Preoperative risk factors for massive blood loss in adrenalectomy for pheochromocytoma

Background: This retrospective analysis of patients who underwent adrenalectomy for pheochromocytoma aimed to determine preoperative risk factors for intraoperative massive blood loss. Preoperative identification of patients at high-risk of massive blood loss may be helpful in anesthesia management and preoperative preparation. Materials and Methods: The study involved data of 268 patients who had undergone pheochromocytoma surgery at the Peking Union Medical College Hospital between January 1, 2013 and October 31, 2016. For analysis, the patients were grouped according to intraoperative blood loss: = 20% of estimated blood volume (group A, n = 38) and < 20% of estimated blood volume (group B, n = 230). Perioperative characteristics were compared between the two groups. Significant variables were selected for a forward stepwise binary logistic regression analysis to determine the independent risk factors for massive blood loss. Results: The two groups showed significant differences in tumor location, tumor size, operative approach, preoperative 24-hour urine level of total noradrenaline, preoperative hemoglobin concentration, phenoxybenzamine maximum daily dose, preoperative preparation time, intraoperative urine volume, crystalloid and colloidal fluid volumes, allogeneic red blood cell transfusion, plasma and autologous blood transfusion volumes, incidence of prolonged hypotension, postoperative drainage volume, lowest and discharge hemoglobin concentrations, length of stay in intensive care unit and length of postoperative hospitalization. Binary logistic regression analysis indicated increased risk of intraoperative massive blood loss in subjects with tumors proximal to vessels or other organs (odds ratio (OR): 4.227), with tumors >= 5 cm (OR: 7.321), or with preoperative preparation time of <= 14 days (OR: 17.747). Conclusions: Tumors proximal to vessels and other organs or with maximum diameter of >= 5 cm (as shown by preoperative radiographic evidence), and preoperative preparation time of <= 14 days were independent risk factors of intraoperative massive blood loss in patients treated with adrenalectomy for pheochromocytoma.