Introduction: The use of Indocyanine Green (ICG) dye for fluorescent guided surgery is increasing in
children. In many cases, ICG is injected intravenously peri-operatively and is known to falsely alter
peripheral oxygenation readings because of interference with the measured red/infrared
absorbance ratio of pulsatile blood.
Methods: The study occurred at a single centre tertiary children’s hospital. ICG was delivered peri-
operatively. SpO2 was monitored real-time in all patients. Blood pressure, heart rate, expired carbon
dioxide and electrocardiographic data were collected from anaesthetic records. Data is median
(interquartile range) RESULTS: Twenty-five patients(13 F;12 M) age 60(77)months and weight
17(18.7)kg were included between 01/April/2021 and 31/Nov/2022. Fifteen patients received
0.5(0.38) mg/kg ICG at induction of anesthesia with ΔSpO2 of 6(2)%. Median time to ΔSpO2 fall was
25(6)seconds with recovery taking 74(68)seconds. Time to recovery and ΔSpO2 were proportional to
ICG dose/kg with r2 of 0.7993 and 0.597 and p of 0.0008 and 0.001 respectively on linear regression.
Five patients had intralesional ICG and one had an enteral dose with no effect on SpO2. Eight
patients had a total of 20 intraoperative bolus doses of ICG with no effect on SpO2 in 11. In 9, time
to SpO2 fall was 26(12)seconds with ΔSpO2 of 4(1)% and recovery at 24(50)seconds. No corrective
anaesthetic manoeuvres were required.
Conclusion: Understanding the timings of the transient artefactual fall and recovery in SpO2
following ICG injection is essential for safe anesthesia. This is the first study to evaluate this effect
in children prospectively.
