Erector Spinae Plane Block vs Local Infiltration Following Fusion Surgery

A Randomized Controlled Trial Comparing the Effect of Erector Spinae Plane Blocks Versus High Volume Local Infiltration Analgesia on Pain, Inflammation and Cognitive Outcomes Following Thoraco-Lumbar Fusion Surgery

The proposed intervention will examine two alternative methods for postoperative pain control. Two treatment arms of this study will include subjects who receive an erector spinae block (ESP) after induction of anesthesia but prior to the start of surgery and subjects who will receive a high volume of local anesthetic infiltration at the end of the procedure before emergence from anesthesia. The control group of subjects will undergo spinal surgery with general anesthesia but without any regional anesthesia. Outcome measurements include evaluation of serum inflammatory markers, pain scores, opioid usage and standardized evidence-based assessment methodologies.

Treatment arms include:

• Group ESP (Erector Spinae Plane). This group receives general anesthesia with ESP (Erector Spinae Block) regional pain block prior to incision.
• Group LIA (Local Infiltration Anesthesia). This group receives general anesthesia and surgical procedure will take place as planned. Prior to being awakened, the area of procedure will be infiltrated using local anesthetic (LIA).
• Group GA. This group receives general anesthesia (GA) only and surgical procedure will follow standard conditions.

Pre-procedure activities for all groups will include survey evaluations. If the surveys demonstrate pre-procedure cognitive deficits, the subject's participation will cease.

All subjects who do not display deficits will complete baseline evaluations that include social history, pain medication history and rate their pain (scored from 1 to 10). The subjects will be randomized to a treatment group. Once the subject is asleep and prior to incision, laboratory blood tests will be drawn and again approximately 24 hours after the subject is received into the recovery unit. Following their surgical procedure, pain control for all subjects will be at the discretion of their primary care team. However, as part of the study, the amount of opioid medications required to control their pain and their pain rating score for the first 72 hours post surgery will be collected from the subject's medical record unless discharged from the hospital before this cutoff time. On post-operative days when subject remains in the hospital facility, repeat survey evaluations will be carried out and during the first 7 days of the subject's hospital stay and unanticipated event will be recorded from the subject's medical record.

Inclusion Criteria for all groups:

1. Age: Greater than 18 years but less than 80
2. Surgical procedure: 1 to 2 level thoraco-lumbar fusion between T8 and S2; non-emergent surgery
3. Opioid naive (less than 6 oxycodone/day or 30 mg oxycodone equivalent)
4. No contraindication to local anesthetics or regional procedures.

Exclusion Criteria for all groups:

1. Emergency surgery
2. Allergy to study medications
3. BMI less than 20 or greater than 50
4. Major liver or kidney dysfunction or other pre-existing major organ dysfunction
5. Revision surgery
6. Opioid tolerant (60 mg morphine equivalents/day for 1 week) or narcotic dependence (opioid intake morphine equivalent greater than10 mg/day for more than 3 months)
7. Other sources of chronic pain (e.g. fibromyalgia)
8. Patients with associated significant central nervous system (CNS) or respiratory disease (home oxygen use)
9. Pre-operative neurological deficits
10. Co-existing hematological disorders or deranged coagulation parameters
11. Significant psychiatric illnesses that impedes the subject's ability to provide informed consent
12. Language barrier
13. Vulnerable population (e.g. prisoners)
14. Pregnant females
15. History of recent myocardial infarction
16. History of recent cardiac stent procedure (within 3 months)
17. Cardiac ejection fraction < 30%