Trends in fungal colonization of pancreatic necrosis in patients undergoing necrosectomy for acute pancreatitis

Pancreatic colonization of fungi in the development of severe acute pancreatitis

Acute pancreatitis is a common emergent disorder, a significant population of which develops the life-threatening condition, called severe acute pancreatitis (SAP). It is generally accepted that bacterial infection is associated with the development and persistence of SAP. In addition to bacterial infection, recent clinical studies disclosed a high incidence of fungal infection in patients with SAP. Moreover, SAP patients with fungal infection exhibit a higher mortality rate than those without infection. Although these clinical studies support pathogenic roles played by fungal infection in SAP, beneficial effects of prophylactic anti-fungal therapy on SAP have not been proved. Here we summarize recent clinical findings as to the relationship between fungal infection and the development of SAP. In addition, we discuss molecular mechanisms accounting for the development of SAP in the presence of fungal infection.

Microbial Spectra and Clinical Outcomes from Endoscopically Drained Pancreatic Fluid Collections: A Descriptive Cohort Study

Pancreatic pseudocyst (PC) and walled-off necrosis (WON) are dreaded complications of acute pancreatitis. Standard therapy consists of endoscopic ultrasound-guided transmural placement of stents to expedite resolution through internal drainage of fluids or necrotic material. Either double pigtail plastic stents (DPPS) or lumen-apposing metal stents (LAMS), or a combination of both, are available for this purpose. The objective of this study was to examine the impact of different stent types on infection rates in addition to clinical outcome measures such as periprocedural adverse events. We conducted a retrospective study comprising 77 patients who had undergone endoscopic drainage for PC or WON in a pancreatitis tertiary referral center. Analysis revealed that both bacterial and fungal infections occurred more frequently in patients treated with LAMS with or without DPPS compared to DPPS only. The use of antibiotics and antimycotics followed the same pattern. Furthermore, a prolonged length of hospital stay and a higher likelihood of transfer to an intermediate care unit were observed in patients with LAMS with or without DPPS. These differences were eliminated if only WON patients were analyzed. Our data imply that the clinical course is primarily influenced by the complexity of the pancreatic fluid collection (PFC) itself rather than the stent type. Prospective large-scale cohort studies are mandatory to underpin these findings.

Fungal Infections in Patients With Walled-off Pancreatic Necrosis

OBJECTIVES

This study aimed to evaluate the influence of fungal infection and antifungal treatment on outcome in patients with walled-off pancreatic necrosis (WON).

METHODS

A retrospective description of fungal infections in a cohort of consecutive patients undergoing endoscopic, transmural drainage and necrosectomy for WON, treated in a tertiary referral center was reviewed.

RESULTS

Between 2005 and 2013, fungal infection in WON was documented in 57 (46%) of 123 patients. The most common isolates at first positive culture were Candida albicans (55%) and Candida glabrata (20%). Thirty-nine (70%) patients were treated with antifungals after the first fungal finding. There was no significant difference in mortality (21% vs 13%, P = 0.517) or organ failure (34% vs 33%, P = 0.903) between the group treated with adequate antifungals after the first fungal finding compared to the group not treated or treated inadequately.The in-hospital mortality was 18% (10 patients). Concomitant fungemia was found in 6 patients, of which 3 died, as opposed to 7 with fungi in the necrosis only (50% vs 14%, P = 0.027).

CONCLUSIONS

This study demonstrates a high incidence and associated high in-hospital mortality of fungal infection in WON, thus emphasizing the importance of fungal infections in WON.

Infection increases mortality in necrotizing pancreatitis: A systematic review and meta-analysis

OBJECTIVES

To assess the influence of infection on mortality in necrotizing pancreatitis.

METHODS

Eligible prospective and retrospective studies were identified through manual and electronic searches (August 2015). The risk of bias was assessed using the Newcastle-Ottawa Scale (NOS). Meta-analyses were performed with subgroup, sensitivity, and meta-regression analyses to evaluate sources of heterogeneity.

