Unit 2: Pheochromocytoma Flashcards
(29 cards)
Pheochromocytoma
rare catecholamine-secreting tumors of the adrenal medulla; tumor that secretes excess catecholamines
- 50% of cases are diagnosed upon autopsy
- b/c of excessive catecholamine (epinephrine and norepinephrine) secretion, pheochromocytoma may precipitate life-threatening hypertension or cardiac arrhythmias leading to sudden death
Catecholamines
ex: adrenaline, epinephrine, norepinephrine, cortisol
“stimulant’s on steroids”; drives everything up
Pathophysiology of Pheochromocytoma
pheochromocytomas are catecholamine-secreting tumors of the adrenal medulla and are usually unilateral
- release of epinephrine and norepinephrine is paradoxical, rather than continuous, and leads to vasoconstriction, increased HR, increased stroke volume leading to a rise in systolic BP and a widening pulse pressure
- catecholamine release also stimulates gluconeogenesis = hyperglycemia
Clinical Manifestations of Pheochromocytomas
associated w/ the systemic actions of epinephrine and norepinephrine
-tachycardia (High HR)
-hypertension (high BP)
-severe headache
-palpitations
-tremors
-hyperhidrosis (excessive sweating)
-hypermetabolism
-hyperglycemia
>severity of attacks correlates to the amount of catecholamine release
>paroxysmal (sudden-onset) hypertension may be seen with elevations up to 250/140 mmHg; life threatening
The classic presentation of Pheochromocytoma
-sudden elevation of blood pressure accompanied by other clinical manifestations of catecholamine excess
Diagnosing Pheochromocytoma
- recognition of signs and symptoms
- measurements of catecholamines in urine and serum (catecholamine release 2 times a day; early in morning, late afternoon)
- imaging (CT or MRI) to visualize tumor
Patient Preparation for Direct Measurements of Plasma Catecholamines: to prevent elevations of circulating catecholamines
- urine + blood samples
- supine and rests for 30 minutes prior to test
- small IV catheters are placed 30 minutes prior to the actual collection of the blood samples
- catecholamine metabolites (metanephrine and vanillylmandelic acid) and free catecholamines are also measured in urine; 24-hour urine collection test
- avoid bananas, chocolate, vanilla, and tea or coffee (including decaffeinated)
CT or MRI Scans
to determine whether tumor is unilateral or bilateral
-also helps guide the surgeon performing a adrenalectomy
Medical Management for Pheochromocytoma
patient presenting w/ signs of hypertension, tachycardia and other clinical manifestations of pheochromocytoma require:
- Bed rest with HOB elevated
- Cardiac monitor to assess for cardiac dysrhythmias
- Pharmacological: focuses on quickly lowering BP; includes alpha-adrenergic blocking agents or smooth muscle relaxants, and beta blockers and calcium channel blockers to low HR and BP
Pharmacological Management
focuses on quickly lowering the BP
- alpha-adrenergic blocking agents
- smooth muscle relaxants
- beta blockers and calcium channel blockers to lower HR and BP
Adrenalectomy
- definitive treatment
- goal: complete tumor resection, minimal tumor manipulation, and adequate exposure of the adrenal gland to avoid injury to other organs
- different approaches; standard approach is open transabdominal anterior approach through a bilateral subcostal incision; or a laparoscopic approach
Patient Preparation for Adrenalectomy (preop)
focuses on control of blood pressure and heart rate
- treatment w/ alpha-adrenergic blockers is started 7 to 10 days prior to scheduled procedure w/ a goal of 120/80 mmHg or lower in a seated position
- a beta blocker may be used to control HR but only AFTER blood pressure is lowered
- fluid management preoperatively b/c of vasodilation secondary to alpha-adrenergic blockers
During an Adrenalectomy what is the patient at risk for?
- a hypertensive crisis b/c the vascular pheochromocytoma is manipulated and removed
- sodium nitroprusside (Nipride) or alpha-adrenergic blockers cautiously administered
Postoperative management of Adrenalectomy
focuses on monitoring blood pressure, heart rate, and blood glucose
- b/c of sudden decrease in circulating catecholamines as a result of tumor removal, patient may develop hypotension and or hypoglycemia
- monitor for blood loss d/t the vascular nature of the adrenal gland
- several days post-op, plasma and urine samples are collected for measurement of catecholamine levels and catecholamine metabolites
What if a Patient Requires Bilateral Adrenalectomy
-necessitates life-long adrenal cortex hormone replacements
-required to take cortisol daily and may acquire additional doses during physiological or emotional stress
-are at risk for adrenal insufficiency for the remainder of their lives
>catecholamines from the adrenal medulla do not require replacement b/c they are also produced in the sympathetic nervous system)
Nursing Management: Assessment and Analysis
clinical presentation of pheochromocytoma is r/t the effects of increased levels of circulating epinephrine and norepinephrine >Hypertension >Tachycardia >Hyperglycemia >Pounding Headaches
Nursing Diagnoses
- Risk for injury: Cerebrovascular Hemorrhage r/t severe hypertension
- Acute pain: Headache r/t increased levels of circulating catecholamines secondary to the hypersecreting tumor
- Risk for injury: Postoperative hemorrhage rt/t adrenalectomy
Nursing Interventions: Assessments
- Vital Signs
- Cardiac Monitoring
- Headache (from hypertension)
- Plasma and catecholamine metabolite measurements (VMA)
Assessments: Vital Signs
- hypertension and tachycardia develop secondary to excessive circulating catecholamines
- pt who undergo adrenalectomy, may develop signs of hypovolemia and chock secondary to hemorrhage
Assessments: Cardiac monitoring
patient is at risk for tachydysrhythmias secondary to elevated catecholamines
Assessments: Plasma and Catecholamine metabolite measurements (VMA)
elevated levels of catecholamines result in increased levels of catecholamine metabolites
Nursing Actions
- Administer sodium nitroprusside (Nipride)
- Administer alpha-adrenergic blocking agents
- Administer beta-adrenergic blocking agents
- Best rest w/ HOB elevated
- Maintain calm, quiet environment
- Administer Glucocorticoid the morning of surgery for adrenalectomy
Sodium Nitroprusside (Nipride)
quickly decreases BP through direct action on blood vessels, leading to peripheral vasodilation
Alpha-adrenergic Blocking Agents
decreases blood pressure by blocking the alpha-adrenergic effects of blood vessels that lead to vasoconstriction
-blocking action results in vasodilation
