Correlation Between Wound Volume and Depth of Decubitus Ulcers And Resting Energy Expenditure

Adequate nutrition is an important aspect of wound healing because it provides an anabolic environment necessary for tissue repair. Without proper nutrition support, healing can be prolonged and even inhibited. Provision of adequate energy is essential in patients with decubitus ulcers to maximize nitrogen retention and facilitate wound healing. (1,2) There are few published studies that measure energy needs in patients with decubitus ulcers. Spinal cord injured patients are one of the few populations where studies have utilized indirect calorimetry to measure energy expenditure. Individuals with spinal cord injuries are particularly at risk for developing pressure ulcers. Liu, et al. (3) measured energy expenditure in 16 individuals with quadriplegia and pressure ulcers and in 16 individuals with quadriplegia but no pressure ulcers. Measured energy expenditure was significantly higher in subjects with quadriplegia and pressure ulcers. Additionally, pressure ulcer surface area was significantly correlated with predicted resting energy expenditure. In a study of paraplegic individuals, Alexander, et al. (4) found resting metabolic rate was significantly higher in those individuals with pressure ulcers compared to those with paraplegia without pressure ulcers. Additional research is needed to confirm these findings.

To determine nutrition requirements specific to each patient, energy needs must be estimated, taking into account weight, height, age, activity level as well as the size of the wound and the patient's co-morbidities. Although indirect calorimetry is the gold standard for measuring metabolic rate, it is impractical and time consuming to use this method to determine needs of every patient. Therefore, the clinician uses predictive formulas for estimating energy needs. The most commonly cited guideline for energy requirements for healing pressure ulcers is 30-35 kcal/kg (recommendation, National Pressure Ulcer Advisory Panel).(1) The European Pressure Ulcer Advisory Panel has also recommended a minimum of 30-35 kcal/kg.(2) Several equations have been derived to predict metabolic rate based on age, height, weight, and sex. Two of these predictive equations are the Harris Benedict (5) and the Mifflin-St. Jeor. (6) These equations can be adjusted for injury factors, but it is unclear if they fully account for the size of wound in patients with decubiti.