Investigation Of The Effects Of Unilateral And Bilateral Spinal Anesthesia On Cerebral Blood Flow

March 7, 2025 updated by: MEHTAP BALCI, Nuh Naci Yazgan University

Spinal anesthesia is a widely used method in anesthesia practice. Unilateral spinal block refers to a neuroaxial technique that induces motor and sensory blockade on the surgical side. While spinal anesthesia offers numerous advantages, it is associated with complications such as hypotension, headache, transient neurological symptoms, and meningitis. Among these, hypotension is the most common. To mitigate hemodynamic issues, intravenous fluid preloading and vasopressor use are standard practices in many centers.

This study aimed to compare regional cerebral oxygenation (rSO₂) values in patients undergoing unilateral and bilateral spinal blocks to identify the least complicated and most effective method. Minimizing complications can facilitate early mobilization, reduce hospital stays, and lower infection risks.

The study included 60 male patients (aged 18-65 years) scheduled for unilateral inguinal hernia surgery at Kayseri City Hospital. Inclusion criteria were the absence of coagulation disorders, infections, or systemic diseases, hemoglobin levels >10 g/dL, and BMI <30. Patients were randomized into two groups:

Group I: Unilateral spinal anesthesia with 15 mg hyperbaric bupivacaine. Patients were placed in a lateral position on the surgical side for 5 minutes, then moved to the supine position.

Group II: Bilateral spinal anesthesia with 15 mg hyperbaric bupivacaine. Patients were placed in the supine position for 5 minutes.

Sensory block levels were assessed using the pin-prick test, and motor blocks were evaluated with the Bromage scale. Surgery commenced when the sensory block reached the T10 level. Patient data, including age, BMI, hemoglobin, baseline systolic/diastolic blood pressure (SBP/DBP), mean arterial pressure (MAP), heart rate (HR), oxygen saturation (SpO₂), and rSO₂, were recorded before and after spinal anesthesia. SBP, DBP, MAP, HR, SpO₂, and rSO₂ values were monitored at 5-minute intervals for 30 minutes.

Study Overview

Status

Completed

Conditions

Detailed Description

This study was conducted with the approval of the Kayseri City Hospital Scientific Research and Publication Ethics Committee (approval number: 2022/605). Written informed patient consent was obtained (A Guide to Good Clinical Practice, 609, Mehtap Balcı, 24.03.2022). This manuscript adheres to the applicable TITCK - Turkish Pharmaceutical and Medical Device Authority guideline. It was determined that meaningful results could be obtained with a minimum of eight patients by performing a power analysis.

A total of 60 male volunteer patients, aged 18-65 years, scheduled for unilateral inguinal hernia surgery in the Kayseri City Hospital operating room, were included. The inclusion criteria were the absence of coagulation disorders or prolonged bleeding times, no infections at the injection site or systemic infections, ability to cooperate, no history of opioid use or local anesthetic allergy, no cardiovascular, respiratory, or metabolic diseases, hemoglobin levels >10 g/dL, and BMI <30. Patients were randomly assigned to two groups of 30 each.

Before surgery, patients were informed about the procedure and the anesthesia method. After reading and signing the informed consent form, volunteer patients were brought to the operating table. Intravenous access was established for all patients, and non-invasive monitoring was initiated. Patients were placed in a seated position, and the intervention area was cleaned with 10% povidone-iodine. Under sterile conditions, a 22G (Quincke) spinal needle was slowly advanced into the L4-5 spinal interspace, and free, clear cerebrospinal fluid (CSF) flow was observed.

Group I: Spinal anesthesia was performed with 15 mg of hyperbaric bupivacaine (3 cc, Buvasin 0.5% Spinal Heavy), followed by placing the patient in a lateral position on the surgical side for 5 minutes and then switching to the supine position.

Group II: Spinal anesthesia was performed with 15 mg of hyperbaric bupivacaine (3 cc, Buvasin 0.5% Spinal Heavy), followed by placing the patient in the supine position for 5 minutes.

The sensory block level was assessed using the pin-prick test, and the motor block level was evaluated using the Bromage scale. Surgery commenced once the sensory block reached the T10 level. Throughout the surgery, all patients received 3 L/min of 100% oxygen via a face mask.

