Total Knee Replacement, Optic Nerve Sheath Diameter Measurement, Intracranial Pressure Change
Conditions
Keywords
neuraxial anesthesia, spinal anesthesia, epidural anesthesia, ocular sonography, optic nerve sheath diameter
Brief summary
This study investigates the effects of epidural anesthesia on intracranial pressure (ICP) by using ultrasonographic optic nerve sheath diameter (ONSD) measurements as a non-invasive indicator. The study aims to determine if the volume of local anesthetic applied to the epidural space during total knee replacement surgery leads to transient increases in ONSD compared to spinal anesthesia. Participants are randomized into two groups to receive either epidural or spinal anesthesia, and their ONSD measurements are tracked before, during, and after the surgery.
Detailed description
Neuroaxial techniques like spinal or epidural anesthesia are gold standards for lower extremity surgeries. However, injecting local anesthetics into the epidural space can compress the dural sac, potentially causing a cranial displacement of cerebrospinal fluid (CSF) and a subsequent increase in intracranial pressure (ICP). Since the optic nerve is surrounded by CSF, ONSD measurement serves as a reliable non-invasive surrogate for monitoring these pressure changes. In this prospective randomized study, 60 patients (ASA I-III) undergoing total knee prosthesis surgery are assigned to one of two groups: Group 1 (Spinal Anesthesia): Patients receive 15 mg of 0.5% heavy bupivacaine at the L4-L5 level. Group 2 (Epidural Anesthesia): Patients receive 20 cc of 0.25% bupivacaine at the L4-L5 level. ONSD measurements are recorded at four specific time points: before anesthesia (t0), 10 minutes after anesthetic onset (t1), 40 minutes after tourniquet removal (t2), and 24 hours postoperatively (t3). The study also monitors secondary outcomes, including postoperative complications and clinical safety profiles related to ICP changes.
Interventions
in epidural group A total volume of 20 ml of 0.25% bupivacaine is administered into the epidural space.
in spinal group A dose of 15 mg (3 ml) of 0.5% heavy bupivacaine is administered into the subarachnoid space.
Sponsors
Bursa City Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
aged 18-75 years with ASA I-III risk group who were scheduled for total knee replacement and volunteered to participate.
Exclusion criteria
Patients with contraindications to regional anesthesia, hypersensitivity to the drugs used, pregnancy, current or past ocular disease/operation history, orbital trauma, optic nerve pathology, glaucoma history; increased intracranial pressure, pseudotumor cerebri, coagulopathy and local infection; and those who refused to participate were excluded.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Optic Nerve Sheath Diameter (ONSD) Changes | Baseline (T0), 10 minutes after anesthesia (T1), 40 minutes after tourniquet removal (T2), and 24 hours postoperatively (T3). | Ultrasonographic measurement of the optic nerve sheath diameter (in millimeters) to evaluate indirect changes in intracranial pressure. Measurements are taken 3 mm behind the globe using a 7.5-12 MHz linear probe. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Mean Arterial Pressure (MAP) and Heart Rate (HR) | Baseline (T0), 10 minutes after anesthesia (T1), 40 minutes after tourniquet removal (T2), and 24 hours postoperatively (T3). | Monitoring of blood pressure and heart rate to assess the hemodynamic stability of patients during and after neuroaxial anesthesia. |
Countries
Turkey (Türkiye)
Outcome results
None listed