Isosulfan blue affects pulse oximetry

Certain vital dyes are known to cause pulse oximetry (Spo2) desaturation. The authors studied the effect of isosulfan blue (IB) on Spo2.

Thirty-three women, aged 34-81 yr, who were undergoing surgery for breast cancer were studied. IB, 5 ml (50 mg), was injected intraparenchymally around the tumor area by the surgeon. A pulse oximeter was used to continuously record Spo2 values up to 130 min after IB injection. Friedman repeated-measures analysis of ranks was used to analyze the baseline Spo2 and values at 5, 10, 20, 30, 40, 50, and 60 min.

Spo2 values were significantly different from baseline values at 5, 10, 20, 30, 40, 50, and 60 min (P < 0.05). In a typical patient, a maximum Spo2 decrease of 3% can be anticipated 25 min after injection of IB.

After peritumoral administration of IB, 50 mg, a significant interference with Spo2 will occur.