CLINICAL EVALUATION OF PERFUSION INDEX (PI) AS A PREDICTOR OF POST-SPINAL HYPOTENSION IN LOWER SEGMENT CESAREAN SECTION (LSCS)

Abstract

Background: Hypotension is a frequent complication following spinal anaesthesia during lower segment cesarean section (LSCS), leading to adverse maternal and fetal outcomes. The Perfusion Index (PI), derived from pulse oximetry, is a non-invasive indicator of peripheral perfusion and autonomic tone.

Objective: To evaluate the usefulness of baseline PI in predicting post-spinal hypotension in parturients undergoing LSCS.

Methods: This was a prospective observational study involving 60 ASA I–II parturients scheduled for elective LSCS under spinal anaesthesia. Baseline PI was measured using a Masimo pulse oximeter before administering spinal anaesthesia. The primary outcome was the occurrence of hypotension post spinal block. Receiver Operating Characteristic (ROC) analysis and Karl Pearson correlation were used for statistical evaluation. Results: The incidence of post-spinal hypotension was 34.5%. A PI cutoff value >3.5 predicted hypotension with 97% specificity. A significant positive correlation was observed between baseline PI and the magnitude of blood pressure drop (r = 0.436, p < 0.05). Conclusion: A higher baseline PI (>3.5) is a strong, non-invasive predictor of post-spinal hypotension in parturients. This parameter may be valuable in pre-anaesthetic assessment and for initiating early preventive measures.