What Researchers Did
Researchers conducted a retrospective chart review of 124 patients with carbon monoxide poisoning to compare pulse oximetry readings with actual oxyhemoglobin saturation determined by arterial blood gas measurements.
What They Found
Measured oxyhemoglobin saturation averaged 88.7% and decreased linearly with rising carboxyhemoglobin levels, which averaged 10.7%. In contrast, pulse oximetry saturation remained elevated at 99.2% and failed to detect the actual decrease in oxyhemoglobin saturation, with a pulse oximetry gap of 10.5% approximating the carboxyhemoglobin level.
What This Means for Canadian Patients
Canadian patients suspected of carbon monoxide poisoning should be aware that standard pulse oximetry may provide misleadingly high oxygen saturation readings. Clinicians should not rely solely on pulse oximetry for accurate oxygen status assessment in these cases.
Canadian Relevance
There is no direct Canadian connection mentioned in this study.
Study Limitations
A limitation of this study is its retrospective design, which relies on existing chart data and may be subject to selection bias.