Can a phentolamine infusion or IVP be used for hypertensive crisis associated with adrenal gland tumor ablation? What dosing recommendations exist?

Can a phentolamine infusion or IVP be used for hypertensive crisis associated with adrenal gland tumor ablation? What dosing recommendations exist?

Comment by InpharmD Researcher

Phentolamine infusion or IV push has been used to manage hypertensive crises during adrenal gland tumor ablation, though no standardized guidelines exist. Case reports suggest it as an effective, short-acting option for perioperative blood pressure control, typically administered as a 5 mg IV bolus followed by a continuous infusion, with dosing titrated based on hemodynamic response. Its use has been documented in both surgical resection and radiofrequency ablation, where catecholamine release can cause abrupt hypertension. While data remain limited, phentolamine’s rapid onset and irritability make it a viable option, often used alongside beta-blockers to mitigate reflex tachycardia.

Background

A 2019 review provided an in-depth analysis of postoperative management strategies for patients undergoing pheochromocytoma and paraganglioma (PPGL) resection. The review outlined the complex perioperative hemodynamic challenges associated with these tumors, particularly the abrupt fluctuations in catecholamine levels during and after surgery. Methods for managing postoperative complications were extensively discussed, including the use of intravenous fluids, vasopressors, and antihypertensive agents to stabilize blood pressure. The review emphasized the importance of a multidisciplinary approach involving endocrinologists, anesthesiologists, and intensivists to mitigate cardiovascular risks such as hypertensive crises, hypotension, arrhythmias, and myocardial infarctions. Perioperative hypertension following PPGL resection requires prompt management with short-acting and easily titratable agents. Phentolamine, administered as a 5 mg intravenous bolus and maintenance dose of 0.5 mg/min, is commonly used to counter hypertensive crises during and after surgery. To mitigate reflex tachycardia associated with α-adrenoceptor blockade, esmolol is often co-administered, starting with a loading dose of 0.5–1.0 mg/kg followed by an infusion titrated to effect. Alternative options such as nicardipine, clevidipine, nitroglycerin, and magnesium sulfate provide additional strategies for blood pressure control, particularly in patients with contraindications to β-blockade. [1]

Literature Review

A search of the published medical literature revealed 2 studies investigating the researchable question:

Can a phentolamine infusion or IVP be used for hypertensive crisis associated with adrenal gland tumor ablation? What dosing recommendations exist?

Level of evidence

D - Case reports or unreliable data Read more→

Please see Tables 1-2 for your response.

Phentolamine continuous infusion in a patient with pheochromocytoma
Design	Case report
Case presentation	A 2011 case report detailed the use of continuous phentolamine infusion therapy in a 38-year-old woman undergoing adrenalectomy for pheochromocytoma. Despite receiving phenoxybenzamine for 25 days as standard preoperative α-adrenergic blockade, inadequate dosage adjustments led to poorly controlled hypertension, resulting in severe intraoperative blood pressure fluctuations and cardiac arrest, which necessitated aborting the surgical procedure. Following resuscitation, the patient was admitted to the surgical intensive care unit, where intermittent phentolamine boluses and continuous esmolol infusion failed to sufficiently stabilize hemodynamics. On the first postoperative day, phentolamine infusion was initiated at 1 mg/hr and titrated hourly to achieve blood pressure targets of 120-140 mmHg, leading to gradual stabilization over four days. Concurrent administration of phenoxybenzamine and metyrosine further improved blood pressure control, allowing for successful tumor resection with reduced intraoperative complications. The case report outlined the advantages of continuous phentolamine infusion as a nontraditional but effective strategy for managing perioperative hypertensive crises in pheochromocytoma, particularly when outpatient α-blockade proves insufficient. Unlike phenoxybenzamine, which has a prolonged duration of action requiring preoperative discontinuation, phentolamine’s short half-life and titratability allowed real-time blood pressure modulation until the time of surgery. Previous case series and reports have documented the use of phentolamine infusions in similar contexts; however, evidence remains limited regarding optimal dosing and its role in comprehensive perioperative management. The report highlighted the need for individualized pharmacologic strategies in high-risk patients and reinforced the importance of interdisciplinary collaboration in optimizing hemodynamic control before pheochromocytoma resection.
Study Author Conclusions	A continuous infusion of phentolamine was used in a patient with pheochromocytoma to control perioperative hypertensive episodes during surgical adrenalectomy.

References:
[1] McMillian WD, Trombley BJ, Charash WE, Christian RC. Phentolamine continuous infusion in a patient with pheochromocytoma. Am J Health Syst Pharm. 2011;68(2):130-134. doi:10.2146/ajhp090619

Hypertensive Crisis during Radiofrequency Ablation of the Adrenal Gland
Design	Case report
Case presentation	A 2009 case report described a hypertensive crisis occurring during radiofrequency (RF) ablation of a left adrenal metastatic deposit in a 78-year-old normotensive man with inoperable non–small cell lung carcinoma. Pre-procedural imaging confirmed a solitary 2 × 2.4-cm enhancing left adrenal mass without evidence of pheochromocytoma, as urinary metanephrine and vanillylmandelic acid levels were within normal limits. Under general anesthesia and CT guidance, a spinal needle was used to administer 5 mL of absolute alcohol into the adrenal lesion before advancing a single cooled-tip RF probe into the mass. RF ablation commenced, but within four minutes, the patient's blood pressure sharply increased to 211/110 mm Hg, accompanied by tachycardia and premature ventricular contractions. Ablation was halted, and an intravenous bolus of 5 mg phentolamine, followed by a continuous infusion, was administered, resulting in rapid blood pressure normalization. RF ablation was subsequently resumed with minimal further hemodynamic instability. The report highlighted similar cases of hypertensive crises during adrenal RF ablation, attributing the phenomenon to catecholamine release from heated adrenal tissue into systemic circulation. Unlike surgical adrenalectomy, which involves adrenal vein ligation to prevent such hemodynamic disturbances, RF ablation leaves the vein patent, allowing for systemic catecholamine release. Prior literature suggested β-blockade as a potential preemptive strategy to mitigate this risk, though no standardized approach exists. The authors emphasized the importance of close coordination between interventional radiologists and anesthetists to ensure prompt management of hypertensive crises and considered pre-procedural β-blockade as a preventive measure in select patients.
Study Author Conclusions	RF ablation of adrenal tumors can lead to life-threatening hypertensive crises. Preablation beta-blockade and close collaboration between interventional radiologists and anesthetists are recommended to manage and prevent such complications

References:
[1] Keeling AN, Sabharwal T, Allen MJ, Hegarty NJ, Adam A. Hypertensive crisis during radiofrequency ablation of the adrenal gland. J Vasc Interv Radiol. 2009;20(7):990-991. doi:10.1016/j.jvir.2009.03.039