Although surgery-related morbidity has been largely reduced in recent years, perioperative haemodynamic instability in patients with pheochromocytomas and paragangliomas (PPGLs) is not easily predictable; pre and postoperative medical management of PPGLs remains still controversial. This retrospective study was aimed to identify risk factors for postoperative hypotension (PH) and instability requiring intensive postoperative monitoring and amines infusion in patients undergoing surgery for PPGLs.

Seventy-nine patients undergoing surgery for PPGLs were included. Demographics, clinical, biochemical, radiological, histopathological and cardiovascular data were collected. PH was defined as systolic arterial blood pressure < 90 mmHg, needing for vasopressor support with intravenous amines infusion within 24h after surgery and postoperative monitoring in intensive care unit.

PH occurred in 25 patients (32%). At univariate analysis, tumour size (p=0.007), acute cardiovascular events at diagnosis (p=0.04), the preoperative use of Beta-blockers (p=0.04), elevated 24h-urinary norepinephrine (p=0.001) and normetanephrine levels (p=0.02) were identified as predictive factors for PH. The ROC curve analysis revealed a cut off value at 4 and 1.6 times the upper normal range for 24-h urinary norepinephrine and normetanephrine, respectively, for prediction of risk of PH, with a sensitivity of 70.6% and 82%, respectively, and a specificity of 82.5% and 53%, respectively, (p<0.05). At multivariate analysis, preoperative 24h-urinary norepinephrine higher than 4 times the upper normal range value remained the only independent predictive factor for PH (OR 8.5, 95% CI 1.75-41.4; p=0.008).

The increased preoperative 24h-urinary norepinephrine levels is an independent predictor of PH and may be used to stratify patients needing intensive postoperative monitoring.