Unexpected Falsely Low Pulse Oximeter Measurements in a Child with Hemoglobin Cheverly

To the Editor:

Hemoglobin Cheverly is rare inheritable variant of unstable hemoglobin resulting from a mutation that determines abnormal structure of one of the globin chains, modifying the amino-acid β chain sequence (¹). We report a case of a boy with hemoglobin Cheverly, in whom the pulse oximeter showed false low measurements.

A 3-yr-old, 17-kg, boy with an unremarkable medical history, presented for repair of a right inguinal hernia. After induction of general anesthesia via facemask, an oxygen saturation (Spo₂) value of 85% was noted. Adequate mask ventilation with Fio₂ = 1 and change of probe site did not change the result (despite a good plethysmographic waveform). Arterial blood gas showed normal oxygenation (arterial oxygen saturation = 100%). The surgical procedure was performed uneventfully. Postoperative Spo₂ values ranged 82%–89%.

Further investigation into the family tree revealed a 5-yr-old brother with a room air Spo₂ value of 76%, a 27-yr-old father with room air Spo₂ of 61%–62% and a paternal grandfather with room air Spo₂ of 80%–82%. Results of hemoglobin electrophoresis showed an abnormal hemoglobin variant, known as hemoglobin Cheverly (Table 1).

Table 1: Hemoglobin Values

In summary, a pulse oximeter is not an accurate monitor for patients with unstable hemoglobin Cheverly and possibly other hemoglobinopathies (^2,3).

Uriel A. Yodfat, MD

Riverside Anesthesia Associates

Harrisburg, PA

Sonia J. Vaida, MD

Visiting International Associate Professor

Department of Anesthesiology

Penn State Milton S. Hershey Medical Center

Hershey, PA

[email protected]

[email protected]