Acute Prehospital Spinal Injury Assessment and Clearance
Spinal injuries are divisible into two categories: spinal column (bones, muscles, ligaments) and spinal cord (the CNS part). When thinking spinal injury, think whole of spine. Most responders talk about cervical collar and head stabilisation but don’t reflect that the thoracic, lumbar and even sacral spine can also be injured in some instances. These are better protected and less commonly injured.
Spinal care is an approach rather than one tool or method. A cervical collar alone is not spinal care, it is just a part. Neutral head position, lumbar support, coordinated lifting and log rolling, talking to the patient so as not to make them turn their head are all part of the spine care approach. Even allowing conscious patients to self-extricate can cause less movement and pain (Cowley et al. 2017).
Column is spinal structure; structure is ‘my neck hurts’. Spinal Cord Injury (SCI) is the more concerning ‘I can’t feel my legs’. Structural injury is much more commonly observed and uncommonly serious. It literally is a pain in the neck or back. Cord injury is the opposite. It is uncommonly observed but always serious when found. Cord injury is a time critical problem. Any patient with suspected cord injury should go to the nearest major trauma centre within specified time frames. In contrast, structural injury can be transported to the nearest local medical facility able to provide x-ray and medical examination.
Both still receive good spinal care on the way there. Primary SCI happens at the time of trauma. Secondary injury follows from oedema, haemorrhage, inflammation and eventual cell death around the primary (Anwar et al. 2016; Witiw and Fehlings 2015). The ever present concern is that improper care can turn a structural injury into a cord injury. Statistically this is very unlikely to happen but not impossible.
It turns out thought that not every patient ends up with a spinal injury. In days gone by every trauma patient had a cervical collar applied and received full spinal immobilisation. The historical dogma that drove this has largely fallen away now. Many of these patients had no prospect of a spinal injury at all and could be easily and safely screened and cleared pre-hospital. To do this, a normal spinal examination is first performed on the patient to assess for both cord and structural injury.
Cord injury typically involves changes in neurological function such as motor or sensation. The spinal cord is not one solid nerve. Rather it is many nerves in tracts that run up and down cord length through the vertebra with branches coming off at each spinal cord segment. Assessment involves looking for any change in sensation including the fingers/hands, the chest or the lower legs. It also looks for changes in motor function including ability to flex and extend the hands and feet. Both sides of the body must be compared making use of the spinal cord segment and corresponding skin dermatomes during assessment. Compare gentle touch versus sharper using the cranially supplied forehead as the reference point for what functioning sensation feels like for the patient.
Nerves travel in tracts within the spinal cord. Direction of force during injury can hyperextend, hyperflex, rotate, stretch or compress the cord injuring part or all of the spine. Changes may occur to either sensation or motor function separately, both together or even be limited to one side of the body depending on which of the tracts in the cord are damaged. Changes may also present as tingling or numbness. Any neurological changes prompts suspected spinal cord injury until proven otherwise.
Next, look for structural injury signs. Commonly this will be where there is no cord injury observed. Pain or tenderness along the vertebra of the spine is assessed for. Again more commonly this will be in the cervical area but may be lower or in more than one place. If any pain or tenderness is noted then spinal structural injury should be suspected.
Where neither are noted, the patient can be considered possible for spinal clearance. To clear remaining patients, a systematic checklist can be followed. The first thing to consider is the patient at increased risk of injury. Older patients are at greater risk of injury, even from lesser trauma. The exact age is debatable but from around 55 years is reasonable. Bone disease, including osteoporosis or neuromuscular increases spinal injury risk. If either are present, the patient should not be pre-hospital spinally cleared.
If neither are found the next question is whether the patient can be reliably assessed. Clearly unconscious patients cannot be assessed so all should be managed as if there is a spinal injury present. Patients who have been unconscious and are now confused or poorly oriented should similarly not be cleared. Nor should patients with altered awareness including those with dementia or affected by drugs or alcohol. Finally, where there is a significant distracting injury such as a major fracture the patient may not be relied on to describe lesser symptoms caused by spinal injury.
In patients who are not covered by any of these findings, there is only an extremely low chance of any spinal injury. These patients can be effectively cleared pre-hospital. These principles derive from the Canadian C-spine Rule and the National Emergency X-Radiography Utilisation Study (NEXUS) Low Risk Criteria. Both are aimed at ED screening and avoiding radiology but have been morphed for prehospital use (Larson et al. 2017). Except for one other group that is – the child patient.
The child patient has weaker muscle and ligament structure supporting the spine. Smaller children also have relatively larger heads making them unstable and more likely to sustain head injury. Vertebra can move more than in adults leading to potential injury of the spinal cord but not the vertebra structure. Cord injury can be present but not detectable on x-ray nor found looking for pain and tenderness. Children less than eight years of age should never be spinally cleared pre-hospital.
So the patient has a mechanism/pattern of injury that puts them at risk of SCI. They cannot be prehospital cleared. What about other vital signs? That’s part two.
Anwar, M.A., Al Shehabi, T.S. and Eid, A.H., 2016. Inflammogenesis of secondary spinal cord injury. Frontiers in cellular neuroscience, 10, p.98.
Cowley, A., Hague, A. and Durge, N., 2017. Cervical spine immobilization during extrication of the awake patient: a narrative review. European Journal of Emergency Medicine, 24(3), pp.158-161.
Larson, S., Delnat, A.U. and Moore, J., 2017. The Use of Clinical Cervical Spine Clearance in Trauma Patients: A Literature Review. Journal of Emergency Nursing.
Witiw, C.D. and Fehlings, M.G., 2015. Acute spinal cord injury. Clinical Spine Surgery, 28(6), pp.202-210.
Jeff Kenneally – www.prehemt.com