(648) Use of Neuromuscular Blocking Agents and Their Reversal in Pregnant Women for Non-Obstetric Cases

Introduction: Neuromuscular blockade is an important aspect of modern anesthesia, assisting with endotracheal intubation, mechanical ventilation, and optimizing surgical outcomes. The most commonly used neuromuscular blocking drugs (NMBDs) are steroidal nondepolarizing NMBDs including rocuronium and vecuronium, which bind directly to postsynaptic nicotinic receptors, preventing ACh from binding to the motor endplate and causing widespread muscle paralysis. These drugs often necessitate reversal agents at the conclusion of the case. Use of sugammadex is increasing in the U.S. for reversing rocuronium or vecuronium, but limited studies have been conducted for parturients due to the interaction between sugammadex and progesterone, which might alter the viability of the fetus. Additionally, sugammadex has demonstrated skeletal teratogenicity in animal models, but no evidence of teratogenicity has been demonstrated in humans at the maximum recommended dose (16 mg/kg)

Description: A pregnant 24 y/o female with a history of right breast cancer presented for segmental mastectomy at 15 weeks gestation. During the procedure, the patient was placed in the left lateral decubitus position with standard ASA monitors. Induction of general anesthesia was performed with propofol and fentanyl, and the patient was given rocuronium for paralysis. General anesthesia was maintained via TIVA with propofol, and the procedure was uneventful. To reverse the neuromuscular blockade, neostigmine and atropine were administered. A postoperative fetal heart rate was performed and within normal limits in concordance with her preoperative ultrasound. The patient was discharged home from the PACU with no sequela.

Discussion: In pregnant patients undergoing non obstetric procedures, it is critical to determine the safest method of NMBD reversal. Neostigmine’s ability to cross the placental barrier creates potential complications with the fetus including fetal bradycardia. The muscarinic anticholinergic glycopyrrolate is commonly given with neostigmine, but glycopyrrolate is unable to cross the placenta. Atropine may be administered alongside neostigmine in pregnant women instead of glycopyrrolate since atropine crosses the placenta and can provide protection against fetal bradycardia in pregnant women receiving NMBD reversal.