NEW YORK (Reuters Health) – Compared with standard blood gas analysis, the Masimo Radical 7 multiwave pulse oximeter measures carboxyhemoglobin noninvasively with acceptable accuracy and can be used to screen emergency department patients for occult carbon monoxide poisoning, an Austrian team has shown.
Dr. Harald Herkner and colleagues at the Medical University of Vienna note in the Annals of Emergency Medicine online April 4 that the timely diagnosis of CO poisoning is difficult because symptoms are nonspecific. To assess the value of noninvasive COHb oximetry in this setting, the team conducted a diagnostic accuracy study within a tertiary care hospital emergency department.
All triage nurses were trained in the use of the Masimo Radical 7 CO oximeter. Over a 1-year period, 1578 patients had CO saturation (SpCO) levels measured by the device and COHb measured by blood gas analysis, with the interval between the two reading no longer than 60 minutes.
A final diagnosis of CO poisoning was made in 17 of the patients. The mean difference between SpCO and COHb was 2.32%, according to the report.
On further analysis, the multiwave oximeter SpCO readings were seen to be consistently biased 2.99% higher than the blood gas COHb measurement. The bias was most pronounced in non-smokers, the team found.
The authors say that