Myocardial metabolic monitoring with the microdialysis technique during and after open heart surgery.

Abstract

BACKGROUND:

Post-operative ischemia after coronary artery bypass grafting (CABG) is well described but effective intervention requires immediate diagnosis. One possible way of increasing efficacy of peri-operative myocardial monitoring is using the microdialysis technique.

METHODS:

In 30 patients undergoing routine CABG, a microdialysis catheter was inserted in the left heart in an area of abnormal ventricular contraction. A second catheter was placed in normal tissue of the right ventricle. Microdialysis measurements were performed at time intervals before, during and 24 h after cardiopulmonary bypass (CPB) and retrospectively compared with standard clinical monitoring and clinical course.

RESULTS:

During CPB, both ventricles showed signs of poor tissue oxygenation. Glycerol was significantly higher in the left myocardium (146 +/- 67 vs. 72 +/- 36 micromol/l) and the glucose/lactate ratio (GLR), as a marker of nutritional disorder of the right ventricle (41 +/- 15% vs. 67 +/- 17%, P < 0.05), had significantly better values at this time point. Myocardial lactate concentrations were significantly higher in the dyskinetic segments (2.82 +/- 0.81 vs. 1.5 +/- 0.81 microM). During this period, no abnormal clinical standard monitoring results were observed. Post-operative significantly increased lactate/pyruvate ratios of three patients were clinically associated with peri-operative myocardial infarction (108 +/- 67 vs. 38 +/- 9, P < 0.05). The lactate/pyruvate ratio started rising before any other standard monitoring tools showed abnormal values.

CONCLUSIONS:

Peri-operative microdialytic measurements of parameters related to ischemia can be safely performed in a clinical setting, resulting in faster and more reliable detection of ongoing or new ischemia.

• Authors: J Pöling, W Rees, S Klaus, L Bahlmann, N Hübner, V Mantovani, H Warnecke
• Journal: Acta anaesthesiologica Scandinavica (Acta Anaesthesiol Scand) Vol. 51 Issue 3 Pg. 341-6 (Mar 2007) ISSN: 0001-5172 [Print] England
• PMID: 17257174 (Publication Type: Journal Article)

Chemical References

• Biomarkers
• Blood Glucose
• Lactic Acid
• Glycerol

Topics

• Aged
• Analysis of Variance
• Biomarkers (blood)
• Blood Glucose (analysis)
• Coronary Artery Bypass (adverse effects)
• Glycerol (blood)
• Humans
• Lactic Acid (blood)
• Microdialysis (instrumentation, methods)
• Middle Aged
• Myocardial Ischemia (diagnosis, etiology)
• Myocardium (metabolism)
• Postoperative Period
• Retrospective Studies