Evaluation Of Pain In Children Under General Anesthesia By Functional Near-infrared Spectroscopy

Objective:To evaluate pain in children under general anesthesia by functional near-infrared spectroscopy（f NIRS）.Methods:This prospective study included 45 children aged 0～14 years who underwent hypospadias repair and cryptic penile correction in the Seventh Medical Center of PLA General Hospital from November 2021 to September 2022.They were divided into general anesthesia group（G group,n=30）and general anesthesia+dorsal penile nerve block group（N group,n=15）according to whether or not they underwent dorsal penile nerve block.Two groups adopt continuous wave functional near-infrared spectroscopy to collect the blood oxygen parameters and heart rate of the left prefrontal brain tissue from5 minutes before skin resection to 5 minutes after skin resection.The mean value and peak value of blood oxygen parameters and heart rate of the left prefrontal brain tissue before and after skin resection were compared.Results:Compared with baseline before skin resection（T₁）,the left prefrontal cortex of group G was activated after skin resection,the blood oxygen parameters of brain tissue all reached the peak within 3s（T₂）,and the mean concentration of oxygenated hemoglobin,deoxyhemoglobin,total hemoglobin and average heart rate increased significantly at T₂,with statistical significance（P<0.05）.However,compared with baseline before skin resection（T₁）,the left prefrontal cortex of group N was not significantly activated after resection,and there were no significant changes in the average oxygenated hemoglobin concentration,the average deoxyhemoglobin concentration,the average total hemoglobin concentration and the average heart rate at T₂,with no statistical significance（P>0.05）.After G group receiving the stimulation of skin resection,compared with the time when the heart rate reached the peak,the blood oxygen parameter of the left prefrontal brain tissue reached the peak time earlier than the heart rate（2.100±0.845s）,in which the Deoxy-Hb concentration（1.723±0.783s）,P=0.041)and Total-Hb concentration（1.763±0.770s,P=0.028）had a statistically significant difference in the peak time.Conclusion:Functional near-infrared spectroscopy（FNIRS）can be used to evaluate pain in children under general anesthesia.Compared with conventional physiological indicators,it is more sensitive and has great potential in optimizing clinical pain assessment and management.