Background
Canadian Emergency Medical Services (EMS) annually transport 1.3 million patients who may have injured their neck (c-spine) in falls or motor vehicle collisions to local emergency departments (ED). Less than 1% of all such patients have a c-spine fracture (bones), and even less (0.5%) have a spinal cord injury (nerves). Most spinal cord injuries occur before EMS arrival and not during transport to hospital, yet most trauma victims (with or without c-spine injury) are transported in ambulances using backboard, collar, and head immobilizers. They stay fully immobilized until an ED bed is made available (sometimes up to 3 hrs, also holding up the EMS crew), or until physician assessment and/or X-rays are complete. This prolonged immobilization is often unnecessary, adds considerably to patient discomfort, and also adds to the burden of our overtaxed EMS systems and overcrowded EDs.

A clinical decision rule is derived from original research and is defined as a decision making tool that incorporates three or more variables from the history, examination, or simple tests. This study builds on previously funded projects by the investigators to develop a decision rule for c-spine evaluation. We have developed the Canadian C-Spine Rule (CCR) to be used by physicians (JAMA 2001, New Engl J Med 2003), nurses, and paramedics for alert and stable trauma patients. After evaluating more than 30,000 patients, the CCR has never missed a significant injury. Physicians and some nurses already use the CCR in clinical practice to remove immobilization devices without the need for X-rays. Our recent paramedic validation study (Ann Emerg Med 2009) was highly successful with 1,949 patients assessed and all injuries were identified by the paramedics.

Paramedics from several U.S. States already use a less precise decision aid (NEXUS Criteria) to selectively immobilize blunt trauma victims before transportation. In Canada, the CCR is currently used in the city of Calgary and the province of Nova Scotia. Most other Canadian EMS systems are awaiting further safety evaluation studies before implementing such a program with paramedics.

Objectives
The goal of this study is to evaluate the safety and potential impact of an active strategy that allows paramedics to assess very low-risk trauma patients with the CCR and transport them without immobilization. Specific objectives, with regards to use of the CCR in the field by trained paramedics, are to: 1) determine safety; 2) determine clinical impact; and 3) evaluate performance.

Methods
We will do a cohort study which evaluates outcomes during a 36-month period in Ottawa. Enrolled will be consecutive, alert and stable adult trauma patients assessed by paramedics for the necessity to immobilize the c-spine.

All paramedics will undergo a structured educational strategy to learn the CCR; most of these paramedics were already involved in the prehospital validation study. Paramedics will be empowered by medical directive to not immobilize the c-spine of selected patients according to the CCR, thus allowing them to rapidly transport patients to a less acute area of the ED.

Outcomes to be assessed are: 1) measures of safety: a) Number of missed fractures, and b) Number of serious adverse outcomes; 2) measures of clinical impact: a) Proportion of low-risk patients transported without immobilization, b) Time spent in the field before transport, c) Time from ED arrival to transfer of patient care to ED staff; and d) Total patient length of stay in the ED; and 3) performance of the Canadian C-Spine Rule: a) Rule accuracy, b) Paramedic accuracy of interpretation, and c) Paramedic agreement and level of comfort with the decision suggested by the CCR. We will compare outcomes in the evaluation period of this study to those during the validation study at the same site (Ottawa). We estimate a sample size of 3,000 patients will be accrued.

Importance
Approximately 40% of all very low-risk trauma patients could be transported safely, without c-spine immobilization devices, if paramedics were empowered to make clinical decisions using the CCR. This would result in EMS crews spending less time at the scene, and less time at the receiving hospital before transfer of care. In addition, less ED stretcher areas would be occupied by minor trauma victims resulting in shorter lengths of stay. This safety study is an essential step before allowing all paramedics across Canada to selectively immobilize trauma victims before transport. Once safety and potential impact are established, we intend to implement a multi-center trial to study actual impact.

• Vaillancourt C, Stiell IG, Beaudoin T, Maloney J, Anton AR, Bradford P, Cain E, Travers A, Stempien M, Lees M, Munkley D, Battram E, Banek J, Wells GA. The Out-of-Hospital Validation of the Canadian C-Spine Rule by Paramedics. Ann Emerg Med. 2009 Nov;54(5):663-671.e1. Epub 2009 Apr 24.
  
  

OHRI members:

Dr. Christian Vaillancourt
Dr. Ian Stiell
Dr. George Wells
Manya Charette
Ann Kasaboski