Shorter Versus Extended Course of Antibiotic Therapy for Necrotizing Soft Tissue Infections

Necrotizing soft tissue infection (NSTI) is a devastating disease that results in a high rate of in-hospital complications and despite advances in critical care, wound care, and early intervention, NSTI continues to be associated with a mortality rate of nearly 30%. The antibiotics used in this treatment are Clindamycin, Vancomycin, Piperacillin Tazobactam; these antibiotics may be administered combined or individually, based on individualized patient treatment. Although one of the tenets of management for NSTI is early broad-spectrum intravenous antibiotics (listed above), the duration of antibiotics needed is not well defined. Currently, there exists wide variation in the duration of antibiotics for NSTI ranging between 2-16 days. The objective of this study is to evaluate the safety of a shorter course of antibiotics hypothesizing that a short duration of antibiotics for 48-hours after source-control is achieved will have similar risk of morbidity and mortality compared to a 7-day course of antibiotics post source control. A second aim of this study will be to identify if serum procalcitonin levels/ratio correspond to resolution of systemic infection in patients with NSTI.

The objective of this study is to evaluate the safety of a shorter course of antibiotics hypothesizing that a short duration of antibiotics for 48-hours after source-control is achieved will have similar risk of morbidity and mortality compared to a 7-day course of antibiotics post source control. The proposed shortened duration is considered within standard of care as the IDSA suggests 48-72 hours of antibiotics after source control, however this was due mostly to expert opinion until a recent single-center study using historical controls demonstrated a 48-hour duration of antibiotics to be safe. A second aim of this study will be to identify if serum procalcitonin levels/ratio correspond to resolution of systemic infection in patients with NSTI. This pilot study may help limit use of antibiotics which are associated with both cost and significant adverse events including antimicrobial resistance and clostridium difficile infections. In addition, the data would support grant submission of a larger, multi-center study with sufficient power to demonstrate the safety profile and potential benefits of a shorter duration of antibiotics, which has been shown to be beneficial in previous large surgical infection studies.

Specific Aims:

Aim#1: Establish the safety of an abbreviated course (48 hours after source control) compared to a prolonged (7 days after source control) course of antibiotics in terms of in-hospital mortality.

Aim#2: Compare the incidence of hospital length of stay and in-hospital complications including unplanned return to the operating room, ventilator days, and antibiotic associated complications (e.g., clostridium difficile infection) in the two comparison groups: abbreviated (48-hours) and prolonged antibiotics (7-days) after source control.

Aim#3: Identify a critical threshold of biochemical procalcitonin or a % decrease in procalcitonin from the initial procalcitonin obtained upon admission that suggests resolution of systemic infection in patients with NSTI. This will be done by obtaining a serum procalcitonin upon admission and daily for up to 7 days from admission or once source control has been achieved.