Lactate level as a predictor of outcomes in patients with acute upper gastrointestinal bleeding: A systematic review and meta-analysis

There remains no consensus on the prognostic value of lactate in predicting adverse outcomes such as mortality, rebleeding and higher intensive care unit (ICU) admission rates in patients with upper gastrointestinal bleeding (UGIB). The present study aimed to determine the prognostic accuracy of lactate level in predicting adverse clinical outcomes in patients with acute UGIB. Systematic literature search was conducted in PubMed Central, SCOPUS, EMBASE, MEDLINE, Google Scholar and ScienceDirect databases for studies published up to February 2023. Random-effects model was used for the meta-analysis and the results were presented as pooled standardized mean differences or odds ratio (OR) with 95% confidence interval (CIs). A total of 11 studies were included in the present review. Most of the studies had a high risk of bias. Pooled OR were as follows: 1.39 (95% CI: 1.29-1.51; I2=85%) for the prediction of mortality; 1.29 (95% CI: 1.17-1.42; I2=85.9%) for prediction of ICU admission, 1.14 (95% CI: 1.06-1.23; I2=42.4%) for rebleeding and 2.84 (95% CI: 2.14-3.77; I2=8.1%) for the need of packed red blood cell (pRBC) transfusion. Sensitivity and specificity for the mortality prediction were 72% (95% CI: 57-83%) and 75% (95% CI: 61-85%), respectively, with the area under the curve of 0.79 (95% CI: 0.72-0.85). In conclusion, the results showed that lactate level is a moderately accurate early prediction marker of most adverse clinical outcomes such as mortality, rebleeding, ICU admission and the need for pRBC transfusion in acute UGIB patients.