Pheochromocytoma: Adrenal Gland Tumors
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Questions and Answers

What is the origin of the term 'pheochromocytoma'?

  • Phios means tumor, chroma means dusky, and cytoma means color
  • Phios means dusky, chroma means color, and cytoma means tumor (correct)
  • Phios means color, chroma means dusky, and cytoma means tumor
  • Phios means tumor, chroma means color, and cytoma means dusky

    • What is the most common location of a pheochromocytoma?

  • Adrenal medulla (correct)
  • Paravertebral sympathetic chain
  • Abdominal cavity
  • Extraadrenal sites

    • What percentage of pheochromocytomas produce norepinephrine?

  • 75%
  • 50%
  • 90% (correct)
  • 100%

    • What is a common symptom of pheochromocytoma?

    <p>Headache</p> Signup and view all the answers

    What can excessive and prolonged alpha-1 receptor stimulation result in?

    <p>Intravascular volume depletion</p> Signup and view all the answers

    What is a preoperative concern in managing pheochromocytoma?

    <p>All of the above</p> Signup and view all the answers

    What is a postoperative concern in managing pheochromocytoma?

    <p>Treating pain and stabilizing blood pressure</p> Signup and view all the answers

    What is the most common location of extraadrenal pheochromocytomas?

    <p>Abdominal cavity</p> Signup and view all the answers

    What percentage of pheochromocytomas occur in bilateral adrenal glands?

    <p>50%</p> Signup and view all the answers

    What is the association between pheochromocytoma and other diseases?

    <p>With multiple endocrine neoplasia type Il A and B, neurofibromatosis, tuberous sclerosis, Sturge-Weber syndrome, and von Hippel-Lindau disease</p> Signup and view all the answers

    What is the primary catecholamine released in patients with pheochromocytoma?

    <p>Norepinephrine</p> Signup and view all the answers

    What is the effect of orthostatic hypotension in patients with pheochromocytoma?

    <p>Decreased blood pressure</p> Signup and view all the answers

    What is the reason for catecholamine release in pheochromocytoma not being fully understood?

    <p>Due to unclear precipitating factors</p> Signup and view all the answers

    What is a rare condition associated with pheochromocytoma?

    <p>Sturge-Weber syndrome</p> Signup and view all the answers

    What is a potential complication of pheochromocytoma?

    <p>All of the above</p> Signup and view all the answers

    What percentage of patients with hypertension have pheochromocytoma?

    <p>0.2%</p> Signup and view all the answers

    What is the primary advantage of laparoscopic adrenalectomy over traditional open technique?

    <p>Smaller incision resulting in decreased postoperative pain</p> Signup and view all the answers

    What is the potential complication of prolonged insufflation during laparoscopic adrenalectomy?

    <p>Cardiovascular compromise</p> Signup and view all the answers

    What is the anatomical location of the adrenal glands?

    <p>Superior to the kidneys</p> Signup and view all the answers

    What is the physiological response to the release of catecholamines by a pheochromocytoma?

    <p>Directly proportional to the concentration of catecholamines</p> Signup and view all the answers

    What is the potential consequence of baroreceptor activation in response to extreme hypertension?

    <p>Bradycardia</p> Signup and view all the answers

    What is the common triad of signs and symptoms associated with a pheochromocytoma?

    <p>Headache, diaphoresis, and tachycardia</p> Signup and view all the answers

    What is the benefit of ligating the adrenal vein during adrenalectomy?

    <p>Reduced risk of uncontrolled hemorrhage</p> Signup and view all the answers

    What is the potential complication of surgical dissection during laparoscopic adrenalectomy?

    <p>Pneumothorax</p> Signup and view all the answers

    What is the effect of taking phenelzine sulfate on the concentration of catecholamines within the synaptic junction in adrenergic nerves?

    <p>Increase</p> Signup and view all the answers

    Why does the patient need to discontinue taking phenelzine sulfate 1 to 2 weeks before surgery?

    <p>To prevent an uncontrolled hypertensive response</p> Signup and view all the answers

    What is one of the optimal preoperative cardiovascular criteria that should be achieved before surgery?

    <p>Blood pressure less than 160/90 mm Hg within 48 hours before surgery</p> Signup and view all the answers

    What is a factor that increases the morbidity and mortality associated with removal of a pheochromocytoma?

    <p>Advanced end-organ damage</p> Signup and view all the answers

    What is the primary goal of a clonidine suppression test in diagnosing pheochromocytoma?

