Saturday, April 20, 2013

Pheo

The pheochromocytoma is a fascinating tumor. Originating in the medulla of the adrenal glands, this cancer secretes catecholamines like adrenaline (epinephrine) and noradrenaline. As a result, patients present with pounding headaches, uncontrollably high blood pressures, racing heart rates, palpitations, anxiety, sweating - all the symptoms you or I have when presenting in front of a large audience. When these patients present for surgical resection, they are at very high risk for perioperative complications, and the anesthesia can be challenging.

The biggest risk is in blood pressure lability; a hypertensive surge can cause a stroke, heart attack, pulmonary edema, kidney damage, and other permanent injuries. Yet blood pressures that are too low risk some of the same consequences. If a patient has had proper diagnosis and management, she will be premedicated with blockers to the catecholamines to ameliorate the effects of big swings in circulating adrenaline. Like cardiac cases, we place an arterial line for close blood pressure monitoring prior to induction. We have the full array of blood pressure medications available to manipulate heart rate and pressure up and down as needed. We cannot expect everything to work normally because the body is so used to high surges of catecholamines and the patients have been taking catecholamine blockers. Once patients are asleep, they need a central line for infusions of these medications and occasionally, a pulmonary artery catheter if their heart has taken a hit from the pheo. When the surgeons get close to the tumor, what they do affects us greatly. If they can take out the entire tumor without disturbing its contents, things go smoothly. But if in manipulating the pheochromocytoma they release its contents, we may have to contend with a catastrophic spike in blood pressure and heart rate. After the mass is out, the circulatory system may collapse if it's used to the tumor's hormones, and we may have to supplement adrenaline-like infusions to smooth out the blood pressure. Fortunately, this surgery went well, but this is an example of how the disease and the surgery impact the anesthesia directly.


Image of gross pathology of pheochromocytoma is in the public domain, from Wikipedia.

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