Thursday, June 7, 2012

Clear, Colorless, Odorless

A patient is found with a suicide note in a car and brought in by ambulance. He complains of headache, malaise, nausea, and dizziness. He is too altered to give much more history. His skin looks a little red. Vital signs are: HR 70, BP 110/60, RR 16, O2 saturation 99% on room air, temperature 37. Cardiac biomarkers (CKMB and troponin) are elevated. A CT of the head, taken 16 hours later, is shown above. Weeks later, the patient still has some cognitive deficits, personality changes, and neurologic defects.

Challenge: What diagnostic test should the emergency department order?

Image shown under Fair Use.


Sarah said...

carbon monoxide poisoning, and the test is a carboxyhemoglobin level

Reflex Hammer said...

They need to test carboxyhemoglobin, because carbon monoxide poisoning can have normal O2 sat on pulse oximetry?

Craig Chen said...

yes! nice job! i'm not sure i've ever seen this, but i've definitely been tested on it
Clear, Colorless, Odorless

Carbon monoxide poisoning is diagnosed by cooximetry of a blood gas sample; standard pulse oximetry does not distinguish between carboxyhemoglobin and oxyhemoglobin.

Sources: UpToDate;