Background: In Spain, as in most of the world, the incidence of acute carbo
n monoxide poisoning is probably underestimated. Methods: During an eightee
n-month period we studied, by means of a standardized data collection form,
all the cases of acute carbon monoxide poisoning that were diagnosed in 2
university hospitals. Results: During the study, 154 patients were diagnose
d with carbon monoxide poisoning. The mean age was 32.2 +/- 15.5 years. The
two principal exposure sites Mere the kitchen (43%) and bathroom (23%). Th
e majority of the cases related to malfunction of the water heater (30%) an
d of the central heating (23%) and 68% occurred in the home. Improper combu
stion of butane (31%), propane (13%), and natural gas (12%) were most frequ
ent. The most prevalent clinical manifestations were headache (94%), dizzin
ess (56%), nausea (45%), loss of consciousness (38%), and weakness (34%). F
ive patients died In 14.4%, symptoms suggested delayed neurological syndrom
e. The largest number of cases of poisoning occurred during the months of D
ecember and January. Conclusions: Compared with previous Spanish series ol
with the antecedent year, acute carbon monoxide poisoning has a high preval
ence in our region. Two factors appear to be essential to the accurate diag
nosis of acute carbon monoxide poisoning: 1) the ability of emergency room
physicians to recognize the clinical symptoms of carbon monoxide poisoning
and 2) access to a carbon monoxide-oximeter.