Preoperative perfusion index as a predictor of post-anaesthetic shivering in caesarean section with spinal anaesthesia

Background: Post-anaesthetic shivering is frequently preceded by a decrease in peripheral blood flow. Perfusion index is a fast non-invasive method to assess peripheral blood flow, thus might be correlated with post-anaesthetic shivering. Aim: To analyse the relationship between preoperative perfusion index and post-anaesthetic shivering in patients undergoing caesarean section with spinal anaesthesia. Methods: In this prospective observational study, preoperative perfusion index measurements were performed on 40 participants who were undergoing elective caesarean section under spinal anaesthesia. Spinal anaesthesia was performed using Lidodex (Lignocaine+Dextrose 5%) at vertebrae L4-L5 or L3-L4 interspace. Shivering was observed until 120 minutes according to the Crossley and Mahajan scale. Statistical analysis was performed to examine the correlation and cut-off of preoperative perfusion index as a predictor for post-anaesthetic shivering. Result: There was a significant relationship between preoperative perfusion index with the incidence (p=0.005) and the degree (p=0.014) of post-anaesthetic shivering. The preoperative perfusion index cut-off value based on the ROC curve was 4.2 (AUC=0.762, p=0.002) with a sensitivity of 73.9% and specificity of 88.2%. Participants with preoperative PI<4.2 had a greater risk of post-anaesthetic shivering (p<0.001, RR=3.13). Conclusion: Preoperative perfusion index less than 4.2 can predict post-anaesthetic shivering in patients undergoing caesarean section with spinal anaesthesia.