Antibiotics and the Calculus of Risk

In medicine, as in life, nothing is guaranteed

My patient’s admission to the hospital was elective, certainly nothing emergent. Yet within days he was transferred to the Intensive Care Unit.

How did we get here?

I met Mr. B early in my first year of fellowship. He was recovering from a crushed ankle, which had been repaired with screws. The consult was to become a fairly typical introduction to a long-term relationship: a patient with a joint replacement or fracture repair that had become infected.

Treatment offers two options: Remove the hardware, treat the infection with antibiotics and eventually replace the implants; or leave the hardware in place, “wash out” the infected area in the operating room, and expect the patient to remain on antibiotics for months, or perhaps for life. Hardware can make clearing infection nearly impossible, so the first option is preferred. But when the hardware is hard to reach or necessary for stability, removal may be impossible.

These foreign bodies become magnets for bacteria, which can quickly form a biofilm that resists eradication. After a period of initial intense IV antibiotics, patients transition to oral antibiotics to suppress the recurrence of infection. But antibiotics are often poorly tolerated. A recent study found that, each year, close to 150,000 emergency room visits are prompted by adverse reactions to antibiotics.

Mr. B had developed an infection with multiple bacteria. At first, the hardware stabilizing his ankle had to stay in place, and we treated him with IV antibiotics. Within days he developed a full body rash, and his skin blistered and peeled. His reaction to the antibiotic was one of the worst that I’ve seen, though unlike some he did not end up in the burn ICU.

Switched to a powerful oral antibiotic, Mr. B tolerated it well. After six weeks, we switched him to another, to be taken for at least a year. During that year he was diagnosed with an unrelated progressive lung disease. His ankle remained stable. By year’s end we were discussing the comparative risks of continuing antibiotics and of stopping them. He decided to stop.

Within a week or so, swelling and pain developed in Mr. B’s ankle. In clinic, he wore a look of resignation. He was now on home oxygen and in a wheelchair, his lung condition accelerating.

A small part of his incision had opened and started to drain. Sitting with his wife and daughter, he asked what I thought was happening. When I said that I feared the infection had invaded bone, he did not seem surprised. X-rays showed that several screws holding his ankle together had broken; the bone was not healing. Together, his surgeons and we decided to admit him to remove the hardware.

But Mr. B was found to be in heart failure, and the OR was out of the question. The specter loomed of a potential superimposed pneumonia. Admitted to the ICU, he agreed to a short time on the ventilator if the team felt it might pull him through, but he preferred home to prolonged ventilation. The resident talked him and his family through these tough choices, introducing the concept of hospice.

Then Mr. B pressed me: Which antibiotics should he take for his ankle? He still had some pills at home (as ever, the practical type). I wanted to apologize. How did we go from swelling and pain to near death in a week? Could I—could anybody—have predicted this?

The truth is that nothing in medicine is risk-free. In some cases, the risk/benefit ratio is clear—without antibiotics, the patient will die from sepsis or lose a limb. In other cases, this ratio is uncertain. Could I tell Mr. B for sure that if he stopped the antibiotic, the infection would come back? I could not.

The infection might in fact return despite the antibiotic; moreover, he could have liver or kidney toxicity. And then there was the risk of C. difficile colitis, a serious, sometimes fatal complication of antibiotic use. I provide such warnings to my patients not for medico-legal reasons, but because I have seen these complications, and more, occur. Each time, I reflect on whether the risk was worth it.

Mr. B is now close to leaving the hospital. A couple more days of antibiotics will determine whether treating what may be pneumonia leaves him well enough to be among those he loves—and to spend his last days with them at home.

Erica Seiguer Shenoy, MD–PhD ’07, is a fellow in infectious disease at Massachusetts General Hospital and Brigham and Women’s Hospital.

The opinions expressed are not necessarily those of Harvard Medical School, its affiliated institutions or Harvard University.