Clinical trial NCT06925711: The Effect of Hypotensive Anesthesia on Cognitive Functions in Orthognatic Surgery
Official title: Investigation of the Effect of Hypotensive Anesthesia on Cognitive Functions in Orthognathic Surgery
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Cognitive Dysfunction
Postoperative Complications
Keywords: orthognathic surgery
hypotensive anesthesia
cerebral oxygen saturation
Lead sponsor: Medipol University
Sponsor class: OTHER
First posted: 2025-04-13
Enrollment: 32
Sex: ALL
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: Patients of both genders, over 18 years of age, undergoing elective Orthognathic surgery in general anesthesia.

Brief summary: The purpose of this study is to evaluate the effects of maintaining adequate cerebral oxygen saturation on patients undergoing orthognathic surgery. Orthognathic surgery is performed to repair anomalies in the maxillofacial skeleton for both aesthetic and functional purposes. During these procedures, controlled hypotensive anesthesia is commonly used to reduce bleeding, improve surgical field visibility, and shorten operation time.

In controlled hypotensive anesthesia, mean arterial blood pressure is deliberately reduced to approximately 55-60 mmHg. While this technique offers surgical advantages, it may potentially reduce cerebral blood flow and oxygen saturation, which could affect cognitive function.

This study will investigate the relationship between cerebral oxygen saturation levels maintained during orthognathic surgery and postoperative neuropsychological outcomes. Patients will undergo cognitive assessments before and after surgery while cerebral oxygen saturation is continuously monitored during the procedure. Our findings will help establish safety parameters for hypotensive anesthesia in orthognathic surgery and potentially contribute to improved anesthesia management protocols that better preserve cognitive function.

Detailed description: Orthognathic surgery is a surgical procedure performed to repair anomalies in the maxillofacial skeleton. It can be performed for maxillofacial aesthetics as well as for functional purposes. Since orthognathic surgery is performed in a field where vascular structures are dense, complications such as intraoperative bleeding are likely to occur.

Le Fort I osteotomy and bilateral sagittal split ramus osteotomy (BSSRO) are frequently used treatment methods for dentofacial deformities. Significant bleeding may occur especially during Le Fort I osteotomy. Therefore, controlled hypotensive anesthesia is frequently used during maxillofacial surgery procedures to reduce bleeding, increase the visibility of the surgical field, and prevent blood loss.

During controlled hypotensive anesthesia, mean arterial blood pressure (MAP) is reduced to around 55-60 mmHg. This technique makes the operation more comfortable for both the surgical team and the anesthesia team. Vasoactive and anesthetic agents such as direct-acting vasodilators, autonomic ganglion blockers, beta-adrenergic receptor blockers, and calcium channel blockers are used to provide hypotensive anesthesia.

However, prolonged hypotension may lead to organ damage due to hypoperfusion. Uncontrolled prolongation of systemic hypotension may cause cerebral ischemia, neuronal death, and permanent brain damage by causing a decrease in cerebral blood flow. Cerebral circulation has a complex and unpredictable autoregulatory mechanism. Therefore, it is difficult to maintain the balance between hypotension and cerebral perfusion.

Changes in cerebral blood flow and cerebral tissue perfusion may cause cognitive changes because they affect the nutrition of neural tissues. The aim of this study is to evaluate the effects of controlled hypotensive anesthesia applied in orthognathic surgery on intraoperative cerebral blood flow-cerebral oxygen saturation and cognitive functions of patients and to determine the degree of these effects.

As part of the study, cognitive function tests will be performed on the patient population before and after surgery, and cerebral oxygen saturation will be continuously monitored during surgery. The results may help determine the safety limits of hypotensive anesthesia applied during orthognathic surgery and potentially develop cerebral protection strategies.

The results of this research are expected to contribute to the development of new approaches to improve anesthesia management in patients undergoing orthognathic surgery. Additionally, by testing the hypothesis that maintaining cerebral oxygen saturation may improve cognitive outcomes, it can contribute to increasing patient safety in maxillofacial surgical practices.

Eligibility criteria: Inclusion Criteria:

Patients undergoing Orthognathic surgery under general anesthesia ASA grade ≤ grade III; Patients can communicate normally, can cooperate and complete cognitive function test; Patients volunteered and signed informed consent.

Exclusion Criteria:

BMI \< 18 or \> 27 kg / m2; Previous history of dementia, psychosis or other central nervous system diseases or mental diseases, such as cerebral infarction, stroke, Parkinson's disease, etc; Patients taking sedatives or antidepressants; Alcoholics or drug addicts; Patients with cognitive impairment before operation (MMSE score \< 23); Patients with peripheral vascular diseases and contraindication of arterial puncture and catheterization; Patients unable to carry out long-term follow-up or poor compliance.

Primary outcomes:
measure: Change in cognitive function measured by Mini-Mental State Examination (MMSE) scores
timeFrame: Baseline (7 days before surgery), postoperative 10th day, 1st month, and 3rd month after surgery
Secondary outcomes:
measure: Incidence and severity of cerebral oxygen desaturation events during controlled hypotensive anesthesia
timeFrame: Intraoperatively, from induction of anesthesia until extubation
Other outcomes:
Locations:
city: Istanbul
country: Turkey
facility: Istanbul Medipol University Hospital
Study officials:
References:
citation: Li X, Zheng Y, Zhang J. Cerebral oxygenation and hemodynamic changes during ephedrine and phenylephrine administration for transient intraoperative hypotension in patients undergoing major abdominal surgery: a randomized controlled trial. BMC Anesthesiol. 2025 Feb 20;25(1):87. doi: 10.1186/s12871-025-02944-z.
citation: Hsiao YC, Chang YT, Cheng CS, Lien KH. Dexmedetomidine infusion on blood loss in orthognathic surgery: A retrospective study on its efficacy. J Formos Med Assoc. 2025 Feb 13:S0929-6646(25)00051-8. doi: 10.1016/j.jfma.2025.02.009. Online ahead of print. No abstract available.
citation: Ravelo V, Olate S, Bravo-Soto G, Zaror C, Mommaerts M. Systematic review of soft-to-hard tissue ratios in orthognathic surgery: 3D analysis-update of scientific evidence. Int J Oral Maxillofac Surg. 2025 Mar 17:S0901-5027(25)00073-6. doi: 10.1016/j.ijom.2025.02.008. Online ahead of print.