Background. Alpha-receptor blockade is the mainstay in preoperative treatment of patients with pheochromocytoma and paraganglioma (PPGL). However, evidence regarding optimal dosage regimen is lacking. This study compares the per- and postoperative hemodynamics in patients pre-treated with a high or low dose of phenoxybenzamine.
Methods. 30 consecutive patients with PPGL undergoing laparoscopic adrenalectomy were identified retrospectively. All were pretreated with phenoxybenzamine but at two separate endocrine departments aiming at different blood pressure target. End-dosage of phenoxybenzamine differed significantly between departments with 14 patients receiving a high dose regimen and 16 a low dose regimen. As a control group, we included 42 patients undergoing laparoscopic adrenalectomy for other reasons. Primary purpose was to compare per- and postoperative hemodynamics in the high and low dose groups. Secondly, to compare these endpoints to the control group.
Results. Baseline characteristics did not differ between the phenoxybenzamine treated groups. The high dose group had less intra-operative systolic and diastolic blood pressure fluctuation (p = 0.03) and less periods with heart rate above 100 bpm (p = 0.04) as compared to the low dose group. Use of intravenous fluids were similar between the two groups. However, postoperatively, more intravenous fluids were administered in the high dose group. Overall, the control group was more hemodynamic stable as compared to either group treated for PPGL.
Conclusions. High dose phenoxybenzamine improves per-operative hemodynamic stability but causes a higher postoperative requirement for intravenous fluids. Overall, PPGL surgery is related to greater hemodynamic instability compared to adrenalectomy for other reasons.