Influencing factors of serum lactate in patients undergoing partial hepatectomy with fluid restriction: a prospective cohort study

Background: This prospective cohort study was designed to investigate the factors related to serum lactate in hepatectomy patients with fluid restriction before resection of liver lesions. Methods: Patients for an open procedure for elective partial hepatectomy were chosen for this study. Limited fluid was infused at a rate of 6 ml·kg -1 ·h -1 before liver resection. The infusion speed was increased after resection of liver lesion. Stable hemodynamics was maintained by additional fluid infusion or vasoconstrictor drug. An additional infusion of 200 ml crystalloid liquid over ten min was given when urine output was less than 20ml/h, and/or when systolic blood pressure was less than 90mmHg for 1 minute and for more than 3 times. An injection of 6mg Ephedrine was given when the systolic blood pressure was less than 90 mm Hg for 1 minute. The duration of portal triad clamping, the central venous pressure (CVP), the frequency of additional fluid infusion , the frequency of ephedrine , and the intraoperative blood loss were recorded. The serum lactate was measured from arterial blood-gas analysis at 4 time points: T1: before anesthesia; T2: after liver dissection, and immediately before liver resection; T3: 10 min after the liver lesion was removed; and T4: before the patient was discharged from the post-anesthesia care unit . The lactate clearance rate was calculated and linear regression analysis was employed to identify the relationship between serum lactate level and the influence factors. Results: The highest serum lactate was observed at T3 in all 110 patients. Lactate clearance rate averaged 14.4±17.2% in all patients. The i nfluence factors contributed to the highest serum lactate listed by level of importance: duration of portal triad clamping, frequency of ephedrine, operation time. Conclusions: Hepatic portal clamping can result in the increase of serum lactate. The inadequate perfusion of organ during the fluid restriction may be due to increased serum lactate. Accelerated fluid infusion after resection of liver lesions can improve the tissue perfusion. Trial registration: The registration number is ChiCTR1900023167. Retrospectively registered on 14th, May, 2019