    <p>To centrally mediate alpha-2 agonism and decrease catecholamine output from the brain</p> Signup and view all the answers

    What is the 5-year survival rate for a patient with a benign pheochromocytoma?

    <p>90%</p> Signup and view all the answers

    What is the significance of a 5% decrease in baseline hematocrit level in preoperative management of pheochromocytoma?

    <p>Indicates adequate volume resuscitation</p> Signup and view all the answers

    What happens to the survival rate of a patient with a pheochromocytoma if it is malignant?

    <p>It decreases to 10%</p> Signup and view all the answers

    What is one of the concerns during preoperative management of a patient with a pheochromocytoma?

    <p>Control of excessive catecholamine release</p> Signup and view all the answers

    What is the role of phenoxybenzamine in preoperative pharmacologic preparation for a patient with pheochromocytoma?

    <p>Alpha-receptor blockade</p> Signup and view all the answers

    What is the significance of elevated plasma norepinephrine levels in diagnosing pheochromocytoma?

    <p>Indicates the presence of a pheochromocytoma</p> Signup and view all the answers

    What can prolong the surgical duration and increase the morbidity and mortality associated with removal of a pheochromocytoma?

    <p>Prolonged surgical duration</p> Signup and view all the answers

    What is the medication that can be administered preoperatively to inhibit catecholamine creation in adrenergic nerves?

    <p>Metyrosine</p> Signup and view all the answers

    What is the purpose of a 24-hour urine test in diagnosing pheochromocytoma?

    <p>To assess the levels of urinary metanephrines</p> Signup and view all the answers

    What is the significance of orthostatic hypotension in preoperative management of pheochromocytoma?

    <p>Indicates adequate volume resuscitation</p> Signup and view all the answers

    What is the purpose of imaging studies such as CT scan, PET scan, or MRI in diagnosing pheochromocytoma?

    <p>To identify the presence of a tumor and its size and location</p> Signup and view all the answers

    What is the significance of MIBG scintigraphy in diagnosing pheochromocytoma?

    <p>To localize pheochromocytoma with high sensitivity and specificity</p> Signup and view all the answers

    Why is alpha-receptor blockade instituted before beta-receptor blockade in preoperative management of pheochromocytoma?

    <p>To prevent hypertensive crisis and congestive heart failure</p> Signup and view all the answers

    What should be avoided during intraoperative management of a patient with pheochromocytoma?

    <p>Medications that increase heart rate and blood pressure</p> Signup and view all the answers

    Why is an epidural placed preoperatively in a patient with pheochromocytoma?

    <p>To provide analgesia during the postoperative period</p> Signup and view all the answers

    What is a concern when dosing an epidural catheter with local anesthetic medications during the intraoperative period?

    <p>Hypotension</p> Signup and view all the answers

    Why are two large-bore peripheral intravenous lines indicated in a patient with pheochromocytoma?

    <p>To anticipate and manage rapidly developing hemorrhage</p> Signup and view all the answers

    What is required for blood pressure monitoring in a patient with pheochromocytoma?

    <p>Arterial line placement</p> Signup and view all the answers

    Why should nitrous oxide be avoided in a patient with pheochromocytoma?

    <p>Due to concerns regarding the development of a pneumothorax</p> Signup and view all the answers

    What should be achieved before direct laryngoscopy in a patient with pheochromocytoma?

    <p>Adequate anesthetic depth</p> Signup and view all the answers

    What is the purpose of preoperative sedation in a patient with pheochromocytoma?

    <p>To decrease anxiety and SNS activity</p> Signup and view all the answers

    What is the primary concern during the administration of succinylcholine for muscle paralysis in patients with pheochromocytoma?

    <p>Fasciculations causing abdominal rigidity and release of catecholamines</p> Signup and view all the answers

    What is the most effective way to manage hypertension during intubation, incision, manipulation of the tumor, and ligation of the venous drainage of the affected adrenal gland?

    <p>Using sodium nitroprusside as an intravenous drip</p> Signup and view all the answers

    Why does the heart rate abruptly decrease to less than 50 beats per minute during the extreme hypertensive response?

    <p>Due to the baroreceptor response</p> Signup and view all the answers

    What is the primary cause of hypotension after removal of the tumor?

    <p>Metabolism of catecholamines</p> Signup and view all the answers

    What is the advantage of administering esmolol for beta-receptor blockade?

