Lactate clearance versus lacate levels in sepsis

 

Rahul Valisetty

 

Assistant Professor, Department of General Medicine, Kamineni Academy of Medical Sciences and Research Centre, Hyderabad-563101, INDIA.

Email: rahulvalisetty@gmail.com

 

Abstract              Objectives: 1) To study the role of blood lactate levels in sepsis. 2) To compare blood lactate levels and lactate clearance in sepsis in relation to survival outcome. Materials and Methods: This is an observational cohort study done in 67 patients admitted to R.L. Jalappa Hospital. Subject’s history and clinical examination suggestive of sepsis satisfying the inclusion and exclusion criteria were taken into the study. Arterial Blood lactate levels were measured at the time of admission, 12 hours, 24 hours and 36 hours by using epoc blood gas analyzer. Relevant investigations including haemogram, blood gas analysis, blood urea, serum creatinine, electrocardiogram and x-ray were done. The patients were followed till the time of discharge or death. Results: The mean arterial blood lactate levels at the time of admission, 12 hours, 24 hours, 36 hours in sepsis patients who survived are 3.56 ± 3.16, 2.96 ± 2.86, 2.30 ± 1.52, 2.04 ± 0.88mmol/lit respectively and mean blood lactate levels in non survivors are 5.53 ± 3.83, 4.80 ± 3.30, 3.78 ± 2.05, 3.43 ± 2.76 mmol/lit at the time of admission, 12 hours, 24 hours, 36 hours respectively. There was a significant association between blood lactate levels and outcome. The mean values for lactate clearance at first 12 hours, 12 to 24 hours and 24 to 36 hours are 15.78 ± 12.92, 13.26 ± 20.01, 7.59 ± 15.30 in the survived and 14.75 ± 48.49, 36.12 ± 50.07, 12.91 ± 39.37 in the non survived. The lactate clearance was significant only for first 12 to 24 hours. At admission sensitivity and specificity for lactate in predicting mortality is 76.5% and 30% respectively. Lactate levels at 24 hours has got much higher sensitivity of 77.8% and specificity of 32% in predicting mortality. The sensitivity and specifity for lactate clearance were very less in comparison with lactate levels Conclusion: Arterial blood lactate is elevated in sepsis patients and there is an increased risk of mortality if the elevation is above 4 mmol/lit. Lactate levels are better predictor of mortality than lactate clearance.

Key Words: Sepsis, arterial blood lactate, prognostic marker.