title: Effect of temperature during cardiopulmonary bypass on gastric mucosal perfusion.
abstract: The purpose of our study was to prospectively study the splanchnic response to hypothermic and tepid cardiopulmonary bypass (CPB) using alphastat management of arterial blood-gas tensions. Twenty-four patients for elective CABG surgery were allocated randomly to tepid (35-36 degrees C) or hypothermic (30 degrees C) bypass groups. Measurements were made at four times: (1) baseline, (2) stable during CPB (inflow temperature = nasopharyngeal temperature) 30 degrees C for hypothermic patients, bypass +20 min for tepid patients, (3) 10 min before the end of bypass, (4) after bypass, skin closure. Both groups demonstrated a significant reduction in gastric intramucosal pH (pHim) from time 1 to time 4 and there was no difference in the incidence of a low pHim between the tepid and cold groups (4/12 vs 3/12; ns) at time 4. pHim was significantly lower in the tepid groups at time 3 (P = 0.03) but this discrepancy may have been because of an artefactually high pHim in the cold group. There was a significantly higher incidence of postoperative non-cardiac complications in patients who had a low pHim at time 4 (P = 0.0008). Therefore, we conclude that although the temperature during CPB had a transient effect on pHim it is unlikely to be a major determinant in the pathogenesis of gut mucosal hypoperfusion after bypass.
authors.affiliation: Department of Anesthesiology and Surgery, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: N D
authors.initials: ND
authors.lastname: Croughwell
authors.forename: M F
authors.initials: MF
authors.lastname: Newman
authors.forename: E
authors.initials: E
authors.lastname: Lowry
authors.forename: R D
authors.initials: RD
authors.lastname: Davis
authors.forename: K P
authors.initials: KP
authors.lastname: Landolfo
authors.forename: W D
authors.initials: WD
authors.lastname: White
authors.forename: J L
authors.initials: JL
authors.lastname: Kirchner
authors.forename: M G
authors.initials: MG
authors.lastname: Mythen
mesh_terms: D000328:Adult; D000368:Aged; D001831:Body Temperature; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D001026:Coronary Artery Bypass; D005260:Female; D005753:Gastric Mucosa / Q000098:blood supply*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007036:Hypothermia, Induced; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011446:Prospective Studies; D012039:Regional Blood Flow; D013152:Splanchnic Circulation