Anesthetic management of a pregnant woman undergoing laparoscopic surgery for pheochromocytoma -A case report-
A 27-year-old previously healthy woman was referred from local obstetric clinic to our hospital at 22th week gestational age with persistent uncontrolled high blood pressure (BP). Her BP was 170/100 mmHg, and she complained of intermittent headache and epigastric pain at admission. Pregnancy-induced hypertension (PIH) was diagnosed and antihypertensive treatment was begun. Despite the maximal dose of antihypertensive treatment (hydralazine 100 mg/day), BP persisted uncontrolled.\nAnother cause of hypertension besides PIH was suspected, so further evaluation was performed. Plasma and urine norepinephrine levels were at 3,053.8 pg/ml (normal reference: 15-80 pg/ml) and 1,011.6 mcg/day (15-80 mcg/day) and urine metanephrine 8.1 mg/day (0-0.8 mg/day). MRI scanning of the abdomen revealed a 4 × 4 cm sized cystic mass in the right adrenal gland, suggesting a pheochromocytoma. A multidisciplinary consultation among anesthesiologist, urologist, obstetrician, and endocrinologist was held to determine the most appropriate management of this pregnant patient. We decided to do a surgical resection of pheochromocytoma because the size of fetus (maximum estimated fetal weight: 700 g) and tumor (4 × 4 cm) were small enough to secure the laparoscopic surgical field. She was treated with doxazocin, a selective α1-bloker, as a preoperative α-blockade for 14 days. Her BP ranged from 120/80 to 130/90 mmHg with doxazocin. Laparoscopic adrenalectomy was set for the 25th gestational week.\nArriving at operating room, her BP was 120/85 mmHg and heart rate was 95 beats/min. After sufficient pre-oxygenation, anesthesia was induced with 200 mg of thiopental, 50 mg of rocuronium, and continuous infusion of remifentanil (target effect site concentration 5 ng/ml) using a target controlled infusion system (Orchestra® Fresenius vial, Brezims, France). After tracheal intubation, her blood pressure was 120/75 mmHg and continued at that level. Anesthesia was maintained with 1-3 vol% of sevoflurane and continuous infusion of remifentanil (target effect site concentration 2-5 ng/ml), and the patient's lung was ventilated with volume controlled mode with 50% oxygen.\nLeft radial artery and right subclavian vein were cannulated for hemodynamic monitoring. Vital signs were stable till the manipulation of the tumor. Sodium nitroprusside (SNP) was continuous infused to maintain BP, and it was ranging from 115/65 mmHg to 140/70 mmHg during manipulation of the tumor. After ligation of vein draining the tumor, her BP decreased to 70/40 mmHg even though SNP was discontinued. Fluid resuscitation and phenylephrine infusion were started promptly. The patient's BP increased soon to 100/65 mmHg and held at that level till the end of the operation. Neuromuscular block was reversed with pyridostigmine and glycopyrrolate. She awoke and extubated uneventfully in the operation room. The patient's BP was 125/80 mmHg without support of phenylephrine. After surgery the fetus was reactive and normal in non-stress test and ultrasonography. On the 6th day of operation, she was discharged and engaged to follow up in a week.