Cefepime tissue penetration in experimental acute pancreatitis

Cefepime distribution by microdialysis in peritoneal fluid of rats with or without experimental peritonitis

The aim of this study was to investigate the penetration of cefepime into rat peritoneal fluid by microdialysis and to determine the relationship between unbound drug plasma and tissue concentration in healthy animals and in a sepsis model established through cecal ligation and puncture-induced peritonitis. Probe recovery was performed by dialysis and retrodialysis. Cefepime was administered at a dose of 110 mg/kg intravenously. Samples were collected for about 4 h, and concentrations were determined by liquid chromatography-electrospray ionization-QTOF MS. Tissue penetration was also determined. Probe recovery in vivo was 38.78% ± 3.31% and 38.83% ± 2.74% in the control and peritonitis groups, respectively. Cefepime was rapidly distributed in the peritoneal fluid in both groups. The peritoneal fluid/plasma cefepime ratio was 0.38 and 0.32 for the control and peritonitis groups, respectively. Cefepime concentrations were above the MIC of 4 mg/L for the main enterobacteria. The infection model that was used had no apparent effect on the pharmacokinetics of cefepime in rats. This was the first study to determine free cefepime concentrations in the peritoneal fluid of healthy rats and rats with experimental peritonitis.

Splanchnic Vein Thrombosis: A Harbinger of Infection in Peri/Pancreatic Necrotic Collections

OBJECTIVE

Infected pancreatic necrosis (IPN) is associated with poor outcomes. The present study looked at incidence of infection and predictors, if any, in these collections.

METHODS

This prospective observational study was done between July 2019 and October 2020. Symptomatic patients of acute necrotic collections and walled-off necrosis of pancreas requiring drainage were included. Necrotic fluid and blood were analyzed for growth of organisms.

RESULTS

Sixty-two patients were included. The mean age was 36.8 years (standard deviation, 11.5 years). Male-female ratio was 4:1. Alcohol was the most common etiology. Infection was noted in 44 of the 62 patients (70.9%) and bacteremia noted in 23 of the 62 patients (37%). Escherichia coli was the most common organism in necrotic collections and Staphylococcus was the most common organism isolated from blood culture. The patients with Modified Computed Tomography-Severity Index of 8 of higher ( P < 0.001) had significant association with IPN but not with bacteremia. However, splanchnic vein thrombosis ( P = 0.022) was significantly associated with development of IPN as well as bacteremia on both univariate and multivariate analysis.

CONCLUSIONS

Escherichia coli and Staphylococcus were the most common organisms grown from necrotic collections and blood respectively. Presence of splanchnic vein thrombosis was a significant factor for development of IPN and bacteremia on univariate as well as multivariate analysis.

Rethinking Carbapenems: A Pharmacokinetic Approach for Antimicrobial Selection in Infected Necrotizing Pancreatitis

OBJECTIVE

To provide an overview of pathophysiological changes to the pancreas during infected necrotizing pancreatitis (INP), optimal drug properties needed to penetrate the pancreas, human and animal studies supporting the use of antimicrobials, and carbapenem-sparing strategies in INP.

DATA SOURCES

A literature analysis of PubMed/MEDLINE was performed (from 1960 to September 2020) using the following key terms: infected necrotizing pancreatitis, necrotizing acute pancreatitis, and infected pancreatitis antimicrobial concentration. Individual antimicrobials were investigated with these search terms.

STUDY SELECTION AND DATA EXTRACTION

All relevant studies describing the management of INP, and human and animal pharmacokinetic (PK) data supporting antimicrobial use in the pancreas were reviewed for possible inclusion regardless of sample size or study design.

DATA SYNTHESIS

Piperacillin/tazobactam and cefepime achieve adequate pancreatic tissue concentrations in INP studies. A majority of the literature supporting carbapenem use in INP involves imipenem, and meropenem Monte Carlo simulations suggest that standard dosing regimens of meropenem may not achieve PK targets to eradicate Pseudomonas aeruginosa.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Carbapenems are often utilized for INP treatment based on guideline recommendations. This review discusses PK data, the history of carbapenem use in INP, and the pathophysiology of pancreatitis to suggest carbapenem-sparing strategies and provides stewardship tactics such as when to start antimicrobials, which empirical antimicrobial to use, and when to discontinue antimicrobials in the INP setting.

