3-2 table 1.jpg
3-3 figure 1.jpg
3-3 figure 2.jpg

Early Bacterial Cultures from Open Fractures - Differences Before and After Debridement

Fred Chuma Sitati1, Philip Ogutu Mosi2, Joseph Cege Mwangi1

  1. School of Medicine, University of Nairobi, Kenya

  2. Voi County Hospital, Kenya

Correspondence to: Dr. Fred Sitati, P.O Box 895-00200 Nairobi, Kenya. Email: fredsitati@yahoo.com

Abstract

Background: The pattern of organisms found in open fractures is important in the selection of antibiotics for prophylaxis and empirical treatment. So far, there is paucity of data on local patterns of bacteria contaminating and infecting open fractures and their antibiotic susceptibility profile. Objective: To describe the pattern and antibiotic susceptibility of bacterial isolates obtained within 24 hours of injury from open fractures and to compare these to bacterial isolates from fractures that subsequently develop infection. Methods:A prospective study of 98 patients with open fractures seen at Kenyatta National Hospital (KNH) within 24 hours of injury between November 2015 and March 2016 was conducted. Swabs for culture and sensitivity were taken from the wounds and antibiotics initiated.Surgical debridement was subsequently carried out witha 14 day follow up for wound infection. Wounds thatbecame infected were sampled for cultures And sensitivity. Results: Fifty-one (52.2%) pre debridement wound samples had positive cultures. Staphylococcus aureus and (Coagulase Negative) CON Staphylococci were the predominant gram positive isolates. At 14 days’ follow-up, the infection rate was58.9 %. The predominant gram positive isolate was Staphylococcus aureus. Only 5.7% of the pre-debridement isolates were similar to the post debridement isolates. Conclusions: The contaminating organisms are not similar to the organisms isolated from injuries that later develop infection.

 

Key words: Open fracture, Antibiotics, Infection, Bacterial cultures.

Ann Afr Surg. 2017; 14(2):66-70 DOI:http://dx.doi.org/10.4314/aas.v14i2.3

© 2017 Author. This work is licensed under the Creative Commons Attribution 4.0 International License.

Introduction

Up to 70% of open fractures are contaminated at the time of injury mostly by organisms from the skin and the environment (1). Contamination may also occur in the course of treatment. A few studies suggest that organisms isolated from wounds pre-debridement are similar to those isolated from wounds that get infected (2, 3). On the contrary, others find no association and indicate that infections are largely from nosocomial organisms (4, 5). These bacterial patterns are important in developing antibiotic protocols for prophylaxis and empirical treatment. Local studies on these patterns are lacking. The aim of this study was to describe the pattern of pre-debridement bacterial cultures and antibiotic susceptibility from open fractures within24 hours of injury at Kenyatta National Hospital (KNH).

Methods

This was a prospective longitudinal study conducted over a 5-month period between November2015 and March 2016. Convenience sampling of patients above 18 years presenting within 24 hours of injury at the outpatient and accident and emergency (A&E) departments of KNH with open limb fractures was carried outdone. KNH is Kenya’s national tertiary, teaching and referral hospital with a 2000 bed capacity. We excluded patients who presented more than 24 hours after injury, had antiseptic wound dressing, had received antibiotics, presented with contamination from the gastrointestinal or genitourinary injuries or were known to have diabetes, peripheral vascular disease or immunosuppression. Informed consent was obtained from all participants and confidentiality upheld. A sample was collected from the wound as per Levine’s technique (6).We collected samples from Accident and Emergency (A&E) within 24 hours as per protocol and not debridement samples in theatre because most cases arrived in theatre two to three days after injury. The collected sample was transported to the laboratory in Amies or Stuart transport media. Wounds were covered by sterile gauze pending debridement. Participants had antibiotic prophylaxis initiated at the A&E as per the British Orthopedic Association/British Association of Plastic, Reconstructive and Aesthetic Surgeons (BOA/BAPRAS) protocol (7). This is the usual protocol at KNH. Cefuroxime 1.5 grams was administered parentally in the outpatient department and continued 8 hourly until first debridement. During the initial debridement, cefuroxime 1.5 g and gentamicin (1.5 mg/kg) was administered and continued 8 hourly until soft tissue closure or for a maximum of 72 hours, whichever occurred ea