In a field scenario with a contaminated open fracture, which principle best guides initial antibiotic coverage?

• A. Broad-spectrum coverage initially
• B. Narrow-spectrum coverage tailored to suspected organisms
• C. No antibiotics until definitive debridement
• D. Prophylactic coverage limited to previous infection risk

Answer: (A)

When a field-open fracture is contaminated, you don’t know the exact organisms you’re dealing with, and the wound is at high risk for polymicrobial infection from skin flora, soil, and environmental contaminants. Starting broad-spectrum antibiotics right away ensures coverage of a wide range of likely pathogens, including gram-positive organisms (like Staphylococcus), gram-negative rods, and anaerobes, which is crucial in preventing deep infection and osteomyelitis while definitive surgical management proceeds. This empiric approach buys time until debridement and cultures can guide narrowing of therapy to the specific organisms found. Delaying antibiotics or sticking to a narrow or limited prophylaxis in this scenario would leave gaps in coverage and increase infection risk.