# Noninvasive Hemodynamic Assessment with Impedance Cardiography During Spinal and Epidural Anesthesia in Obstetrics

## TL;DR

This study uses impedance cardiography to noninvasively assess maternal heart function during two types of childbirth anesthesia, revealing how different drugs affect blood flow and pressure.

## Contribution

The study introduces noninvasive impedance cardiography to compare hemodynamic effects of spinal and epidural anesthesia in obstetrics.

## Key findings

- Cardiac index remained stable and similar between epidural and spinal anesthesia.
- Phenylephrine use in spinal anesthesia resulted in higher blood pressure and vascular resistance but lower cardiac output.
- Epidural analgesia with ropivacaine and bupivacaine showed similar cardiovascular effects.

## Abstract

Background/Objectives: Spinal anesthesia (SA) for cesarean section and epidural analgesia (EA) for vaginal delivery induce hemodynamic changes that may compromise maternal and fetal safety. In this observational, hypothesis-generating study, we used impedance cardiography (ICG) to characterize maternal hemodynamic responses to EA for labor versus SA for cesarean delivery and to describe hemodynamic profiles associated with commonly used local anesthetic and vasopressor regimens. Methods: In this observational study, 132 women at term were included (52 with epidural analgesia (EA), 80 with spinal anesthesia (SA)). Hemodynamic parameters were measured using the ICON electrical cardiometry monitor (Osypka Medical GmbH). ICON and oscillometric blood pressure (BP) monitoring captured cardiac index (CI), stroke volume (SV), heart rate (HR), systemic vascular resistance index (SVRI), and thoracic fluid content (TFC) at T0 (baseline), approximately 5 and approximately 10 min, skin incision, delivery, and oxytocin administration. Results: CI remained stable and comparable between EA and SA (3.9 ± 0.6 vs. 3.9 ± 0.6 L/min/m2; p = 0.530). SV was higher in EA (85.1 ± 11.3 vs. 78.1 ± 9.7 mL; p < 0.001), whereas HR was higher in SA (92.2 ± 12.9 vs. 85.8 ± 12.5 bpm; p = 0.009). In EA, ropivacaine and bupivacaine showed similar hemodynamic profiles. Within the SA cohort, women managed with phenylephrine infusion had lower CI and HR but higher MAP and SVRI compared with those receiving ephedrine boluses, consistent with the expected pharmacodynamic profiles of these agents. Conclusions: ICG was feasible and provided dynamic, noninvasive estimates of maternal cardiovascular adaptation during obstetric anesthesia. In this non-randomized, exploratory cohort, descriptive differences in hemodynamic profiles between vasopressor strategies were more pronounced than between local anesthetics. Phenylephrine-based management showed a pattern of higher BP and SVRI but lower CI and HR, whereas ephedrine-based management tended to preserve CI through chronotropic effects.