Antibiotics Overused for Osteomyelitis in Sacral Pressure Ulcers

Doctors are overusing antibiotic therapy for suspected osteomyelitis in patients with sacral pressure ulcers, according to a new review of existing literature.

Absent wound coverage, antibiotics are ineffective, the review found. Even in cases where osteomyelitis is confirmed, and wound coverage is feasible, researchers found lengthy antibiotic therapy isn’t necessary—in many cases 2 weeks of antibiotics are effective.

Corresponding author Brad Spellberg, MD, of the Keck School of Medicine at the University of Southern California, said the review helps answer what has been a persistent question.

“This topic about how to treat exposed bone below sacral pressure ulcers comes up all the time, and as [infectious disease] doctors we are frustrated by the profligate use of antibiotics in this setting with no clear rationale or plan,” he told Contagion ^®. “We have long questioned the utility of such therapy.”

Dr Spellberg said the study contradicts the notion that it’s best to err on the side of prescribing antibiotics.

“Doctors have this belief that antibiotics are a panacea for all ailments, and they are not,” he said.

Dr Spellberg and colleagues also found that many patients with chronically exposed bone show no evidence of osteomyelitis when biopsied, and MRI can be unreliable as a diagnostic tool for osteomyelitis, often failing to distinguish between osteomyelitis and bone remodeling.

The review was based on 20 existing studies, all of which were either retrospective analyses or case series. None of the studies was a randomized controlled study.

The authors write that the lack of reliable diagnostic methods, short of bone biopsy, combined with the lack of evidence to support non-surgical interventions, can be frustrating for physicians. However, they noted that there are other ways physicians can go about combating osteomyelitis, such as looking at the psychosocial factors that often underlie the condition.

“Achieving complete healing is unlikely absent mitigation of these underlying drivers no matter what other medical or surgical interventions are applied,” Dr Spellberg and colleagues wrote.

In light of those psychosocial factors, the question of antibiotics is “peripheral”—of lesser importance than addressing the root issues at play in the patient’s case.

The authors noted several additional conclusions. First, clinicians shouldn’t assume osteomyelitis is present unless they have done a bone biopsy with debridement. Even if osteomyelitis is found, antibiotics won’t be effective in the long-term unless wound coverage is achieved.

In the majority of cases, those where the osteomyelitis is restricted to the superficial bony cortex, 2 weeks of antibiotics should be sufficient. If a medullary bone is affected, antibiotics should be given for 4 to 6 weeks. There’s no evidence to support a round of antibiotics beyond 6 weeks, they write.

Dr Spellberg told Contagion^® that this isn’t just an issue of using antibiotics in a way that isn’t actually helpful. He stressed that antibiotic overuse is actually harmful and can be dangerous.

“The fact that we found no evidence of a role for antibiotics unless there is a plan to cover the wound, that the majority of cases of exposed bone do not contain infection when biopsied, and that there is no advantage of prolonged or IV antibiotics over shorter and oral antibiotics, all fits in with the overall theme that doctors abuse antibiotics without knowing why,” he said.