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Updated: Aug 15, 2026

Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
Published on: January 29, 2011
Remember 'a posteriori diagnosis' of carbon monoxide poisoning
Andreas Perren1, Claudio Marone
1Intensive Care Unit, Ospedale Regionale Bellinzona e Valli, Bellinzona, Switzerland. andreas.perren@eoc.ch
Objectives:
To raise awareness of the possibility of carbon monoxide poisoning as a diagnosis in the emergency department and to present the little known fact that it is possible to diagnose carbon monoxide poisoning retrospectively.
Method:
Presentation of a case report, review of the literature.
Results:
Persistence of elevated carboxyhaemoglobin levels in a stored vacutainer blood sample.
Conclusion:
Carbon monoxide poisoning is common but often goes unrecognized. This method may help to decrease the number of overlooked cases and thereby possibly prevent further exposure and acute or chronic sequelae.
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