Elevated intraoperative blood carboxyhemoglobin levels in surgical patients--Georgia, Illinois, and North Carolina.

In October 1990, three hospitals, one each in Georgia, Illinois, and North Carolina, reported 26 episodes of elevated blood carboxyhemoglobin (COHb) levels (normal: less than 3% in a nonsmoker, less than 10% in a smoker) during surgery in patients with no known carbon monoxide (CO) exposure. All three hospitals are large, medical-school-affiliated, training institutions. Hospital A (Georgia) reported 15 episodes from January 1987 through September 1989; hospital B (North Carolina), eight episodes from January through October 1990; and hospital C (Illinois), three episodes from January through September 1990. All of the episodes were detected during routine blood gas analyses that included COHb measurements (co-oximetry). In eight episodes, peak COHb levels were greater than 20%. Usually, when an elevated COHb level was detected intraoperatively, 100% oxygen was administered, an alternate gas source was instituted, and COHb levels returned to normal. No deaths or serious complications were reported.