• laryngeal edema from water retention
• lingual, nasal mucosa swelling from capillary engorgement
• increased facial adipose tissue affecting space for maneuvering laryngoscope handle
• increased abdominal contents elevating diaphragm with anterior shifting larynx
• morbid obesity (heavier than 300 pounds): mask ventilation may also be difficult due to increased intra-­abdominal pressure and low chest compliance.¹¹

Neuromuscular blockade (e.g., succinylcholine, vecuronium, atracurium) can be used in conventional doses. Transplacental passage is insignificant at usual dose for intubation relaxation. If a paralytic agent is used, it crosses placenta in dose-dependent fashion and will cause fetal heart rate tracing to become non-reactive.¹²

Induction agents such as thiopental, propofol, and etomidate appear to have a positive benefit vs. risk when used in the critical setting for pregnant women.

Hypotension, IV Fluids

Hypotension in pregnancy is sometimes difficult to identify because of physiologic lowering of blood pressure. Additionally, the mother’s blood pressure may be maintained by shunting blood away from the uterus. Up to 25% of maternal intravascular blood volume may be lost without change in maternal vital signs.

To prevent or correct hypotension, place the patient in the left lateral decubitus position. Avoid large loads of IV D5 solutions, as this will cause problems with glucose regulation in the neonate should delivery be imminent. Pregnant women have increased fluid requirements; thus, liberal amounts can be given as indicated. Also, a pregnant patient with hypotension is markedly volume depleted.

Hypertension¹³

Drug treatment is usually reserved for patients with BP greater than 160 systolic and greater than 110 diastolic. Avoid lowering blood pressure below 140/90 because of possible uterine hypoperfusion. Labetalol IV is one recommended choice. If magnesium sulfate has been given, observe its effect on lowering blood pressure before adding antihypertensive medication. Nitroprusside is relatively contraindicated secondary to potential fetal cyanide poisoning.

Blood Transfusion¹⁴

If uncrossmatched blood is indicated, group O Rh-negative blood should be used to prevent antibody development. Autologous transfusion (e.g., from chest tube) should be considered. The goal is to transfuse blood and crystalloid to maintain hematocrit at 25%-30% and urine output greater than 30 cc/hr.

Cytomegalovirus (CMV) infection is a concern with blood transfusion. Consider using CMV antibody-negative or leukocyte-reduced products, because CMV is transmitted only by leukocytes.

Fetal & Uterine Monitoring ²¹

Institute monitoring for viable fetus (see “Viable Fetus” later in article) as soon as the mother’s status allows, preferably in the emergency department. Fetal morbidity or mortality can occur in mothers without significant injury. Abnormal fetal heart rate pattern may not be apparent during initial evaluation and may be the first sign of impending maternal deterioration, especially shock. Continuous monitoring can be discontinued after 4 hours if there are no fetal heart rate abnormalities, uterine contractions, bleeding, or uterine tenderness.