SAT-211 Is Doxazosin the Right Choice for Preoperative Management of Pheochromocytoma in Pregnancy?

Abstract Pheochromocytoma (PCC) in pregnancy is a very rare condition, with a reported incidence of less than 0.2 per 10.000 pregnancies (1), having fetal and maternal mortality of 50% if untreated (2). Choosing between selective vs. nonselective alpha blockers as preoperative management in pregnancy is controversial. We report a case of a 39-year-old female having episodes of nervousness, hand tremors, palpitations, diaphoresis, and headaches since 2012; she also had a history of multiple miscarriages and uncontrolled hypertension(HTN) since 2018. In 2019, she was found to have plasma metanephrines 690pg/mL (0-62) and plasma normetanephrine of 3803pg/mL(0-145). Repeat labs showed: plasma metanephrines 2.071pg/mL(0-62), normetanephrine 6.289pg/mL(0-145), norepinephrine 4.268pg/mL(0-874), epinephrine 555pg/mL(0-62). CT abdomen showed a 6.2x5.1x6.4cm left adrenal mass, with 44 Hounsfield units and less than 50% of washout. She was started on Doxazosin 2mg/d, which eventually was increased to 6mg/d with optimal blood pressure (BP) control. After her preoperative workup, she was found to be 7 weeks pregnant. OB-GYN recommended left adrenalectomy before 14 weeks gestation. She had left open adrenalectomy, with normal range postoperative BP, off of antihypertensive medications. The diagnosis of PCC in pregnancy should be considered in the setting of paroxysmal HTN, with no proteinuria, episodic palpitations, diaphoresis, facial flushing, and orthostatic hypotension. Anterior adrenalectomy early in pregnancy is recommended. The increased intraabdominal pressure, fetal movements, uterine contractions, delivery process, and abdominal surgical intervention can trigger the catecholamine release by the PCC, which could lead to placental abruption and miscarriage; and the rebound hypotension may lead to severe hypoxia, causing fetal demise (2). Definitive preoperative treatment between selective vs non-selective alpha-blockers remains controversial. Phenoxybenzamine, appeared to produce better attenuation of intraoperative HTN, however, it is associated with more maternal intraoperative/postoperative hypotension, and reflexive tachycardia. It crosses the placenta and accumulates in the fetus, increasing the risk of neonatal hypotension and respiratory depression (3,4,5). On the other hand, Doxazosin, can be displaced by high levels of catecholamines, but it is less associated with intraoperative/postoperative hypotension (6,7), with no reports of neonatal hypotension, and respiratory depression. Due to the lack of presynaptic a2-adrenoceptor blockade there is less reflex tachycardia, reducing the use of Beta-blockers (8). Doxazosin seems to be a safe, affordable alternative for preoperative management of PCC in pregnant patients.