Anaesthetic implications of intra-operative Indocyanine Green use in pediatric surgery

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.

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) s with recovery taking 74(68) s. 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) s with ΔSpO₂ of 4(1) % and recovery at 24(50) s. No corrective anaesthetic manoeuvres were required.

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.