Signs of adequate preparation
Preoperative preparation for pheochromocytoma aims to control blood pressure and restore blood volume so that the client can tolerate the sudden fall in catecholamines when the tumor is removed. Per the unit protocol, the target seated blood pressure is below 130/80 mmHg. A seated pressure of 124/76 mmHg meets the target, and mild dizziness on standing is an expected sign that alpha blockade is working. Blood pressure at target with only mild orthostatic symptoms shows effective preparation.
Why some orthostatic effect is expected
Alpha blockade relaxes the blood vessels, so when the client stands, blood pools in the legs before reflexes can compensate. A mild drop with slight dizziness indicates that the vasoconstriction caused by catecholamines has been effectively blocked. However, the effect should be mild. Severe orthostatic hypotension with fainting suggests excessive blockade or that the blood volume has not been restored, both of which increase the risk of severe hypotension after tumor removal.
| Finding | Interpretation |
|---|
| Seated 142/88 mmHg, no dizziness | Above target; blockade not adequate |
| Seated 124/76 mmHg, mild dizziness on standing | At target; adequate preparation |
| Seated 118/74, standing 78/46 mmHg with fainting | Excessive blockade or low volume |
| Seated 126/78 mmHg, heart rate 128 | Ongoing catecholamine effect on the heart |
Why the other findings are not adequate
A seated pressure of 142/88 mmHg is above the protocol target, so blockade is not yet sufficient, even though he has no dizziness. A seated pressure of 118/74 mmHg with a standing pressure of 78/46 mmHg and fainting shows too much blockade or an inadequately restored volume. A seated pressure of 126/78 mmHg with a heart rate of 128 beats/min meets the pressure target but shows continuing catecholamine effect on the heart, which may need beta blockade once alpha blockade is established. Watch out! An adequate result must satisfy all criteria, not just the blood pressure.
Exam takeaway
Evaluate preparation using blood pressure against the target, orthostatic response, heart rate, and signs of restored volume. Key point! Seated blood pressure at target with mild orthostatic dizziness indicates adequate preparation; fainting or marked tachycardia does not.