Fluid management is crucial in both the early 24 hours of acute pancreatitis and during ICU hospitalization. However, we may have excessively focused on early fluid resuscitation goals while neglecting long-term fluid management. In this study, we first assessed the relationship between fluid management during ICU hospitalization and mortality in patients with acute pancreatitis. We found that patients with daily positive fluid balance had a significantly higher mortality rate compared to those with daily negative balance (19.4% vs 35.2%, P < 0.05). Additionally, the daily cumulative fluid volume was positively correlated with mortality, making it an independent risk factor in predicting patient death (P < 0.001). However, it is important to note that despite its optimal cutoff value of 1.162L, its sensitivity and specificity are not high. This suggests that a positive fluid balance during ICU hospitalization significantly increases the risk of patient death, while appropriate negative balance is beneficial. This may be due to the occurrence of abdominal compartment syndrome and respiratory failure caused by fluid overload[3, 10]. Previous studies[2, 11, 12] have also indicated that excessive fluid resuscitation may not improve patient prognosis and instead increases the risk of fluid overload. This serves as a reminder of the importance of fluid management during ICU admission.
Furthermore, a higher Charlson Comorbidity Index indicates a greater number of complications in patients and increases their risk of death(P < 0.05), particularly in patients with a history of myocardial infarction and renal dysfunction. The possible reason is that these patients cannot tolerate excessive fluid in the early stage, leading to pancreatic necrosis. Additionally, fluid overload can aggravate heart failure and worsen renal dysfunction. The Charlson Comorbidity Index can serve as a predictive factor for mortality, which is consistent with the findings of VIKESH K’s trial[13].According to studies[14–16], elevated lactate levels are often indicative of tissue hypoxia or inadequate perfusion, and they are widely used to assess the severity and prognosis of diseases. In this study, we observed a significant elevation in lactate levels among patients in the deceased group compared to the surviving group. Furthermore, the results of the multivariate analysis indicate that lactate levels can also serve as a predictive marker for mortality (P < 0.05). Similar study[17] has also indicated that lactate is a predictive factor for acute pancreatitis, with an AUC of 0.71 (95% CI, 0.64–0.78), which is essentially consistent with the AUC of 0.692 (95% CI, 0.626–0.759) observed in our measurements.
To address the limitations of low sensitivity and specificity observed in single variable analysis, it is recommended to incorporate additional variables or risk factors in the predictive model. We discovered that a combined model incorporating age, Charlson score, lactate levels, and daily fluid balance can further enhance the accuracy of predictive information (AUC 0.778, 95% CI 0.718–0.839). These variables can be readily obtained in clinical practice, assisting clinicians in conducting a comprehensive assessment of a patient’s illness severity and prognosis. By considering multiple indicators, clinicians can consider various factors that impact a patient’s prognosis, ultimately enhancing the accuracy of predictions.
Additionally, we observed a significant difference in enteral nutrition intake between ICU patients who survived and those who did not (P < 0.05). This finding further emphasizes the importance of enteral nutrition in the management of acute pancreatitis. Bakker et al[18], found that early initiation of enteral feeding is safe and feasible in patients with mild to moderate acute pancreatitis. This approach significantly reduces hospital stay and saves costs, without causing any adverse reactions or complications. Marik[19] has also emphasized that enteral nutrition should be the preferred method of nutritional support for patients with acute pancreatitis. Overall, these findings are in line with the current guidelines on enteral nutrition[20].
Certainly, it is important to acknowledge the limitations of our study. Firstly, our study design being retrospective restricts our ability to establish a causal relationship between fluid management and acute pancreatitis, unlike prospective studies which provide more compelling evidence. This lack of a cause-and-effect relationship reduces the strength of our findings. Secondly, our study revealed that deceased patients had a higher age, lactate levels, and more comorbidities upon admission, indicating that these patients had more severe conditions. However, we did not perform baseline adjustments before conducting the comparisons. Lastly, our study utilized trial data obtained from electronic medical records, covering a wide time span. As fluid management practices for acute pancreatitis may have evolved over time, our findings may not fully represent the current landscape of fluid management. Considering these limitations, further prospective studies with larger and more diverse populations, as well as improved methodology, are necessary to provide a more comprehensive understanding of the relationship between fluid management during ICU admission and outcomes in acute pancreatitis patients.