Erector Spinae Plane vs Serratus Anterior Plane Catheter Infusions for Acute Pain Management in Patients With Traumatic Rib Fractures

Erector Spinae Plane vs Serratus Anterior Plane Catheter Infusions for Acute Pain Management in Patients With Traumatic Rib Fractures: a Single Centre, Randomized Controlled Trial

Rib fractures happen in about 10-20% of patients with blunt trauma and can be serious, with higher death rates in older adults. These injuries often lead to lung problems like pneumonia, collapsed lung areas (atelectasis), fluid buildup, or even respiratory failure. A major reason for this is pain-patients avoid deep breathing and coughing, which worsens lung function. Good pain control helps prevent these complications.

Opioids are commonly used for pain but can cause problems such as slowed breathing, delirium, nausea, and longer time on a ventilator. Because of this, regional anesthesia (nerve blocks) is increasingly used to control pain while reducing opioid use. Common options include epidurals, paravertebral blocks, and newer techniques like erector spinae plane (ESP) and serratus anterior plane (SAP) blocks. Continuous catheter techniques are especially useful in trauma patients because they can provide ongoing pain relief and have fewer contraindications than epidurals.

The SAP block is done at the side of the chest and works well for rib fractures in the front and side. It may not work as well for fractures in the back, although trauma may sometimes allow the anesthetic to spread further than expected.

The ESP block is done near the spine and may cover a broader area, including both front and back of the chest. It is relatively easy to perform at the bedside and is considered safe. Studies suggest it provides pain relief similar to epidurals in some patients.

There is still limited evidence directly comparing continuous SAP and ESP catheters. Only one study (using single injections) suggests ESP may provide better pain relief. It is unclear whether that difference holds true with continuous infusions, or whether SAP might be preferable because it is easier and quicker to perform.

We propose a randomized trial comparing continuous ESP and SAP catheters in patients with rib fractures to determine which provides better pain control, reduces opioid use, improves breathing outcomes, and is easier to perform in routine practice.

Our hypotheses are that ESP will provide better pain relief, SAP will be easier and safer to place, and both techniques will reduce opioid use while maintaining good patient comfort and breathing.

Study Overview

• Status: Not yet recruiting
• Conditions: Traumatic Rib Fracture; Traumatic Rib Fracture(s)
• Intervention / Treatment: Procedure: Erector spinae plane catheter; Procedure: Serratus plane catheter

Detailed Description

Traumatic rib fractures occur in 10%-20% of blunt trauma patients and are associated with significant mortality (22% and 10%, in the elderly and young patients, respectively). Patients with rib fractures are predisposed to multiple pulmonary complications including pneumonia, aspiration, pleural effusion, pulmonary embolism, atelectasis and acute respiratory distress syndrome. Effective analgesia, albeit challenging, has been found to reduce the incidence of those complications. It is postulated that pulmonary complications occur post rib fractures due to impaired pulmonary mechanics, inappropriate clearance of secretions, and atelectasis; hence the need for adequate and affective pain control.

Opioids are commonly used for analgesia in critically ill patients but they carry notable adverse effects including: respiratory depression, hemodynamic instability, tolerance, hyperalgesia, delirium and gastrointestinal side effects. They are also associated with prolonged mechanical ventilation, counteracting goals for rib fracture management. Therefore, alternative analgesic option such as regional anesthesia techniques have gained more popularity. Regional anesthetic blocks can improve analgesia and reduce opioid requirements. Options for rib fractures include thoracic epidural analgesia (TEA), paravertebral block, intercostal block, erector spinae plane block (ESP), and serratus anterior plane block (SAP).

Continuous peripheral nerve blockage has gained more popularity in trauma settings; especially continuous fascial plane catheters which can offer effective analgesia without many contraindications associated with thoracic epidurals. Frequent contraindications to thoracic epidural blocks in trauma populations have driven interest in alternative analgesic modalities such as continuous fascial plane infusions, despite the lower pneumonia rates that are associated with thoracic epidural analgesia.

Serratus Anterior Plane Block (SAP Block): The SAP block is an ultrasound guided block that involves the injection of local anesthetic superficial to the serratus anterior muscle in the mid axillary line. It provides effective analgesia for patients with anterolateral rib fractures but might be ineffective for posterior rib fractures. It consistently involves the lateral cutaneous branches of intercostal nerves, which innervate the superficial anterolateral chest wall. It might spare the intercostal nerves supplying the posterior ribs and intercostal muscles. However, a cadaveric study showed that disruption of tissue planes in trauma may promote deeper spread of local anesthetic reaching the intercostal nerves and reaching the posterior rib space.

Erector Spinae Plane Block (ESP Block): The ESP block is an ultrasound guided block which involves injection of local anesthetic into the erector spinae fascial plane. It is thought to work by blocking the lateral cutaneous and intercostal nerves with potential diffusion into the paravertebral space. It is technically easy and can be performed at bedside. Risks are low, particularly when performed under ultrasound guidance, and include hypotension, vascular puncture, contralateral spread via the epidural space, and pneumothorax. A continuous nerve catheter is typically used for rib fractures with the goal of inserting the needle midpoint of the rib levels. A randomized trial has showed that continuous ESP block is as effective is thoracic epidural analgesia for pain control in patients with unilateral rib fractures.