    <p>It is metabolized extremely rapidly and does not cause persistent blockade</p> Signup and view all the answers

    What is the primary reason for assessing blood glucose levels preoperatively and throughout the surgical procedure?

    <p>To monitor for hyperglycemia due to inhibition of endogenous insulin release and glycogenolysis</p> Signup and view all the answers

    What is the significance of ligating the venous drainage of the affected adrenal gland?

    <p>To prevent the release of catecholamines into the systemic circulation</p> Signup and view all the answers

    What is the effect of administering anesthesia and preoperative adrenergic blockade on the blood pressure?

    <p>It decreases the blood pressure</p> Signup and view all the answers

    Why is the inhalation anesthetic concentration decreased during the surgery?

    <p>To reduce the anesthetic depth</p> Signup and view all the answers

    What is the effect of the administration of fluids and decreasing the anesthetic depth on the central venous pressure?

    <p>It increases the central venous pressure</p> Signup and view all the answers

    What is a potential complication that may result from residual alpha-adrenergic receptor blockade after an adrenalectomy for a pheochromocytoma?

    <p>Hypotension</p> Signup and view all the answers

    What is a common cause of hemorrhage after an adrenalectomy for a pheochromocytoma?

    <p>Bleeding from adrenal vein</p> Signup and view all the answers

    What is a potential complication that may result from hypoglycemia after an adrenalectomy for a pheochromocytoma?

    <p>Acute renal failure</p> Signup and view all the answers

    What is a potential cause of pneumothorax after an adrenalectomy for a pheochromocytoma?

    <p>Laparoscopic insufflation</p> Signup and view all the answers

    What is a potential complication that may result from hypovolemia after an adrenalectomy for a pheochromocytoma?

    <p>Hypotension</p> Signup and view all the answers

    Which anesthetic medication should be avoided in patients with pheochromocytoma due to its sympathomimetic effects?

    <p>Ketamine</p> Signup and view all the answers

    Which of the following signs and symptoms is NOT associated with pheochromocytoma?

    <p>Hypotension</p> Signup and view all the answers

    Which medication can cause histamine release, making it a poor choice for patients with pheochromocytoma?

    <p>Atracurium</p> Signup and view all the answers

    What is the primary concern with using desflurane in patients with pheochromocytoma?

    <p>It can exacerbate sympathetic nervous system stimulation</p> Signup and view all the answers

    What is the main reason to avoid droperidol in patients with pheochromocytoma?

    <p>It can cause antidopaminergic effects</p> Signup and view all the answers

    Study Notes

    Definition and Location

    • Pheochromocytoma is a dusky-colored tumor derived from chromaffin cells.
    • Most commonly located in the adrenal medulla, but can also occur in extraadrenal sites.

    Symptoms and Effects

    • 90% of pheochromocytomas cause massive norepinephrine production and release into systemic circulation.
    • Epinephrine can also be the predominant catecholamine produced.
    • Common triad of symptoms: headache, diaphoresis, and tachycardia.
    • Excessive and prolonged alpha-1 receptor stimulation can lead to:
      • Intravascular volume depletion
      • Renal insufficiency
      • Hemorrhagic cerebral infarct
      • Myocardial irritability
      • Ischemia and infarction
      • Congestive heart failure and cardiomyopathy (if hypertension remains untreated)

    Management and Anesthetic Concerns

    • Preoperative management includes:
      • Adrenergic receptor blockade (alpha-receptor blockade followed by beta-receptor blockade)
      • Intravascular volume replacement
      • Assessment of end-organ damage
    • Intraoperative surges in catecholamine release can occur during:
      • Laryngoscopy
      • Intubation
      • Manipulation of the tumor
      • Ligation of the adrenal vein
    • Postoperative anesthetic concerns include:
      • Treating pain
      • Stabilizing blood pressure
      • Prompt diagnosis and treatment of:
        • Pneumothorax
        • Hypoglycemia
        • Hypoadrenocorticism

    Pathophysiology

    • Pheochromocytomas are catecholamine-secreting tumors that originate in the adrenal gland (90% of cases) or extraadrenal sites (paravertebral sympathetic chain).
    • Tumors are composed of chromaffin cells that produce, store, and secrete catecholamines.
    • Most extraadrenal pheochromocytomas occur in the abdominal cavity.
    • Unilateral adrenal gland is most frequently affected, and most tumors are benign.
    • Familial pheochromocytomas occur in bilateral adrenal glands (50% of cases) and are frequently benign.

