An Early Phase 1 interventional study of Bupivacaine (erector spinae plane block) in Erector Spinae Plane Block, sponsored by University of California, Irvine. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-17.
Sponsored by University of California, Irvine · Early Phase 1, Interventional, and Treatment
Currently, the standard treatment of nonsurgical abdominal pain in the Emergency Department (ED) includes narcotic pain medication. This can be addictive and contributes to the current opioid epidemic. Recent studies have shown that the Erector Spinae Plane Block (ESPB) is an alternative approach to achieving abdominal analgesia without the use of any systemic pain medications. It is a regional nerve block that can be used by emergency medicine physicians by injecting anesthetic into the erector spinae plane under ultrasound guidance, which effectively anesthetizes the abdomen. This procedure is within the scope of practice of Emergency Medicine residents, fellows, and attendings who have received training in Point-of-Care Ultrasound (POCUS) and who have also received specialized training on how to perform the ESPB under ultrasound guidance. Adult patients will be screened for intractable abdominal pain (persistent pain despite systemic pain medications) and eligibility to receive the nerve block (for example, patients cannot be pregnant, must be able to verbalize pain and satisfaction scores, and must have no contraindication to receiving the nerve block). In this study, the investigators will perform a small pilot study to determine how effective the ESPB is compared to systemic pain medications, and how easy or difficult it is to perform the ESPB in the Emergency Department as a means of controlling abdominal pain.
This study takes an effectiveness-implementation Hybrid Type 2 trial design with a dual purpose: (i) to examine the effectiveness of the Erector Spinae Plane Block (ESPB) compared to standard systemic pain medication in patients with intractable, nonsurgical abdominal pain in the Emergency Department (ED); and (ii) to qualitatively analyze the feasibility of implementing the ESPB in the Emergency Department as a means of controlling abdominal pain. The investigators hypothesize that patients with intractable, nonsurgical abdominal pain who receive the ESPB will have non-inferior pain scores compared to patients who receive systemic pain medications. The investigators further hypothesize that patients who receive the ESPB will require fewer Morphine Milligram Equivalents (MME) to achieve abdominal pain control than patients who do not receive the ESPB. The investigators aim to identify potential challenges that could affect the feasibility of implementing the ESPB in the Emergency Department setting, such as time constraints, lack of provider willingness to perform the block, lack of patient willingness to receive the block, and difficulty finding the appropriate supplies.
Exclusion Criteria:
Patients receive the erector spinae plane block (ESPB) via ultrasound-guided injection of bupivacaine, with systemic analgesics provided as needed if pain persists.
Drug: Bupivacaine (erector spinae plane block)
Patients receive standard-of-care systemic pain medication (non-opioid analgesics or opioids such as Norco/hydrocodone-acetaminophen).
Ultrasound-guided erector spinae plane block (ESPB) performed with injection of bupivacaine, administered in place of standard systemic pain medication.
Change in Pain Score
Change from baseline in patient-reported pain intensity, measured on a standardized Numeric Rating Scale (NRS) ranging from 0 (no pain) to 10 (worst possible pain). Higher scores indicate greater pain.
Time frame: Baseline (time of consent), 30 minutes post-intervention, and 3 hours post-intervention
Patient Satisfaction Score
Patient-reported satisfaction with pain management, measured on a Numeric Rating Scale (NRS) ranging from 0 (not at all satisfied) to 10 (completely satisfied). Higher scores indicate greater satisfaction.
Time frame: Prior to Emergency Department discharge, up to 24 hours
Total Emergency Department Length of Stay
Total time in hours from Emergency Department (ED) arrival to ED disposition.
Time frame: From Emergency Department arrival to disposition, up to 24 hours
Time Required to Perform the Erector Spinae Plane Block (ESPB)
Time in minutes required to complete the ultrasound-guided erector spinae plane block (ESPB) procedure, reported by operator training level (resident, fellow, or attending).
Time frame: At the time of the procedure, up to 3 hours
Number of Participants With Pneumothorax
Number of participants with pneumothorax identified as a complication of the erector spinae plane block (ESPB).
Time frame: Through Emergency Department stay, up to 24 hours
Number of Participants With Local Anesthetic Systemic Toxicity (LAST)
Number of participants meeting clinical criteria for Local Anesthetic Systemic Toxicity (LAST), including cardiac dysrhythmia or seizure.
Time frame: Through Emergency Department stay, up to 24 hours
Number of Participants With Opioid-Related Adverse Events
Number of participants experiencing an adverse event attributed to systemic opioid analgesia.
Time frame: Through Emergency Department stay, up to 24 hours
Plan to share: No — The investigators do not plan to share individual participant data (IPD).
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University of California, Irvine