American journal of hematology
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Unexpectedly low hemoglobin oxygen saturation as determined by pulse-oximeter analysis was observed in a patient who underwent an elective surgical procedure. Specific hemoglobin derivatives such as carboxyhemoglobin, methemoglobin, and reduced hemoglobin that have been described to lower pulse-oximetry determination of oxygenation were not detected. Absorbance spectra revealed the patient's hemoglobin to be different than that obtained from two normal volunteers. ⋯ Hemoglobin Hammersmith and another unstable hemoglobin, hemoglobin Köln, have previously been described to have unexpectedly low pulse-oximeter-determined oxyhemoglobin levels. That we find hemoglobin Cheverly to result in a similar phenomenon suggests that pulse-oximeter monitoring of oxygenation status may not be appropriate for the unstable hemoglobins. Low pulse-oximeter oxygenation determinations for these hemoglobins do not appear to predict clinical hypoxemia.