New Immobilization Guidelines Change EMS Critical Thinking in Older Adults With Spine Trauma
Authors: Underbrink L, Dalton A, Leonard J, et al.
Published in: Prehospital Emergency Care, 2018; 22(5): 637–44.
Best practices for caring for spinal trauma patients have changed. We used to believe that to prevent additional injury, it was necessary to immobilize all patients with suspected spinal injury by strapping them to a backboard, placing a cervical collar, and immobilizing the head.
We now know there are subsets of patients who may require full spinal immobilization, but most do not. Many studies have found that full spinal immobilization is associated with unwanted consequences, including increased pain and discomfort, contributing to further injury, and pressure ulcers, to name a few. This has led to adoption of protocols that discourage the use of full spinal immobilization.
The study we review this month compared the types of spinal precautions used by EMS and outcomes for older adult patients (60 or older) with cervical spinal trauma before and after implementation of an updated immobilization protocol. The authors chose to study older patients because they make up a sizable proportion of adult trauma patients (about 15%), have higher mortality rates, and are often undertriaged.
This was a multicenter retrospective observational study. Twenty-four diverse EMS transporting agencies from a five-county region of Colorado participated.
The protocol was implemented on July 1, 2014. The study compared the pre-implementation period (January 1, 2012 through June 30, 2014) to the postimplementation period (July 1, 2014 to December 31, 2015) with respect to type of spinal precaution used and patient outcome.
This protocol was implemented on one day. Not only is that impressive, but it makes a pre-/post- study much easier to conduct, the statistical analysis less complex, and the results easier to interpret. The protocol allowed EMS professionals to “practice discretion when choosing immobilization methods” and provided guidance for full immobilization and the use of only a cervical collar. Patients with midline spine tenderness, neurological deficits, altered mental status, potentially distracting injuries, or barriers to spinal evaluation received a cervical collar. Those with neurological deficits and those unable to comply received full spinal immobilization. Each agency chose its preferred training method.
The outcomes of interest were immobilization type, the presence of neurological deficits, patient disposition at discharge, and in-hospital mortality/hospice. The authors compared four categories of immobilization: full (rigid backboard, scoop stretcher, or full-body vacuum splint, plus a cervical collar and head immobilization); cervical collar only; other (using a variety of immobilization devices and combinations); and no immobilization.
To be included in the study, a patient had to be 60-plus years old, transported by one of the 24 EMS agencies, and admitted to one of nine participating trauma centers with ICD-9 diagnosis codes indicating cervical fracture without cord injury, cervical fracture with cord injury, or cord injury without cervical fracture. Patients were excluded if they arrived at the hospital without vital signs, were transported by private vehicle or subject to some other triage, came via interfacility transport, or were missing data identifying their immobilization type.
The analysis used appropriate statistical tests for categorical demographic data (sex, cause of injury, type of fracture) and continuous demographic data (age, GCS, ISS). The analysis also calculated the odds of in-hospital mortality/hospice when adjusting for demographics.
There were 7,737 trauma patients 60-plus years old, and 237 (3.1%) had a diagnosis of cervical spine fracture or cervical cord injury. There were 123 patients evaluated from the pre-protocol period and 114 from the post-protocol period. Pre-protocol patients had higher median ISS scores, and the difference was statistically significant (10 vs. 9, p = 0.02). There was no statistically significant difference when comparing any other demographic variable.
When comparing the pre- and post-protocol periods, the use of full immobilization was significantly higher in the pre-protocol group (59.4% vs. 28.1%, p < 0.001). The immobilization category of “other” was also represented more in the pre-protocol period; however, this difference was not statistically significant (16.3% vs. 13.2%, p = 0.50). In the post-protocol period, there were statistically significant increases in the use of both cervical collars only (8.9% vs. 27.2%, p < 0.001) and no immobilization devices (15.5% vs. 31.6%, p = 0.003).
Further, there was no difference in neurological deficit (6.5% vs. 5.3%, p = 0.69) or patients transported to a skilled nursing facility (40.7% vs. 44.7%, p = 0.52). While there was a statistically significant difference in percentage of death/hospice reported in the pre-protocol period compared to the post-protocol period (19.5% vs. 9.7%, p = 0.03), this difference was no longer statistically significant after adjusting for injury severity (adjusted OR 0.56; 95% CI: 0.24–1.30; p = 0.18).
The authors warned against generalizing these results to all adult trauma patients and other trauma systems. This study only included patients who were at least 60 years old, and population demographics and geography were similar in the five included counties. They also noted the lack of standardized training across agencies as a limitation. The authors did not have the ability to evaluate protocol adherence, nor did they know pre-injury status or comorbidities. Finally, data describing the EMS professionals’ reasons for using specific immobilization types were not available.
It is not clear whether the authors performed a sample size calculation. Sample size calculations allow the investigator to understand how much data needs to be collected to see a statistically significant difference, if one exists. They chose a pre-protocol period of 2.5 years and a post-protocol period of 1.5 years, likely to have similar-size groups to compare.
The authors may have chosen the start of the pre-protocol period simply because that was the first year for which data were available. However, this is unclear. It is possible some of the assessments that didn’t reach statistical significance might have if more data were collected and/or analyzed. However, both groups were large, and the p-values were well above 0.05, so this is unlikely.
This is an interesting study that adds to the body of evidence supporting restricted use of full spinal immobilization in the emergency services.
Antonio R. Fernandez, PhD, NRP, FAHA, is research director at the EMS Performance Improvement Center and an assistant professor in the Department of Emergency Medicine at the University of North Carolina–Chapel Hill. He is on the board of advisors of the Prehospital Care Research Forum at UCLA.