Abstract PR098

Abstract

Background & Objectives: The accurate identification of patients likely to deteriorate after cardiac surgery is difficult. Hyperlactatemia in cardiac surgical patients is a manifestation of systemic inflammation, excess pro-inflammatory cytokine production, systemic hypoperfusion and tissue hypoxia. The aim of this study was to investigate the effect of the increased post-operative serum lactate on extubation time following elective open heart surgery. Materials & Methods: Patients who had undergone elective open heart surgery from September 2013 to March 2014 were retrospectively analyzed. A simple extubation protocol was implemented, and patients were divided into two groups. Group 1, before an extubation protocol was in place and group 2, after the extubation protocol implementation. Data collected included mechanical ventilation time, age, sex, type of open heart surgery and lactate on admission. Urgent and emergency operations were excluded. Data was presented as median with interquartile range (IQR), and groups were compared using Mann-Whitney U test and Fisher’s exact test for categorical data. Correlations were identified using Spearmans rho. A p-value of < 0.05 was considered significant. Results: 201 patients with elective open heart surgery patients were identified, 79% were male and median age was 60 (IQR 54–68 years) and median logistic euroSCORE (ES) was 2.38 (IQR 1.51–4.60). There were no significant differences between group 1 and 2 for gender (79 vs 80; p=1.0), median age (60 vs 60 yr; p=0.90), median ES (2.54 vs 2.28; p=0.44) or type of surgery (CABG 78.8% vs 81.2%; p=0.73). Overall median serum lactate was 2.6 mmol/L (IQR 1.6–4.7) and elevated lactate (>2 mmol/L) was common before and after the extubation protocol was implemented (73.7% vs 60.4%; p=0.051). Median time to extubation was 470 min (IQR 350–753). Prior to implementation of the extubation protocol there was significant correlation between initial lactate level and time to extubation (Spearman’s rho 0.22; p=0.04). Patients who had lactate > 2 mmol/L had a significant reduction in median extubation time (680 vs 415 min; p<0.001) post protocol, while this was insignificant if lactate < 2 mmol/L (462 vs 363; p=0.07). Conclusion: Elevated initial serum lactate prolongs extubation time following cardiac surgery. The implementation of an extubation protocol reduces extubation time when initial lactate is elevated. Further studies are required to determine if aggressive correction of lactate, combined with an extubation protocol, can further reduce extubation times.