The UK College of Emergency Medicine has produced guidelines on the management of cervical spine injury in the ED
Since I have a bit of a ‘thing’ about the obsession with cervical immobilisation, I’m reproducing here an excerpt from the guideline regarding this topic:
In 1998, Hauswald published retrospective data that compared the neurological outcomes of 334 patients with blunt traumatic cervical spinal injury who all had spinal immobilisation performed (New Mexico) with 120 patients with blunt traumatic cervical spinal injury that had no spinal immobilisation performed (Malaya). There was a non-significant increase in neurological disability in the immobilised group. Though this comparison is flawed, the author’s argument that any cord injury from blunt trauma occurs at the time of the impact, that subsequent movement is very unlikely to cause further damage, and that alert patient will develop a position of comfort with muscle spasm protecting the spine appears credible. It is widely accepted that it may be harmful for patients with pre-existing vertebral anatomical abnormalities eg ankylosing spondylitis to have their neck forced into an unnatural position and such patients usually have their neck supported in a position of comfort with or without a collar.
A Cochrane review updated in 2009 by Kwan et al concluded that in the absence of any randomised controlled trials the low incidence of unstable injuries of the cervical spine amongst those immobilised raised the possibility that immobilisation may be associated with a higher morbidity and mortality than non-immobilisation. In a recent literature review, Benger and Blackman concluded that alert, co-operative trauma patients do not require cervical spine immobilisation unless their conscious level deteriorates or they find short-term support of a collar helpful.
The evidence both for and against cervical spine immobilisation is weak. Although Hauswald’s study is intriguing, if we accept a 1-2% prevalence of unstable cervical spine injury following blunt trauma and hypothesise that 1 in 10 patients with unstable cervical spinal injuries would suffer a spinal cord injury as a consequence of non-immobilisation of their neck then only 1 in 500 -1,000 patients would be harmed as a result, which exceeds Hauswald’s study population. There is a need for large randomised multi-centre trials to determine the risk:benefit ratio of neck immobilisation. However, the current practice of cervical spine immobilisation has been so widely adopted and the consequence of causing or exacerbating a spinal injury so catastrophic that such trials may not be supported by ethical committees….Though evidence that the use of cervical collars prevents secondary injury is lacking, no evidence could be found to contradict this statement and it is, therefore, supported.
The guideline does not specify what exactly they mean by cervical spine immobilisation. Clinical practice ranges from one-piece hard or semi-rigid collars (eg. Stifneck) to more comfortable two-piece collars (eg. Philadelphia), tape and sandbags alone, or ‘triple immobilisation’ (collar, sandbags and tape). It is perhaps the obsessive adherence to the latter in the absence of a single piece of supportive evidence that I find bewildering.
Fortunately most Australian practice I’ve witnessed settles on a collar or manual immobilisation, with early application of a two-piece collar in those patients who require prolonged immobilisation.
The College guideline provides a helpful and pragmatic summary of the evidence to date and a digestible list of recommendations that could guide both departmental practice and postgraduat exam revision.
Guideline on the management of alert, adult patients with potential cervical spine injury in the Emergency Department
College of Emergency Medicine 2010 (PDF)
Laryngoscopy and tracheal intubation transiently increase arterial pressure, heart rate (HR), and circulating catecholamines, in part attributed to reflex sympathetic discharge. In a complete spinal cord injury, the sympathetic nervous system and hence the cardiovascular responses to the intubation may be differentially affected according to the level of injury. Patients with acute quadriplegia often have a low resting arterial pressure due to inappropriate vasodilatation and loss of cardiac inotropy. Moreover, they frequently exhibit arrhythmias, reflex bradycardia, and cardiac arrest, especially during tracheal suction. In the days to weeks after injury, however, the reflex functioning of the lower cord recovers to maintain normal vascular tone. In the chronic stage, peripheral vascular changes and a loss of descending inhibitory control result in paroxysmal hypertension.
SAP decreased after the induction of anaesthesia with thiopental in all subjects including the controls (P<0.05).
SAP then increased in response to tracheal intubation in the control and paraplegics (P<0.001), whereas it remained unaltered in the quadriplegics regardless of the time since injury.
In the paraplegics, the magnitude of maximum increase from baseline values was similar within 10 yr of injury, but was higher thereafter compared with that in the controls (P<0.05).
