The Ability of Infrared Thermography to Detect Successful Caudal Block in Children Undergoing Infra-Umbilical Surgery

Mina Adolf Helmy ¹, Ingy Hamed Mohamed ¹, Maha Mostafa ¹

⁰Department of Anesthesia and Critical Care Medicine, Cairo University, Cairo, Egypt.

Paediatric Anaesthesia +

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December 1, 2025

View abstract on PubMed

Summary

Infrared thermography accurately confirms caudal block success in pediatric surgery. A skin temperature increase of 1.2°C-1.4°C at the foot within 10 minutes indicates a successful block with 95% accuracy.

Area Of Science

Pediatric Anesthesiology
Pain Management
Medical Imaging

Background

Caudal epidural blocks are common in pediatric surgery but can fail due to anatomical variations or operator inexperience.
Early detection of block effectiveness is crucial for optimal pain management and improved patient outcomes.

Purpose Of The Study

To evaluate the efficacy of infrared thermography in determining the success of caudal blocks in children.
To establish reliable temperature change thresholds for confirming successful caudal blocks.

Main Methods

A prospective observational study involving 143 children (2-12 years) undergoing infra-umbilical surgery with caudal blocks.
Infrared thermography (FLIR C2) measured skin temperature at the foot, toe, and suprapubic area pre-block and at 2, 5, 10, and 15 minutes post-block.
Area Under the Curve (AUC) analysis assessed the ability of temperature change (Δ) at 10 minutes to predict block success.

Main Results

20% of caudal blocks failed. Successful blocks showed significantly higher temperature increases compared to failed blocks at 10 and 15 minutes.
At 10 minutes, AUC for successful block detection was highest at the dorsum of the foot (0.92) and little toe (0.87).
A Δ temperature of 1.2°C (foot) and 1.4°C (toe) at 10 minutes predicted successful blocks with 95%-96% positive predictive value.

Conclusions

Infrared thermography is a reliable, non-invasive tool for confirming caudal block success in anesthetized children.
A 1.2°C-1.4°C skin temperature increase at the foot/toe 10 minutes post-block accurately indicates success with high predictive value.

Keywords:

caudal block general anesthesia infrared thermography pediatric anesthesia predictive value of tests skin temperature surgery