Antimicrobial Stewardship in a Hematological Malignancy Unit: Carbapenem Reduction and Decreased Vancomycin-Resistant Enterococcus Infection.

BACKGROUND: Antibiotic stewardship is challenging in hematological malignancy patients. METHODS: We performed a quasiexperimental implementation study of 2 antimicrobial stewardship interventions in a hematological malignancy unit: monthly antibiotic cycling for febrile neutropenia that included cefepime (± metronidazole) and piperacillin-tazobactam and a clinical prediction rule to guide anti-vancomycin-resistant Enterococcus faecium (VRE) therapy. We used interrupted time-series analysis to compare antibiotic use and logistic regression in order to adjust observed unit-level changes in resistant infections by background community rates. RESULTS: A total of 2434 admissions spanning 3 years pre- and 2 years postimplementation were included. Unadjusted carbapenem and daptomycin use decreased significantly. In interrupted time-series analysis, carbapenem use decreased by -230 days of therapy (DOT)/1000 patient-days (95% confidence interval [CI], -290 to -180; P < .001). Both VRE colonization (odds ratio [OR], 0.64; 95% CI, 0.51 to 0.81; P < .001) and infection (OR, 0.41; 95% CI, 0.2 to 0.9; P = .02) decreased after implementation. This shift may have had a greater effect on daptomycin prescribing (-160 DOT/1000 patient-days; 95% CI, -200 to -120; P < .001) than did the VRE clinical prediction score (-30 DOT/1000 patient-days; 95% CI, -50 to 0; P = .08). Also, 46.2% of Pseudomonas aeruginosa isolates were carbapenem-resistant preimplementation compared with 25.0% postimplementation (P = .32). Unit-level changes in methicillin-resistant Staphylococcus aureus and extended-spectrum beta lactamase (ESBL) incidence were explained by background community-level trends, while changes in AmpC ESBL and VRE appeared to be independent. The program was not associated with increased mortality. CONCLUSIONS: An antibiotic cycling-based strategy for febrile neutropenia effectively reduced carbapenem use, which may have resulted in decreased VRE colonization and infection and perhaps, in turn, decreased daptomycin prescribing.

Amino Acid Oxidation Increases with Dietary Protein Content in Adult Neutered Male Cats as Measured Using [1-13C]Leucine and [15N2]Urea.

BACKGROUND: Cats are unique among domestic animals in that they are obligate carnivores and have a high protein requirement. However, there are few data on protein turnover and amino acid (AA) metabolism in cats. OBJECTIVE: The aim of this study was to examine the effects of dietary protein content on urea production and Leu metabolism in cats. METHODS: Eighteen neutered male cats (4.4 ± 0.11 kg body weight, aged 4.6 ± 0.41 y) fed to maintain body weight for 3 wk with 15%, 40%, or 65% metabolizable energy intake as crude protein (CP) had [1-(13)C]Leu administered in the fed state. Urea production was measured by the infusion of [(15)N2]urea. Leu flux, nonoxidative Leu disposal (NOLD; protein synthesis), Leu rate of appearance (Ra; protein degradation), and Leu oxidation were determined. RESULTS: Urea production and Leu oxidation were both ∼ 3 times greater in cats fed 65% CP compared with those fed 15% CP, whereas those fed 40% CP were ∼ 1.6 times greater (P < 0.05). Leu flux was 1.9 and 1.3 times greater in cats fed 65% CP compared with those fed 15% and 40% CP (P < 0.001). Almost 39% of total Leu flux was oxidized by cats fed 15% CP, whereas this increased to 58% in cats fed 65% CP (P < 0.002). There were no differences for Ra, but cats fed 65% CP tended to have 30% greater NOLD (P = 0.09) and to be in positive protein balance (P = 0.08) compared with those fed 15% CP. CONCLUSION: The high protein requirement of cats combined with a low rate of whole-body protein synthesis ensures that an obligate demand of AAs for energy or glucose (or both) can be met in an animal that evolved with a diet high in protein with very little or no carbohydrate.

Effect of age, sex and body weight on the serum concentrations of cobalamin and folate in cats consuming a consistent diet.

Objectives Multiple feline diseases involving the gastrointestinal tract, pancreas, liver and biliary tract are known to cause abnormal serum cobalamin and folate concentrations. Measuring the serum concentration of these vitamins can therefore be a helpful diagnostic tool. However, factors other than disease, in particular age, have also been suggested to have an effect on the serum concentration of cobalamin and folate. In previous studies, the dietary intake was not standardised, or even known, despite diet being the prinicpal source of both vitamins. Therefore, we evaluated the effect of age, sex and body weight on the serum concentration of folate and cobalamin in cats fed the same diet. Methods The serum cobalamin and folate concentrations were measured in 65 apparently healthy cats in a nutrition colony that had been fed an identical diet. A linear model was used to test the relationship between the serum concentration of cobalamin and folate with the variables age, sex and body weight. Results There was a large variation in the serum concentration of both folate and cobalamin, despite identical intake. Serum cobalamin was inversely associated with age ( P = 0.002), and males had higher concentrations than females ( P = 0.039). Serum folate was positively associated with age ( P = 0.01). Conclusions and relevance Independent of diet, serum cobalamin concentration decreases with age. Changes in gastrointestinal function, microflora or metabolism may be responsible. Older cats may be more susceptible to cobalamin deficiency secondary to inappetence or gastrointestinal disease.