COMPARISON OF THE EFFECT OF LACTATE LEVELS DURING CARDIOPULMONARY BYPASS ON PATIENT OUTCOME

Abstract

Objective: To compare the effect of high and normal lactate levels during cardiopulmonary bypass (CPB) on postoperative outcome.
Study Design: Comparative cross-sectional study.
Place and Duration of Study: Army Cardiac Center, Lahore from 1st Nov 2015 to 30th Jun 2016.
Material and Methods: Ninety eight consecutive patients undergoing coronary artery bypass grafting (CABG) on
CPB were divided in two groups according to lactate levels at the time of re-warming on CPB, group A with
lactate <4mmol/L and group B with lactate >4mmo/L. Outcome was measured in the post-operative intensive
care unit (ICU) in terms of duration of ventilation; need for re-ventilation, increase in inotropic support and / or
IABP; and ICU length of stay (LOS).
Results: About 59.18% patients had hyperlactatemia during CPB. There was no statistically significant difference
in the pre-operative characteristics of the patients in two groups. Mean duration of ventilation in group A was
longer (3.54 ± 2.76 hours) compared to group B (4.09 ± 2.96 hours) with a higher frequency of need of reventilation in group B (p<0.01); need of increase in inotropic support (p=0.01); and need of intra-aortic balloon
pump in the post-operative ICU (p<0.01). There was no statistically significant difference in the duration of postoperative inotropic support (p=0.14) and ICU length of stay (p=0.08). The mortality was significantly higher in the
group with high lactate during CPB (3.45% vs Nil).
Conclusion: High lactate levels during CPB can lead to post-operative complications including hemodynamic
compromise and longer duration of ventilation.