Early Rib Analgesia with SERratus: ERASER Trial 

A pragmatic, randomised control trial that assesses the best treatment for pain management of multiple broken ribs. The trial will compare whether serratus anterior plane block (SAP) decreases the rates of Pneumonia five days after randomisation compared to usual/standard care.

With regret, the National Institute of Health Research (NIHR) has made the difficult decision to stop recruitment to the Eraser Trial as of Friday, 13th March 2026.

We are incredibly grateful to all participants and site teams for their time, effort, and dedication - you have played a vital role in supporting this important research.

You can find a summary of recruitment on the Recruitment and participating centres page. Please also visit the Latest News page for updates on any scientific publications or events related to the Eraser Trial. 

Eraser Twitter Account

 

Design

Eraser is a randomised controlled trial to investigate the clinical and cost effectiveness serratus anterior plane block with catheter insertion compared to usual care in patients with multiple rib fractures

Aim of the study

The primary aim of the study is to determine whether treating multiple rib fractures (MRF) patients with serratus anterior plane block (SAP) decreases the rates of pneumonia five days after randomisation.

Settings

Intensive Care Units and wards within NHS Trauma Centres in the United Kingdom who treat MRF patient populations.

Target Population

Suitable patients will be identified as meeting the eligibility criteria if they meet the following three criteria:-

  • Patients ≥16 years with unilateral or bilateral
  • ≥3 rib fractures following blunt chest trauma
  • Traumatic injury that occurred ≤72 hours before hospital admission.

Intervention

SAP + usual care

SAP catheter inserted, under ultrasound guidance, in the lateral chest wall between latissimus dorsi and serratus anterior muscles in the midaxillary line. A local anaesthetic will be infused using a continuous infusion pump, according to local standard practice.

Usual Care

Usual NHS trauma care, which may consist of twice a day physiotherapy, multimodal analgesia, incentive spirometry when possible and rib fixation.

Measurement of otcomes

The objectives are:

Primary objectives:

  • New diagnosis of pneumonia, as agreed by a blinded end point assessment committee, five days after randomisation.

Secondary Objectives:

  • Pain assessed using a numerical rating scale (0-10), recorded every 4 hours, day 1 to 5, day 14 and before discharge, and by the patient-reported BPI at one and three-months post-randomisation.
  • Number of days ventilated and the requirement for invasive/non-invasive methods
  • 30 day and 90 day mortality
  • Complications and safety data associated with SAP
  • Opiate consumption such as morphine and related compounds
  • Length of stay in hospital and critical care level two/three facility
  • Hospital re-admission within 30 days of discharge
  • Patient-Reported Outcome Measures (PROMs) at 30 and 90 days:
              • EQ-5D-5L
              • Medical Research Council (MRC) dyspnoea scale at 90 days only
              • Brief Pain Index (BPI)
              • McGill Pain Questionnaire (SF-MPQ-2)