CONCLUSIONS

Noncarbapenem antipseudomonals, such as piperacillin/tazobactam and cefepime, are appropriate carbapenem-sparing options in INP, based on PK data, spectrum of activity, and risk of collateral damage.

Impact of prior antibiotics on infected pancreatic necrosis microbiology in ICU patients: a retrospective cohort study

Background

Recent guidelines advise against prophylactic antibiotics in patients with necrotizing pancreatitis, advocating instead a step-up drainage and necrosectomy strategy with antibiotics as dictated by microbiological findings. However, prompt antibiotic therapy is recommended in patients with sepsis or septic shock, a possible presentation of infected pancreatic necrosis (IPN). Consequently, in many critically ill patients with IPN, pancreatic samples are collected only after broad-spectrum antibiotic therapy initiation. Whether this prior antibiotic exposure alters the microbiological findings is unknown. The main objective was to determine whether prior antibiotic exposure sterilized the samples collected during procedures for suspected IPN in patients admitted to the intensive care unit (ICU) for acute pancreatitis with suspected IPN. We retrospectively studied 56 consecutive ICU patients admitted with suspected IPN. We collected details on the microbiological samples and antimicrobials used. A definite diagnosis of IPN was given when bacteria were identified in pancreatic samples.

Results

In all, 137 pancreatic samples were collected, including 91 (66.4%) after antibiotic therapy initiation. IPN was confirmed in 48 (86%) patients. The proportion of positive samples was 74 (81.3%) in antibiotic-exposed patients and 32/46 (69.5%) in unexposed patients (p = 0.58). Of the 74 positive samples from exposed patients, 62 (84%) had organisms susceptible to the antibiotics used. One-third of samples contained more than one organism. Among patients with IPN, 37.5% had positive blood cultures. Multidrug- or extensively drug-resistant bacteria were identified at some point in half the patients. Enterobacter cloacae complex was more frequent in the exposed group (p = 0.02), as were Gram-negative anaerobic bacteria (p = 0.03).

Conclusion

Antibiotic exposure before sampling did not seem to affect culture positivity of pancreatic samples to confirm IPN, but may affect microbiological findings. Our results suggest that, in patients with sepsis and suspected IPN, antibiotics should be started immediately and pancreatic samples obtained as soon as possible thereafter. In other situations, antibiotics can be withheld until the microbiological results of pancreatic samples are available, to ensure accurate targeting of the spectrum to bacterial susceptibility patterns.

ClinicalTrials.gov number NCT03253861

Clinical pharmacokinetics of meropenem in pancreatic juice and site-specific pharmacodynamic target attainment against Gram-negative bacteria: dosing considerations

BACKGROUND AND OBJECTIVE

Very few studies have revealed the dynamics of meropenem penetration into the pancreas or pancreatic juice in humans. This study of the clinical pharmacokinetics and pharmacodynamics of meropenem in human pancreatic juice was performed to establish a basis for the validation of dosing regimens for pancreatic infections.

METHODS

Ten patients with endoscopic naso-pancreatic drainage received 500 mg meropenem over 0.5 h via intravenous infusion. Venous blood and pancreatic juice samples were collected post-infusion for up to 5.0 h and used to obtain measures of meropenem concentration. The probability of attaining the pharmacodynamic target (40% of the time above the minimum inhibitory concentration [MIC]) in pancreatic juice against MIC distributions for clinical isolates of Gram-negative bacteria was determined using a Monte Carlo simulation.

RESULTS

The mean maximum concentration of meropenem in pancreatic juice was 2.08 ± 0.94 μg/mL at 1.025 ± 0.18 h. The pancreatic juice/plasma ratio was 0.055 ± 0.028. A 0.5-h infusion of 500 mg meropenem every 8 h achieved a 99.4% probability of target attainment against Escherichia coli, 96.4% against Klebsiella species, 94.3% against Enterobacter species and 96.2% against Proteus species, but only 41.3% against Pseudomonas aeruginosa isolates.

CONCLUSION

Intravenous meropenem exhibits low penetrance into pancreatic juice. However, a dosing regimen of 500 mg meropenem (0.5-h infusion) every 8 h provides sufficient drug-exposure time in pancreatic juice against the four common Gram-negative bacteria populations.

