Correlation of perfusion index with baseline heart rate and post spinal hypotension in pregnant parturients undergoing lower segment cesarian section: A prospective observational study

• Author Details:   
• Sandip Narayan Baheti
• Perni Tharun Dasarath ^*
• Siddharth S Baheti

---

View PDF

Background: Post-spinal hypotension is a frequent complication in parturients undergoing lower segment cesarean section (LSCS). Perfusion Index (PI), a non-invasive indicator derived from pulse oximetry, is being explored as a predictor for intraoperative hypotension. This study aimed to evaluate the correlation between pre-induction PI, baseline heart rate (HR), and the incidence of post-spinal hypotension.

Materials and Methods: A prospective observational study was conducted on 150 pregnant women undergoing elective LSCS under spinal anaesthesia. Pre-induction PI and HR were recorded, and hemodynamic changes were monitored post-spinal block. Hypotension was defined as a >20% fall in baseline systolic blood pressure (SBP) or mean arterial pressure (MAP). Statistical analyses included Mann-Whitney U test, chi-square test, ROC curve analysis, and correlation coefficients.

Results: The incidence of SBP-based hypotension was 36.7%, and MAP-based hypotension was 52%. No statistically significant correlation was found between PI and hypotension (p>0.05). ROC analysis revealed poor predictive accuracy for PI, with an AUC of 0.542 for SBP and 0.534 for MAP. However, patients who developed hypotension had significantly higher pre-induction HRs (SBP: 97.02 ± 14.73 vs. 88.4 ± 13.67 bpm; MAP: 94.44 ± 15.23 vs. 88.44 ± 13.35 bpm; p<0.05).

Conclusion: Pre-induction PI alone is not a reliable predictor of post-spinal hypotension. However, elevated baseline heart rate is significantly associated with hypotension and may serve as a more useful clinical marker.