Infrared Thermal Imaging as a Predictor of Lumbar Paravertebral 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.