Objective To investigate the clinical efficacy and prognostic influencing factors of open abdomen technique for acute pancreatitis with abdominal compartment syndrome (ACS).

Methods The retrospective cohort study was conducted. The clinical data of 186 patients of acute pancreatitis with ACS who were admitted to 6 hospitals, including 65 cases in the 910th Hospital of Joint Logistics Support Force of Chinese People′s Liberation Army, 46 cases in the First Affiliated Hospital of Wenzhou Medical University, 33 cases in the Fujian Provincial Hospital, 31 cases in the Second Affiliated Hospital of Fujian Medical University, 7 cases in the People′s Hospital Affiliated to Quanzhou Medical College, 4 cases in the Shishi General Hospital, from January 2013 to December 2020 were collected. There were 142 males and 44 females, aged (43±8)years. Observation indica-tors: (1) patients conditions after being treatment with open abdomen technique; (2) analysis of clinical characteristics in patients with different treatment outcomes; (3) changing trend of the volume of urine output, levels of lactic acid, levels of enteral nutrient intake and the sequential organ failure score in patients with different treatment outcomes; (4) influencing factors for prognosis of patients. Measurement data with normal distribution were represented as Mean±SD, and compari-son between groups was analyzed using the t test. Measurement data with skewed distribution were represented as M(Q₁,Q₃), and comparison between groups was analyzed using the Mann‑Whitney U test. Count data were described as absolute numbers, and comparison between groups was analyzed using the chi‑square test or the continuity correction chi‑square test. Repeated measurement data were analyzed using the repeated ANOVA. Spearman correlation analysis was used for correlation analyses. The COX regression model was used for univariate analysis and COX regression model with forward regression was used for multivariate analysis.

Results (1) Patients conditions after being treatment with open abdomen technique. Intra‑abdominal pressure, oxygena-tion index, levels of lactic acid and sequential organ failure score of the 186 patients were (23.3±1.9)mmHg (1 mmHg=0.133 kPa), (121±24)mmHg, (5.0±3.4)mmol/L and 10.4±3.6 before the treatment with open abdomen technique and (11.2±2.9)mmHg, (222±38)mmHg, (3.2±2.1)mmol/L and 4.4±2.3 at postoperative 168 hours, showing significant differences in time effects before and after the treatment (F_time=855.26,208.50, 174.91,208.47, P<0.05). (2) Analysis of clinical characteristics in patients with different treatment outcomes. Of the 186 patients, 166 cases survived and were discharged, and 20 cases died during hospitalization. Age, sequential organ failure score, duration of ACS and levels of lactic acid during hospitalization before the treatment with open abdomen technique were (41±7)years, 9.4±3.4, 13(10,21)hours and (4.2±0.6)mmol/L in surviving patients, versus (45±6)years, 11.5±2.4, 65(39,84)hours and (5.2±0.5)mmol/L in dead patients, respectively, showing significant differences between them (t=-2.10, -2.71, Z=-5.36, t=-7.16, P<0.05). Duration of postoperative acute gastro-intestinal injury, duration of continuous renal replacement therapy, time to liberation from mech-anical ventilation, duration of vasoactive drugs therapy, cases undergoing early abdominal closure, cases without intestinal fistula or with postoperative high-order intestinal fistula and low‑order intestinal fistula during hospitalization after the treatment with open abdomen technique were 4(2,6)days, 4(3,7)days, 34(21,41)days, 3(2,6)days, 126, 131, 23, 12 in surviving patients, versus 13(10,17)days, 10(8,18)days, 0(0,3)days, 8(6,12)days, 1, 2, 15, 3 in dead patients, respectively, showing significant differences between them (Z=-5.60, -3.75, -3.64, -3.06, χ²=41.43, 45.86, P<0.05). (3) Changing trend of the volume of urine output, levels of lactic acid, levels of enteral nutrient intake and the sequential organ failure score in patients with different treatment outcomes. The volume of urine output, levels of lactic acid, levels of enteral nutrient intake and the sequential organ failure score in surviving patients during hospitalization were (0.29±0.10)mL/(kg·h), (4.2±0.6)mmol/L, 0.0 kcal/(kg·d) and 9.4±3.4 before the treatment with open abdomen technique and (2.22±0.15)mL/(kg·h), (1.9±0.7)mmol/L, (20.7±2.9)kcal/(kg·d) and 3.7±2.2 at postoperative 168 hours. The above indicators in dead patients during hospitalization were (0.28±0.08)mL/(kg·h), (5.2±0.5)mmol/L, 0.0kcal/(kg·d) and 11.5±2.4 before the treatment with open abdomen technique and (0.28±0.09)mL/(kg·h), (7.7±0.8)mmol/L, (4.6±1.8)kcal/(kg·d) and 12.4±2.1 at postoperative 168 hours. There were significant differences in time effects in the above indicators in surviving patients and dead patients before and after the treatment with open abdomen technique (F_time=425.57, 188.59, 394.84, 37.52, P<0.05). There were interactive effects between the above indicators and the treatment outcome at different time points (F_interaction=383.14, 233.04, 169.83, 36.61, P<0.05). There were signifi-cant differences in the change trends of the above indicators between the surviving patients and the dead patients during hospitalization (F_gouprs=2 739.56, 877.98, 542.05, 240.85, P<0.05). (4) Influen-cing factors for prognosis of patients. Results of univariate analysis showed that age, sequential organ failure score, duration of ACS before surgery, procalcitonin, lactic acid, postoperative high-order intestinal fistula, abdominal hemorrhage, duration of postoperative acute gastrointestinal injury, duration of continuous renal replacement therapy, duration of vasoactive drugs therapy, early abdominal closure were related factors influencing prognosis of patients under-going treatment with open abdomen technique (hazard ratio=1.07, 1.18, 1.39, 1.16, 8.25, 12.26, 2.83, 1.29, 1.56, 1.41, 0.02, 95% confidence interval as 1.00-1.15, 1.45-2.27, 1.22-1.57, 1.02-1.32, 1.75-38.90, 7.37-41.23, 1.16-6.93, 1.22-1.37, 1.23-1.99, 1.08-1.84, 0.00-0.16, P<0.05). Results of multivariate analysis showed that extended duration of ACS before surgery, postoperative high‑order intestinal fistula and extended duration of postoperative acute gastrointestinal injury were independent risk factors influencing prognosis of patients undergoing treatment with open abdomen technique (hazard ratio=1.05, 7.95, 1.17, 95% confidence interval as 1.01-1.32, 2.05-30.87, 1.13-1.95, P<0.05) and early abdominal closure was an independent protective factor (hazard ratio=0.10, 95% confidence interval as 0.01-0.89, P<0.05). Results of Spearman correlation analysis showed that duration of ACS was positively correlated with sequential organ failure score before surgery (r=0.71, P<0.05).

Conclusions Open abdomen technique is effective for acute pancreatitis with ACS. Extended duration of ACS before surgery, postoperative high‑order intestinal fistula and extended duration of postoperative acute gastrointestinal injury are independent risk factors for prognosis of patients during hospitalization and early abdominal closure is an independent protective factor.