Early outcome of culture-negative infection in open fractures of the lower limb: A prospective study.

Background: Culture-negative infections in open long bone fractures are frequently encountered in clinical practice. We aimed to identify the rate and outcome of culture-negative infections in open long bone fractures of lower limb. Methodology: A prospective cohort study was conducted from November 2015 to May 2017 on Gustilo and Anderson Grade III open long bone fractures of the lower limb. Demographic data, injury details, time from injury to receiving antibiotics and index surgical procedure were noted. Length of hospital stay, number of additional surgeries and occurrence of complications were also noted. Patients with infected open fractures were grouped as culture positive or culture negative depending on the isolation of infecting microorganisms in deep intraoperative specimen. The clinical outcome of these two groups was statistically analysed. Results: A total of 231 patients with 275 open fractures involving the femur, tibia or fibula were studied. There was clinical signs of infection in 84 patients (36.4%) with 99 fractures (36%). Forty-three patients (51.2%) had positive cultures and remaining 41 patients had negative cultures (48.8%). The rate of culture-negative infection in open type III long bone fractures in our study was 17.7%. There was no statistical difference in the clinical outcome between culture-negative and culture-positive infections. Conclusion: Failure to identify an infective microorganism in the presence of clinical signs of infection is routinely seen in open fractures and needs to be treated aggressively.

Ustilago echinata: Infection in a Mixed Martial Artist Following an Open Fracture.

Ustilago, a common fungal parasite of grains, is infrequently isolated as a pathogen in humans. We describe a case of Ustilago echinata infection following an open distal tibia fracture, review the current literature of this genus as a cause of invasive fungal infection in humans, and discuss management issues.

Bacterial contamination of open fractures - pathogens, antibiotic resistances and therapeutic regimes in four hospitals of the trauma network Cologne, Germany.

INTRODUCTION: The bacterial contamination of soft tissues and bone in open fractures leads to an infection rate of up to 50%. Pathogens and their resistance against therapeutic agents change with time and vary in different regions. In this work, our aims were to characterize the bacterial spectrum present in open fractures, analyze the bacterial resistance to antibiotic agents and question the EAST guideline recommendations for antibiotic prophylaxis after open fractures in a German Trauma Network. MATERIALS AND METHODS: We conducted a retrospective cohort study and included all patients with open fractures from 1(st) of January 2011 until the 31(st) of December 2014 in four hospitals of the trauma network cologne. Soft tissue damage was classified according to the Gustilo Anderson classification. RESULTS: We included 123 patients. Forty-five injuries (37%) were classified I°, 45 (37%) as II° and 33 (27%) as III°. Lower leg (34%) was the most commonly injured location. An antibiotic prophylaxis was administered to 109 patients (89%). In 107 of them (98%) a cephalosporin or cephalosporin combination was given. In 35 of the patients (28%), microbiological samples were taken of the fracture site. Wound cultures were positive in 21 patients (60%). Fifty percent of the bacterial detections occurred in III° fractures. Coagulase negative Staphylococci (COST) were the most frequent pathogens. In II° open fractures one gram-negative strain was isolated. Fewest resistances were seen against quinolones and co-trimoxazole. DISCUSSION: The recommended EAST guideline prophylaxis would have covered all but one bacterium (97% of positive cultures). One Escherichia coli was found in a II° open fracture and would have been missed. One of the isolated Staphylococci epidermidis and an Enterococcus faecium were resistant against gentamycin and first- and second-generation-cephalosporin's which were used as prophylaxis frequently. However, a regional adaption of the EAST guidelines seems not justified due to the rather low number of cases in our study. CONCLUSION: The EAST guideline seems to be adequate in a high percentage of cases (97%) in the setting of the trauma network cologne. Further research should be guided at identification of initial open fracture pathogens to improve the efficiency of antibiotic prophylaxis.

Pharmacokinetics of cefuroxime in traumatic wound secretion and antibacterial activity under vacuum therapy.

The objective of this study was to investigate the pharmacokinetics of cefuroxime in wound secretion and the antibacterial activity of the traumatic wound secretion in patients receiving cefuroxime and in those not receiving antibiotics. Included in the present controlled, prospective, non-randomized study were 12 patients with an open fracture who needed vacuum therapy (group A) and 12 patients with a closed fracture, who, due to soft tissue damage, also underwent treatment with vacuum therapy (group B). Wound secretion was obtained on the first, third and fifth postoperative days and exposed to the test bacteria, Staphylococcus aureus and Staphylococcus epidermidis. Patients in group A underwent systemic antibiotic treatment with cefuroxime administered intravenously at a dose of 1.5 g every 8 hours. Patients in group B did not receive antibiotics. Cefuroxime concentrations were determined using high-performance liquid chromatography (HPLC). Antibacterial activity was determined using the inhibition test. Maximum cefuroxime concentrations in wound secretion were measured at 4-5 hours following intravenous administration and, with a mean concentration of 10 mg/l, remained consistently above the minimum inhibitory concentration (MIC) for the test bacteria at all points during the measurement period. As expected, the antibacterial activity of the wound secretion in patients in group A (cefuroxime) was higher than that in group B (no antibiotics). In group A, antibacterial activity against S. aureus was 94.6% and 100% against S. epidermidis. In group B, antibacterial activity against S. aureus was 61% and 81% against S. epidermidis. Cefuroxime reaches the highest level in wound secretion after 4 hours. The high antibacterial activity of the wound secretion in traumatic closed fractures is elevated by cefuroxime. in addition, our findings show that vacuum therapy of wounds is suitable as a non-invasive method for studying the pharmacokinetics of antibiotics.

Use of antimicrobials in the management of open fractures.

The role of antibiotic therapy in open fractures is secondary to adequate debridement, irrigation, and definitive wound care. Experimental and clinical studies indicate that parenteral administration of appropriate antibiotics within three hours after injury helps to prevent wound sepsis. Intial wound cultures of 158 open fracture wounds revealed bacterial growth in 70.3%. Eighty-six were Gram-positive, 57 were Gram-negative, and 32 yielded mixed bacterial growth. Sensitivity studies of these organisms suggest that cephalothin sodium is the most effective antibiotic for prophylaxis. In a prospective study from 1969 to 1975, treatment of 520 patients was as follows: debridement, copious irrigation, and primary closure for types 1 and 2 fractures and secondary closure for type 3 fractures. No primary internal fixation was done except in vascular injuries. Cultures were taken of all wounds and antibiotics were given before surgery and for three days postoperatively. In type 3 open fractures, severe soft tissue injury, and segmental or traumatic amputation, the infection rate was 9%, compared to a 44% infection rate in the retrospective study from 1955 to 1968.