Changes in antibiotic distribution due to pancreatitis

This work sought to define how pancreatitis affected antibiotic distribution in a perfused rat pancreas model. The distribution kinetics of four antibiotics were examined in control animals and animals with pancreatitis. Meropenem and piperacillin distributed into the extracellular space, and their distribution kinetics were unaffected by pancreatitis. In contrast, in pancreatic cells from animals with pancreatitis, ciprofloxacin showed a reduced uptake and clindamycin showed a reduced distribution.

Antibiotic prophylaxis in acute necrotizing pancreatitis revisited

OBJECTIVE

To review studies of antibiotic prophylaxis in acute necrotizing pancreatitis published in the last decade and update recommendations.

DATA SOURCES

A search of PubMed (1998-July 2009) was conducted using the terms necrotizing pancreatitis, antibiotics, prophylaxis, and treatment. Clinical studies, meta-analyses, and review articles published in English were included. Additional references were obtained from article bibliographies. Randomized trials published before 1998 were included if indicated.

STUDY SELECTION AND DATA EXTRACTION

Relevant studies or meta-analyses on antibiotic prophylaxis since our previous review in 1998 were evaluated; older data were included if still relevant.

DATA SYNTHESIS

Since our previous review, 4 more randomized trials, including 2 double-blind trials, have been conducted. The blinded studies found no significant difference in mortality with antibiotic prophylaxis compared with placebo, while the unblinded studies found a significant decrease in infections. Given these disparate results, available guidelines and meta-analyses provide different conclusions, usually based on exclusion or inclusion of a single trial. Based on all available data, antibiotic prophylaxis should not be used in patients with necrotizing pancreatitis. Instead, a more measured, on-demand use of antibiotics is preferred. Antibiotics should be added if signs and symptoms of infection are present (eg, fever, leukocytosis, positive results of cultures). Given improvements in intensive care and nutritional support, recent trials have found a lower incidence of infected necrotizing pancreatitis than before. Therefore, future trials are likely to need higher numbers of patients.

CONCLUSIONS

Use of antibiotic prophylaxis for patients with necrotizing pancreatitis is not indicated, based on 2 blinded trials. Instead, on-demand use of antibiotics appears to be appropriate. Given progress in intensive care and the high crossover rate in studies, the need for antibiotic prophylaxis may continue to be debated for decades.

Modification of intestinal flora with multispecies probiotics reduces bacterial translocation and improves clinical course in a rat model of acute pancreatitis

BACKGROUND

Infection of pancreatic necrosis by gut bacteria is a major cause of morbidity and mortality in patients with severe acute pancreatitis. Use of prophylactic antibiotics remains controversial. The aim of this experiment was assess if modification of intestinal flora with specifically designed multispecies probiotics reduces bacterial translocation or improves outcome in a rat model of acute pancreatitis.

METHODS

Male Sprague-Dawley rats were allocated into 3 groups: (1) controls (sham-operated, no treatment), (2) pancreatitis and placebo, and (3) pancreatitis and probiotics. Acute pancreatitis was induced by intraductal glycodeoxycholate and intravenous cerulein infusion. Daily probiotics or placebo was administered intragastrically from 5 days prior until 7 days after induction of pancreatitis. Tissue and fluid samples were collected for microbiologic and quantitative real-time PCR analysis of bacterial translocation.

RESULTS

Probiotics reduced duodenal bacterial overgrowth of potential pathogens (Log(10) colony-forming units [CFU]/g 5.0 +/- 0.7 [placebo] vs 3.5 +/- 0.3 CFU/g [probiotics], P < .05), resulting in reduced bacterial translocation to extraintestinal sites, including the pancreas (5.38 +/- 1.0 CFU/g [placebo] vs 3.1 +/- 0.5 CFU/g [probiotics], P < .05). Accordingly, health scores were better and late phase mortality was reduced: 27% (4/15, placebo) versus 0% (0/13, probiotics), respectively, P < .05.

CONCLUSIONS

This experiment supports the hypothesis that modification of intestinal flora with multispecies probiotics results in reduced bacterial translocation, morbidity, and mortality in the course of experimental acute pancreatitis.

Effect of a pneumoperitoneum on systemic cytokine levels, bacterial translocation, and organ complications in a rat model of severe acute pancreatitis with infected necrosis

BACKGROUND

Infection of pancreatic necrosis (IPN) is strongly associated with sepsis and multiple organ dysfunction and is an absolute indication for surgery. Patients with IPN are critically ill at the time of surgery and may benefit from a minimally invasive approach with reduced surgical trauma. Recently, several minimally invasive necrosectomy techniques have been reported. However, the effects and potential dangers of a pneumoperitoneum in IPN cases are unknown. This study aimed to determine the effects of a pneumoperitoneum on systemic cytokine levels, bacterial translocation, and systemic organ complications in a rat model of IPN.

