Clinical trial NCT04587401: The Effects of Anesthesia on Cerebral Perfusion in Patients With High Blood Pressure
Official title: The Effects of Anesthesia on Cerebral Perfusion Identified by Transcranial Doppler During Lumbar Surgery in Prone Position in Patients With High Blood Pressure.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Lumbar Disc Disease
Lumbar Spinal Stenosis
Lumbar Disc Herniation
Lumbar Fracture
Keywords: transcranial doppler ultrasonography
high blood pressure
cerebral perfusion
prone position
Lead sponsor: Akdeniz University
Sponsor class: OTHER
First posted: 2020-10-14
Enrollment: 102
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: FACTORIAL
Intervention model description: Patients, aged between 18 and 85, who were scheduled for lumbar surgery under general anesthesia by neurosurgery department and were classified as Class I, II, and III according to the ASA (American Association of Anesthesiologists) classification, were included in the study.
Primary purpose: TREATMENT

Brief summary: High blood pressure is a serious and common health problem. This disease affects 1 billion people all over the world and responsible for 7,1 million deaths. Trials involving more than 1 million people state that stroke incidence rises as blood pressure rises. The effects of high blood pressure on cerebral perfusion is not well realized. Intraoperative blood pressure management of patients with high blood pressure is not well known. And it is still not clear how autoregulation of cerebral perfusion is affected by high blood pressure.

Systemic arterial pressure changes have little effect on cerebral perfusion. This is regulated by changes of precapillary resistance. When systemic arterial blood pressure drops, it is regulated by vasodilatation of arteriolar smooth muscles. And when systemic blood pressure rises, it is regulated by vasoconstriction of arterioles. Cerebral perfusion is well preserved between 50-125 mmHg changes of mean arterial blood pressure (MAP). Patients with high blood pressure have higher ranges. Patients with chronic high blood pressure can better tolerate higher blood pressures. But even physiologic drops of systemic blood pressure can cause ischemia.

Anesthetic drugs have variable effects on cerebral blood flow and physiology. The drugs used with anesthetic drugs, the noxious stimulus of surgery, intracranial compliance, blood pressure, and carbon dioxide pressure can all alter and complicate these effects. Anesthetic drugs must be selected carefully in patients with high blood pressure. It is still investigated whether, management of blood pressure under anesthesia, should be individualized.

For patients with high blood pressure, some neuromonitorization technics have been evaluated to prevent neurologic complications under anesthesia. But there is not a technic, which is considered as a gold standard. Cerebral blood pressure has been studied by, nitrous oxide method, krypton uptake method, and xenon injection methods previously. Near-infrared spectroscopy (NIRS) is the best monitorization technic of intracranial pressure (ICP), cerebral blood flow (CBF), and cerebral metabolism. But it can not be applied to all patients. Recently, it is possible to measure blood flow of cerebrum with transcranial Doppler ultrasound in anesthesia practice.

In this trial, the investigators aim to evaluate cerebral perfusion of hypertensive patients with transcranial Doppler during lumbar disc surgery to optimize the blood pressure under anesthesia.

To best of our knowledge, there is no trial evaluating cerebral perfusion of hypertensive patients with transcranial Doppler ultrasound.

Detailed description: In this trial, the investigators aim to evaluate the cerebral perfusion of patients with transcranial doppler ultrasound (TCD) and near-infrared spectroscopy (NIRS) during lumbar disc surgery.

The investigators will divide participants into three groups according to their blood pressure history after preoperative evaluation of the participants.

The investigators will enroll normotensive participants in group 1(control group). Participants with diagnosis of high blood pressure will be enrolled to group 2. In the third group, participants who don't have any diagnosis of high blood pressure, but actual blood pressure is higher than the physiological levels at the preoperative evaluation will be enrolled to group 3.

First measurements of TCD and NIRS, will be performed at preoperative period. Second measurements will be obtained after anesthesia induction. Third measurement will be performed after prone position. Forth measurement will be taken after 1 hour of surgical incision. The last measurement will be performed at the postoperative period.

During all these measurements, blood gas samples, invasive arterial blood pressures, pulse variation index (PVI), electrocardiography (ECG), peripheral oxygen saturation (SpO2), peak pressure of airway and end-tidal carbon dioxide (EtCO2) levels will also be recorded.

All participants will be evaluated for their cognitive functions with mini-mental and confusion assessment method (cam) tests at the preoperative and postoperative periods.

Eligibility criteria: Inclusion Criteria: Clinical diagnosis of lumbar stenosis Clinical diagnosis of lumbar fracture Clinical diagnosis of lumbar mass -

Exclusion Criteria: Patients who had an intracranial incident Patients with anesthetic risk classification higher than American Society of Anesthesiology (ASA) 3 Carotid atherosclerosis

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Primary outcomes:
measure: Mean cerebral perfusion pressure of hypertensive patients under anesthesia
timeFrame: time from the preoperative period of the surgery until the postoperative 24th hour of the surgery
Secondary outcomes:
measure: Comparison of transcranial doppler and near-infrared spectroscopy for determining of cerebral perfusion
timeFrame: time from the preoperative period of the surgery until the postoperative 24th hour of the surgery
Other outcomes:
measure: Determination of changes of the cerebral perfusion in patients with actual high blood pressure who has not been diagnosed for hypertension before.
timeFrame: time from the preoperative period of the surgery until the postoperative 24th hour of the surgery
Locations:
city: Antalya
country: Turkey
facility: Akdeniz University Hospital
Study officials:
affiliation: Akdeniz University Medical School Anesthesiology and Reanimation Department
name: Neval Boztug, Prof
role: STUDY_DIRECTOR
References: