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UltrasouNd-guided Percutaneous Intercostal Nerve Cryoneurolysis for Analgesia Following Traumatic Rib Fracture

UltrasouNd-guided Percutaneous Intercostal Nerve Cryoneurolysis for Analgesia Following Traumatic Rib Fracture, a Pilot Randomized Control Trial (UNPIN Trial)

Status
Recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05865327
Acronym
UNPIN
Enrollment
24
Registered
2023-05-18
Start date
2023-10-23
Completion date
2025-12-31
Last updated
2025-09-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Pain, Pain, Acute, Pain, Chronic, Rib Fracture Multiple, Rib Fractures, Rib; Fracture, With Flail Chest, Trauma, Trauma Injury

Keywords

Cryoneurolysis, Rib Fracture Pain, Intercostal Nerve Block

Brief summary

Traumatic rib fractures (i.e., broken ribs caused by a physical injury) are common and very painful. They also often lead to serious complications, more time spent in hospital, and can even lead to death. Even after rib fractures have healed, they can lead to long-term pain and a lower quality of life. A technology called cryoneurolysis, which acts to freeze nerves causing pain using a small tool which can turn very cold, is a promising new way to manage rib fracture pain. This study is a test with a small number of people to see if it is feasible to use this technology for patients with rib fractures. If this is successful, we will recruit more people for a larger study to see if cryoneurolysis, along with standard pain control techniques, is better at stopping pain, compared to just the normal techniques alone. Participants in our study will be asked to rate their pain, and record pain medications that they take for 3 months after their pain procedure.

Detailed description

More than 100,000 people a year suffer from traumatic rib fractures. Pain from rib fractures impairs the ability to inspire deeply and cough effectively, predisposing patients to severe, potentially life threatening complications and increased healthcare costs. For many patients, this pain can also persist long after the acute injury has healed, delaying recovery and reducing quality of life. Current pain interventions, including multimodal analgesia and local anesthetic-based nerve blocks, are useful, but are limited by a short duration of effectiveness, and/or risk of complications. Cryoneurolysis (CN) is a new method to control pain which acts to freeze intercostal nerves (ICNs) associated with fractured ribs using a handheld device. This freezing action causes neurons to undergo Wallerian degeneration distally from the site of ablation and thus exhibit an extended but reversible block. This study is a single-site, randomized, pilot study to assess the feasibility of recruitment, randomization, and protocol adherence of providing cryoneurolysis for patients with traumatic rib fractures. Secondary data from the pilot trial designed to assess the effectiveness of the intervention (pain scores, opioid usage, etc.) will be included in the analysis of the full trial if feasible. The objective of the full trial is to demonstrate that cryoneurolysis of ICN, in addition to standard analgesic practice, provides superior, prolonged analgesia. Participants (individuals aged 18-85, with 3-8 unilateral traumatic rib fractures) will be randomized 1:1 in blocks of 4, stratified by number of rib fractures (\> 4 or ≤4) and the presence/absence of flail segment, to receive the current standard of practice for rib fractures (multimodal analgesia and erector spinae plane (ESP) catheter infusion) with or without the addition of CN. Participants in the standard care group will receive a sham CN procedure to maintain blinding. All participants (both groups) will receive standard of care analgesia. Specifically, an ultrasound-guided ESP catheter will be placed as per standard protocols. 20cc of 0.5% ropivacaine and 1% lidocaine will be injected through the catheter, followed by a basal infusion of 2 cc/hr of 0.2% ropivacaine (to maintain catheter patency) with an on demand patient controlled regional anesthesia (PCRA) dose of 10cc 0.2% ropivacaine available hourly until patient has met criteria for APS discharge or pain is controlled such that PCRA use is \< 2 boluses over 12 hrs and NRS \< 3 with deep breathing and coughing. Standard multimodal analgesia including Tylenol 1000mg QID, Celebrex 200mg BID (or ketorolac 7.5 QID), Pregabalin 50mg BID, and/or PRN oral hydromorphone (1-4mg) will also be provided. Additional analgesics include intravenous ketamine at a dose of 0.1-0.2 mg/kg/hr of lean body weight in the event of consistent NRS pain scores \> 6, and up to 0.05 mg/kg of intravenous midazolam for anxiolysis and 1mcg/kg of intravenous fentanyl for comfort during positioning, as required. Participants will remain in the study for 3 months from the date of the block procedure. They will be followed daily while in hospital and using a pain diary following discharge (weekly pain scores and daily opioid usage). Additionally, follow-ups will be completed at 1h, 24h, 48h, 1 week, 1 month, and 3 months post block procedure.

Interventions

PROCEDURECryoneurolysis

Cryoneurolysis will be performed on the intercostal nerve associated with each fractured rib using a handheld cryoneurolysis machine (Iovera). Cryoneurolysis will consist of two 103 second cycles (includes cooling, ice ball formation and warming time) per rib fracture level. Ultrasound guidance will be used to identify appropriate rib fracture levels and to target the device tip in real time. All participants will also receive standard multimodal analgesia and ESP catheter infusion.