Groups:

Group I: Intrathecal 15 mg hyperbaric bupivacaine (3 cc), lateral position for 5 minutes.

Group II: Intrathecal 15 mg hyperbaric bupivacaine (3 cc), supine position for 5 minutes.

Data regarding the patients' demographic characteristics (age, height, weight, BMI), baseline hemoglobin (Hb), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), oxygen saturation (SpO₂), and regional cerebral oxygenation (rSO₂) were recorded before and after spinal anesthesia. SBP, DBP, MAP, HR, SpO₂, and rSO₂ values were recorded at 5, 10, 15, 20, 25, and 30 minutes after spinal anesthesia. The data obtained will be analyzed using SPSS 25. If the parametric assumptions (Shapiro-Wilk test) are met, a t-test will be applied to determine the significance of the difference between independent groups, and variance analysis (ANOVA) will be applied for repeated measurements within groups.

Study Type

Observational

Enrollment (Actual)

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Turkey
- Kocasinan
  - Kayseri, Kocasinan, Turkey, 38000
    - Nuh Naci Yazgan University Faculty of Dentistry

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

Adult
Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

A total of 60 male volunteer patients, aged 18-65 years, scheduled for unilateral inguinal hernia surgery in the operating room of Kayseri City Hospital, were included.

Description

Inclusion Criteria:

No coagulation disorders or prolonged bleeding times
No infections at the injection site or systemic infections
Ability to cooperate
No history of opioid use or local anesthetic allergy
No cardiovascular, respiratory, or metabolic diseases
Hemoglobin levels >10 g/dL
BMI <30

Exclusion Criteria:

Coagulation disorders present
Infections at the injection site or systemic infections
Inability to cooperate
History of opioid use or local anesthetic allergy
Cardiovascular, respiratory, or metabolic diseases present
Hemoglobin levels <10 g/dL
BMI >30

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Number of groups / cohorts

Cohorts and Interventions

Group / Cohort
unilateral Spinal Block(GroupI) Group I: After appropriate area cleaning, under sterile conditions, the spinal space was accessed through the L4-L5 interspace, and 15 mg of hyperbaric bupivacaine (3 cc, Buvasin 0.5% Spinal Heavy) was administered following the observation of free, clear cerebrospinal fluid (CSF) flow. The patient was then kept in the lateral position on the surgical side for 5 minutes before being moved to the supine position.
Bilateral Spinal Block (Group II) Group II: After appropriate area cleaning, under sterile conditions, the spinal space was accessed through the L4-L5 interspace, and 15 mg of hyperbaric bupivacaine (3 cc, Buvasin 0.5% Spinal Heavy) was administered following the observation of free, clear cerebrospinal fluid (CSF) flow. The patient was then kept in the supine position for 5 minutes.

Group / Cohort

unilateral Spinal Block(GroupI)

Group I: After appropriate area cleaning, under sterile conditions, the spinal space was accessed through the L4-L5 interspace, and 15 mg of hyperbaric bupivacaine (3 cc, Buvasin 0.5% Spinal Heavy) was administered following the observation of free, clear cerebrospinal fluid (CSF) flow. The patient was then kept in the lateral position on the surgical side for 5 minutes before being moved to the supine position.

Bilateral Spinal Block (Group II)

Group II: After appropriate area cleaning, under sterile conditions, the spinal space was accessed through the L4-L5 interspace, and 15 mg of hyperbaric bupivacaine (3 cc, Buvasin 0.5% Spinal Heavy) was administered following the observation of free, clear cerebrospinal fluid (CSF) flow. The patient was then kept in the supine position for 5 minutes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Regional Cerebral Oxygenation Time Frame: 5-minute intervals for 30 minutes.	rSO₂ values were monitored	5-minute intervals for 30 minutes.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Nuh Naci Yazgan University

Collaborators

Kayseri City Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 27, 2022

Primary Completion (Actual)

November 29, 2022

Study Completion (Actual)

March 27, 2023

Study Registration Dates

First Submitted

January 19, 2025

First Submitted That Met QC Criteria

March 7, 2025

First Posted (Actual)

March 25, 2025

Study Record Updates

Last Update Posted (Actual)