P076: MULTIPLE CARDIOVASCULAR COMORBIDITIES AND ACUTE INTERMITTENT PORPHYRIA IN THE PARTURIENT
Richa Sutaria, MD; Aaron Hanson, MD; M. Anthony Cometa, MD; University of Florida- College of Medicine
Introduction: Cardiovascular disease is the most common cause of non-obstetric maternal mortality in developed countries. We present a case of a patient with bicuspid aortic valve, severe aortic stenosis, moderate aortic regurgitation, increasing dilated ascending aorta, and acute intermittent porphyria undergoing cesarean section. Patients with bicuspid aortic valves have a higher prevalence of ascending aortic dilation due to degeneration of the intima media. They are also at higher risk of aortic dissections during the peripartum period as well as myocardial ischemia and arrhythmias. These cardiovascular structural defects pose several challenges for the anesthesiologist providing care for an obstetric patient. Patients with aortic stenosis have very little tolerance to hemodynamic instability and require preservation of intravascular volume, afterload, and heart rate. Patients with acute intermittent porphyria can have exacerbations that are precipitated by pregnancy (estrogens), emotional stress, fasting states, and medications including barbiturates, sulfa drugs, and etomidate. We present the anesthetic management of a patient with these multiple comorbidities.
Case Presentation: A 32-year-old Gravida 1 Para 0 at 37 weeks and 1 day gestation with medical history of bicuspid aortic valve, severe aortic stenosis (aortic valve area 0.77 cm2 with mean gradient 66 mmHg and peak gradient 97 mmHg, dimensionless index 0.21), moderate aortic regurgitation, increasing dilated ascending aorta (4.3 cm to 4.7 cm), and acute intermittent porphyria presents requesting a vaginal delivery. After a multidisciplinary meeting with Obstetrics, Cardiology, and Anesthesia discussing risks of various delivery options, a planned cesarean delivery was chosen as the safest route. To preserve pre-load, the anesthesia team decided on an epidural for the primary anesthetic rather than a spinal or general anesthesia. 2% lidocaine with 1:100,000 epinephrine was dosed slowly to effect. In order to maintain mean arterial pressures, phenylephrine infusion was initiated and the patient also required norepinephrine as a second line agent throughout the case. Diluted oxytocin was given slowly with caution after the neonate was delivered. She was titrated off of all vasopressors by the end of the case. It was of high priority that her pain was controlled in the perioperative period to minimize the risks of acute intermittent porphyria exacerbations. The cesarean delivery was successful without any complications.
Discussion: This case illustrates the recognition of high-risk cardiovascular comorbidities and the implications on the obstetric anesthetic plan. A multidisciplinary team approach with close communication about the surgical and anesthetic plan is of utmost importance. Although regional anesthesia is a relative contraindication in patients with severe aortic stenosis, a slow and careful titration of local anesthetic through an epidural can be a safe alternative.