Imipenem versus piperacillin/tazobactam for empiric treatment of neutropenic fever in adults

Effect of carbapenem restriction on prescribing trends for immunocompromised wards at an academic medical center

The recently described proportion of carbapenem consumption metric was used to assess the effectiveness of formulary restriction for carbapenems for 2 units housing predominantly immunocompromised patients at a large academic medical center. Interrupted time series analysis revealed a significant decrease in meropenem use for hematology-oncology and bone marrow transplant units after restriction.

Decrease in vancomycin-resistant Enterococcus colonization associated with a reduction in carbapenem use as empiric therapy for febrile neutropenia in patients with acute leukemia

OBJECTIVE

To compare the effects of empiric carbapenems versus cycling cefepime and piperacillin/tazobactam on the rates of vancomycin-resistant Enterococcus (VRE) colonization, bloodstream infections, and outcomes of patients admitted with acute leukemia.

DESIGN

Retrospective clinical study with VRE molecular strain typing and gastrointestinal microbiome comparison.

SETTING

A regional referral center for acute leukemia.

PATIENTS

342 consecutive patients admitted with newly diagnosed acute leukemia.

METHODS

In September 2015, we changed our empiric antibiotic of choice for neutropenic fever from a carbapenem to the cycling regimen. We studied 214 consecutive patients during the carbapenem period and 128 during the cycling period. Surveillance for VRE stool colonization was conducted weekly. Representative stool samples were analyzed for VRE MLST types and changes in the composition and diversity of the fecal microbiota.

RESULTS

The change in empiric antibiotics was associated with a significant decrease in VRE colonization (hazard ratio [HR], 0.35; 95% confidence interval [CI], 0.27-0.66), a switch in the dominant VRE MLST types on the unit, and some modifications in the gastrointestinal microbiome. There were no differences in total gram-positive or gram-negative BSIs. During the carbapenem period, we observed higher absolute numbers of Candida spp and fewer ESBL BSIs, but these did not reach statistical significance. Patients during the carbapenem period had longer lengths of stay and durations of severe neutropenia and 10% higher hospital cost.

CONCLUSIONS

Carbapenem-sparing empiric antibiotic regimens may have advantages related to VRE ecology, gastrointestinal dysbiosis, duration of neutropenia, cost and length of stay.

A randomized controlled feasibility trial of paracetamol during febrile neutropenia in hemato-oncology patients

The efficacy of paracetamol (acetaminophen) as an antipyretic during febrile neutropenia (FN) has not previously been established. We conducted a randomized double-blind placebo-controlled feasibility trial: hemato-oncology patients at high FN risk were randomly assigned to six hourly oral paracetamol (1 g) or placebo during the first 42 hours of FN. Fifty-three participants were screened, thirty-seven enrolled; 22 developed FN and commenced treatment (13 paracetamol; 9 placebo); recruitment rates were below, and retention rates met, pre-defined feasibility criteria. During the first 24 hours of FN, paracetamol recipients had significantly lower peak temperature than placebo: mean 38.2 (standard deviation 0.8) °C versus 38.9 (0.4) °C; difference -0.78 °C (95% CI -1.38 to -0.18); p = .013. Bacterial load measurement was not informative. Paracetamol lowers body temperature during FN, and definitive trials to determine its impact on FN outcomes are needed. Australian New Zealand Clinical Trials Registry reference ACTRN12613000601730; funded by Health Research Council of New Zealand.

Evaluation of a risk-guided strategy for empirical carbapenem use in febrile neutropenia

Febrile neutropenia (FN) is associated with substantial morbidity and necessitates empirical broad-spectrum antimicrobial treatment. In this prospective cohort study, a risk-guided management strategy for FN using empirical piperacillin/tazobactam (TZP) or a carbapenem was evaluated. The analysis involved 723 FN episodes in hospitalised adult patients, including those with severe sepsis or prior infection/colonisation with extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. Propensity score matching analysis was used to adjust for baseline differences between treatment groups and produced 267 matched pairs. The primary outcome was all-cause mortality. Secondary outcomes were the incidences of drug-resistant Gram-negative (including ESBL-producing) and Gram-positive bacterial isolates and of invasive pulmonary aspergillosis (IPA) and their associated mortality. There was no difference in mortality between empirical carbapenem and TZP [18/267 (6.7%) vs. 14/267 (5.2%); P = 0.466]. Higher incidences of drug-resistant Gram-negative isolates [77/267 (28.8%) vs. 26/267 (9.7%); P < 0.001], including ESBL-producing bacteria [57/267 (21.3%) vs. 16/267 (6.0%); P < 0.001], were observed in carbapenem-treated episodes where its use lowered mortality. Mortality rates for ESBL-positive infections were 5.3% (3/57) and 25.0% (4/16) (P = 0.037) and for drug-resistant Gram-negative infections were 6.5% (5/77) and 23.1% (6/26) (P = 0.018) in carbapenem- and TZP-treated episodes, respectively. More IPA was observed with carbapenem use [16/267 (6.0%) vs. 6/267 (2.2%); P = 0.029]. Antifungal prophylaxis reduced the risk of death (odds ratio = 0.39, 95% confidence interval 0.17-0.87; P = 0.017). Risk-guided carbapenem prescribing in FN correctly identified cases prone to drug-resistant Gram-negative infections and reduced the mortality in these episodes.

Temporal changes in neutropenic blood culture isolates and disease associations: a single centre series of 1139 episodes

Neutropenic infections are life-threatening and require empiric antibiotic treatment. We examined 1139 blood culture isolates from our institution over a 36-year period from neutropenic patients to examine temporal trends and disease associations. Positive associations were found between viridans streptococci and acute myeloid leukaemia, coagulase negative staphylococci and acute lymphoblastic leukaemia and Pseudomonas aeruginosa and indolent B-cell malignancies.