    Epidemiology

    • Pheochromocytomas affect males and females equally.
    • Most frequently manifest between 30 and 50 years of age.
    • Associated with multiple endocrine neoplasia type II A and B, neurofibromatosis, tuberous sclerosis, Sturge-Weber syndrome, and von Hippel-Lindau disease.

    Clinical Manifestations

    • Sympathetic nervous system (SNS) stimulation causes a massive release of catecholamines, predominantly norepinephrine.
    • Common clinical manifestations include:
      • Headache
      • Diaphoresis
      • Tachycardia
      • Arrhythmias with palpitations
      • Anxiety
      • Pallor
      • Hypertension
      • Hyperglycemia
      • Paresthesias to the extremities
      • Orthostatic hypotension
      • Polycythemia
      • Cerebral hemorrhage
      • Myocardial infarction
      • Cardiomyopathy
      • Congestive heart failure
      • Renal insufficiency

    Surgical Procedure for Adrenalectomy

    • Adrenalectomy is traditionally performed through an open transperitoneal approach, but laparoscopic adrenalectomy has become the most common surgical technique for removal of a pheochromocytoma.
    • The patient is placed in the lateral decubitus position for maximal exposure to the surgical site in laparoscopic adrenalectomy.
    • The adrenal vein is located and ligated, and the adrenal gland is then excised and removed.
    • Laparoscopic approach has advantages, including small incision, decreased postoperative pain, and potential for developing a pneumothorax during the surgical dissection.

    Signs and Symptoms of Pheochromocytoma

    • A triad of signs and symptoms associated with a pheochromocytoma include headache, diaphoresis, and tachycardia.
    • Other physiologic signs and symptoms include hypertension, arrhythmias, ST-segment changes, nervousness, and anxiety.
    • Hypertension associated with tachycardia is most common, but the physiologic response is directly proportional to the concentration of catecholamines that are released.

    Diagnosis of Pheochromocytoma

    • The initial diagnosis of pheochromocytoma is difficult to make due to nonspecific symptoms, varying among individuals, and the rarity of the disease.
    • Diagnostic tests include:
      • Plasma free metanephrines
      • Urine catecholamine and metanephrine levels
      • Clonidine suppression test
      • 24-hour urine test: three urine samples are collected within a 24-hour period, and the concentration of metanephrines is analyzed.
      • Imaging studies: CT scan, positron emission tomography (PET) scan, or magnetic resonance imaging (MRI) to identify the presence of a tumor and its size and location.
      • MIBG scintigraphy: a chemical with a high affinity for secretory granules present in chromaffin cells.

    Preoperative Pharmacologic Preparation

    • Preoperative pharmacologic management includes alpha-receptor blockade, beta-receptor blockade, and volume expansion.
    • Alpha-receptor blockade is instituted before beta-receptor blockade, usually accomplished by the administration of phenoxybenzamine.
    • Beta-receptor blockade is initiated once adequate alpha-receptor blockade is established, managed with beta-receptor blockade, most often propranolol.
    • Volume expansion is achieved by a decrease of 5% from the baseline hematocrit level or orthostatic hypotension associated with a decline in the systolic blood pressure.

    Preoperative Cardiovascular Criteria

    • The goal of preoperative therapy is to control excessive catecholamine release that causes extreme physiologic aberrations.
    • The following criteria must be met before surgical intervention and anesthesia administration:
      • Blood pressure must remain less than 160/90 mm Hg within 48 hours before surgery.
      • Orthostatic hypotension must occur, but the blood pressure must be greater than 80/45 mm Hg.
      • The ECG must not have ST/T-wave abnormalities for at least 1 week and have no more than one PVC within 5 minutes.
      • Adequate hydration is achieved by a decrease in the hematocrit by approximately 5% from the baseline value.

    Factors that Increase Morbidity and Mortality

    • Factors that increase the potential for morbidity and mortality include:
      • The activity of the pheochromocytoma
      • Inadequate preoperative alpha-receptor and then beta-receptor blockade
      • Advanced end-organ damage (cardiovascular, renal failure)
      • Whether the pheochromocytoma is malignant or benign
      • Prolonged surgical duration

    Intraoperative Period

    • Medications that increase blood pressure or heart rate or cause histamine release should be avoided during intraoperative management.
    • Alternative drugs that stimulate the release or inhibit the breakdown of catecholamines should be used.
    • General anesthesia and endotracheal intubation are necessary for patients with pheochromocytoma.
    • An epidural placed preoperatively can be used to provide anesthesia during surgery and analgesia during the postoperative period.

