Vitamin and Trace Element Loss from Negative-Pressure Wound Therapy

OBJECTIVE: This study investigated select vitamin and trace element loss from wound exudates in burn and trauma patients treated with negative-pressure wound therapy (NPWT). DESIGN: A prospective observational study was performed using wound exudate samples. SETTING: A level I trauma center acute care hospital. PARTICIPANTS: The study was composed of 8 patients with open abdomens and 9 patients with 12 soft-tissue wounds. MAIN OUTCOME MEASURES: The goal was to collect wound exudate samples daily for 3 days, then every other day to day 9 or until NPWT was discontinued, and to analyze for vitamins A (retinol), C, and E and zinc (Zn), iron (Fe), and copper (Cu). Daily loss of each micronutrient was calculated from their concentration and 24-hour volumes of the exudates. MAIN RESULTS: Exudate loss in the open-abdomen group was significantly higher than in the patients with soft-tissue wounds (900 ± 547 vs 359 ± 246 mL/d). The mean 24-hour loss of vitamins A, C, and E were 0.3, 2.8, and 11 mg, respectively, in the open-abdomen group. Over the same period, the losses of Zn, Fe, and Cu were 0.5, 0.4, and 0.25 mg, respectively, in these patients. Micronutrient 24-hour loss was significantly lower in the soft-tissue wound patients than in the open-abdomen group. CONCLUSIONS: The data support the concept that significant amounts of micronutrients can be lost from NPWT wound exudates, particularly in open abdomens. These losses should be considered in the nutritional support of these patients who typically are in a hypermetabolic and catabolic state.