///2015 Abstract Details
2015 Abstract Details2019-08-02T16:54:43-06:00

Tracheal Dilation During the Third Trimester: Anesthetic Considerations

Abstract Number: T-28
Abstract Type: Case Report/Case Series

Holly Briggs M.D.1 ; Dominique Moffitt M.D.2

Introduction

Non-obstetric surgery occurs in 2% of pregnancies, which presents unique challenges to providers, who must consider effects of anesthesia on both mother and fetus.

Case

A 22yo G1 at 34 weeks gestation with a history of tracheal stenosis presented with worsening dyspnea and stridor. Her clinical picture was complicated by fetal congenital heart disease. Heliox was initiated in the ED, and she was taken to the OR for bronchoscopy and balloon dilation. With continuous FHR monitoring, general anesthesia was delivered using sevoflurane via LMA and remifentanil boluses. Her symptoms returned on postop days six and ten requiring repeat tracheal dilations. The first two cases were complicated by negative FHR changes thought to be caused by remifentanil. During the third case the patient was paralyzed, avoiding remifentanil. The procedure was uneventful, and paralysis was reversed using neostigmine and glycopyrrolate. Following extubation the patient developed progressive hypercapnia accompanied by rapid shallow breathing and subjective air hunger, which necessitated re-insertion of the LMA and positive pressure ventilation. Secondary to limitations ventilating across the stenosis, hypercarbia persisted with ETCO2 >60. During this period, a prolonged deceleration was noted on FHR monitoring, prompting resuscitation with fluid bolus, pressors, and increased left uterine displacement. Ultimately a STAT cesarean delivery of a baby girl with Apgars 2 and 4 was performed.

Discussion

Non-obstetric surgery in pregnancy presents many unique challenges in regards to pharmacology, airway management, ventilation, and uteroplacental perfusion. Pharmacologic effects on both mother and fetus must be considered. Most anesthetic medications cross the placenta and can affect FHR. Volatiles can indirectly affect the fetus by causing maternal hypotension and decreased uteroplacental perfusion or can directly depress fetal cardiovascular and CNS function. Their use, however, is generally well tolerated up to 1.0 MAC. Opioids also cross the placenta and can lead to decreased FHR variability, but in the absence of other physiologic derangements this is usually attributed to an anesthetized fetus and requires no intervention. Airway management in the routine obstetric patient can be difficult, with tracheal stenosis adding additional challenges. Difficulty in ventilating past a fixed intrathoracic obstruction can lead to hypercarbia, which increases uterine vascular resistance and decrease uterine blood flow (1). In the absence of CHD, early delivery of the fetus may have been preferred to avoid complications associated with tracheal stenosis; however, in the setting of cardiac anomalies, delivery after 39 weeks significantly decreases fetal morbidity and mortality (2).

1. Walker et al. J Appl Physiol. 1976 Nov;41(5 Pt. 1):727-33

2. Costello et al. Pediatrics. 2010 Aug;126(2):277-84

SOAP 2015