The maximum increase in SAP from baseline values after tracheal intubation was greater in the paraplegics than in the quadriplegics (P<0.0001).
Korean investigators KY Yoo and colleagues1 aimed to determine the effect of the level (quadriplegia vs paraplegia) and duration of spinal cord injury on haemodynamic and catecholamine responses to laryngoscopy and tracheal intubation in patients with spinal cord injury. The outcome measures were the changes in systolic arterial pressure (SAP), HR, and catecholamine levels above awake baseline values after intubation.
Patients were divided into two groups: quadriplegia (above C7) and paraplegia (below T5). Each group was divided into six subgroups according to the time elapsed after the injury: <4 weeks (acute), 4 weeks– 1 yr, 1–5, 5–10, 10–20, and >20 yr. Twenty non-disabled patients undergoing surgery requiring tracheal intubation served as controls.
Patients with high-level paraplegia (T1–T4) were excluded because they were few in number and they had previously ‘shown different haemodynamic and catecholamine responses from the other groups‘ 2 which refers to work published by the same authors, in which high-paraplegic patients had a more pronounced increase in heart rate compared with other groups. Confusingly the ‘patients who were at increased risk of hyperkalemia after succinylcholine were excluded‘ although this statement appears only in the discussion, not the methods.
Anaesthesia was induced with sodium thiopental 5 mg/kg administered i.v. over 20 s, followed by succinylcholine 1 mg/kg for 5 s, and was followed by direct laryngoscopy and tracheal intubation.
Results were as follows:
An increase in SAP.130% of preinduction baseline values or 160 mm Hg was noted in three (4.2%) of 71 quadriplegics and 94 (65.7%) of 143 paraplegics.
The incidence of hypertension was significantly lower and that of hypotension significantly higher in the quadriplegics than in the control.
HR increased after induction ofanaesthesia in all groups, but less so in the quadriplegic groups.
Although baseline bradycardia was common in the acute quadriplegics, none of them showed further slowing during induction of anaesthesia and tracheal intubation.
Tracheal intubation increased plasma norepinephrine concentrations in all subjects except the acute quadriplegics.
Epinephrine concentrations were not significantly different between before and after intubation either in the quadriplegics or in the paraplegics, nor were they different between the groups with regard to the duration of injury.
The authors summarise: The pressor response was abolished in all quadriplegics regardless of the time elapsed after the injury. In contrast, the chronotropic and catecholamine responses differed over time. The chronotropic response was attenuated and the catecholamine response abolished in the acute quadriplegics. The chronotropic and catecholamine responses were improved in the quadriplegics after 4 weeks since the injury. In the paraplegic patients, cardiovascular responses did not change in the 10 yr after injury and the pressor response was enhanced at 10 yr or more after injury.
1.Altered cardiovascular responses to tracheal intubation in patients with complete spinal cord injury: relation to time course and affected level
Br J Anaesth. 2010 Dec;105(6):753-9
2. Hemodynamic and catecholamine responses to laryngoscopy and tracheal intubation in patients with complete spinal cord injuries.
Anesthesiolgy 2001; 95: 647–51
A cadaveric study using a 3-dimensional electromagnetic tracking device to asses cervical motion compared the application of a scoop stretcher with two other manual transfer techniques, including log rolling onto an extrication (spine) board. The scoop method restricted cervical spine movement more than log rolling, although this was not statistically significant.
The authors conclude: the effectiveness of the scoop stretcher to limit spinal motion in the destabilized spine is comparable or better than manual techniques currently being used by primary responders.
Are scoop stretchers suitable for use on spine-injured patients?
Am J Emerg Med. 2010 Sep;28(7):751-6
In a retrospective study of 45,284 penetrating trauma patients, unadjusted mortality was twice as high in the 4.3% of patients who underwent spine immobilisation, compared with those who were not immobilised.
An accompanying editorial comments: ‘The number needed to treat with spine immobilization to potentially benefit one penetrating trauma patient was 1,032. The number needed to harm with spine immobilization to potentially contribute to one death was 66.‘
Spine immobilization in penetrating trauma: more harm than good?
J Trauma. 2010 Jan;68(1):115-20
Prolonged collar use and spinal immobilisation in ICU patients can contribute to pressure sores, increased intracranial pressure, venous obstruction, difficulties with airway management, difficulties with central venous access, respiratory complications, and DVT, so a reliable investigation to rule out unstable cervical spine injury is required. Several studies demonstrate the high sensitivity of CT, and now a prospective study from Canada attempts to lend further support to this.
