Routine Glucose Monitoring in Postoperative Pheochromocytoma Patients: Yes or No?
Pheochromocytomas are rare neuroendocrine tumors characterized by the release of catecholamines. In the preoperative setting, the release of these catecholamines can lead to hyperglycemia by promoting liver glycogenolysis and gluconeogenesis, inhibiting pancreatic insulin secretion, and enhancing peripheral insulin resistance. Postoperatively, there is often a period of rebound hypoglycemia that can be dangerously prolonged given the preoperative depletion of glycogen stores secondary to high catecholamine levels. This complication of postoperative hypoglycemia can be extremely detrimental given that it often goes unrecognized secondary to the masking effects of anesthesia. The change in mental status associated with hypoglycemia may be incorrectly attributed to residual anesthesia. Alpha and beta-blockade further blunt the body’s natural response to hypoglycemia which is usually tachycardia, palpitations, and sweating. Prolonged, unrecognized hypoglycemia can lead to severe neurologic consequences such as seizures, unconsciousness, or even irreversible brain damage. This complication must therefore be preemptively anticipated and acutely managed. A thorough literature search over the years provides data in favor of routine postoperative glucose monitoring after pheochromocytoma resection. Given the high stakes involved with missing this relatively common diagnosis seen in 4–15% of pheochromocytoma patients undergoing resection, a GRADE 1C recommendation for routine monitoring in all postoperative pheochromocytoma patients for the first 5 h has been deemed appropriate.
KeywordsPheochromocytoma resection Postoperative hypoglycemia Unrecognized hypoglycemia Routine postoperative glucose monitoring in all patients Elevated preoperative urine metanephrine levels Alpha and beta blockade Neurologic complications
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