title: Negative mesenteric effects of lung recruitment maneuvers in oleic acid lung injury are transient and short lasting.
abstract: OBJECTIVE
  To test the hypothesis that repeated recruitment maneuvers (RMs) have sustained negative effects on mesenteric circulation, metabolism, and oxygenation 60 mins after RMs in pigs with oleic acid lung injury. Further, we aimed to test the hypothesis that an infusion of prostacyclin (PC) at 33 ng.kg.min would attenuate such possible negative mesenteric effects.
  
  
  METHODS
  Randomized, experimental, controlled study.
  
  
  METHODS
  University hospital animal laboratory.
  
  
  METHODS
  A total of 31 anesthetized, fluid-resuscitated pigs with oleic acid lung injury.
  
  
  METHODS
  : Animals were randomized to one of the following four groups: a control group (n = 7) that received no intervention, recruitment group (n = 8) that underwent the RM sequence, a prostacyclin group (n = 8) that received an infusion of PC, and a recruitment-prostacyclin group (n = 8) that received an infusion of PC and concomitant RM sequence.
  
  
  RESULTS
  We measured systemic and mesenteric hemodynamic variables, jejunal mucosal perfusion, mesenteric lactate flux, jejunal tissue oxygen tension, and mesenteric oxygen delivery, uptake, and extraction ratio. Five minutes after RMs, mesenteric oxygen extraction ratio and mesenteric lactate flux were more prominently increased in the recruitment group, giving evidence of worsened mesenteric conditions after RMs. These signs of worsened conditions were further supported by more decreased jejunal tissue oxygen tension and portal vein oxygen saturation in the recruitment group. PC preserved mesenteric oxygenation, as indicated by less of a decrease in portal vein oxygen saturation at the time corresponding to 5 mins after RM and less of a decrease in mesenteric oxygen delivery at the time corresponding to 15 mins after RM. PC preserved mesenteric oxygenation as indicated by less of a decrease in portal vein oxygen saturation at 5 mins after RM and an attenuated increase in mesenteric oxygen extraction ratio at 5 mins after RM. There was a trend toward worsened jejunal mucosal perfusion, although not significant.
  
  
  CONCLUSIONS
  In an oleic acid lung injury model, three repeated RMs did not improve systemic oxygenation or lung mechanics. Negative effects on mesenteric oxygenation and metabolism were transient and short lasting. The intestinal effects of PC during RMs were minor and opposing, showing preserved oxygenation but a trend toward worsened mucosal perfusion.
authors.affiliation: Anesthesiology and Intensive Care, Department of Surgical and Perioperative Sciences, Umeå University Hospital, Umeå, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Claesson
authors.forename: Stefan
authors.initials: S
authors.lastname: Lehtipalo
authors.forename: Ulf
authors.initials: U
authors.lastname: Bergstrand
authors.forename: Conny
authors.initials: C
authors.lastname: Arnerlöv
authors.forename: Ola
authors.initials: O
authors.lastname: Winsö
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001783:Blood Flow Velocity / Q000187:drug effects; D001784:Blood Gas Analysis; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D011464:Epoprostenol / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D007262:Infusions, Intravenous; D007413:Intestinal Mucosa / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism; D007583:Jejunum / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D008176:Lung Volume Measurements; D019301:Oleic Acid; D010101:Oxygen Consumption / Q000187:drug effects; D011897:Random Allocation; D012121:Respiration, Artificial / Q000009:adverse effects / Q000379:methods; D012128:Respiratory Distress Syndrome / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D015656:Respiratory Mechanics / Q000187:drug effects; D013152:Splanchnic Circulation / Q000187:drug effects; D013552:Swine; D013997:Time Factors
chemical_list: D000959:Antihypertensive Agents; D019301:Oleic Acid; D019344:Lactic Acid; D011464:Epoprostenol