METHODS

For this study, IPN was induced in Wistar rats using retrograde intraductal infusion of 3% taurocholate. After 8 h, the animals were subjected to either laparoscopy (pneumoperitoneum at 8 mmHg) or laparotomy for 1 h and killed after 1 or 3 h. Severe acute pancreatitis with IPN was proved by serum amylase and lipase, histology, tissue activity of myeloperoxidase (MPO), and bacteriology. Systemic levels for interleukin-10 (IL-10), IL-6, tumor necrosis factor-alpha (TNF-alpha), and lipopolysaccarides were determined by enzyme-linked immunoassay (ELISA). Systemic organ damage and dysfunction were evaluated using MPO activity (lung), serum creatinine (kidney), and serum aminotransferases (liver).

RESULTS

Necrotizing pancreatitis developed in all the animals. Most of the animals (85%) had proven infected necrosis. Elevated cytokine levels and deteriorated organ parameters demonstrated systemic inflammation and organ failure. Although there was a tendency toward a higher level of proinflammatory cytokines after laparotomy, there were no significant differences between laparotomy and laparoscopy. Furthermore, these alterations were not accompanied by any differences in bacterial translocation (lipopolysaccharides), systemic organ damage, or mortality between laparoscopy and laparotomy.

CONCLUSION

In the current model of infected pancreatic necrosis, a pneumoperitoneum did not result in increased cytokine release or bacterial translocation. However, the putative advantage of less surgical trauma with the laparoscopic approach did not play a significant role in the setting of severe acute pancreatitis with IPN.

Severe acute pancreatitis: case-oriented discussion of interdisciplinary management

The clinical course of an episode of acute pancreatitis varies from a mild, transitory illness to a severe often necrotizing form with distant organ failure and a mortality rate of 20-40%. Patients with severe pancreatitis, representing about 15-20% of all patients with acute pancreatitis, need to be identified as early as possible after onset of symptoms allowing starting intensive care treatment early in the disease process. An episode of severe acute pancreatitis progresses in two phases. The first 10-14 days are characterized by a systemic inflammatory response syndrome maintained by the release of various inflammatory mediators. The second phase, beginning about 10-14 days after the onset of the disease is dominated by sepsis-related morbidity due to infected peripancreatic and pancreatic necrosis. This state is associated with septic multiple organ systemic failure. The importance of infection on the outcome of necrotizing pancreatitis has been clearly delineated and the pre-emptive use of broad-spectrum antibiotics that achieve effective tissue concentrations is considered standard management of patients with severe necrotizing pancreatitis, especially if associated with organ failure or extended necrosis. Patients with infected necrosis should undergo a surgical intervention. The standard open technique consisting of an organ preserving necrosectomy followed by a postoperative concept of lavage and/or drainage to evacuate necrotic debris occurring during the further course has recently been challenged by various minimally invasive approaches.

Prophylaxis with meropenem of septic complications in acute pancreatitis: a randomized, controlled trial versus imipenem

OBJECTIVES

Prophylactic antibiotics are helpful in decreasing the incidence of septic complications in acute pancreatitis. The aim of this study was to compare the efficacy of meropenem, a new carbapenem antibiotic, with that of imipenem, which is the standard prophylactic treatment in patients with severe acute pancreatitis.

METHODS

One hundred seventy-six patients with necrotizing pancreatitis were prospectively randomized to prophylactic treatment with 0.5 g meropenem t.i.d. intravenously or 0.5 g imipenem q.i.d. intravenously. The occurrence of infection of pancreatic necrosis, rate of extrapancreatic infections, systemic and local complications, need for surgery, mortality rate, and length of hospitalization were recorded for each group. When a septic complication of pancreatic necrosis was suspected, fine needle aspiration with cultures of the sample was performed. Surgery was performed in cases of verified infected necrosis.

CONCLUSION

No difference was observed between patients treated with meropenem and those treated with imipenem in terms of incidence of pancreatic infection (11.4% versus 13.6%) and extrapancreatic infections (21.6% versus 23.9%) and clinical outcome. Meropenem is as effective as imipenem in preventing septic complications of patients with severe acute pancreatitis.