Intraoperative management focuses on preventing and managing hypertensive crises, especially during tumor manipulation. Continuous invasive monitoring, including arterial blood pressure and central venous pressure (CVP), is essential to guide fluid management and maintain hemodynamic stability. The arterial line is placed before induction; central access is chiefly for vasoactive infusions, since CVP itself is a poor guide to volume, and dynamic indices or transesophageal echocardiography are added when cardiomyopathy is suspected.
Despite preoperative preparation, hypertensive surges may still occur during tumor manipulation. These episodes are managed with vasodilators such as nicardipine or nitroglycerin, and magnesium sulfate (4 to 6 g IV load, then 1 to 2 g/h) is often used because it inhibits catecholamine release from the adrenal medulla and nerve terminals, blunts their receptor effects, dilates arterioles, and is antiarrhythmic; it is already familiar in obstetric practice, though it potentiates neuromuscular blockers and can reduce uterine tone. Phentolamine in 1 to 5 mg boluses gives rapid alpha-blockade for breakthrough surges. Maintaining an appropriate depth of anesthesia and avoiding unnecessary abdominal compression help reduce the likelihood of sudden hypertensive episodes.
Post-Tumor Resection Hypotension
After tumor removal, particularly following adrenal vein ligation, patients often experience hypotension due to the sudden drop in circulating catecholamines. This can be managed with fluid resuscitation and the use of vasopressors like phenylephrine or norepinephrine. In cases where hypotension is resistant to catecholamine-based treatments, vasopressin may be required, as it acts on vasopressin receptors to restore blood pressure when traditional vasopressors are ineffective. The drop is anticipated: vasodilator and beta-blocker infusions are stopped as the adrenal vein is clamped, volume is loaded beforehand, and norepinephrine or vasopressin infusions are ready. When the tumor is removed at the time of cesarean, the uterotonic plan matters too: oxytocin is given slowly by infusion (a bolus causes hypotension), and ergot alkaloids are avoided because they can precipitate a hypertensive crisis. Hypoglycemia is the other post-resection trap: catecholamines suppress insulin release, and once they fall a rebound rise in insulin can drop the glucose within the first hours, so glucose is checked frequently for 24 to 48 hours and dextrose-containing fluid is often started.
