title: Effects of abdominal decompression on cardiopulmonary function and visceral perfusion in patients with intra-abdominal hypertension.
abstract: OBJECTIVE
  Increased intra-abdominal pressure (IAP) compromises cardiopulmonary function and visceral perfusion. Our goal was to characterize acute changes in these subsystems associated with operative abdominal decompression.
  
  
  METHODS
  A series of 11 consecutive injured patients monitored with a pulmonary artery catheter and nasogastric tonometer in whom operative decompression was performed. Indications for decompression included oliguria or progressive acidosis despite aggressive resuscitation in the presence of elevated IAP (>25 mm Hg).
  
  
  METHODS
  Studied hemodynamic variables included pulmonary artery occlusion pressure (PAOP), right ventricular end-diastolic volume index (RVEDVI), and cardiac index (CI). Pulmonary variables included shunt fraction (Qs/Qt) and dynamic compliance (Cdyn). Visceral perfusion was assessed using hourly urine output 4 hours before and after decompression (UOP) and gastric intramucosal pH (pHi). Mean values before and after decompression were compared using the paired t test. Linear regression and Fisher's z transformation were used to evaluate the relationships between RVEDVI, PAOP, CI, and IAP. IAP was transduced via bladder pressures. Significance was defined as p < 0.05. Data are expressed as means+/-SD.
  
  
  RESULTS
  IAP decreased with decompression (49+/-11 to 19+/-6.8 mm Hg; p < 0.0001). RVEDVI improved independent of CI and correlated better (p < 0.01) with CI (r =0.49, p=0.04) than PAOP did (r=-0.36, p=0.09). PAOP correlated significantly with IAP (r=0.45, p=0.04). Decompression resulted in significant improvements in Qs/Qt, Cdyn, UOP, and pHi.
  
  
  CONCLUSIONS
  Abdominal decompression in patients with increased IAP improves preload, pulmonary function, and visceral perfusion. Elevated IAP has important effects on PAOP, which makes the PAOP an unreliable index of preload in these patients.
authors.affiliation: Department of General Surgery, The Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Chang
authors.forename: P R
authors.initials: PR
authors.lastname: Miller
authors.forename: R
authors.initials: R
authors.lastname: D'Agostino
authors.forename: J W
authors.initials: JW
authors.lastname: Meredith
mesh_terms: D000007:Abdominal Injuries / Q000150:complications*; D000293:Adolescent; D000328:Adult; D005260:Female; D006439:Hemodynamics; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000503:physiopathology* / Q000628:therapy*; D016014:Linear Models; D008150:Lower Body Negative Pressure; D008170:Lung Compliance; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011652:Pulmonary Circulation; D012151:Resuscitation / Q000379:methods; D014781:Viscera / Q000098:blood supply