Comparing against their chosen gold standard of dynamic radiography, ie. flexion/extension views (F/E) in 402 patients who received both tests, there was one case of injury detected by F/E but not by CT, leading to quoted sensitivity of 99.75%. However this negative CT turned out to be a reporting error – the scan, which the authors include in their article, was clearly abnormal.
One weakness of this study is that they excluded patients who died on ICU. More worrying are the stats quoted. The authors stat ‘four hundred one patients (99.75%) had normal CT and F-E images facilitating clinical clearance of their C-spine and discontinuation of spinal precautions‘. So in other words, there was only one patient in their series of 402 with an injury (according to the gold standard), and this was missed. The sensitivity is therefore zero percent, not 99.75%. What seems to be a further error is the reporting in a table of 401 patients who had ‘Positive CT and Negative F-E’, which if true, would give a specificty of zero too!
This paper covers an important topic for intensivists but it seems to me to be too flawed to add meaningfully to the existing evidence that necks can be ‘cleared’ by CT in patients without signs of cervical spine injury, in whom it has been said that the risks of prolonged collar use and immobilisation may outweigh the risks of missed cervical injury.
Cervical spine clearance in obtunded blunt trauma patients: a prospective study
J Trauma. 2010 Mar;68(3):576-82
Using a sophisticated infrared six camera motion capture system, investigators demonstrated decreased cervical spine movement when collared volunteers self-extricated from a mock smashed up Toyota Corolla, when compared with extrication by paramedics using a backboard.
The authors conclude that in ambulatory subjects who do not complain of back pain, the least motion of the cervical spine may occur when the subject is allowed to exit the car in a c-collar without backboard immobilisation.
Cervical spine motion during extrication: a pilot study
West J Emerg Med. 2009 May;10(2):74-8
Full text article
British military physicians reported the outcomes of patients sustaining penetrating neck injury from the Iraq and Afghanistan conflicts. Three quarters were injured in explosions, one quarter from gunshots.
Of 90 patients, only 1 of the 56 survivors to reach a surgical facility sustained an unstable cervical spine injury that required surgical stabilisation. This patient later died as result of a co-existing head injury. The authors conclude that penetrating ballistic trauma to the neck is associated with a high mortality rate, and their data suggest that it is very unlikely that penetrating ballistic trauma to the neck will result in an unstable cervical spine in survivors. In a hazardous environment the risk/benefit ratio of mandatory spinal immobilisation is unfavourable and may place medical teams at prolonged risk, and cervical collars may hide potential life-threatening conditions.
Learning the lessons from conflict: Pre-hospital cervical spine stabilisation following ballistic neck trauma
Injury. 2009 Dec;40(12):1342-5
This short cut review in the Best Bets format attempted to answer the question: “is cervical spine protection always necessary following penetrating neck injury?”
From the available evidence they draw the following conclusions:
- In stab wounds to the neck (with or without neurological deficit) an unstable spinal injury is very unlikely and c-spine immobilisation is not needed
- In gunshot wounds the value of cspine immobilisation is limited: for gunshot wounds without neurological deficit no immobilisation is required, while in cases of gunshot wounds with neurological deficit, or where the diagnosis cannot be made (ie, altered mental status), a collar or sandbag is advised once ABCs are stable, with close observation and intermittent removal to inspect and reassess.
- In the rare event of penetrating injury with combined blunt force trauma, a collar or sandbag is advised if possible, once ABCs are stable, with intermittent removal to reassess.
Emerg Med J. 2009 Dec;26(12):883-7
Full text at BestBets.org
A retrospective review of 4204 patients sustaining gunshot wounds (GSW) to the head, neck or torso examined the incidence of spinal cord injury and bony spinal column injury required operative spinal intervention. None of the patients demonstrated spinal instability requiring operative intervention, and only 2/327 (0.6%) required any form of operative intervention for decompression. The authors concluded that spinal instability following GSW with spine injury is very rare, and that routine spinal imaging and immobilisation is unwarranted in examinable patients without symptoms consistent with spinal injury following GSW to the head, neck or torso.
The role of routine spinal imaging and immobilisation in asymptomatic patients after gunshot wounds
Injury. 2009 Aug;40(8):860-3