Effects of Controlled Hypotension on Postoperative Cognitive Outcomes Following Nasal Surgery

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.

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.

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.

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).

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.

Controlled hypotension, Cerebral oxygenation, Delirium, Cognitive dysfunction, Rhinoplasty, Septoplasty.