GA + ESP vs. SA + ESP in Lumbar Decompression Surgeries

Study Overview
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Brief Summary
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The purpose of this study is to determine the optimal anesthetic routine for lumbar decompression surgery. General Anesthesia is the standard of care in spine surgery. Spinal anesthesia in decompressive procedures can be the new standard of care. Recently, it has been found that regional analgesia is option that has been shown to improve pain and opioid-related outcomes after spine surgery, but has not yet been studied in combination with spinal anesthesia. This is study that consists of two groups: standard of care general anesthesia with a nerve block and a spinal anesthesia with nerve block. Patients are randomized to either of the two groups. There will be 71 patients enrolled in each group for this study.

Detailed Description
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An early comparative analysis between GA and SA in spine surgery explored perioperative effects of the technique on cost and satisfaction among patients, anesthesiologists, and surgeons. Patients who underwent surgery under SA had better outcomes, including hemodynamic stability, shorter hospitalization time, and shorter time to return to work. Postoperatively, SA was associated with lower numeric pain rating scale (NPRS) scores and earlier time to mobilization and first oral intake. Moreover, SA had lower costs and higher reported satisfaction among patients, surgeons, and anesthesiologists. Subsequent studies have consistently concluded that SA is associated with shorter surgical duration and less blood loss in patients compared to GA for spine surgery. Additionally, hospital length of stay has been reported to be shorter after SA, perhaps due to lower incidence of complications found in several series. Early postoperative pain control may also be superior after SA in patients undergoing microdiscectomy, attributed to residual sensory block after SA. In addition to higher peaks in pain scores and significantly greater analgesic requirements among the GA group, more episodes of nausea were described, and more antiemetic medications were given. Intraoperative neurophysiological monitoring (IONM) during procedures such as one and two-level microdiscectomies and laminotomies, use somatosensory evoked potentials (SSEPs), motor evoked potentials (MEPs), and electromyograms (EMGs) as routine during surgery. Surgeons can monitor spinal cord and nerve root function in real-time, take measures to prevent/lessen irritation or potential damage and can detect intraoperative neurologic injuries. Microdiscectomies and laminotomies are one of the most common spinal procedures, which can be performed in both its open and minimally invasive variations, is a well-established, safe procedure. However, studies have shown that the use of IONM in smaller, less complicated procedures such as microdiscectomies or laminotomies, may add to the overall cost without providing many benefits. Decompressive surgeries under SA cover only the spine and nerve roots within a specific region. Subsequently, SA does not transmit sensory impulses to the brain, therefore, neuromonitoring such as somatosensory evoked potentials (SSEPs) are not required in cases such as these. Certain types of IOMN can be performed under GA, as transmissions of sensory impulses are sent to the brain to identify neural irritation or injury and define the nature of the injury, which will allow the surgeon to complete the procedure without risking further injury. Despite broad patient acceptance of SA for lower extremity procedures, and abundant evidence to support superior outcomes after orthopedic surgery, SA has never gained wide acceptance in lumbar spine surgery. Arguments against SA for lumbar decompression surgeries include the potential for airway complications in sedated prone positioned patients, the possibility for neural injury if an awake patient moves during decompressive procedures, the potential for intraoperative conversion to GA due to insufficient duration or failed SA, and confounding of the early postoperative neurologic examination. The Erector Spinae Plane Block (ESP) is a novel fascial plane block, originally described as an effective treatment for thoracic neuritis. Since its first description, the ESP block has been applied to a broad range of surgical procedures, with benefits for opioid-sparing analgesia, a good safety profile, and few complications. The ESP block is considered to be relatively easy to perform when compared to other thoracic or neuraxial blocks, such as epidural and paravertebral blocks. The clinical findings of early studies have been supported by anatomical studies in cadavers demonstrating the appropriate spread of local anesthetic to the dorsal and ventral rami of the nerve roots of the thoracic spine. The value of ESP block for spine surgery has likewise been suggested in case reports case series, and retrospective cohort studies. Each concludes significant opioid-sparing capacity and improved NRS pain scores in patients who receive ESP blocks for a variety of spine surgery procedures. More recently, results from 2 RCTs describing outcomes after ESP block for lumbar decompression have been reported. In the first, 60 patients were randomized to receive bilateral ESPB or no intervention. NRS scores and tramadol consumption were significantly lower in the first 24 hours after surgery, and the time to requesting opioid analgesia was significantly longer in patients were received ESPB. In the second RCT, postoperative morphine consumption was lower in patients who received ESPB compared to patients who did not receive ESPB. NRS scores were lower up to 6 hours after surgery in the ESPB group, and patient satisfaction scores were higher HSS anesthesiologists have been offering ESP blocks for spine surgery via posterior approach since 2017. A recent retrospective analysis of over 800 patients at HSS supports ESP blocks as analgesic and opioid-sparing in our spine surgery population. As the above literature review suggests, there is unmet clinical and research need to explore the optimal anesthetic-analgesic regimen in patients undergoing minimally invasive lumbar decompression. This study has the potential to address the risk, benefits advantages and disadvantages of SOC GA for patients undergoing spine surgery.

