title: Motion of the diaphragm in patients with chronic obstructive pulmonary disease while spontaneously breathing versus during positive pressure breathing after anesthesia and neuromuscular blockade.
abstract: BACKGROUND
  Diaphragmatic excursion during spontaneous ventilation (SV) in normal supine volunteers is greatest in the dependent regions (bottom). During positive pressure ventilation (PPV) after anesthesia and neuromuscular blockade and depending on tidal volume, the nondependent region (top) undergoes the greatest excursion, or the diaphragm moves uniformly. The purpose of this study was to compare diaphragmatic excursion (during SV and PPV) in patients with chronic obstructive pulmonary disease (COPD) with patients having normal pulmonary function.
  
  
  METHODS
  Twelve COPD patients and 12 normal control subjects were compared. Cross-table diaphragmatic fluoroscopy was performed while patients breathed spontaneously. After anesthetic induction and pharmacologic paralysis and during PPV, diaphragmatic fluoroscopy was repeated. For analytic purposes, the diaphragm was divided into three segments: top, middle, and bottom. Percentage of excursion of each segment during SV and PPV in normal subjects was compared with the percentage of excursion of each segment in patients with COPD.
  
  
  RESULTS
  There was no significant difference in the pattern of regional diaphragmatic excursion (as a percentage of total excursion)-top, middle, bottom-when comparing COPD patients with control subjects during SV and PPV. In the control subjects, regional diaphragmatic excursion was 16 +/- (5), 33 +/- (5), 51 +/- (4) during SV and 49 +/- (13), 32 +/- (6), 19 +/- (9) during PPV. In COPD patients, regional diaphragmatic excursion was 18 +/- (7), 34 +/- (5), 49 +/- (7) during SV and 47 +/- (10), 32 +/- (6), 21 +/- (9) during PPV.
  
  
  CONCLUSIONS
  Regional diaphragmatic excursion in patients with COPD during SV and PPV is similar to that in persons with normal pulmonary function.
authors.affiliation: Anesthesiology and Diagnostic Radiology Services and Section of Cardiothoracic Surgery at the Edward Hines Jr. Veterans Affairs Hospital, Hines, Illinois, 60141, USA. bkleinm@lumc.edu
authors.forename: Bruce S
authors.initials: BS
authors.lastname: Kleinman
authors.forename: Kerry
authors.initials: K
authors.lastname: Frey
authors.forename: Mark
authors.initials: M
authors.lastname: VanDrunen
authors.forename: Taqdees
authors.initials: T
authors.lastname: Sheikh
authors.forename: Donald
authors.initials: D
authors.lastname: DiPinto
authors.forename: Robert
authors.initials: R
authors.lastname: Mason
authors.forename: Theodore
authors.initials: T
authors.lastname: Smith
mesh_terms: D000368:Aged; D000768:Anesthesia, General; D016022:Case-Control Studies; D003964:Diaphragm / Q000502:physiology*; D005471:Fluoroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D019148:Neuromuscular Blockade; D011175:Positive-Pressure Respiration; D029424:Pulmonary Disease, Chronic Obstructive / Q000601:surgery*; D011659:Pulmonary Gas Exchange; D012119:Respiration; D013990:Tidal Volume; D014797:Vital Capacity