A study to evaluate perfusion index as a predictor of hypotension following spinal anesthesia for caesarean section

Background and Aims: The perfusion index (PI) has been used as a marker of peripheral perfusion. A lower PI indicates greater peripheral vascular tone and increased risk of hypotension following spinal anesthesia. The present study was conducted to evaluate and correlate perfusion index (PI) with incidence of hypotension following spinal anesthesia for caesarean section. Material and Methods: The present prospective, double blind, observational study included sixty full term parturients in the age group 18-35 years belonging to American Society of Anesthesiologists (ASA) physical status I and II, having singleton pregnancy undergoing caesarean section under spinal anesthesia. On the basis of baseline PI, patients were allocated into one of the two groups: Group I (n = 30) Patients with baseline PI <=.3.5 and Group II (n = 30) Patients with PI >3.5. Results: The incidence of hypotension in group I was 40% as compared to 73.3% in group II (p = 0.009). Thus, the incidence of hypotension in group II with baseline PI >.3.5 was more as compared to group I. Patients in group II with baseline PI >.3.5 had significantly more episodes of hypotension as compared to those in group I with baseline PI <= 3.5. Conclusion: PI can be used as a useful tool for predicting hypotension in parturients undergoing elective caesarean section under spinal anesthesia in everyday practice.