects [male 4 and female 6; age (26 ± 4) years] were studied.
  
  
  RESULTS
  Linear relationship between EMGdi and end-tidal CO2 (r = 0.83-0.98, all P < 0.01) was better than that between Pdi and end-tidal CO2 (r = 0.48-0.96, all P < 0.01) during CO2 rebreathing, Z = -2.731, P < 0.05. The slope of linear relation between EMGdi and end-tidal CO2 (16.3-32.5) was significantly higher than that between Pdi and end-tidal CO2 (0.4-11.1), Z = -3.780, P < 0.01. The maximal EMGdi derived from TLC maneuver (211 ± 48) µV was larger than those from the MIP maneuver (161 ± 48) µV and the Sniff maneuver (145 ± 37) µV, F = 5.931, P < 0.05, whereas the maximal Pdi derived from TLC maneuver (58 ± 27) cm H2O (1 cm H2O = 0.098 kPa) was significantly lower than those from the MIP maneuver (92 ± 32) cm H2O and the Sniff maneuver (95 ± 27) cm H2O, F = 5.155, P < 0.05.
  
  
  CONCLUSIONS
  EMGdi is more sensitive than Pdi in the assessment of neural respiratory drive.
authors.affiliation: State Key Laboratory of Respiratory Diseases (Guangzhou Medical College), the First Affiliated Hospital of Guangzhou Medical College, Guangzhou 510120, China.
authors.forename: Zhi-da
authors.initials: ZD
authors.lastname: Liu
authors.forename: Zhi-hui
authors.initials: ZH
authors.lastname: Qiu
authors.forename: Kang-xin
authors.initials: KX
authors.lastname: Tan
authors.forename: Si-chang
authors.initials: SC
authors.lastname: Xiao
authors.forename: Miao-fang
authors.initials: MF
authors.lastname: Liu
authors.forename: Yuan-ming
authors.initials: YM
authors.lastname: Luo
mesh_terms: D000328:Adult; D002245:Carbon Dioxide; D003964:Diaphragm / Q000502:physiology*; D004417:Dyspnea / Q000503:physiopathology; D004576:Electromyography; D004947:Esophagus / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D011312:Pressure; D012119:Respiration; D012125:Respiratory Center / Q000502:physiology*; D012129:Respiratory Function Tests / Q000379:methods*; D012680:Sensitivity and Specificity; D014109:Total Lung Capacity / Q000502:physiology; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide