Drug-Resistant Epilepsy, Epilepsy, Vagus Nerve Stimulation
Conditions
Keywords
Vagus Nerve Stimulation, Cervical Plexus Block, Pain, Postoperative, Analgesics, Opioid, Regional Anesthesia, Epilepsy
Brief summary
This prospective, randomized, double-blind, placebo-controlled clinical trial aims to evaluate the analgesic efficacy of ultrasound-guided intermediate cervical plexus block (ICB) in patients undergoing vagus nerve stimulation (VNS) implantation surgery under general anesthesia. Participants are randomly assigned to receive either an ultrasound-guided ICB with 10 mL of 0.25% bupivacaine or a placebo injection with 10 mL of normal saline following induction of general anesthesia. The primary outcome is total postoperative morphine consumption during the first 24 hours after surgery. Secondary outcomes include intraoperative remifentanil consumption, postoperative pain intensity assessed using the Numeric Rating Scale (NRS), time to first analgesic request, length of hospital stay, and postoperative seizure incidence.
Detailed description
Postoperative pain following vagus nerve stimulation (VNS) implantation surgery originates from both cervical and infraclavicular surgical incisions. Although opioid analgesics are commonly used for postoperative pain control, minimizing opioid exposure is particularly desirable in patients with drug-resistant epilepsy because opioid-related adverse effects may delay recovery and potentially influence neurological assessment. The intermediate cervical plexus block (ICB) is an ultrasound-guided regional anesthesia technique that provides sensory blockade of the superficial branches of the cervical plexus while allowing accurate deposition of local anesthetic between the investing and prevertebral layers of the deep cervical fascia. Previous studies have demonstrated the effectiveness of cervical plexus blocks in various cervical surgical procedures; however, evidence regarding their use during VNS implantation surgery remains limited. This prospective, randomized, double-blind, placebo-controlled study compares ultrasound-guided ICB using 10 mL of 0.25% bupivacaine with a placebo injection of 10 mL normal saline administered after induction of general anesthesia. The primary objective is to determine whether ICB reduces postoperative opioid requirements during the first 24 hours after surgery. Secondary objectives include evaluation of intraoperative remifentanil consumption, postoperative pain scores, time to first rescue analgesic, length of hospital stay, and postoperative seizure incidence. The findings are expected to provide evidence regarding the effectiveness and safety of ultrasound-guided intermediate cervical plexus block as part of multimodal analgesia for patients undergoing VNS implantation surgery.
Interventions
Ultrasound-guided intermediate cervical plexus block performed after induction of general anesthesia.
DRUGSodium Chloride 0.9% in 10 ml injection
10 mL of 0.9% sodium chloride administered as a placebo injection under ultrasound guidance.
DRUGBupivacaine
10 mL of 0.25% bupivacaine administered during ultrasound-guided intermediate cervical plexus block.
Sponsors
Firat University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Masking description
Participants, postoperative care providers, and outcome assessors were blinded to treatment allocation. Study solutions were prepared in identical syringes by an independent anesthesiologist not involved in postoperative assessments or data analysis. The anesthesiologist performing the block was aware of the assigned intervention but did not participate in postoperative outcome assessment.
Intervention model description
Participants were randomly assigned in a 1:1 ratio to receive either an ultrasound-guided intermediate cervical plexus block with 10 mL of 0.25% bupivacaine or a placebo injection with 10 mL of 0.9% normal saline following induction of general anesthesia. Each participant received only one study intervention.
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
No
Inclusion criteria
* Adults aged 18-60 years * American Society of Anesthesiologists (ASA) physical status II-III * Drug-resistant epilepsy * Scheduled for elective vagus nerve stimulation implantation surgery under general anesthesia * Written informed consent obtained
Exclusion criteria
* Allergy or contraindication to local anesthetics * Coagulopathy or current anticoagulant therapy * Infection at the injection site * Pregnancy or breastfeeding * Severe pulmonary disease * Inability to understand or use the Numeric Rating Scale (NRS) * Refusal to participate
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Total postoperative morphine consumption during the first 24 hours after surgery | 24 hours after surgery | Total cumulative intravenous morphine consumption during the first 24 hours after vagus nerve stimulation implantation surgery, recorded in milligrams (mg). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Intraoperative remifentanil consumption | From induction of anesthesia until the end of surgery | Total intraoperative remifentanil consumption recorded in micrograms (µg) from induction of anesthesia until completion of surgery. |
| Postoperative pain intensity | From admission to the post-anesthesia care unit (PACU) through 24 hours postoperatively | Pain intensity was assessed using the Numeric Rating Scale (NRS; 0 = no pain, 10 = worst imaginable pain) at PACU admission, 30 minutes after PACU admission, and at postoperative 1, 6, 12, and 24 hours. |
| Time to first rescue analgesic request | Within 24 hours after surgery | Time from arrival in the post-anesthesia care unit (PACU) until the first administration of rescue analgesia, measured in minutes. |
| Length of hospital stay | From arrival in the post-anesthesia care unit (PACU) until the first rescue analgesic request, assessed up to 24 hours postoperatively | Time to first rescue analgesic request was defined as the time from PACU arrival to the first request or administration of rescue analgesia. Patients who did not require rescue analgesia within 24 hours were censored at 24 hours. |
| Postoperative seizure incidence | Within 24 hours after surgery | Occurrence of clinically observed postoperative seizure episodes during the first 24 postoperative hours. |
Countries
Turkey (Türkiye)
Contacts
PRINCIPAL_INVESTIGATORAhmet Aksu, Assistant Professor
Fırat University Faculty of Medicine Department of Anaesthesiology and Reanimation
Outcome results
None listed