Rectal lactate levels in endoluminal microdialysate during routine coronary surgery.
The aim of this prospective study was to determine the feasibility of intestinal endoluminal microdialysis as a new method for clinical monitoring of the adequacy of splanchnic perfusion in the large bowel. A microdialysis catheter for continuous lactate, glycerol, glucose and pyruvate measurements attached to a tonometric catheter was placed into the lumen of the recto-sigmoid junction prior to surgery in 13 patients undergoing elective cardiac surgery with cardiopulmonary bypass (CPB). Lactate was also measured in blood and muscle. CPB was associated with a 10-fold increase in luminal lactate from 0.16 (0.01) to 1.67 (0.38) mmol x l(-1) (p < 0.001). Muscular lactate increased from baseline levels 1.20 (0.21) to 1.77 (0.36) mmol x l(-1) during CPB (p = 0.01), but the muscular lactate-pyruvate ratio remained unchanged. Arterial lactate increased only slightly from 0.9 (0.05) to 1.1 (0.06) mmol x l(-1) (p = 0.027) during CPB. Increased lactate concentrations in the large bowel during CPB are suggestive of local lactate production consistent with impaired oxygen delivery. Intestinal endoluminal microdialysis is a potential clinically applicable method for monitoring intestinal metabolism. Combined with tonometry, microdialysis provides the opportunity to monitor both circulation and metabolism in the rectal mucosa.
Solligård
E
E
Department of Anaesthesiology and Intensive Care, St Olav University Hospital, Norwegian University of Science and Technology, N-7006 Trondheim, Norway. erik.solligard@ntnu.no
Wahba
A
A
Skogvoll
E
E
Stenseth
R
R
Grønbech
J E
JE
Aadahl
P
P
D000328:Adult; D000368:Aged; D001794:Blood Pressure; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass; D005240:Feasibility Studies; D006801:Humans; D007413:Intestinal Mucosa / Q000098:blood supply / Q000378:metabolism; D019344:Lactic Acid / Q000097:blood / Q000378:metabolism*; D008297:Male; D008365:Manometry / Q000379:methods; D017551:Microdialysis / Q000379:methods*; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D010101:Oxygen Consumption; D011184:Postoperative Period; D011446:Prospective Studies; D012007:Rectum / Q000098:blood supply / Q000378:metabolism*; D013152:Splanchnic Circulation; D014655:Vascular Resistance
D019344:Lactic Acid