Lactate clearance and mortality in septic patients with hepatic dysfunction

Background: Serum lactate clearance (LC) during initial resuscitation is a potentially useful prognostic marker in patients with severe sepsis or septic shock. However, it is unclear whether LC is also associated with the outcome in septic patients with hepatic dysfunction that may impair lactate elimination, which may contribute to elevated serum lactate levels or decreased LC.

Methods: The relationships between LC measured within 6 and 24h after initial resuscitation and hospital mortality were evaluated with multiple logistic regression analysis.

Results: Of 770 patients with severe sepsis or septic shock, 208 (27%) with hepatic dysfunction were included in the analysis. The median LC within 6h in survivors (31.4%) was significantly higher than that of non-survivors (9.3%) (P=.010). In addition, the median LC within 24h was also significantly different between groups (51% vs. 12%, P<.001). Low LCs, defined as less than 10% of clearance, at 6 and 24h were associated with in-hospital mortality. After adjusting for potential confounding factors, low LCs at 6 and 24h remained associated with hospital mortality (adjusted OR 4.940, 95% CI 1.762-13.854 at 6h; adjusted OR 5.997, 95% CI 2.149-16.737 at 24h). However, LC at 24h (area under the curve of 0.704) had higher discriminatory power to predict hospital mortality than LC at 6h (area under the curve of 0.608) (P=.033).

Conclusions: LC may be useful for predicting outcomes in septic patients with hepatic dysfunction.