RESULTS

We included 71 studies (n = 6970 patients). Thirty-seven (52%) studies used a prospective design and 25 scored ≥5 points on the NOS suggesting a low risk of bias. Forty studies were descriptive and 31 studies evaluated invasive interventions. In total, 801 of 2842 patients (28%) with infected necroses and 537 of 4128 patients (13%) with sterile necroses died with an odds ratio [OR] of 2.57 (95% confidence interval [CI], 2.00-3.31) based on all studies and 2.02 (95%CI, 1.61-2.53) in the studies with the lowest bias risk. The OR for prospective studies was 2.96 (95%CI, 2.51-3.50). In sensitivity analyses excluding studies evaluating invasive interventions, the OR was 3.30 (95%CI, 2.81-3.88). Patients with infected necrosis and organ failure had a mortality of 35.2% while concomitant sterile necrosis and organ failure was associated with a mortality of 19.8%. If the patients had infected necrosis without organ failure the mortality was 1.4%.

CONCLUSIONS

Patients with necrotizing pancreatitis are more than twice as likely to die if the necrosis becomes infected. Both organ failure and infected necrosis increase mortality in necrotizing pancreatitis.

Candida and severe acute pancreatitis: we won't be fooled again

Several studies have suggested a role of candida in infected cases of severe acute pancreatitis. This commentary reports high incidence and mortality rates of candida infection in this setting and demonstrates the value of the colonization index to detect patients at risk for fungal infection. These findings indicate the need to review the place of antifungal therapy and prophylaxis.

Prediction of invasive candidal infection in critically ill patients with severe acute pancreatitis

Introduction

Patients with severe acute pancreatitis are at risk of candidal infections carrying the potential risk of an increase in mortality. Since early diagnosis is problematic, several clinical risk scores have been developed to identify patients at risk. Such patients may benefit from prophylactic antifungal therapy while those patients who have a low risk of infection may not benefit and may be harmed. The aim of this study was to assess the validity and discrimination of existing risk scores for invasive candidal infections in patients with severe acute pancreatitis.

Methods

Patients admitted with severe acute pancreatitis to the intensive care unit were analysed. Outcomes and risk factors of admissions with and without candidal infection were compared. Accuracy and discrimination of three existing risk scores for the development of invasive candidal infection (Candida score, Candida Colonisation Index Score and the Invasive Candidiasis Score) were assessed.

Results

A total of 101 patients were identified from 2003 to 2011 and 18 (17.8%) of these developed candidal infection. Thirty patients died, giving an overall hospital mortality of 29.7%. Hospital mortality was significantly higher in patients with candidal infection (55.6% compared to 24.1%, P = 0.02). Candida colonisation was associated with subsequent candidal infection on multivariate analysis. The Candida Colonisation Index Score was the most accurate test, with specificity of 0.79 (95% confidence interval [CI] 0.68 to 0.88), sensitivity of 0.67 (95% CI 0.41 to 0.87), negative predictive value of 0.91 (95% CI 0.82 to 0.97) and a positive likelihood ratio of 3.2 (95% CI 1.9 to 5.5). The Candida Colonisation Index Score showed the best discrimination with area under the receiver operating characteristic curve of 0.79 (95% CI 0.69 to 0.87).

Conclusions

In this study the Candida Colonisation Index Score was the most accurate and discriminative test at identifying which patients with severe acute pancreatitis are at risk of developing candidal infection. However its low sensitivity may limit its clinical usefulness.

Intra-abdominal fungal infections complicating acute pancreatitis: a review

Intra-abdominal infections of pancreatic or peripancreatic necrotic tissue complicate the clinical course of severe acute pancreatitis (SAP) and are associated with significant morbidity. Fungal infection of necrotic pancreatic tissue is increasingly being reported. The incidence of intra-abdominal pancreatic fungal infection (PFI) varies from 5% to 68.5%. Candida albicans is the most frequently isolated fungus in patients with necrotizing pancreatitis. Prolonged use of prophylactic antibiotics, prolonged placement of chronic indwelling devices, and minimally invasive or surgical interventions for pancreatic fluid collections further increase the risk of PFI. Computed tomography- or ultrasound-guided fine-needle aspiration of pancreatic necrosis is a safe, reliable method for establishing pancreatic infection. Amphotericin B appears to be the most effective antifungal treatment. Drainage and debridement of infected necrosis are also critical for eradication of fungi from the poorly perfused pancreatic or peripancreatic tissues where the antifungal agents may not reach to achieve therapeutic levels. Fungal infection adversely affects the outcome of patients with SAP and is associated with increased morbidity, although the mortality rate is not increased specifically because of PFI. Although antifungal prophylaxis has been suggested for patients on broad-spectrum antibiotics, no randomized controlled trials have yet studied its efficacy in preventing PFI.

