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Pheochromocytoma Cheat Sheet by

Pheochromocytoma and anesthetic management

Catech­olamine Secreting Tumor

Occu­ren­ce: 90% of the time is isolated; 10% familial. Pts are usually 30-40 years old upon diagnosis. 80% of the time occur within adrenal medulla or at organ of Zucker­kandl (near the aortic bifurc­ation); 2% at the neck and thorax.
NE: Epi secretion ratio = 85:15 (opposite of normal adrenal secretion)
Mort­ality Rate with surgery: 0-3%
Sign and Sympto­ms: HTN, sweating, headache, pallor, palpit­ations, orthos­tatic hypote­nsion. NE (alpha) - systolic & diastolic HTN with reflex bradyc­ardia. Epi (beta) - systolic HTN and diastolic hypote­nsion with tachyc­ardia. Cardio­myo­pathy - dilated and hypert­rophic and left ventri­cular outflow obstru­ction. Coronary vasoco­nst­riction leads to decreased coronary blood flow. ECG changes: ST segment changes, T wave changes, prolonged QT, peaked P waves, left axis deviation and dysrhy­thmias. Increased blood glucose due to glycog­eno­lysis and inhibited insulin release.
Diag­nos­is: Pts with low probab­ility: 24-hour urine collection will show vanill­yma­ndelic acid (metab­olites of NE/Epi). Pts with high probab­ility: plasma free metane­phrines (catec­hol­amine metabo­lites). Clonidine supression test: no effect to clonidine means positive for pheoch­rom­ocytoma
Pre-op Manage­ment: Phenox­ybe­nza­mine: (non-c­omp­etitive alpha 1 antago­nist) has a long duration so, discon­tinue 24-48 hours pre-op. Prazosin and doxazosin: (alpha 1 compet­itive antago­nist) short acting and causes less tachyc­ardia. Labetalol: (non-s­ele­ctive beta-b­locker) for heart rates greater than 120 bpm. Esmolo­l:(Beta 1 selective) good for Epi secreting pheo's. Alpha-­met­hyl­par­aty­rosine: inhibits tyrosine hydrox­ylase - rate limiting enzyme. Nifedi­pine, diltiazem, verapamil, captopril: (CCBs) decrease catech­olamine release. ACE inhibi­tors.
Intra-op Manage­ment: Histamine releas­ers: morphine and atracu­rium. Catac­hol­amine inducers: atropine, pancur­onium, succin­ylc­holine. Hyper­ten­sion - Nitrop­russide (direct vasodi­lator). Phento­lamine (compe­titive alpha blocker). Nitrog­lyc­erine can cause tachyc­ardia and you need a large dose. Labetalol (epi secreting tumors). Magnesium - decreased catech­olamine release, decreases sensit­ivity of the alpha receptor to NE/Epi and is a direct vasodi­lator. Ventr­icular Arrhyt­hmias - Lidocaine or Beta blockers. Fluids - LR, NS, D5W. Glucoc­ort­icoids.
Post-op Manage­ment: Take 7-10 days for plasma catech­olamine levels to decrease. Goal BP : <165/90 >80/45 mmHg for the first 48 hours.

Presen­tation with different catech­olamine release

NE
EPI
Other SS
HTN
Palpit­ations
Dysrht­hmias
Headache
Tachyc­ardia
Cardio­myo­pathy
Sweating
Panic/­Anxiety
MI
Pallor
Tremors
Enceph­alo­pathy
Bradyc­ardia
Hyperg­lycemia
Stroke
  
Renal Insuff­iciency
  
Tumar mass effects (i.e. compre­ssion)
       
 

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