Changes in blood pressure, blood sugar, and quality of life in patients undergoing pheochromocytoma surgery: a prospective cohort study.

Introduction: Pheochromocytoma surgery is associated with significant hemodynamic and metabolic changes that require post-operative monitoring. We prospectively evaluated the trends of blood pressure, blood sugar, body mass index (BMI), and quality of life (QoL) changes in a cohort of patients undergoing pheochromocytoma surgery to determine the minimum duration of monitoring and assess factors that could predict these changes.

Materials and Methods: Consecutive patients undergoing surgery for pheochromocytoma over a 20-month period were included in this ethics review board-approved, prospective cohort study. Blood pressure and sugar levels were serially monitored using a fixed protocol in the perioperative period and subsequently at 3 months after surgery. BMI and QoL (using World Health Organization Quality of Life [WHOQOL-BREF] questionnaire) were recorded at baseline and 3 months. Changes were compared and assessed for the predictive factors.

Results: Twenty-six patients undergoing 31 procedures were included in the study of whom 8 (30%) developed hypotension and 4 (15%) developed hypoglycemia after surgery. All hypotension episodes occurred within 6 hours of surgery. However, while 3 of the 4 patients who developed hypoglycemia manifest in the first 4 h after surgery, one occurred after 12 h. Occurrence of hypotension correlated with preoperative 24-h urinary vanillylmandelic acid (VMA) levels ( P = 0.02) and the total daily dose of prazosin ( P = 0.04). Out of 21 hypertensive patients, 7 (33%) had persistent hypertension (HTN) at 3 months and this was associated with age ( P = 0.04) and diabetes mellitus (DM) at presentation ( P = 0.04). Among six diabetic patients, 1 (16%) had persistent DM. There was significant increase in the BMI ( P < 0.0001) and in WHOQOL-BREF scores postoperatively.

Conclusions: Hypotension occurs in 30% patients and hypoglycemia in 15% after pheochromocytoma surgery. Hypotension occurs immediately but hypoglycemia may manifest upto 12h after surgery. Older, diabetic patients are more likely to have persistent HTN. Surgery results in increase in BMI and improvement in QoL.