Early antibiotics and debridement independently reduce infection in an open fracture model

Abstract

Most animal studies indicate that early irrigation and debridement reduce infection after an open fracture. Unfortunately, these studies often do not involve antibiotics. Clinical studies indicate that the timing of initial debridement does not affect the rate of infection but these studies are observational and fraught with confounding variables. The purpose of this study was to control these variables using an animal model incorporating systemic antibiotics and surgical treatment. We used a rat femur model with a defect which was contaminated with Staphylococcus aureus and treated with a three-day course of systemic cefazolin (5 mg/kg 12-hourly) and debridement and irrigation, both of which were initiated independently at two, six and 24 hour time points. After 14 days the bone and hardware were harvested for separate microbiological analysis. No animal that received antibiotics and surgery two hours after injury had detectable bacteria. When antibiotics were started at two hours, a delay in surgical treatment from two to six hours significantly increased the development of infection (p = 0.047). However, delaying surgery to 24 hours increase the rate of infection, but not significantly (p = 0.054). The timing of antibiotics had a more significant effect on the proportion of positive samples than earlier surgery. Delaying antibiotics to six or 24 hours had a profoundly detrimental effect on the infection rate regardless of the timing of surgery. These findings are consistent with the concept that bacteria progress from a vulnerable planktonic form to a treatment-resistant biofilm.

An analysis of risk factors associated with traumatic extremity amputation stump wound infection in a Nigerian setting

“…Although the crushing form of amputation was the only independent risk factor identified in this study, the other significantly associated factors especially the ones that are [2,8,13]. The prolonged interval between injury and presentation to hospital is potentially related to a delay in appropriate emergency trauma care (such as antibiotics administration and early wound care) especially in our setting where it has been documented in a previous study that there was no pre-hospital care given to over 80 % of patients with traumatic amputation [12].…”

Perspectives on the prevention and treatment of infection for orthopedic tissue engineering applications

“…Surgical irrigation and debridement can also be attempted. Pre-clinical animal studies show that early irrigation and debridement, especially in concert with antibiotics, may prevent infection, but clinical studies show that the failure rate of this approach is high if the site is already infected [13][14][15][16]. If the infection is persistent, removal or replacement of the implant becomes necessary.…”

From model to molecules: the development and experimental manipulation of anin vivocontaminated extremity war wound

“…This has been demonstrated in a murine fracture model, showing that surgery and antibiotic administration within 2 h of contamination with a challenge dose of 1×10 5 colony-forming units of S aureus resulted in complete eradication of the contaminating organism 15. Subsequent development of our model has demonstrated a similar impact of antibiotic administration on wound contamination, rendering meaningful analysis of treatment interventions by dressings impossible 13.…”