Participants in the control group will receive sham CN (i.e., application of device without skin puncture or activation of unit) to maintain participant blinding. All participants will also receive standard multimodal analgesia and ESP catheter infusion.

Sponsors

Sunnybrook Health Sciences Centre
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Masking description

Only the anesthesiologist responsible for performing cryoneurolysis will be aware of group allocation. All others, including participants, other clinical team, data collectors and analysts will be blinded. Participants in the control group will receive sham cryoneurolysis to maintain blinding.

Intervention model description

Single-centre, prospective, parallel, randomized, blinded (participant, data collectors/analysts) pilot feasibility trial

Eligibility

Sex/Gender
ALL
Age
18 Years to 100 Years
Healthy volunteers
No

Inclusion criteria

* Aged ≥18 * Unilateral traumatic rib fractures (3 to 8) * Candidate for ESP block catheter * Within 48hrs of admission to hospital

Exclusion criteria

* Lack of patient consent; unlikely to comply with follow up * Unable to use Patient Controlled Regional Analgesia (Ventilated/sedated patients or Moderate to severe traumatic brain injury) * Chronic pain (opioid use \> 30mg oral morphine equivalent per day) * Substance use disorder * CrCl \< 50 * BMI \> 45 * Significant distracting injuries (unreduced long bone fractures, unstable pelvic or spine fractures and patients requiring trauma laparotomy- also preclude positioning for block placement (lateral decubitus or sitting up)) * Contraindications for ESP catheter placement (pre-existing medical/neurological/hematologic diseases, localized infection/trauma at site of intervention, allergy to amide local anesthetics) * Contraindications to CN (cryoglobulinemia, paroxysmal cold hemoglobinuria, multiple myeloma and cold urticarial). * Unable to return to Trauma Recovery Clinic (in-person or virtual) at 3 months

Design outcomes

Primary

MeasureTime frameDescription
Rate of Adverse events3 month follow-upEnsure no adverse events (short or long term) associated with CN
Number of participants randomized over an 8 month periodEntire pilot study (approximately 8 months)Goal of 3 participants per month for 8 months
Number of participants able to adhere to the protocolEntire pilot study (approximately 8 months + 3 month follow-up)Goal of \> 90%
Number of participants able to adhere to the follow-up3 month follow-upGoal of \> 90%

Secondary

MeasureTime frameDescription
Opioid consumption in hospital and after dischargeDaily for 90 days after block placementDetermined from medical records (in-hospital) and via a daily pain diary (post-discharge). Calculated in Oral Morphine Equivalents.
Pain Intensity at 1 and 3 months1 and 3 month follow-upsAs measured using Numeric Pain Rating Scale (0-10) , at rest and during deep inspiration
Oxygen requirementsPre-intervention, post intervention, then daily until dischargeRoom air oxygen saturation (SpO2) and requirement for supplementary O2 to maintain SpO2 \> 92%
Pulmonary Function TestingPre-intervention, post intervention, then daily until dischargeFVC
Length of Stay in hospitalDate of admission to date dischargeHospital discharge date
Time to achieve discharge criteria for isolated chest injuryDate of admission until discharge criteria metCriteria include on oral meds without continuous regional analgesia, chest tube out and chest well evacuated (e.g. no evidence of retained hemothorax), and no supplemental O2
Patient satisfaction48 post block procedure, and 1 week, 1 month and 3 month follow-upsPatient satisfaction assessed using Patients' Global Impression of Change (PGIC) scale
Incidence of chronic rib fracture pain3 month follow-upAs assessed using Brief Pain Inventory (BPI) questionnaire
Adverse eventsuntil 3 month follow-upAdverse events to be recorded include: local anesthetic complications, catheter related complications (clotting, migration), procedural complications (pneumothorax, bleeding, infection), and neurological disturbances (dysesthesia, hyperalgesia, allodynia) in area of rib fracture
Length of Stay on acute pain service (APS)Date of admission to date of discharge from acute pain serviceCriteria include on oral meds without continuous regional analgesia or intravenous opioids
Pain Severity during deep inspiration 24 hours post ESP catheter placement24 hours post placement of ESP catheterPain measured using Numeric Pain Rating Scale
Time to discontinuation of ESP catheterUntil ESP catheter removal (usually < 7 days)Based on when patient has met criteria for APS discharge or pain is controlled such that PCRA use is \< 2 boluses over 12 hrs and NRS \< 3 with deep breathing and coughing
ESP catheter useUntil ESP catheter removal (usually < 7 days)Cumulative volume of local anesthetic solution used via ESP catheter patient controlled reginal analgesia

Other

MeasureTime frameDescription
Pain Intensity1h and 48h, post block placement, daily in hospital, weekly post discharge and at 1 week follow-upAs measured using NRS-11, at rest and during deep inspiration

Countries

Canada

Contacts

Primary ContactBen Safa, MD
ben.safa@sunnybrook.ca416-480-4864

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026