Screening by pulse CO-oximetry for environmental tobacco smoke exposure in preanesthetic children

Paediatric Anaesthesia, 05/16/2012

Cardwell K et al. – The point–of–care multiple wavelength pulse CO–oximeter does not appear to be a useful preoperative screening tool for environmental tobacco smoke (ETS) exposure in children.


  • Following IRB approval and parental consent, 220 children aged 1–16years having outpatient surgical procedures were enrolled.
  • SpCO was measured preoperatively three times with the Radical-7 Rainbow SET CO-oximeter (Masimo, Irvine, CA, USA).
  • Immediately following induction of anesthesia, a blood sample for laboratory measurement of carboxyhemoglobin (COHb) and serum cotinine was obtained.
  • Regression analysis determined the correlation of SpCO with serum cotinine values.
  • Receiver operator characteristic (ROC) curves analyzed the discriminating ability of SpCO or COHb to predict ETS exposure based on cotinine cutoff values known to be present in children exposed to ETS.
  • Agreement of SpCO and COHb values was assessed using Bland–Altman plots.


  • SpCO did not correlate with cotinine (R2=0.005).
  • Both SpCO and COHb had poor discriminating ability for ETS exposure (area under the ROC curve=0.606 and 0.562, respectively).
  • SpCO values had poor agreement with COHb values.

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