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

Abstract

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.

Predictors of mortality in acute pancreatitis complicated with multidrug-resistant Klebsiella pneumoniae infection

“…Consistent with the previous analysis of infections, our microbiologic result demonstrated that bloodstream (n = 32) was the most common extra-pancreatic site of MDR- K. pneumoniae infections which may verify our hypothesis for bacterial translocation to the bloodstream [ 32 ]. According to previous studies, drug resistance of MDR- K. pneumoniae pathogens causing AP secondary infections was quite serious [ 5 , 15 ].…”

Predictors of Mortality and Drug Resistance Among Carbapenem-Resistant Enterobacteriaceae-Infected Pancreatic Necrosis Patients

“…Overused prophylactic antibiotic treatments for 'suspected' IPN could result in the acquisition of MDR or carbapenem resistance [1]. Precious studies reported that CRE, as a mainly infectious MDR pathogen, has spread worldwide and influenced the outcome of IPN patients especially in India and China [7,[12][13][14][15][16].…”

Impact of prior antibiotic therapy on severe necrotizing soft-tissue infections in ICU patients: results from a French retrospective and observational study

“…The use of amoxicillinclavulanate was not significantly different between the two groups (22 (29%) vs. 3 (13%), p = 0.174), while piperacillin/ tazobactam or carbapenems were more frequently administered in the exposed group than in the unexposed group (15/23 (65%) vs. 28/77 (36%), respectively p = 0.0175). Interestingly, the severity scores were similar in patients receiving piperacillin/tazobactam or carbapenems vs. the other patients (SAPS-II: 27 [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] vs. 28 [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38], p = 0.542; SOFA score: 4 [3][4][5][6] vs. 5 [4][5][6][7], p = 0.085). Moreover, in the specific group of patients exposed to antimicrobial therapy, no difference was found between patients receiving these regimens and the other patients (SAPS-II: 25 [21-37] vs. 23 [21-32], p = 0.332; SOFA score: 4 [3][4][5][6] vs. 5 [3][4]…”

“…Several studies addressed this issue, all of them out of the field of NSTI. In a study by Garret et al involving 137 patients with necrotizing pancreatitis, the proportion of patients developing an infection from pancreatic samples with MDR bacteria was similar in the exposed and unexposed groups (24 and 26%, respectively; p = 0.99) [ 25 ]. The results of other studies are more controversial.…”

“…In addition, the heterogeneity of the cohort (limb, pelvis, cephalic, trunk) could be a source of bias. We chose a 24-h cutoff, as reported by some other authors [ 25 ], because it seemed to be a good reflection of clinical rationality. Nevertheless, other more restrictive cutoffs could have been used.…”