Wednesday, May 14, 2008

Antibiotic TX for Seawater Injuries

I wanted to share this article (reference below) as many of us may either see these patients as tourists or after they return from vacation. It is nice to have a logical choice for empiric antibiotic therapy. (photo credit)

The proposal of the article was "that the analysis of seawater pathogens will act as a guide for rational empiric antibiotic therapy, either as prophylaxis at the time of penetrating injury or as early treatment of a developing infection." To do this, 50 ml samples of seawater were collected from 25 preselected locations along a 12-km segment of the southern portion of the Galveston beach area in Texas. These water samples were taken over four seasons, the fall and winter of 2002 and the spring and summer of 2003.

"Despite variations in water temperature and beachgoer population size, the seasonal variations of bacterial species were minimal. Throughout all four studies, the most effective antibiotics against most Gram-positive microorganisms were penicillin, ampicillin, vancomycin, and levofloxacin, whereas the most effective antibiotics against all Gram-negative microorganisms were levofloxacin, lomefloxacin, and cefepime. Because all four studies contained similar trends in both Gram-positive and Gram-negative microorganisms, these authors believe that it is necessary to prescribe initial antibiotics that provide dual coverage of Gram-positive and Gram-negative organisms to patients with seawater-contaminated wounds, regardless of the season. Although the majority of organisms analyzed showed some sensitivity to levofloxacin, this drug has somewhat limited Gram-positive coverage that the addition of penicillin will address more appropriately. Thus, prescribing a combination of penicillin or ampicillin with levofloxacin to patients with seawater-contaminated penetrating wounds at any time throughout the fall, winter, spring, or summer should provide the necessary coverage to promote proper wound healing and functional recovery of the injured site. As is usually practiced, antibiotic therapy should be administered for a period of 5 to 7 days, with further changes being made based on the treating physician's clinical judgment. Using this regimen will also cover the dangerous Vibrio species and aid in preventing the morbidity and mortality associated with such infections."

The decision to treat any wound with antibiotic therapy should be based on clinical judgment. Abrasions and superficial injuries may only require debridement and copious irrigation. Lacerations and penetrating wounds that have a clearly visible base and no signs of infection in the wound or surrounding tissues may be irrigated and closed primarily using clinical judgment. However, seawater-contaminated wounds that are penetrating deeper than the dermis and associated with erythema and/or edema in the surrounding tissue will most likely benefit from dual-coverage prophylactic antibiotic therapy pending culture results.

REFERENCES

Empiric Antibiotic Therapy for Seawater Injuries: A Four-Seasonal Analysis; Plastic & Reconstructive Surgery. 121(4):1249-1255, April 2008; Jennifer S. Kargel, B.S.; Vanessa M. Dimas, B.S.; Dennis S. Kao, M.D.; John P. Heggers, Ph.D.; Peter Chang, M.D., D.M.D.; Linda G. Phillips, M.D.

1 comment:

Midwife with a Knife said...

Hm... it occurs to me that there aren't many pathogens (maybe a few anaerobes and MRSA) that ampicillin + quinolone won't cover.