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

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. SpO 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 ΔSpO of 6(2) %. Median time to ΔSpO fall was 25(6) s with recovery taking 74(68) s. Time to recovery and ΔSpO were proportional to ICG dose/kg with r 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 SpO. Eight patients had a total of 20 intraoperative bolus doses of ICG with no effect on SpO2 in 11. In 9, time to SpO fall was 26(12) s with ΔSpO of 4(1) % and recovery at 24(50) s. No corrective anaesthetic manoeuvres were required.

Conclusion: Understanding the timings of the transient artefactual fall and recovery in SpO following ICG injection is essential for safe anesthesia. This is the first study to evaluate this effect in children prospectively.