# Infrared Thermal Imaging as a Predictor of Lumbar Paravertebral Block Effectiveness in Cattle

## TL;DR

This study shows that infrared thermal imaging can help determine if a pain-blocking procedure in cattle is working by measuring changes in skin temperature.

## Contribution

The study introduces thermography as a novel, non-invasive method to assess the effectiveness of lumbar paravertebral blocks in cattle.

## Key findings

- An increase in skin temperature correlated with reduced pain response in blocked dermatomes.
- Thermography was found to be a simple and efficient tool for evaluating block success in cattle.
- The study supports the potential use of thermal imaging in clinical practice for cattle anesthesia.

## Abstract

Locoregional anaesthesia is commonly used in cattle to provide pain relief during standing surgeries. For these procedures, it is essential to confirm that the block is effective before beginning the surgery. The lumbar paravertebral block is one of the most frequently applied techniques in cattle. In this pilot study we evaluated the efficacy of thermography in assessing this block. Twelve cows underwent an ultrasound-guided lumbar paravertebral block with lidocaine, and thermal images were taken at different time points alongside pain response tests. The results showed that an increase in skin temperature correlated with a reduced response to painful stimulation, supporting the use of thermography as a simple and efficient tool to evaluate block effectiveness in cattle.

In the daily clinical practice of cattle, the use of locoregional anaesthesia is needed to provide analgesia during standing surgical procedures. It is important to ensure the success of the blockade before starting the surgery. One of the most used techniques is the paravertebral lumbar block. In this pilot study we evaluated the efficacy of thermography in assessing this block. For this matter, 12 cows from our university research and teaching farm, with similar characteristics, were included and in which an ultrasound-guided technique of lumbar paravertebral block (T13/L1) or (L1/L2) with lidocaine was performed. Thermal photographs were taken with a FLIR® One camera at 0, 15, 30 and 45 min and at the same time a test to evaluate the response to a painful stimulus was performed in each dermatome (T13, L1, L2 and L3). The data was collected in predesigned cards and placed in the Excel programme for further statistical analysis with the R programme. The analysis determined a correlation between the increase in skin temperature of the dermatomes that had been blocked and the increase in skin temperature and the negative response to the painful stimulus test. Although the pilot study has some limitations, this allows us to assess the use of thermography as an efficient method for assessing the success of lumbar paravertebral blockade in cattle.