Multiple analyses of factors related to intraoperative blood loss and the role of reverse Trendelenburg position in endoscopic sinus surgery

Objective/Hypothesis: To find out the factors related to the volume of intraoperative blood loss during endoscopic sinus surgery and to validate the role of reverse Trendelenburg position (RTP) in controlling blood loss. Study Design: Prospective, controlled, single-blind study. Methods: Endoscopic sinus surgeries for chronic rhinosinusitis with or without polyposis were performed in 60 patients, which were randomly categorized into two groups. The study group (RTP group) consisted of 30 patients laid on operation table with the RTP of 10° during the whole surgery, and the control group with 30 patients completely laid supine. All operations were performed by the same operator (the first author) without using hemostatic agents during the operation. Intraoperative blood loss was estimated by total volume of blood loss, blood loss per minute, and surgical field scale. Multiple factors related to blood loss, such as computed tomography scores, operation time, mean arterial pressure, polyposis, fungal sinusitis, and anesthetic agents were compared. Results: There existed significant differences in total blood loss, blood loss per minute, and surgical field between the RTP group and supine group. In multiple analyses within the two groups, presence of polyp, non-fungal sinusitis and use of microdebrider exhibited a significant higher blood loss rate in the RTP group. Conclusion: RTP may reduce intraoperative blood loss. Besides, fungal sinusitis and rhinosinusitis without polyposis may contribute to a lesser intraoperative blood loss.