Predictive value of the ratio of venoarterial PCO2 to arteriovenous O2 content difference for organ injury in patients with severe acute pancreatitis.

BACKGROUND Severe acute pancreatitis (SAP) is a common but severe disease with high mortality. Organ injury is the primary risk factor for death in SAP patients. The purpose of this study was to explore the predictive value of the ratio of venoarterial PCO2 to arteriovenous O2 content difference [P(cv-a)CO2/C(a-cv)O2] for organ injury in patients with SAP to provide evidence for further clinical intervention. METHODS We retrospectively collected data from 108 patients with SAP admitted to Huzhou Central Hospital between January 2018 and January 2021. Forty-five patients who experienced organ injury were defined as the organ injury group, and 63 patients without organ injury were defined as the control group. The differences in P(cv-a)CO2/C(a-cv)O2, lactate, hematocrit (HCT), Acute Physiology and Chronic Health Evaluation (APACHE II) scores, and Ranson scores between the two groups were analyzed, and a receiver operating characteristic curve (ROC) was used to analyze the value of P(cv-a)CO2/C(a-cv)O2 in the prediction of organ injury in SAP patients. RESULTS At admission, the organ injury group demonstrated significantly higher Ranson scores and APACHE II scores than the control group (Ranson scores: 6.09±1.35 vs. 3.97±2.02, respectively, P=0.000; APACHE II scores: 11.64±2.91 vs. 10.08±2.91, respectively, P=0.007). The value of P(cv-a)CO2/C(a-cv)O2 was also elevated compared to the control group (1.47±0.41 vs. 1.09±0.33, respectively, P=0.000) as was the level of lactate (3.33±0.86 vs. 2.56±0.70 mmol/L, respectively, P=0.000). There was no significant difference in HCT between the two groups at admission (44.47%±6.29% vs. 44.53%±5.75%, respectively, P=0.957). The Ranson score, APACHE II score, P(cv-a)CO2/C(a-cv)O2 and lactate levels were all significant predictors of organ injury in patients with SAP. The area under the curve of P(cv-a)CO2/C(a-cv)O2 was 0.733 (0.637-0.829), P=0.000. CONCLUSIONS P(cv-a)CO2/C(a-cv)O2 is a potential predictor of organ injury in patients with SAP.