N. Goel1, E. Lin1, V. Patel1, R. Askari1 1Brigham And Women’s Hospital,Trauma, Burn, And Surgical Critical Care,Boston, MA, USA
Introduction: There are few studies that describe patient outcomes with necrotizing soft tissue infection (NSTI) based on the type of nutritional support they received. It is also unknown whether the obesity paradox, a phenomenon where obesity exhibits a protective effect on the mortality of patients in severe sepsis, exists in the NSTI population. We sought to examine the association of body mass index (BMI) and outcomes in patients with NSTI, while also trying to identify the best route of nutrition for these patients.
Methods: A retrospective cohort study of all NSTI patients from 1995 to 2011. Using the hospital nutrition database, patients were categorized by type of nutritional intake—artificial (tube feeds and total parenteral nutrition (TPN)) or non-artificial. Each population was further subdivided by baseline BMI (weight in kilograms divided by the square of height in meters) as underweight (BMI <18.5), normal (BMI, 18.5-24.9), overweight (BMI, 25.0-29.9), and obese (BMI ≥30.0) according to the WHO guidelines. This database also provided the percentage of goal caloric and protein needs achieved for each NSTI patient on artificial nutrition. Pre and post nutrition CRP and prealbumin were also measured.
Results: In total, 148 patients with NSTI from 1995-2011 were identified. Forty-six patients were tube fed, 13 patients received TPN, and 89 patients received non-artificial nutrition. Mortality in patients receiving TPN was 15.4%, mortality in tube fed patients was 15.2%, and mortality in patients receiving non-artificial nutrition was 3.4%. Using the WHO guidelines for BMI, 29 patients were categorized as obese, 17 overweight, 9 normal, and 3 underweight in the artificially fed population. Within the non-artificially fed population, there were 37 obese patients, 26 overweight, 25 normal, and 1 underweight patient. Mortality in the obese population was the lowest at 0% in the non-artificially fed population. Mortality in the obese population was also the lowest at 10.3% in the artificially fed population. The artificially fed obese population, on average, achieved suboptimal percentages of their goal caloric and protein intake at 63% and 10%, respectively. This compares to 58% and 124% in the overweight group, 76% and 84% in the normal group, and 94% and 85% in the underweight group, of their goal caloric and protein intake, respectively. In all groups, CRP decreased with nutrition. Prealbumin also improved in all groups on discharge, except in the obese population.
Conclusion: Though patients receiving artificial nutrition through tube feeds and TPN experience higher rates of mortality compared to patients receiving non-artificial nutrition, obese patients may fare better than normal weight patients regardless of their nutritional support. In the artificially fed population, obese patients experienced lower mortality rates despite achieving lower percentages of their goal caloric and protein needs.