Unit 2: Pheochromocytoma Flashcards
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
Beta-adrenergic Blocking Agents
leads to increased chronotropic (rate) and inotropic (force) effects of the heart
-decreases HR and force of contraction
Why should you administer glucocorticoid the morning of surgery for Adrenalectomy?
minimizes risk of adrenal insufficiency post-op caused by the surgical manipulation of the adrenal glands, particularly pts undergoing bilateral adrenalectomy
Nursing Teachings
> Clinical manifestations of adrenal insufficiency
- in bilateral adrenalectomy, lifelong cortisol replacement is required
- patient is at risk for adrenal insufficiency, especially at times of stress
> Postoperative teaching r/t adrenalectomy
- monitor body temp
- monitor surgical site
Evaluating Care Outcomes
- definitive treatment w/ adrenalectomy results in compete resolution of the disease process
- b/c there is possibility of incomplete resection of the pheochromocytoma or recurrence in patients w/ a family hx of this disorder, need to have periodic checks of their blood pressure
- patients w/ bilateral adrenalectomy require lifelong cortisol replacement
Connection Check: Which assessment maneuver is contraindicated in the patient suspected of having a pheochromocytoma?
A. having the patient attempt to touch the chin to the chest
B. Inflating the BP cuff above 200 mmHg
C. Attempting to dorsiflex the feet
D. Palpating the abdomen
D. Palpating the abdomen
adrenal gland on kidneys
