I recently took care of an eighty year old man who lived at home and was admitted with pneumonia. He arrived in septic shock with acute renal failure and required mechanical ventilation, aggressive fluid resuscitation, medications to support his blood pressure, and emergency dialysis. This isn't all that unusual. What was unusual was the organism which caused his pneumonia: methicillin-resistant Staphylococcus aureus (MRSA).
MRSA is a aggressive bacteria which is resistant to most of the antibiotics that are first-line therapies for pneumonia. Hospitals are breeding grounds for resistant bacteria like MRSA, so it's much more common for people to develop MRSA pneumonia after they've been in the hospital, especially if they're on a ventilator. MRSA is not the usual organism that doctors think of when people come to the hospital from home. But this is clearly changing. In a recent study in the New England Journal, between 8% - 20% of all MRSA infections were acquired in the community.
The standard of care has evolved. Any life-threatening infection that could be caused by Staphylococcus aureus -- even if the patient is not hospitalized -- should be initially treated with vancomycin or another antibiotic that covers MRSA. This is one of those situations where you can't afford to be wrong.
Surprisingly, the patient did well. After MRSA was identified, he was treated with a prolonged course of Zyvox (linezolid), which has more activity against MRSA than vancomycin. He stayed in the hospital for two months and eventually came off dialysis, was weaned from the ventilator, and went home.
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