Indexed on: 25 Nov '11Published on: 25 Nov '11Published in: Journal of Anesthesia
To evaluate the value of blood lactate value in predicting postoperative mortality (primary outcome), duration of ventilation, and length of stay in an intensive care unit (ICU) and hospital (secondary outcomes).We performed a prospective observation study on 1,820 consecutive patients undergoing open heart surgery in a tertiary university medical center. Blood lactate levels were obtained from patients on admission to the cardiac surgical ICU and measured serially.All patients were divided into three groups according to their maximum blood lactate levels: group I (normolactatemia, lactate ≤2.2 mmol/l), 332 patients; group II (mild hyperlactatemia, lactate 2.2-4.1 mmol/l), 1,054 patients; and group III (severe hyperlactatemia, lactate ≥4.4 mmol/l), 434 patients. Maximum blood lactate levels ≥4.4 mmol/l during the first 10 h post admission were associated with prolonged ventilation time, longer ICU stay, and increased mortality (P < 0.001).Hyperlactatemia is common after cardiac surgery. Maximal lactate threshold ≥4.4 mmol/l in the first 10 h after operation accurately predicts postoperative mortality.