title: The effect of prolonged pneumoperitoneum on renal function in an animal model.
abstract: BACKGROUND
  Prolonged, increased intra-abdominal pressure (IAP) during laparoscopic surgery has been associated with oliguria and anuria.
  
  
  METHODS
  The objective of this study was to evaluate the effects of various levels of IAP on renal function. Ten groups of three adult female farm pigs were given a general anesthetic, followed by establishment of an IAP of 0, 5, 10, 15, or 20 mm Hg with CO2, 20 mm Hg with argon gas, abdominal wall lift device, renal vein occlusion (RVO), 15 mm Hg with CO2 plus dopamine administration at 2 microgram/kg/minute, or 20 mm Hg retroperitoneal CO2 insufflation. The following studies were recorded: baseline central venous pressure (CVP), pulmonary wedge pressure (PWP), cardiac output (CO), renal vein flow (RVF), renal artery pressure (RAP), selective urine output (UO), urinary osmolarity, and creatinine clearance; the parameters were repeated every 30 minutes for the four hours of the IAP study and two hours after release of the IAP.
  
  
  RESULTS
  The results were analyzed within two main IAP groups: less than 15 mm Hg and greater than or equal to 15 mm Hg. There was no clinically significant variation in the CVP, PWP, and RAP. The CO decreased slightly and this was more significant in the greater than or equal to 15 mm Hg group. The RVF and UO decreased concomitantly and significantly in the greater than or equal to 15 mm Hg group. Even after two hours of desufflation, the RVF did not return to baseline, although the UO improved. Creatinine clearance decreased significantly in the greater than or equal to 15 mm Hg group. The RVO group exhibited similar changes in the study parameters as those seen in the greater than or equal to 15 mm Hg group, although the RVF did not improve on release of the renal vein in the RVO group. Changes were the same with an argon or CO2 IAP of 20 mm Hg. The abdominal wall lift device had an associated decrease in RVF at 15 KG force but no alteration in UO. Retroperitoneal insufflation resulted in the same decrease in RVF and UO as seen with the same IAP. Dopamine did not afford a protective effect on UO during an IAP of 15 mm Hg.
  
  
  CONCLUSIONS
  The decreased UO during prolonged IAP greater than or equal to 15 mm Hg in the animal model is associated with a corresponding decrease in RVF, but does not appear to be associated with any permanent renal derangement nor any transient histologic changes.
authors.affiliation: Division of Urologic Surgery, Washington University School of Medicine, St Louis, Missouri 63110, USA.
authors.forename: E M
authors.initials: EM
authors.lastname: McDougall
authors.forename: T G
authors.initials: TG
authors.lastname: Monk
authors.forename: J S
authors.initials: JS
authors.lastname: Wolf
authors.forename: M
authors.initials: M
authors.lastname: Hicks
authors.forename: R V
authors.initials: RV
authors.lastname: Clayman
authors.forename: S
authors.initials: S
authors.lastname: Gardner
authors.forename: P A
authors.initials: PA
authors.lastname: Humphrey
authors.forename: T
authors.initials: T
authors.lastname: Sharp
authors.forename: K
authors.initials: K
authors.lastname: Martin
mesh_terms: D000818:Animals; D002302:Cardiac Output; D002496:Central Venous Pressure; D003404:Creatinine / Q000097:blood; D004195:Disease Models, Animal; D004298:Dopamine / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D007668:Kidney / Q000503:physiopathology*; D009846:Oliguria / Q000209:etiology / Q000517:prevention & control; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects*; D011188:Potassium / Q000097:blood; D011669:Pulmonary Wedge Pressure; D012079:Renal Circulation; D013552:Swine; D013997:Time Factors; D014556:Urine
chemical_list: D003404:Creatinine; D011188:Potassium; D004298:Dopamine