Perfusion index as a predictor of hypotension during spinal anesthesia for lower segment cesarean section: A prospective, observational study

Abstract

Abstract Background and Aims: Hypotension following subarachnoid block (SAB) for lower segment cesarean section (LSCS) has adverse fetal and maternal implications. Perfusion index (PI) has been used for assessing peripheral perfusion dynamics. This study aimed to determine whether a baseline PI can predict hypotension after spinal anesthesia for LSCS. Materials and Methods: In this prospective, observational study, 152 term parturients were divided into two groups: Group I (PI of ≤ 3.5) and Group II (PI >3.5). SAB was performed using bupivacaine 0.5% (hyperbaric) 10 mg with dexmedetomidine 5 μg. PI, vital parameters, and correlation between baseline PI and hypotension were observed. Receiver operating characteristic (ROC) curve was plotted for PI and the occurrence of hypotension. Statistical analysis was performed using Chi-square test, independent sample t-test, Mann–Whitney U-test, and regression analysis with Spearman’s rank correlation coefficient test. Results: The incidence of hypotension was higher in Group II (57.89%) compared to Group I (18.42%) (P < 0.0001). The correlation between baseline PI >3.5, the number of episodes of hypotension, and the total dose of mephentermine required were also significant. The sensitivity and specificity of baseline PI of 3.5 to predict hypotension were 72.37% and 81.58%, respectively. The area under the ROC curve for PI to predict hypotension was 0.830. Conclusion: Parturients with baseline PI >3.5 are at higher risk of developing hypotension following SAB compared to those with baseline PI ≤3.5; hence, PI is a safe and reliable device for predicting hypotension following SAB.