Official Title
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Evaluating General Anesthesia With Erector Spinae Plane Block vs. Spinal Anesthesia With Erector Spinae Plane Block in Lumbar Decompression Surgeries

Conditions
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Lumbar Disc Herniation, Lumbar Disc Disease, Lumbar Radiculopathy

Intervention / Treatment
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* Drug: General anesthetic
* Drug: SA + ESP


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients from the ages 18- 80 years Patients with one or two-level microdiscectomy, laminotomy, or foraminotomy - prior spine surgery is allowed only if surgery was preformed at other levels. Able to follow study protocol Able to provide informed consent Exclusion Criteria: Surgery with planned need for postoperative surgical drain. Allergies of contraindication to any study anesthetic or analgesic medications. Morbid obesity, defined as BMI > 35 kg/m2. Involved in the study of another investigational product that may affect the outcome.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: SA + ESP Block<br>Spinal Anesthesia: Patients will be provided with iv sedation, if desired, to facilitate placement of spinal anesthetic. Midazolam (2-5mg, iv), ketamine (up to 20 mg, lv) and/or propofol (0.1-0.2 mg/kg) will be permitted. | Drug: SA + ESP<br>* The choice of local anesthetic for spinal anesthesia will be confirmed after consultation with the attending surgeon to determine duration of surgery. For expected surgical times less than 90 minutes, up to 4 mL 1.5% mepivacaine (60 mg) will be used. Where the anticipated surgical duration is longer than 90 minutes, 2 mL 0.5% bupivacaine (10 mg) may be substituted. After patient (prone) positioning, maintenance of sedation will be achieved with a target RASS score of 0 to -1. Propofol (25-50 μg.kg.min-1) and ketamine (up to 50 mg total dose) infusions will be titrated to effect. Intermittent boluses of propofol (10-20mg) may be used to achieve the desired sedation, as needed. Patients will be offered to option of awake surgery, where no sedation will be provided, if preferred. Patients will be informed that at any time before or during the procedure, they may change their mind, and receive sedation.<br>* Other names: Erector Spinae Block;|
| Active Comparator: GA + ESP Block<br>General anesthesia: induction of general anesthesia to facilitate endotracheal intubation: fentanyl (up to 2μg.kg.min-1), propofol (1-2 mg.kg-1), vecuronium (1-2 mg.kg-1). | Drug: General anesthetic<br>* Maintenance of general anesthesia: propofol infusion (50-150 μg.kg.min-1); ketamine infusion (up to 50 mg total); and inhaled anesthetic agent (isoflurane or sevoflurane) up to 0.5 MAC. N20 is not permitted. Emergence from general anesthesia: N20 may be used during closure of the surgical incision to facilitate rapid emergence.<br>* Other names: GA + ESP;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| QoR15 survey scores | The primary outcome is the difference in the quality of recovery-15 (QoR15) score between the groups at each timepoint (before surgery, after surgery, and at their first 2 week follow-up visit). For this survey, a high number represents something that occurs often, while a low number indicates something that rarely or never occurs. Depending on the category/question asked, this may be good or bad. The questions on the survey will be split and compared so that for one subset of questions a high number is good while the opposite is true for the other subset of questions. This will be done so the comparison between groups is more accurate and meaningful. | The QoR15 survey will be assessed preoperatively (in holding area). It will be assessed again immediately after surgery in the PACU and then at 2-weeks postoperatively at the patient's first follow-up visits | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| NRS Survey Pain Scores | Numeric rating scale (NRS) survey will be asked in holding (before surgery), in the PACU (after surgery), and at the patients first 2week follow-up visit. Most patients will be discharged a few hours after waking up, barring no complications, therefore may only be assessed the NRS survey immediately after surgery (same as QoR15). For this scale (0-10), a higher number indicates more pain in that specified body part, while a lower score indicates little or no pain in that body part. | The NRS will be assessed preoperatively (in holding area), postoperatively in PACU, and 2 weeks postoperatively at the patient's first follow-up | 
| Opioid Consumption | Opioid consumption will be tracked intraoperatively and total from PACU arrival to 24 hours surgery | From surgery through 24 hours postoperatively | 
| Anesthetic(s) Time | induction (from induction to anesthesia-ready), emergence (from surgery-end to out-of-OR for SA group; and from surgery-end to extubation for GA groups); duration of SA (from placement to resolution). | Intraoperatively | 
| Surgical Duration | Time of surgery will be compared between groups from skin incision to skin closure | Intraoperatively | 
| Complications | nausea, vomiting, urinary retention, escalation to a higher level of postoperative care, conversion from SA to GA, neurologic (extremity numbness, weakness, paresthesia). | Length of stay at the hospital (up to 3 days postoperatively) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Lumbar Spine, Degenerative Disc Disease