Friday, February 10, 2012

Margin of Error

The thing about the intensive care unit is the margin of error is really small. While medicine is a delicate enterprise and each intervention we make or withhold has implications to someone's health, this is accented in critically ill patients. For example, last year on the medicine wards, I never thought too much about sending someone down to the MRI scanner if that's what they needed. But yesterday in the ICU, I was faced with a situation where we wanted to obtain an MRI on someone who had a tenuous respiratory status. Lying flat for an hour could be an ordeal; he could stop breathing and arrest. We ended up settling for a less ideal but more practical CT angiogram because of the confines set on us by the patient's illness.

Likewise, in the operating room, I manage fluids pretty nonchalantly. Whether someone gets 1.5L or 2L of fluids during surgery generally won't make a big difference in the run-of-the-mill surgery. However, in a patient in heart failure, the extra 500mL of intravenous fluids could be the difference between breathing on one's own and needing a ventilator; on the other hand, in sepsis, withholding that 500mL of fluid can lead to low blood pressures, higher vasopressor requirements, and kidney injury. The problem is that on my last call, I admitted a patient with both heart failure and sepsis. My margin of error is so small. How do I walk that fine line between not enough and too much? Sometimes, that space doesn't even exist.

No comments: