Estimation of Protein Requirements According to Nitrogen Balance for Older Hospitalized Adults with Pressure Ulcers According to Wound Severity in Japan
Article first published online: 30 OCT 2012
© 2012, Copyright the Authors Journal compilation © 2012, The American Geriatrics Society
Journal of the American Geriatrics Society
Volume 60, Issue 11, pages 2027–2034, November 2012
How to Cite
J Am Geriatr Soc 60:2027–2034, 2012.
- Issue published online: 13 NOV 2012
- Article first published online: 30 OCT 2012
- Japanese Society of Pressure Ulcers
- Japan Society for the Promotion of Science. Grant Number: #22–2766
- wound care
To estimate protein requirements in older hospitalized adults with pressure ulcers (PrU) according to systemic conditions and wound severity.
Secondary nitrogen balance study over 3 days.
Long-term care facility.
Twenty-eight older adults with PrU using a urinary catheter.
Nitrogen balance over 3 days was evaluated from habitual nitrogen intake measured using a food weighing record and nitrogen excretion from urine, feces and wound exudate. Nitrogen intake required to maintain nitrogen equilibrium was estimated as an average protein requirement using a linear mixed model.
Nitrogen intake at nitrogen equilibrium was 0.151 gN/kg per day (95% confidence interval = 0.127–0.175 gN/kg per day) for all participants. The amount of protein loss from wound exudate contributed little to total nitrogen excretion. A Charlson comorbidity index of 4 or greater (the median value) was related to lower nitrogen intake at nitrogen equilibrium (P = .005). Severe PrU with heavy exudate amounts and measured wound areas of 7.9 cm2 or greater (the median value) were related to higher nitrogen intake at nitrogen equilibrium in individuals with a Charlson comorbidity index of 3 or less (both P = .04). Larger wound area (correlation coefficient (r) = 0.55, P = .003) and heavier exudate volume (r = 0.53, P = .004) were associated with muscle protein hypercatabolism measured according to 3-methylhistidine/creatinine ratio.
The average protein requirement is 0.95 g/kg per day for older hospitalized Japanese adults with PrU, but protein requirements depend on an individual's condition and wound severity and range from 0.75 to 1.30 g/kg per day. Severe PrU can require higher protein intakes because of muscle protein hypercatabolism rather than direct loss of protein from wound exudate.