This a recent email to my chief of service from a recent graduate of the Emergency Medicine program with which I am loosely affiliated. She works in another state now. I'm copying her email intact because I like the voice.
x2: 'times two', i.e, twice.
N/V: nausea and vomiting
s/p: 'status post', i.e., it happened in the past
syncope: passing out
aaox3: awake, alert, and oriented to person, place, and time. A rough measure of cognitive status.
tachy: tachycardic, fast heart rate
CO: carbon monoxide
carboxy-hgb: carboxyhemoglobin, the amount of hemoglobin bound to CO, usually expressed as a percent of total hemoglobin. Normal is close to zero. Smokers in urban areas may have 'normal' values of up to 10%.
And now, the email:
around 4:30am an ambulance brought a 33yo F from home with N/V who was found s/p syncope lying in her own feces on floor. When I talked to her, she was a bit slow, but aaox3, responding appropriately and giving a complete history, tachy at upper 90's to low 100's, o/w normal vitals. has hx of ha and has been having 1-2/wk x2mos. no other illness lately and felt fine when went to bed at 11pm, got up to take care of cat who was ill w/vomiting, and then felt ill herself, vomiting x2 and head pounding. Cat's been ill a cpl months and taken to vet x2 and can't find anything wrong with it. So, I say, how's your heating system? ... The moment she mentioned her cat being ill, I just heard a voice saying, "remember, HA, N/V in the winter is CO poisoning, esp if other occupants of the home are ill (in this case, the cat)... check for it!" Turns out she doesn't use her central heat 'cause the bookcase is in front of the radiator (studio, cramped for space) so uses the stove at night to keep the place warm; has a gas water heater in the apt space as well. Had a carboxy-hgb back within 30mins of seeing her: CO-Hg = 29.2%, venous O2 52% - can't recall which one of you said this to me, maybe both, but I give you guys cudos, it saved this girl...Headache is a common sign of carbon monoxide poisoning. However, headache is also very common in general, with a bewildering array of causes, a few life-threatening, most not. Do we have to draw a carboxyhemoglobin level on everyone who comes to the ER with a headache?
thanks for all the good training!
As the writer says, one screening question is: "Does anyone else who lives in the same house with you also have a headache?" If the answer is no, then CO poisoning is unlikely, because everyone in the same living space will have been exposed to the same atmosphere. What's cool about this young physician's experience is that it occurred to her to expand this concept to include non-human occupants of the patient's living space. "In this case, the cat." Excellent!
I've mentioned CO poisoning here a couple of times before. Why is it of special interest? 1) it's neither rare nor common: it comes up just often enough to worry about, without becoming routine; 2) it kills otherwise perfectly healthy people, and can knock off an entire family without warning, which shocks us; 3) it's a moderately difficult diagnosis, with no unique symptoms in its early, treatable stages, and if the physician doesn't consider it, it may easily be missed and disaster result.
Do you have a CO detector? If not, you should.