Case Presentation:
In our morning report at WCH, we discussed a case of a patient presenting with severe hypertension and episodic headaches. Subsequent laboratory investigation and imaging confirmed the presence of a unilateral adrenal mass which was a pheochromocytoma.
Learning Points:
- Establishing the diagnosis of hypertension
- Recognizing the difference between hypertensive urgency and emergency
- Differential diagnosis of secondary hypertension
- Diagnosis and management of pheochromocytoma
Establishing the Diagnosis:
CHEP Guidelines
Hypertensive Urgency vs Emergency:
- Urgency=asymptomatic marked BP elevation without target organ damage
- Emergency=marked BP elevation + presence of acute symptoms or progressive target organ damage
- Brain (Stroke, ICH, encephalopathy)
- Eyes (hypertensive retinopathy)
- Heart (MI, CHF, Dissection)
- Kidneys (hematuria, AKI)
Causes of secondary hypertension:
Pheochromocytoma:
- Risk factors: family history, genetic syndromes (Von Hippel-Lindau disease, MENIIa or IIb, Neurofibromatosis-I)
- Clinical features: “triad” of headache, palpitations, diaphoresis seen only a fraction of the time
- Triggers of episodes: anesthesia, drugs (contrast, glucagon, metoclopramide, TCA, foods/beverages)
- When to consider testing for possible pheochromocytoma:
- Clinical triad
- Hyperadrenergic spells (episodic palpitations diaphoresis, headache tremor, pallor)
- Early onset HTN, resistant HTN, or HTN with new onset DM2 in slender patient
- Familial syndrome (VHL, MEN, NF1)
- Adrenal incidentaloma + HTN
- Paroxysmal HTN with anesthesia/surgery
- Family History of pheochromocytoma
- History of gastric stromal tumor or pulmonary chondroma
- Biochemical Testing:
- Caveat: levels altered by certain drugs and diseases so must take clinical context into consideration and stop drugs, if able
- Drugs: TCAs, psychotropics, prochlorperazine, decongestants, levodopa
- 24 hour urinary fractionated metanephrines & catecholamines
- plasma fractionated metanephrines
- Note:
- Metanephrines: metanephrine and normetanephrine
- Catecholamines: Norepinephrine, epinephrine, and dopamine
- Caveat: levels altered by certain drugs and diseases so must take clinical context into consideration and stop drugs, if able
- Imaging:
- Proceed with imaging if biochemical analysis positive
- CT or MRI
- If CT or MRI negative (but biochemical positive), possibilities include:
- Wrong diagnosis (false positive biochemistry)
- Extra-adrenal mass (i.e. paraganglioma)
- Evaluate with MIBG scan
- Other indications for MIBG: very large adrenal mass (higher malignant/metastatic risk)
- Genetic Testing:
- indicated if:
- unilateral pheochromocytoma, age <45 years
- Associated genetic syndrome
- Extra-adrenal paraganglioma
- Bilateral pheochromocytoma
- Unilateral pheochromocytoma with family history
- indicated if:
- Management considerations:
- surgical adrenalectomy (laparoscopic preferred)
- Preparation for surgery:
- Start alpha blockade first (phenoxybenzamine or alpha 1 antaongists like doxazosin/terazosin)
- Then start high salt intake (i.e. 5 g/day)-reverse catecholamine-related volume contraction/prevent CV collapse post-resection
- Start beta blockade once adequate alpha blockade achieved
- start low, go slow (risk of CHF due to catecholamine-related cardiomyopathy)
- Patient to measure home BP BID; target <120/80 seated and sBP>90 standing
- Start alpha blockade first (phenoxybenzamine or alpha 1 antaongists like doxazosin/terazosin)
- Perioperative considerations:
- Hemodynamic monitoring
- Acute HTN-IV infusion of nitro good option
- Post-op HoTN: IV fluids
- Post-op hypoglycemia: IV dextrose-containing solution