title: Effect of controlled hypotension on regional cerebral oxygen saturation during rhinoplasty: a prospective study.
abstract: The aim of this study was to investigate the effect of controlled hypotension on cerebral oxygen saturation (rSO2) using near infrared spectroscopy (NIRS) and evaluation of postoperative cognitive function in patients undergoing rhinoplasty. Fifty adult patients who were scheduled for elective rhinoplasty surgery and required controlled hypotension were enrolled in this prospective study. Controlled hypotension was provided using a combination of propofol and remifentanil infusion supplemented with nitroglycerin infusion as necessary. rSO2 was evaluated during controlled hypotension by NIRS. Cerebral desaturation was observed in 5 out of 50 patients (10 %) during hypotensive anesthesia. The greatest decrease from baseline was 28 % when MAP was 57 mmHg. In both non-desaturated and desaturated patients, postoperative MMSE scores were significantly lower than preoperative scores. There was a 4 % decrease in the non-desaturated patients and a 7 % decrease in the desaturated patients when preoperative and postoperative MMSE scores were compared. A decline in cognitive function 1 day after surgery was observed in 23 patients (46 %) and in all patients with intraoperative cerebral desaturation. The current study showed that even if SpO2 is in the normal range, there might be a decrease of more than 20 % in cerebral oxygen saturation during controlled hypotension.
authors.affiliation: Department of Anesthesiology, Faculty of Medicine, Sakarya University, Sakarya, Turkey.
authors.forename: Ali Fuat
authors.initials: AF
authors.lastname: Erdem
authors.affiliation: Department of Otorhinolaryngology, Faculty of Medicine, Sakarya University, Sakarya, Turkey.
authors.forename: Gurkan
authors.initials: G
authors.lastname: Kayabasoglu
authors.affiliation: Department of Anesthesiology, Faculty of Medicine, Sakarya University, Sakarya, Turkey. aycatas@yahoo.com.
authors.forename: Ayca
authors.initials: A
authors.lastname: Tas Tuna
authors.affiliation: Department of Anesthesiology, Sakarya University Training and Research Hospital, Sakarya, Turkey.
authors.forename: Onur
authors.initials: O
authors.lastname: Palabiyik
authors.affiliation: Department of Anesthesiology, Faculty of Medicine, Sakarya University, Sakarya, Turkey.
authors.forename: Yakup
authors.initials: Y
authors.lastname: Tomak
authors.affiliation: Department of Anesthesiology, Faculty of Medicine, Sakarya University, Sakarya, Turkey.
authors.forename: Serbulent Gokhan
authors.initials: SG
authors.lastname: Beyaz
mesh_terms: D000328:Adult; D002560:Cerebrovascular Circulation; D003071:Cognition; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D007023:Hypotension, Controlled / Q000379:methods*; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D005996:Nitroglycerin / Q000737:chemistry; D010100:Oxygen / Q000378:metabolism; D010880:Piperidines / Q000008:administration & dosage; D011184:Postoperative Period; D057234:Preoperative Period; D015742:Propofol / Q000008:administration & dosage; D011446:Prospective Studies; D000077208:Remifentanil; D012225:Rhinoplasty / Q000379:methods*; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors; D055815:Young Adult
chemical_list: D010880:Piperidines; D005996:Nitroglycerin; D000077208:Remifentanil; D010100:Oxygen; D015742:Propofol
keywords: Cerebral oxygen saturation; Controlled hypotension; Near infrared spectroscopy; Rhinoplasty