The combination of ulinastatin and somatostatin reduces complication rates in acute pancreatitis: a systematic review and meta-analysis of randomized controlled trials

Currently, there is no specific pharmaceutical agent for treating acute pancreatitis (AP). Somatostatin and its analogues have been used to prevent the autolysis of the pancreas in AP, however, their effectiveness has not been confirmed. This investigation aimed to examine the efficacy of ulinastatin, a protease inhibitor, combined with somatostatin analogues in the treatment of AP. We conducted a systematic database search in 4 databases to identify randomized controlled trials in which the efficacy of ulinastatin in combination with somatostatin analogue was compared to somatostatin analogue alone in patients with AP. Since the patient populations of analysed papers were slightly different, we used random effect models to pool odds ratios (OR) and mean differences (MD) and the corresponding 95% confidence intervals (CI). A total of 9 articles comprising 1037 patients were included in the meta-analysis. The combination therapy significantly reduced the complication rates for acute respiratory distress syndrome, acute kidney injury, and multiple organ dysfunction. Symptoms were relieved threefold with the combination therapy compared to somatostatin alone, and combination therapy significantly shortened the length of hospital stay. The decrease in mortality was not statistically significant..

Pharmacological interventions for acute pancreatitis

BACKGROUND

In people with acute pancreatitis, it is unclear what the role should be for medical treatment as an addition to supportive care such as fluid and electrolyte balance and organ support in people with organ failure.

OBJECTIVES

To assess the effects of different pharmacological interventions in people with acute pancreatitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, 2016, Issue 9), MEDLINE, Embase, Science Citation Index Expanded, and trial registers to October 2016 to identify randomised controlled trials (RCTs). We also searched the references of included trials to identify further trials.

SELECTION CRITERIA

We considered only RCTs performed in people with acute pancreatitis, irrespective of aetiology, severity, presence of infection, language, blinding, or publication status for inclusion in the review.

DATA COLLECTION AND ANALYSIS

Two review authors independently identified trials and extracted data. We did not perform a network meta-analysis as planned because of the lack of information on potential effect modifiers and differences of type of participants included in the different comparisons, when information was available. We calculated the odds ratio (OR) with 95% confidence intervals (CIs) for the binary outcomes and rate ratios with 95% CIs for count outcomes using a fixed-effect model and random-effects model.

MAIN RESULTS

We included 84 RCTs with 8234 participants in this review. Six trials (N = 658) did not report any of the outcomes of interest for this review. The remaining 78 trials excluded 210 participants after randomisation. Thus, a total of 7366 participants in 78 trials contributed to one or more outcomes for this review. The treatments assessed in these 78 trials included antibiotics, antioxidants, aprotinin, atropine, calcitonin, cimetidine, EDTA (ethylenediaminetetraacetic acid), gabexate, glucagon, iniprol, lexipafant, NSAIDs (non-steroidal anti-inflammatory drugs), octreotide, oxyphenonium, probiotics, activated protein C, somatostatin, somatostatin plus omeprazole, somatostatin plus ulinastatin, thymosin, ulinastatin, and inactive control. Apart from the comparison of antibiotics versus control, which included a large proportion of participants with necrotising pancreatitis, the remaining comparisons had only a small proportion of patients with this condition. Most trials included either only participants with severe acute pancreatitis or included a mixture of participants with mild acute pancreatitis and severe acute pancreatitis (75 trials). Overall, the risk of bias in trials was unclear or high for all but one of the trials.

SOURCE OF FUNDING

seven trials were not funded or funded by agencies without vested interest in results. Pharmaceutical companies partially or fully funded 21 trials. The source of funding was not available from the remaining trials.Since we considered short-term mortality as the most important outcome, we presented only these results in detail in the abstract. Sixty-seven studies including 6638 participants reported short-term mortality. There was no evidence of any differences in short-term mortality in any of the comparisons (very low-quality evidence). With regards to other primary outcomes, serious adverse events (number) were lower than control in participants taking lexipafant (rate ratio 0.67, 95% CI 0.46 to 0.96; N = 290; 1 study; very low-quality evidence), octreotide (rate ratio 0.74, 95% CI 0.60 to 0.89; N = 770; 5 studies; very low-quality evidence), somatostatin plus omeprazole (rate ratio 0.36, 95% CI 0.19 to 0.70; N = 140; 1 study; low-quality evidence), and somatostatin plus ulinastatin (rate ratio 0.30, 95% CI 0.15 to 0.60; N = 122; 1 study; low-quality evidence). The proportion of people with organ failure was lower in octreotide than control (OR 0.51, 95% CI 0.27 to 0.97; N = 430; 3 studies; very low-quality evidence). The proportion of people with sepsis was lower in lexipafant than control (OR 0.26, 95% CI 0.08 to 0.83; N = 290; 1 study; very low-quality evidence). There was no evidence of differences in any of the remaining comparisons in these outcomes or for any of the remaining primary outcomes (the proportion of participants experiencing at least one serious adverse event and the occurrence of infected pancreatic necrosis). None of the trials reported heath-related quality of life.

AUTHORS' CONCLUSIONS

Very low-quality evidence suggests that none of the pharmacological treatments studied decrease short-term mortality in people with acute pancreatitis. However, the confidence intervals were wide and consistent with an increase or decrease in short-term mortality due to the interventions. We did not find consistent clinical benefits with any intervention. Because of the limitations in the prognostic scoring systems and because damage to organs may occur in acute pancreatitis before they are clinically manifest, future trials should consider including pancreatitis of all severity but power the study to measure the differences in the subgroup of people with severe acute pancreatitis. It may be difficult to power the studies based on mortality. Future trials in participants with acute pancreatitis should consider other outcomes such as complications or health-related quality of life as primary outcomes. Such trials should include health-related quality of life, costs, and return to work as outcomes and should follow patients for at least three months (preferably for at least one year).