utility of delta lactate for predicting early allograft dysfunction in adult patients undergoing liver transplantations- A prospective observational study

Liver transplantation (LT) is the definitive treatment for patients with end-stage liver disease

The postoperative course following LT can be complicated by a variety of graft dysfunctions, ranging from Early Allograft dysfunction (EAD) to primary non-function of the liver graft

EAD has been shown to have a negative impact on early postoperative complications such as Acute kidney injury (AKI), Sepsis, biliary issues leading to prolonged ICU and hospital stay and, in some instances, decreased patient survival

Lactate is a metabolite produced from pyruvate by the enzyme lactate dehydrogenase (LDH), which is involved in glycolysis during normal metabolism and exercise

Under physiological conditions, approximately 1500 mmol of lactate is produced daily and metabolized predominantly in the liver (approximately 60 %), kidneys (approximately 30 %), and other organs

                                                                                                                 Reduction in lactate levels, improvement in core temperature and improvement in urine output were considered early signs of good allograft function

Lactate clearance after transplantation is also considered a good surrogate marker of liver graft function. This association has also been demonstrated in previous studies

Hyperlactatemia at the end of liver resection surgery was an independent risk factor for postoperative morbidity

Static lactate values in the immediate postoperative period after LT have been established as useful markers for increased hospital stay and ICU mortality.

In contrast, dynamic indices of lactate metabolism, which measure the magnitude of change over time, should be more useful in predicting outcomes. Hence, we conducted a study to evaluate the decrease in lactate over time and its association with graft dysfunction

Intraoperative lactate levels will be checked every 1-2 hours, including immediately after reperfusion of the liver graft. After admission to the ICU after LT, lactate levels will be checked every 2nd hourly till it is less than 2 mmol/L and 4th hourly thereafter for 24 hours and then daily till discharge from the ICU. Lactate clearance [delta lactate, that is, ∆ lactate] will be calculated as the reduction rate of lactate between the time of reperfusion and admission to the ICU as follows:

∆ lactate0-12 = [Lactate at 30 minutes after reperfusion – Lactate at 12 hrs after reperfusion]

Lactate level at 30 minutes after reperfusion

Continuous variables are expressed as medians with interquartile ranges, and categorical data are presented as percentages, as appropriate. Continuous variables will be compared using the Mann–Whitney U test, and categorical variables will be compared using the chi-squared test or Fisher’s exact test. Receiver operating characteristic (ROC) curves will be used to examine the accuracy of lactate. Statistical analyses were performed using IBM SPSS for Windows version 20.0 (Armonk, NY, USA