Surprising findings presented at ATS 2011, summarized in this Medscape report, suggest that many hospitalized patients who die of pneumonia do not follow the expected trajectory of hypoxia and organ failure. Rather, they die suddenly on the general wards of arrhythmia not preceded by hemodynamic deterioration. From the report:
"Our study found a compelling signal that a significant portion of pneumonia patients who suffer a cardiac arrest in the hospital do so abruptly," he said. "We found that 56% of cases of cardiac arrest among these patients were not caused or preceded by hypotension, and almost 40% happened outside of the ICU...”
"This does raise the possibility that we are not triaging patients appropriately at the time of admission. It also raises the possibility that there is a confounding issue or set of issues. For example, is there a significant rate of previously undetected heart disease in this group? Is this the result of certain antibiotics causing heart rhythm issues? Were low oxygen levels not treated aggressively enough on a general medical unit? Hopefully, this large dataset will allow for future retrospective analyses of these issues," Dr. Fenster said.
The fact that arrhythmia was the leading cause of cardiac arrest among the patients is also notable, he said.
"If arrhythmia is indeed the most common cause of arrest, perhaps there is a role for more aggressive oxygen supplementation, electrolyte repletion, and avoidance of proarrhythmic drugs in an at-risk population."
Hypokalemia and hypomagnesemia are common in hospitalized patients. I have to wonder if these conditions combined with hypoxemia and the use of fluoroquinolone antibiotics which prolong the QT interval might predispose patients to arrhythmias.