Methicillin-resistant Staphylococcus aureus bloodstream infections are associated with a higher energy deficit than other ICU-acquired bacteremia.

Abstract

Caloric insufficiency during the first week of intensive care unit (ICU) stay was reported to be associated with increased infection rates, especially ICU-acquired bloodstream infection (ICU-BSI). However, the predisposition to ICU-BSI by a given pathogen remains not well known. We aimed to determine the impact of early energy-calorie deficit on the pathogens responsible for ICU-BSI. Prospective, observational, cohort study in a 18-bed medical ICU of a tertiary care hospital. Daily energy balance (energy-calorie intakes minus calculated energy-calorie expenditure) was compared according to the microbiological results of the blood cultures of 92 consecutive prolonged (at least 96 h) acute mechanically ventilated patients who developed a first episode of ICU-BSI. Among the 92 ICU-BSI, nine were due to methicillin-resistant Staphylococcus aureus (MRSA). The cumulated energy deficit of patients with MRSA ICU-BSI was greater than those with ICU-BSI caused by other pathogens (-1,348 ± 260 vs -1,000 ± 401 kcal/day from ICU admission to day of ICU-BSI, p = 0.008). ICU admission, risk factors for nosocomial infections, nutritional status, and conditions potentially limiting feeding did not differ significantly between the two groups. Patients with MRSA ICU-BSI had lower delivered energy and similar energy expenditure, causing higher energy deficits. More severe energy deficit and higher rate of MRSA blood cultures (p = 0.01 comparing quartiles) were observed. Early in-ICU energy deficit was associated with MRSA ICU-BSI in prolonged acute mechanically ventilated patients. Results suggest that limiting the early energy deficit could be a way to optimize MRSA ICU-BSI prevention.