[Analysis of risk factor of hyperlactacidemia after gastrointestinal surgery: a clinical data analysis of 216 patients].

Objective To investigate the risk factors that cause arterial blood lactate ( Lac ) elevation in patients after gastrointestinal operation. Methods The data of 216 patients who had undergone gastrointestinal operation, and transferred to intensive care unit ( ICU ) of Ningxia Medical University General Hospital from November 2013 to November 2014 were retrospectively analyzed. According to the initial level of blood Lac after operation, the patients were divided into two groups: high Lac group ( Lac > 2 mmol/L, n = 100 ) and normal Lac group ( Lac ≤ 2 mmol/L, n = 116 ). The baseline data of two groups were recorded as follows: ① baseline data: gender, age, preoperative acute physiology and chronic health evaluation Ⅱ ( APACHE Ⅱ) score, previous diseases, initial Lac level after operation; ② preoperative risk factors: 24-hour total amount of fluid, and the amount of colloid for resuscitation; ③ intraoperative risk factors: the proportion of emergency operation, operation time, site of operation, usage of antibacterial drug, the highest and lowest mean arterial pressure and its difference ( MAPmax, MAPmin, ΔMAP ), total amount of fluid and colloid for resuscitation. The risk factors of increasing Lac post gastrointestinal operation was evaluated using multiple linear regression analysis. Results ① There were no significant differences in baseline data such as gender, age, preoperative APACHEⅡscore and previous diseases between the two groups ( all P > 0.05 ). Initial Lac level in high Lac group was significantly higher than that of normal Lac group ( mmol/L: 5.1±3.6 vs. 1.3±0.4, t = 10.584, P = 0.000 ). ② There were no significant differences in 24-hour amount of fluid and colloid for resuscitation before operation, and intraoperative MAPmax between two groups. Compared with normal Lac group, intraoperative ΔMAP [ mmHg ( 1 mmHg = 0.133 kPa ): 35.8±14.4 vs. 28.7±13.7, t = 3.727, P = 0.000 ], the proportion of emergency operations ( 19.0% vs. 9.5%, χ2 = 9.869, P = 0.007 ), intraoperative transfusion volume [ mL: 4 500 ( 3 500, 5 800 ) vs. 3 700 ( 2 812, 5 075 ), Z = -3.244, P = 0.001 ], intraoperative colloid volume [ mL: 1 000 ( 1 000, 1 900 ) vs. 1 000 ( 1 000, 1 787 ), Z = -2.347, P = 0.019 ], and operation time ( minutes: 222.0±91.5 vs. 187.0±75.9, t = 3.026, P = 0.003 ) in high Lac group were significantly increased, and the levels of intraoperative MAPmin ( mmHg: 68.7±11.6 vs. 75.9±10.6, t = -4.716, P = 0.000 ) and intraoperative antibiotics usage ( 62.0% vs. 86.2%, χ2 = 18.318, P = 0.000 ) were significantly decreased.③The patients undergoing operation of esophagus, stomach, duodenal and intestine, and colon accounted for 6.9%, 22.7%, 16.7%, and 53.7%, respectively, their Lac was 2.8 ( 1.6, 5.4 ), 2.3 ( 1.2, 5.8 ), 2.5 ( 1.5, 5.2 ), 1.7 ( 1.1, 2.9 ) mmol/L, respectively, indicating that surgical site had an influence on the occurrence of postoperative hyperlactacidemia ( χ2 = 11.032, P = 0.012 ). ④ It was showed by multiple linear regression analysis that the operation site ( t = -2.725, P = 0.007 ), MAPmin ( t = -4.533, P = 0.000 ), non-antibiotics usage during operation ( t = 2.441, P = 0.016 ) were the risk factors of Lac increase in patients after gastrointestinal operation. ⑤ The incidence of postoperative incipient procalcitonin ( PCT ) increase ( PCT > 0.5 μg/L ) in patients and usage of antibiotics was significantly lower than that in patients who did not receive antibiotics during operation [ 17.89% ( 17/95 ) vs. 67.74% ( 21/31 ), χ2 = 27.572, P = 0.000 ]. Conclusions The surgical site showed an influence on the occurrence of hyperlactacidemia in patients after gastrointestinal operation, and the lowest occurrence rate was found in the colonic operation. In patients suffering from gastrointestinal operation, antibiotics should be routinely used to improve MAP. Excessive preoperative and intraoperative fluid infusion cannot reduce the occurrence of hyperlactacidemia. Key words: Gastrointestinal operation; Hyperlactacidemia; Risk factor; Hypotension