Addressing evidence gaps: A recent scoping review published by our research group indicated that SAP and ESP are the most common regional anesthesia techniques for acute traumatic rib fractures. There has been one head-to-head study comparing SAP to ESP that demonstrated superior analgesia in favour of ESP for traumatic rib fractures however it was designed as a single injection study. Given that the SAP catheter is potentially easier to perform (i.e., no need to place patient in lateral decubitus position and shallower sonographic target), is ESP superior to SAP catheter infusion to warrant the additional time and effort? To our best knowledge, no prospective comparative studies on SAP and ESP catheters have directly evaluated analgesic efficacy, opioid consumption, respiratory outcomes, and ease of performance between these two catheter techniques in a systematic manner. Understanding which technique provides superior analgesia while remaining technically straightforward for widespread implementation is critical for standardizing regional anesthesia practice in rib fracture management. We propose a pragmatic, randomized controlled trial (RCT) comparing ESP and SAP to identify the best regional anesthesia catheter technique regardless of the pattern of rib fracture (anterior vs. posterior) and to allow adoption of a single technique to facilitate streamlined care. This knowledge gap represents an important opportunity to advance our understanding of the two established techniques in this trauma population.

• Study Type: Interventional
• Enrollment (Estimated): 66
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Howard Meng, MD; Phone Number: 416-480-4864; Email: howard.meng@sunnybrook.ca
• Study Contact Backup: Name: Lilia Kaustov, PhD; Phone Number: 416-480-4864; Email: lilia.kaustov@sunnybrook.ca

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M4N 3M5
      • Sunnybrook Health Sciences Centre
      • Contact: Howard Meng, MD; Phone Number: 416-480-4864; Email: howard.meng@sunnybrook.ca
      • Principal Investigator: Howard Meng, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age >18;
• Traumatic rib fractures (unilateral or bilateral);
• Minimum of 3 rib fractures per side;
• Admitted to hospital for <72 hours
• NRS pain score > 4 at rest or with movement for chest pain at the time of eligibility assessment

Exclusion Criteria:

• Severe traumatic brain injury (Glasgow Coma Scale < 9);
• Surgery performed/planned within 72 hours of catheter infusion start;
• Uncontrolled coagulopathy;
• Skin infection or anatomical abnormality (i.e. open fracture) at insertion sites;
• Allergy to local anesthetic;
• Chronic high dose opioid use preadmission (Morphine Equivalent Dose > 30mg per day);
• Pregnancy;
• Acute respiratory failure requiring intubation at enrolment;
• Inability to comply with Intravenous Patient-Controlled Analgesia use;
• Contraindications to nerve blocks
• High likelihood of loss to follow-up

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Erector spinae plane catheter; Participants receive erector spinae plane catheter	Procedure: Erector spinae plane catheter; Participants receive erector spinae plane catheter infusion
Experimental: Serratus plane catheter; Participants receive serratus anterior plane catheter	Procedure: Serratus plane catheter; Participants receive serratus plane catheter infusion

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain with movement	Pain Numerical Rating Scale scores with movement from baseline through 72 hours post-placement. Numerical Rating Scale minimum is 0, maximum is 10, higher score = worse pain.	72 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total opioid consumption	Total opioid consumption (IV and oral) between the SAP and ESP groups at 24, 48, and 72 hours post-catheter placement	72 hours
Respiratory function	forced expiratory volume in 1 second (FEV1), FEV1% of predicted, forced vital capacity (FVC), and peak inspiratory and expiratory flow will be measured using portable spirometry at baseline, 24 (± 4 hours), 48 (± 6 hours), and 72 (± 6 hours) hours post-catheter placement	72 hours
Ease of catheter insertion between techniques	Number of skin puncture attempts	At time of catheter insertion
Pain at rest	Pain Numerical Rating Scale scores at rest from baseline through 72 hours post-placement. Numerical Rating Scale minimum is 0, maximum is 10, higher score = worse pain.	72 hours
Procedure related complications	Procedural complications (vascular puncture, local anesthetic toxicity signs, pneumothorax, infection at insertion site).	72 hours
Duration of catheter insertion procedure	Time from patient positioning to final catheter insertion and confirmation (in minutes)	At the time of catheter insertion

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient satisfaction	Patient satisfaction scores using Patient Global Impression of Change (PGIC)	72 hours
Catheter-related complications	Catheter-related complications including infection, dislodgement, local anesthetic toxicity, and pneumothorax within the 72 hour study period	72 hours
Catheter function	Duration of catheter function (days of infusion)	Through hospital admission, an average of 7 days
Hospital length of stay	Total hospital length of stay (measured in days)	Duration of hospital admission, an average of 7 days
Intensive care stay	Duration of intensive care stay	Through hospital admission, an average of 7 days
Pulmonary complications	Documented pneumonia, ARDS, need for mechanical ventilation	Through hospital admission, an average of 7 days

Collaborators and Investigators

• Sponsor: Sunnybrook Health Sciences Centre

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): June 30, 2028

Study Registration Dates

• First Submitted: July 3, 2026
• First Submitted That Met QC Criteria: August 4, 2026
• First Posted (Actual): August 10, 2026

Study Record Updates

• Last Update Posted (Actual): August 10, 2026
• Last Update Submitted That Met QC Criteria: August 4, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: trauma; acute pain; regional anesthesia; rib fracture; fascial plane catheter
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Fractures, Bone; Thoracic Injuries; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Wounds and Injuries; Acute Pain; Rib Fractures
• Other Study ID Numbers: 7157

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No