    Anesthetic Considerations

    • Two large-bore peripheral intravenous lines are indicated due to the risk of rapidly developing hemorrhage.
    • Arterial line placement is required for blood pressure monitoring.
    • A central line is indicated to monitor central venous pressure and assess the patient's volume status.

    Anesthetic Management

    • Preoperative sedation is necessary to decrease anxiety and sympathetic nervous system (SNS) activity.
    • An adequate anesthetic depth should be achieved before direct laryngoscopy to avoid an exaggerated SNS response.
    • Nitrous oxide should be avoided due to concerns regarding pneumothorax development.
    • Succinylcholine administration is controversial due to its potential to increase catecholamine release.

    Blood Pressure Management

    • Hypertension is most common during intubation, incision, tumor manipulation, and ligation of the venous drainage of the affected adrenal gland.
    • Hypertension can be managed by:
      • Increasing the concentration of inhalation anesthetic agent
      • Administering narcotics/dexmedetomidine
      • Using sodium nitroprusside as an intravenous drip
      • Administering clevidipine
      • Administering magnesium sulfate
    • Hypotension is most common after tumor removal and can be treated by:
      • Decreasing the anesthetic depth
      • Administering crystalloids, colloids, or packed red blood cells
      • Administering a direct-acting vasopressor such as phenylephrine

    Blood Glucose Management

    • Blood glucose should be assessed preoperatively and throughout the surgical procedure.
    • Hyperglycemia can occur before tumor removal due to SNS predominance and glycogenolysis.
    • Hypoglycemia can develop rapidly during the postoperative period.

    Intraoperative Course

    • Alpha- and beta-adrenergic blockade may not prevent hypertension and heart rate variability during induction, endotracheal intubation, and epidural catheter placement.
    • Surgical manipulation of the pheochromocytoma can cause an abrupt increase in blood pressure.
    • Ligation of the venous drainage from the adrenal gland can cause a rapid decrease in blood pressure.

    Postoperative Complications after Adrenalectomy for Pheochromocytoma

    • Hypertension can occur due to residual pheochromocytoma, pain, hypoglycemia, hypervolemia, and hypoxia.
    • Hypotension may result from residual alpha-adrenergic receptor blockade, hypovolemia, myocardial ischemia or infarction, bleeding, or sepsis.
    • Pneumothorax is a potential complication.
    • Hemorrhage is a possible postoperative complication.
    • Sepsis is a potential complication after adrenalectomy for pheochromocytoma.
    • Hypoglycemia is a possible postoperative complication.
    • Hypoadrenocorticism is a potential complication after adrenalectomy for pheochromocytoma.
    • Acute renal failure is a possible postoperative complication.

    Anesthetic Medications to Avoid in Pheochromocytoma Patients

    • Desflurane should be avoided due to its sympathomimetic effects
    • Pancuronium should be avoided due to its sympathomimetic effects
    • Atracurium should be avoided due to histamine release
    • Succinylcholine should be avoided as it causes fasciculation, leading to catecholamine release
    • Morphine should be avoided due to histamine release
    • Droperidol should be avoided due to its antidopaminergic effects, which can lead to neuroleptic malignant syndrome
    • Metoclopramide should be avoided due to its antidopaminergic effects, which can lead to neuroleptic malignant syndrome
    • Phenothiazines should be avoided due to their antidopaminergic effects, which can lead to neuroleptic malignant syndrome
    • Ephedrine should be avoided due to its sympathomimetic effects
    • Ketamine should be avoided due to its sympathomimetic effects
    • Atropine should be avoided as it produces tachycardia
    • Naloxone hydrochloride should be avoided due to its sympathetic nervous system predominance

    Signs and Symptoms of Pheochromocytoma

    • Headache is a common symptom
    • Diaphoresis is a common symptom
    • Tachycardia is a common symptom
    • Chest pain is a common symptom
    • Bradycardia is a possible symptom
    • Anxiety is a common symptom
    • Blurred vision is a possible symptom
    • Seizures are a possible symptom

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    Description

    Learn about pheochromocytoma, a type of tumor derived from chromaffin cells, commonly located in the adrenal medulla, and its effects on catecholamine production.

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