CA-38
Management of a Pregnant Congenital Heart Disease Patient for Emergent Cardiopulmonary Bypass Procedure
Owusu-Bediako E, Goodly H, Gibbons K
University of Michigan, Ann Arbor, MI, United states
Introduction
As congenital heart patients survive into adulthood, an increasing number of them will experience pregnancy. With its physiological changes, pregnancy can stress the delicate homeostasis in these patients. Patients who develop heart failure or infections may require cardiopulmonary bypass (CPB), which has an estimated fetal mortality of 16-33%.2 Caring for the congenital cardiac patient and her fetus requires thoughtful consideration of physiologic goals.
Case
A 30 year old female with a history of congenital aortic stenosis, status post valvuloplasty as an infant, a Ross procedure at age five, and transcatheter pulmonary valve (Melody valve) placement at age 23, presented with cough, fatigue, dyspnea on exertion, fever and chills for several weeks. She was 10 weeks pregnant. Echocardiography revealed a 1 x 1 cm vegetation and peak gradient of 65-70 mmHg across her Melody valve, and she was admitted for intravenous antibiotics for endocarditis. After ten days of antibiotics, the vegetation size increased to 2.3 x 1.5 cm and extended into the proximal pulmonary arteries, and she developed septic pulmonary emboli. She was referred for RV-PA conduit replacement with CPB; her fetus was 12 weeks old.
Pre-operative physical exam revealed stable vital signs, a III/VI systolic murmur, clear lungs to auscultation, and fetal heart tones in the 170s. After placement of standard monitors, general anesthesia was induced with midazolam, fentanyl, propofol and cisatracurium. An endotracheal tube, invasive monitoring lines, and trans-esophageal echocardiography probe were placed. Anesthesia was maintained with isoflurane, air and oxygen, and a morphine infusion.
The team’s primary goal was to maintain adequate maternal and placental oxygen delivery. Throughout the case, the target mean arterial blood pressure (MAP) of 65-70 mmHg based on her pre-operative MAP, was achieved utilizing a phenylephrine infusion. Additionally, the patient’s PaCO2 was maintained at 40-45 mmHg to avoid placental vasoconstriction. During CPB, pulsatility was preserved, core temperature was maintained at 37 degrees Celsius and hemodilution was avoided, maintaining a hematocrit of 30%.3 After 69 minutes of CPB, a norepinephrine infusion was initiated, but intrinsic cardiac function recovered quickly and it was weaned. The patient was extubated in the operating room and transferred to the ICU where fetal heart tones were confirmed. Following uneventful recovery, she was discharged on POD #6.
Discussion
Congenital heart disease represents up to 75% of heart disease in pregnancy.1 When maternal condition necessitates CPB, fetal mortality is significant. Knowledge of the pharmacologic effects of medications utilized as well as the physiologic effects of the hemodynamic changes to placental blood flow which occur during CPB, may enable providers to optimize conditions to ensure adequate fetal oxygen delivery during these cases.
References
1. Chandrasekhar S, et al. Cardiac Surgery in the Parturient. AnesthAnalg 2009;108(3):777-785.
2. Kapoor MC, Cardiopulmonary bypass in pregnancy. Ann Card Anaesth 2014;17:33-39.
3. Patel A, et al. Cardiac Surgery during Pregnancy. Texas Heart Institute J 2008;35(3)307-12.
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