[Initial serum lactate level as predictor of morbidity after major abdominal surgery]

To evaluate the value of immediate postoperative arterial lactate level to predict morbidity after major abdominal surgery.

139 patients, 73 males and 66 females, aged (64 +/- 14) (26 - 87), who underwent major abdominal surgery had their levels of arterial lactate, blood routine, blood gas and electrolytes measured after they were sent to the ICU. The physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM) and the simplified acute physiology score II (SAPSII) levels in the first 24-hour postoperative period were calculated Multivariate logistic regression analysis was utilized to examine the independent relationship of the initial lactate, blood gas values, and anion gap with the morbidity.

Sixty-one cases of postoperative complications were recorded in the 47 patients (34%). The median initial lactate level of the patients with postoperative complications was 1.7 mmol/L, significantly higher than that of the patients without complication (1.2 mmol/L, P = 0.001). Multivariate analysis showed that lactate level (odds ratio: 1.81, 95% confidence interval: 1.14 - 2.89; P = 0.013) and Simplified Acute Physiology Score II (SAPSII (odds ratio:1.14; 95% confidence interval:1.08-1.21, P < 0.001) were significantly predictive of postoperative morbidity. The optimal value of lactate to discriminate between the patients who did or did not develop postoperative complications was 2.7 mmol/L as associated with the highest sum of sensitivity and specificity (29.8% and 95.7% respectively). The lactate level more than 2.7 mmol/L was associated with 9.3-fold-higher odds for postoperative complications (95% confidence interval: 2.9 - 30.4, P < 0.001). After adjustment for SAPII, the lactate level > 2.7 mmol/L remained strongly associated with morbidity (odds ratio: 5.9; 95% confidence interval: 1.6 - 21.7; P = 0.007).

Initial serum lactate level is significantly associated with postoperative complications and can independently predict in-hospital morbidity after major abdominal surgery. When hyperlactatemia means the presence of oxygen debt, strategies to resuscitate patients during surgery should include reversing ongoing tissue hypoxia by increasing oxygen delivery.