Fungal infections in severe acute pancreatitis

Severe acute pancreatitis (SAP) is associated with significant morbidity and mortality. The majority of deaths related to SAP are the result of infectious complications. Although bacterial infections are most commonly encountered, fungal infections are increasingly being recognized. Candida is the most common fungal infection. The occurrence of fungal infection in patients with acute pancreatitis adversely affects the clinical course, leading to a higher incidence of systemic complications, and possibly mortality as well. Important risk factors for fungal infection in patients with acute pancreatitis include broad-spectrum antibiotics, prolonged hospitalization and surgical/endoscopic interventions, use of total parenteral nutrition, and mechanical ventilation. Patients with higher severity of pancreatitis are at a greater risk. The pathogenesis of fungal infection in patients with acute pancreatitis is multifactorial. Translocation of microorganisms across the gut epithelium, lymphocyte dysfunction, and the virulence of the invading microorganisms play important roles. Histological demonstration of fungi remains the gold standard of diagnosis, but a positive biopsy is rarely obtained. The role of biomarkers in the diagnosis is being investigated. As early diagnosis and treatment can lead to improved outcome, a high index of suspicion is required for prompt diagnosis. Limiting the use of broad-spectrum antibiotics, early introduction of enteral nutrition, and timely change of vascular catheters are important preventive strategies. The role of antifungal prophylaxis remains controversial. Surgical necrosectomy with antifungal therapy is the most widely used treatment approach. Clinical trials on antifungal prophylaxis are needed, and indications for surgical intervention need to be clearly defined.

Outcomes of intra-abdominal fungal vs. bacterial infections in severe acute pancreatitis

OBJECTIVES

Intra-abdominal infection in severe acute pancreatitis (SAP) has significant morbidity and mortality; however, reports conflict on the outcome of patients with intra-abdominal fungal infection (IFI). We aimed to compare the morbidity and mortality of IFI compared with intra-abdominal bacterial infection (IBI) and no intra-abdominal infection (NII) in patients with SAP.

METHODS

Medical records of 207 consecutive patients admitted with SAP (per the Atlanta classification) to the Mayo Clinic (Rochester, Minnesota) between 1992 and 2001 were reviewed. All intra-abdominal microbiology cultures from pancreatic and peri-pancreatic necrosis, abscess, and/or pseudocyst obtained at operation, endoscopic necrosectomy or computed tomography-guided aspiration were reviewed. Patients were divided into three groups-IFI, IBI, and NII. Primary fungal infections were those for which there had been no prior abdominal interventions, and secondary infections were those that followed a prior intervention. Our main outcome was in-hospital mortality and secondary outcomes included the presence of organ failure (OF), need for surgical intervention, need for intensive care unit (ICU) care, and duration of hospitalization.

RESULTS

The groups were similar in terms of baseline characteristics, use of prophylactic antibiotics, use of enteral/parenteral nutrition, development of necrosis, and peripancreatic fluid collections. Fifty-two percent of patients had an intra-abdominal infection; all of these developed bacterial infections and 30 (15%) developed concomitant fungal infections. There were 7 primary fungal infections and 23 secondary infections-no important outcome differences were noted between these groups. Compared with patients with IBI, patients with IFI had longer hospital (63 vs. 37 days, P<0.01) and ICU (28 vs. 9 days, P<0.01) stays and higher rates of OF (73 vs. 47%, P<0.04), but similar mortality rates (20 vs. 17%, P0.41). Multivariate analysis revealed the presence of OF (odds ratio (OR) 2.4, 95% confidence interval (CI) 1,7) and the need for ICU care (OR 4.3, 95% CI 1,28) to be associated with IFI.

