For patients with necrotizing severe acute pancreatitis, several key clinical risk factors contributed to risk of developing infected pancreatic necrosis, a small study from Finland found.
Independent risk factors included post-interventional pancreatitis (OR 13.5, 95% CI 2.4-76.5), widespread necrotic collections (OR 21.8, 95% CI 6.1-77.8), and having a greater extension of anatomical spread of necrotic collections occurring in the unilateral paracolic/retromesenteric areas (OR 5.7, 95% CI 1.5-21.1), reported Henrik Husu, MD, of the University of Helsinki, and colleagues.
Infected pancreatic necrosis was also associated with an increased hospital/ICU stay length, readmission rate to the ICU, risk for necrosectomy, and most importantly, death rate, the authors wrote in the Journal of Gastrointestinal Surgery.
Previous studies have shown diagnosing infected pancreatic necrosis can be difficult. CT scans can specify infection, showing gas in necrotic collections, but with low sensitivity. Patients may experience a lack of clinical signs, while false-negative fine needle aspirations can occur at high rates. Despite the use of short-term antibiotics, over 25% of patients with necrotizing severe acute pancreatitis develop infectious pancreatic necrosis, worsening prognosis.
If risk of infected pancreatic necrosis is low in patients, diagnostic intervention procedures involving drainage should be avoided to prevent further bacterial contamination. Previous studies also supported performing minimally invasive debridement techniques on patients with pancreatic necrosis using percutaneous retroperitoneal, endoscopic, or laparoscopic routes. Therefore, understanding more about infected pancreatic necrosis risk factors can improve clinical practice.
This study included 163 patients with necrotizing severe acute pancreatitis admitted to the intensive care unit of a Finnish hospital from Jan 1, 2010 to Dec 31, 2018. Patients were excluded from the study if they had developed pancreatitis from a transplant, had edematous pancreatitis, or had acute-on-chronic pancreatitis.
Over 80% of patients were men. Median age of patients was around 50, and median body mass index was just over 29. Almost 70% of all patients enrolled had alcoholic necrotizing pancreatitis.
About 30% of patients had infected pancreatic necrosis within 90 days of hospital admission, with most seen during the first week since ICU admission.
In the ICU, patients were given 5 days of antibiotic treatment, which included 1.5 mg of cefuroxime, three times a day. The treatment strategy attempted to avoid the use of necrotic intervention collections when possible, but if unavoidable, percutaneous or endoscopic drainage was the first-line treatment and then open necrosectomy.
Within the first day of admission, 60% of patients experienced multiorgan failure. All patients experienced a minimum of one organ failure. Within 3 months, 28.8% of patients developed infected pancreatic necrosis.
Other reported infections patients developed within 3 months of ICU admission included pneumonia/bacteremia (12.9%) and intra-abdominal infections (7.4%).
Patients with post-endoscopic retrograde cholangiopancreatography pancreatitis had a greater risk of developing infected pancreatic necrosis than alcoholic necrotizing pancreatitis patients (OR 13.5, 95% CI 2.4-76.5). Other risk factors included preceding bacteremia (OR 4.8, 95% CI 1.3-17.6) and open abdominal treatment (OR 3.6, 95% CI 1.4-9.3).
There were 17.8% of patients who died after 3 months. Among this total, 14.9% were infected pancreatic necrosis patient deaths, while 19% were deaths unrelated to infected pancreatic necrosis. Patients who died within the first week of ICU admission had mortality risk factors related to disease severity, open abdomen treatment, and pre-existing health conditions.
Infected pancreatic necrosis patients showed longer hospital stays (average 69 vs 21 days) and longer ICU length of stays (average 31 vs 8 days) than patients without infected pancreatic necrosis. Patients with infected pancreatic necrosis had a higher ICU readmission rate (33.3% vs 1.0% in those without). They also required use of an open necrosectomy (91.5% vs 5.2%; P<0.001 for all).
The authors stated, “fever and increasing inflammation markers may indicate suspicion of IPN [infected pancreatic necrosis], but these are very common in patients with severe acute pancreatitis (SAP) treated in the ICU; thus additional risk factors for IPN may be useful in clinical decision making.”
The authors mentioned that early antibiotic treatment can be helpful for most severely ill patients with high SOFA scores if suspicion of shock is prevalent.
“The present study was not designed to evaluate the effects of prophylactic antibiotic treatment in necrotizing SAP. However, the observed high number of infections despite the use of prophylactic antibiotics raises questions about the utility of a prophylactic antibiotic protocol,” Husu and colleagues said.
Limitations of this study include bias from the non-standardized treatment protocol. Further, the antibiotic treatment could not have the same effect for all patients. The study’s design also introduced differences among patient survival between groups, where some patients died before others with disease progression, creating survival bias.
This study was also unable to definitively assess the mortality rate associated with infected pancreatic necrosis diagnoses. In addition, it is possible for the infected pancreatic necrosis risk factors to be underestimated or overestimated due to the smaller study size, with few patients reporting arising conditions of interest, which could not be determined if randomly developed by chance.
The authors declared no conflicts of interest.
Research grant funding was received from the Perklens Foundation and the Medical Society of Finland. Competitive government funds in support of medical research were also received.