Korean J Anesthesiol.  2005 Dec;49(6):803-809. 10.4097/kjae.2005.49.6.803.

Effect of Low Dose Norepinephrine Infusion on Myocardial Oxygen Consumption and Lactate Metabolism

• Choi CS
• Lee SS
• Kim BJ
• In JY
• Huh JH
• Lee Y
• Yon JH
• Moon HW

• KMID: 1894318
• DOI: http://doi.org/10.4097/kjae.2005.49.6.803

Abstract

BACKGROUND: Norepinephrine infusion has been reported to be associated with adverse events in ischemic heart disease due to elevation of afterload and cardiac oxygen consumption. During coronary artery bypass graft, we observed changes of hemodynamic and laboratory parameters in low dose norepinephrine infusion. Also, we investigated effects of norepinephrine on cardiac oxygen metabolism by calculating oxygen consumption and lactate extraction ratio.
METHODS
Fifteen patients, ASA PS class IV-V, scheduled for elective coronary artery bypass graft were enrolled in this study. All of the operations were performed under general anesthesia. During harvesting of graft vessels, norepinephrine was infused at the rate of 0.02microgram/kg/min, and then at the rate of 0.05microgram/kg/min. We measured various hemodynamic and laboratory parameters in three periods (baseline, NE 0.02microgram/kg/min, NE 0.05microgram/kg/min). Also we calculated oxygen consumption and lactate extraction ratio of myocardium.
RESULTS
In the baseline period(no norepinephrine infusion), oxygen consumption (VO2) is 159.2 +/- 78.6 ml/min, lactate extraction ratio (LER) is 33.1 +/- 13.0%. After norepinephrine infusion at the rate of 0.02microgram/kg/min, VO2 is 157.6 +/- 55.7 ml/min, LER is 29.9 +/- 10.7%. After norepinephrine infusion at the rate of 0.05microgram/kg/min, VO2 is 212.5 +/- 134.5 ml/min, LER is 27.9 +/- 13.4%. Although VO2 and LER are changed in relation to the rate of norepinephrine infusion, there was no statistical significance.
CONCLUSIONS
In conclusion, infusion of low dose norepinephrine during coronary artery bypass graft did not produce significant differences in myocardial oxygen consumption and lactate extraction ratio associated with myocardial oxygen balance.

Keyword

lactate extraction ratio; low dose norepinephrine infusion; oxygen consumption

MeSH Terms

Anesthesia, General
Coronary Artery Bypass
Hemodynamics
Humans
Lactic Acid*
Metabolism*
Myocardial Ischemia
Myocardium
Norepinephrine*
Oxygen Consumption*
Oxygen*
Transplants
Lactic Acid
Norepinephrine
Oxygen