CONCLUSIONS

Patients with SAP and IFI suffered greater in-hospital morbidity than did patients with IBI alone. Concomitant fungal infection, however, did not increase the in-hospital mortality rate.

Prevalence and outcome of fungal infection in patients with severe acute pancreatitis

BACKGROUND AND AIM

To study the prevalence of risk factors and outcome of fungal infections in patients with severe acute pancreatitis.

METHODS

Fifty consecutive patients with severe acute pancreatitis were investigated for evidence of fungal infection by weekly culture of body fluids and aspirate from pancreatic/peripancreatic tissue and samples collected at necrosectomy. All patients were managed as per a standard protocol. Patients with documented fungal infection were treated with intravenous amphotericin or fluconazole. Data were analyzed using SPSS software (version 13), and risk factors for fungal infection and mortality were determined.

RESULTS

Fungal infection was documented in 18 (36%) of 50 patients with Candida albicans (the commonest species). The incidence of fungal infection steadily increased with increasing duration of hospital stay. Those with fungal infection more often had evidence of respiratory failure (P = 0.031) and hypotension (P = 0.031) at admission, prolonged hospital stay > 4 weeks (P = 0.034), longer duration of antibiotics (P = 0.003), received total parenteral nutrition (P = 0.005), and required mechanical ventilation (P = 0.001) in contrast to those without fungal infection. The logistic regression analysis found the independent risk factors for fungal infection to be antibiotic therapy for > 4 weeks and hypotension at hospitalization. Of the 18 patients with fungal infection, 13 were administered intravenous antifungals; eight of these patients survived, while the five who did not receive antifungals died.

CONCLUSION

Fungal infection was detected in 36% of our patients. The independent risk factors associated with it were hypotension at hospitalization and prolonged antibiotic therapy. Antifungal therapy improved their chances of survival.

Prevalence of primary fungal infections in necrotizing pancreatitis

BACKGROUND/AIMS

Prophylactic use of carbapenems (meropenem and imipenem) and other broad-spectrum antibiotics in necrotizing pancreatitis has been suggested as a risk factor for pancreatic fungal infections. The aim of our study was to determine the prevalence of primary fungal infections and the pattern of antibiotic use in necrotizing pancreatitis at our institution.

METHODS

Records on 689 consecutive patients with acute pancreatitis between 2000 and 2004 were reviewed. Necrotizing pancreatitis was identified by contrast-enhanced computed tomography (CT) scan. Data on antibiotic usage were collected and microbiologic data obtained from radiologic, endoscopic, and surgical interventions (pancreatic aspiration, drain placement or debridement) were reviewed for evidence of fungal infection. Pancreatic fungal infections were classified as primary if the positive culture was obtained at the time of initial intervention.

RESULTS

Among 64 patients with necrotizing pancreatitis, there were no cases of primary pancreatic fungal infections and 7 cases (11%) of secondary pancreatic fungal infections. Fifteen patients (23%) developed pancreatic bacterial infections. Among 62 patients with necrotizing pancreatitis in whom antibiotic exposure was known, 45% received carbapenems for a median duration of only 6 days, and 84% received non-carbapenem antibiotics for a median duration of 14 days.

CONCLUSION

Limited use and short duration of carbapenem therapy may be factors contributing to the absence of primary fungal infections in our study.

Pro/con debate: antifungal prophylaxis is important to prevent fungal infection in patients with acute necrotizing pancreatitis receiving broad-spectrum antibiotics

When critically ill patients with pancreatitis develop infection of the pancreas, the ongoing management of such patients becomes difficult. Sufficient evidence supports the use of broad-spectrum antibiotic prophylaxis to prevent the development of bacterial infection. Since fungal infection is also a relatively common complication of severe pancreatitis--particularly when broad-spectrum antibiotics are used--it seems logical that fungal prophylaxis may be an important component of management. In this issue of Critical Care, two expert groups debate the merits of antifungal prophylaxis in patients with acute necrotizing pancreatitis who are receiving antibiotics.