Cervical collars, while playing an important role when necessary, can also create a frustrating barrier to care. Recent practice patterns often rely on CT imaging for cervical collar clearance in blunt trauma, followed by MRI as needed if the patient is not evaluable or has persistent midline pain. Recent guidelines have been published regarding this practice and suggest that we may be able to clear more collars after negative high quality CT than previously done in practice. Last summer, I came across an email with the subject “Clearing Drunk C-Spines” from Journal Feed that got me interested in this topic.
First, why should you care? As an EM provider you likely have experienced the decreased first pass success for intubation when cervical collar is in place, but collars have multiple other detrimental effects including increased aspiration and pressure ulcers. They can also lead to increased ICP which may be particular troublesome in a head trauma patient. A study by Ala et al. in 2016 showed that lung capacity and other spirometric values in 50 trauma patients improved when cervical collar was removed1. In the setting of overcrowding in emergency departments, downstream testing such as MRI contributes to increased disposition time and place an extra stressor on an already strained system.
The Eastern Association for the Surgery of Trauma published a systematic review of cervical spine clearance in the obtunded adult blunt trauma patient in 2015, accompanied by practice management guidelines2. They ask the question as to whether cervical collar removal should be performed after a negative high-quality cervical spine CT result alone or after negative CT combined with adjunct imaging. This was a systematic review including 11 articles with patients 16 years or greater who were obtunded, including patients with GCS<15, an unreliable exam, or a distracting injury or those who were unconscious, intubated, altered, or intoxicated. They found that no unstable injuries were found after a negative initial CT result; 9% of patients were found to have stable injuries on adjunctive studies. The authors conclude that they “conditionally recommend cervical collar removal after a negative high quality C-spine CT scan result alone” in the obtunded adult blunt trauma patient though qualify this recommendation stating this is based on very low-quality evidence. According to the Eastern Association, to continue indiscriminately performing a two-step sequential screen is not an appropriate use of resources based on the lack of clinically significant injuries missed on CT in their study but this management strategy does not preclude neurologic deterioration2.
This article was followed by a prospective evaluation of the accuracy of CT for the detection of clinically significant C spine injury, published in 2016 by the Western Trauma Association. This multicenter study included about 10,000 adult blunt trauma patients 18 years or older that failed clinical clearance by NEXUS or Canadian C spine and underwent CT of their C spine. 3 patients with negative CT scans were later found to have clinically significant injuries requiring surgical stabilization but all had a focal neurological abnormality consistent with central cord syndrome. The authors suggest performing MRI after negative CT in setting of patient with neuro deficits which triggered the initial imaging3.
Lastly in 2017 the Western Trauma Association published a preplanned nested substudy examining the accuracy of CT at detecting clinically significant cervical spine injury in intoxicated patients. This included patients with ETOH >80, positive UDS, and most importantly those who were deemed intoxicated by the provider. 30% of their larger cohort was included in this analysis; this group had a similar injury severity score. The negative predictive value of CT in this cohort was 99.9% for clinically significant injuries with one of the patients with central cord syndrome mentioned above in this intoxicated group. The authors note that intoxication is a common reason that patients fail clinical clearance, but spinal immobilization is often maintained after negative CT as providers remain concerned about occult injury. Interestingly, after CT is negative the time to collar clearance in intoxicated patients was 8 hours on average compared to 2 hours in the sober group4.
So why not just allow your intoxicated patient to metabolize and be reevaluated. The risks of staying in the collar must be weighed against the potential harms of a missed injury. Some risks such as aspiration and pressure ulcers may be particularly salient in this group.
While these recommendations may not yet be ready for primetime for all of your trauma patients, they should certainly be considered. It may be that C collar clearance after CT may be possible in patients who have no neurologic or gross motor deficits especially in the setting of low injury severity. On your next shift you might consider clearing the C collar of your drunk patient who fell from ground level, the elderly dementia patient who slid out of bed, or your respiratory arrest patient who was found down. If you work in a department like I do where many of your patients are slated for the MRI, your MRI tech will sure thank you.
Resources
Ala A, Shams-Vahdati S, Taghizadieh A, et al. Cervical Collar Effect on Pulmonary Volumes in Patients with Trauma. Eur J Trauma Emerg Surg 2016; 42(5): 657-660.
Patel MB, Humble SS, Cullinane DC, et al. Cervical Spine Collar Clearance in the Obtunded Adult Trauma Patient: A Systematic Review and Practice Management Guideline from the Eastern Association for the Surgery of Trauma. J Trauma Acute Care Surg 2015; 78(2): 430-441.
Inaba K, Byerly S, Bush LD, et al. Cervical Spinal Clearance: A Prospective Western Trauma Association Multi-Institutional Trial. J Trauma Acute Care Surg 2016; 81(6): 1122-1130.
Martin MJ, Bush LD, Inaba K, et al. Cervical Spine Evaluation and Clearance in the Intoxicated Patient: A Prospective Western Trauma Association Multi-institutional Trial and Survey. J Trauma Acute Care Surg. 2017; 83(6): 1032-1040.
More on Martin et al. and the clearance of intoxicated C spines:
Journal Feed: https://journalfeed.org/article-a-day/2017/clearing-drunk-c-spines
EMA: https://www.emrap.org/episode/emajune2018/abstract6