Effects of Controlled Hypotension on Postoperative Cognitive Outcomes Following Nasal Surgery.

[OBJECTIVE] To assess the impact of varying levels of controlled hypotension on cerebral oxygenation and examine their association with postoperative delirium and cognitive dysfunction among individuals undergoing rhinoplasty or septoplasty.

[STUDY DESIGN] A randomised double-blind study. Place and Duration of the Study: Department of Anaesthesiology and Reanimation, Faculty of Medicine, Hitit University, Corum, Turkiye, between May and August 2024.

[METHODOLOGY] Seventy ASA (American Society of Anesthesiologists) I-II patients (aged 18-65 years) undergoing elective rhinoplasty or septoplasty were randomly assigned to two equal groups. Group A (n = 35) received anaesthesia with a target mean arterial pressure (MAP) of 50-57 mmHg, and Group B (n = 35) with 58-65 mmHg. Assessment of cognitive function and delirium was conducted using the Mini-Mental Test (MMT) and the Delirium Rating Scale-Revised-98 (DRS-R-98). Continuous variables were analysed using the independent samples t-test, Mann-Whitney U test, or Friedman test, depending on data distribution. Categorical variables were compared using the Chi-square test. A p <0.05 was considered statistically significant.

[RESULTS] Delirium was significantly more frequent in Group A than in Group B within the recovery unit (31.4% vs. 5.7%, p <0.05). DRS-R-98 scores were also notably higher in Group A than in Group B during both recovery and at the 24-hour mark (p <0.05). There were no statistically significant differences identified between the groups in MMT scores at 24 hours (p = 0.100), 7 days (p = 0.457), or 3 months (p = 0.114). Prolonged operative duration emerged as an independent risk factor for delirium in the recovery phase (p <0.05).

[CONCLUSION] Controlled hypotension with MAP levels reduced to 50 mmHg appears to be safe with respect to medium- and long-term cognitive outcomes. However, the increased rate of early postoperative delirium in this group highlights the importance of close neurological monitoring during the immediate recovery period.

[KEY WORDS] Controlled hypotension, Cerebral oxygenation, Delirium, Cognitive dysfunction, Rhinoplasty, Septoplasty.