Acute spinal cord injury vital signs
Having determined that a patient cannot be prehospital cleared from suspicion of spinal injury, we have to think about the other vital sign changes that might be present. Some of these will be slightly abnormal, some even life threatening. They can aid diagnosis or they can demand immediate management. That’s part two.
Keep in mind the two stereotypical but very different patient presentations with spinal injury. The first is the patient who has sustained major trauma such as a vehicle rollover, or a diving accident. Typically the patient will be younger. The second is less thought of. This is the elderly, more fragile patient who has fallen from a standing height. Though seemingly far less serious, this mechanism of injury can be just as serious for the vulnerable elderly patient.
All good clinical guidelines start with the ABCs so why not here as well. Firstly, any helmet has to come off to avoid unwanted head positioning, allow assessment and avoid possibility of patient rebreathing. Use two people if possible, one to hold the head as neutral as possible and resist unwanted head movements. The spinal injured patient airway can be at risk. Loss of consciousness and associated head or facial trauma predispose to complications. Return the head to the neutral anatomical position for patient age provided there is no resistance though lateral position for the unconscious patient during initial care might be necessary (Hyldmo et al. 2015). Careful log rolling will be needed. Up to 30° upward head incline can help venous drainage and reduce ICP in head injured patients but this is not advisable until SCI is excluded to avoid downward head weight on the injury.
If the patient has an abnormal Kyphosis of the spine, such as can the elderly, support in this position with padding. In any case, allocate one rescuer to support the head with manual inline stabilisation. The best way is to grab a handful of clothing around the clavicle area either side of the head then gently squeeze inward with the forearms. Holding the head alone still allows the possibility of body movement. By holding both together, you meet the principle of supporting above and below a fracture (cervical at least anyway). This person should resist any patient movement, particularly the head, and coordinate all planned rolling or lifting.
If the airway is at risk, rapid sequence intubation is advised. This will necessitate from the neutral position, increasing laryngoscopy difficulties. Rely on laryngeal manipulation, videolaryngoscopy and bougie methods to increase success. Beware bradycardia when using muscle relaxant medications during induction. And if a cervical collar has been applied, it will have to be released to allow mouth opening.
Respiration can be impaired in SCI. The diaphragm is controlled at C3-C5. Injury here or above can stops all breathing control. Injury below this level allows the diaphragm to work but can interfere with thoracic arising intercostal nerves. In such case, nerves from the level of injury down due not stimulate intercostal muscles leading to the diaphragm doing all the work. Lung volumes and cough effectiveness decrease (Berlowitz et al. 2016; Kumar et al. 2017). Relaxation of abdominal musculature allows the diaphragm to lower slightly. When it contracts, it is quite evident in the stomach. However the lack of intercostal contribution allows the chest to be pulled inward during inspiration creating the so called ‘paradoxical’ breathing. The patient may be in respiratory difficulty or even non-ventilating. Support as required.
There are two types of shock that can apply to the patient with a spinal injury. Spinal shock refers to the loss of nerve activity below the level of the injury. This includes loss of bladder and bowel control. The other type of shock is neurogenic shock. Injury to the thoracic spine or above can interfere with sympathetic activity running down the spine. The control of blood vessels below this is lost and unopposed vasodilation results. The vagus nerve remains intact being a cranial nerve and so becomes the dominant nerve activity. This leads to bradycardia.
Marginal hypotension along with slightly slowed heart rate is a distinctive vital sign combination of spinal injury. This will often not require management. On occasion though it may. Other traumatic injuries, especially blunt or penetrating truncal trauma or multiple limb or pelvic fractures, can cause hypovolemia. If suspected, resuscitate following appropriate guidelines. If other injuries are not apparent, a few hundred mls (up to 10mls/kg) of crystalloid is okay to help fill the vasodilation. Excess fluid can cause pulmonary oedema though. If systolic blood pressure remains disturbingly low, this will adversely affect secondary cord injury progression. Vasopressor infusion such as adrenaline or noradrenaline might be necessary to maintain mean arterial pressure at least 90mmHg (Ahuja et al. 2016; Hawryluk et al. 2015).
The loss of control of the blood vessels also means loss of control of thermoregulation. Inability to vasoconstrict much of the periphery, combined with greatly reduced muscle activity, invariably leads to ambient air temperature vulnerability (Hagen 2015). The spinal cord injured patient is very susceptible to hypothermia with it a constant threat.
So to rescue and management. That’s part three.
Ahuja, C.S., Martin, A.R. and Fehlings, M., 2016. Recent advances in managing a spinal cord injury secondary to trauma. F1000Research, 5.
Berlowitz, D.J., Wadsworth, B. and Ross, J., 2016. Respiratory problems and management in people with spinal cord injury. Breathe, 12(4), p.328
Hagen, E.M., 2015. Acute complications of spinal cord injuries. World journal of orthopedics, 6(1), p.17.
Hawryluk, G., Whetstone, W., Saigal, R., Ferguson, A., Talbott, J., Bresnahan, J., Dhall, S., Pan, J., Beattie, M. and Manley, G., 2015. Mean arterial blood pressure correlates with neurological recovery after human spinal cord injury: analysis of high frequency physiologic data. Journal of neurotrauma, 32(24), pp.1958-1967.
Hyldmo, P.K., Vist, G.E., Feyling, A.C., Rognås, L., Magnusson, V., Sandberg, M. and Søreide, E., 2015. Does turning trauma patients with an unstable spinal injury from the supine to a lateral position increase the risk of neurological deterioration?–A systematic review. Scandinavian journal of trauma, resuscitation and emergency medicine, 23(1), p.65.
Kumar, N., Pieri-Davies, S., Chowdhury, J.R., Osman, A. and El Masri, W., 2017. Evidence-based respiratory management strategies required to prevent complications and improve outcome in acute spinal cord injury patients. Trauma, 19(1_suppl), pp.23-29.
Jeff Kenneally – www.prehemt.com