Uncoupling Sensory Analgesia from Sympathetic Blockade via Low-Dose Combined Spinal-Epidural Anesthesia and Proactive Dual-Vascular Counter-Regulation in Obstetric Eisenmenger Syndrome: An Observational Analytic Study

Abstract

Background. Eisenmenger syndrome poses a high maternal risk during cesarean delivery. Neuraxial anesthesia may reduce systemic vascular resistance, while general anesthesia presents additional hemodynamic risks.

Objective. To describe hemodynamic trajectories during low-dose combined spinal-epidural anesthesia with proactive phenylephrine and milrinone support in one parturient.

Methods. A 25-year-old parturient at 32–34 weeks of gestation had a 2.8 cm secundum atrial septal defect, reported Eisenmenger syndrome, and an estimated right ventricular systolic pressure of 95 mmHg. Management comprised intrathecal hyperbaric bupivacaine 7.5 mg with fentanyl 50 µg, fractionated epidural ropivacaine 0.2%, phenylephrine initially at 40 µg/min, and milrinone at 0.25 µg/kg/min. Arterial pressure and central venous pressure guided management across 12 procedural milestones.

Results. A T6 sensory block was reported within 10 minutes. Mean arterial pressure ranged from 79.3 to 91.0 mmHg, with a reported maximum decrease of 12.9%; oxygen saturation remained at 88–91%. A male infant weighing 2,800 g had Apgar scores of 7 and 8. Postoperative urine output was 3,800 mL over 14 hours, and pain scores were 1–2. ICU discharge was reported within 24 hours. Naranjo (+8) and Bradford Hill assessments were interpreted as supporting causality.

Conclusion. Hemodynamic stability was observed during this multimodal protocol in one patient. These observations were interpreted as consistent with sensory–sympathetic uncoupling and dual-vascular counter-regulation.