Carbon monoxide poisoning: baseline levels were ~5% in smokers.

Clinical bottom line (level 4)

  1. Non-smokers had <3% carboxyhaemoglobin, normally.
  2. Smokers had <10% carboxyhaemoglobin, normally.
Stewart et al: Journal of the American Medical Association 1974; 229 (9): 1187-1195
Expires July 2003

The study

Outcome study with ?objective ?blinded outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: continental USA, 1969-72

29000 patients (aged ?, ?% male) blood donors



Outcomes studied:
  • HbCO saturation in non-smokers
  • HbCO saturation in smokers

    • blood carboxyhaemoglobin levels were measured (HbCO)

    The evidence

    outcome time to outcome number of patients/total number %
    (90% CI)
    HbCO saturation in non-smokers ? / 1.5%
    (0.8% to 2.7%)
    HbCO saturation in smokers ? / 5.4%
    (1.6% to 9.8%)

    • Taxi drivers were found to have the highest levels of HbCO.

    Citation

    1. Stewart RD, Baretta ED, Platte LR, et al: Carboxyhemoglobin levels in American blood donors. Journal of the American Medical Association 1974; 229 (9): 1187-1195
    Contributor: Chris Ball and Clare Wotton, July 2000
    Reviewer:

    Clinical Question.
    Patient smokers
    Intervention or Exposure prevalence
    Outcome carboxyhaemoglobin