Changes in pulse oximetry after patent blue dye injection into the uterine cervix

To evaluate changes in pulse oximetry readings in patients with cervical carcinoma after the injection of patent blue dye into the uterine cervix for sentinel lymph node detection.

Fifty-six patients underwent radical hysterectomy and bilateral pelvic lymphadenectomy for the treatment of International Federation of Gynecology and Obstetrics stage I or II cervical cancer. Four milliliters of patent blue dye were injected into the cervix. On the eve of surgery, all patients also received an injection of Dextran 500 labeled with technetium 99 m (Tc-99 m Dextran, 600 to 800 muCi) into the cervix and subsequently underwent pelvic lymphoscintigraphy.

Of the 56 patients, 1 (1.79%) had an anaphylactic reaction, and in 13 (23.22%), pulse oximetry readings were <96%. The lowest median pulse oximetry reading in these patients was 87%. Pulse oximetry readings began to decrease between 2 and 10 minutes after patent blue dye injection into the cervix and lasted for approximately 5 minutes. No changes in blood pressure, heart rate, or electrocardiogram were found during the period in which this alteration was recorded by the pulse oximeter.

The decrease in pulse oximetry readings after patent blue dye injection into the cervix was associated with larger tumors and tumors that surrounded the external cervical os.