Most Patients on Mechanical Ventilation Achieve Positive Nitrogen Balance With Protein

Increasing protein intake appears to prevent a negative nitrogen balance in survivors of critical illness requiring prolonged mechanical ventilation in long-term acute care hospitals (LTACHs), according to a study published in Clinical Nutrition ESPEN.

“To our knowledge, this is the first study that has investigated nutritional intake and its relationship to nitrogen balance in chronically critically ill patients in an LTACH requiring prolonged mechanical ventilation,” researchers wrote.

The retrospective cohort study focused on 16 patients on prolonged mechanical ventilation with orders for 24-hour urine collection for urea nitrogen (24hrUUN) at an urban LTACH affiliated with the University of Maryland Medical Center. Researchers used chart documentation on dietary intake to calculate energy and protein intake during the 24hrUUN period.

According to researchers, patients in the study averaged an energy intake of 21.7 ± 2.9 kcal/kg/day and a protein intake of 1.1 ± 0.1 g/kg/day. The averages corresponded to 86% of the patients’ recommended energy and protein goals.

The average nitrogen balance for all patients was 0.9 ± 1.1. Overall, 10 patients achieved a positive nitrogen balance. Researchers reported a positive linear relationship between protein intake and nitrogen balance.

“Future studies should investigate if these high nutritional-risk patients continue to avoid a negative nitrogen balance during their hospitalization after achieving a steady state of nitrogen intake and excretion, and whether achieving and sustaining positive nitrogen balance impacts clinical outcomes, such as time to weaning from mechanical ventilation and overall weaning success,” researchers advised.

Reference:
Balasubramanian S, Tran DH, Serra M, et al. Assessing calorie and protein recommendations for survivors of critical illness weaning from prolonged mechanical ventilation - can we find a proper balance? Clin Nutr ESPEN. 2021 Oct;45:449-453. doi:10.1016/j.clnesp.2021.07.001