'Clearance' of cervical spine injury in the obtunded patient

‘Clearing’ the cervical spine in the unconscious trauma patient

This is a systemic review of the published evidence regarding cervical spine management in unconscious trauma patients. We examine the literature in the following sections: use of plain radiography; use of flexion/extenson views; use of computed tomography; use of magnetic resonance imaging. We also review surveys of practice and current guidelines.

In contrast to the conscious trauma patient there have been no large prospective multicentre studies to derive a clinical decision rule for the exclusion of cervical spine injury. This review therefore assesses currently available evidence to reach a logical conclusion regarding the most appropriate imaging strategy to exclude significant injury in the cervical spine, whilst minimising the time that a patient needs to remain immobilised.

[Evidence based diagnostic procedures for the determination of suspected blunt cervical spine injuries. Development of an algorithm]

BACKGROUND

The aim of this study was to present existing publications, describing various diagnostic procedures as well as considering the evidence supporting them, to develop a recommendation for diagnosis.

MATERIAL AND METHODS

We reviewed relevant publications between 1966 and 2004 by a systemic literature search in MEDLINE, EMBASE, National Guideline Clearinghouse, Cochrane Library as well as a manual reference search. Keywords were cervical spine, cervical vertebrae, spinal, spinal cord, injury, trauma, fracture, dislocation, imaging, radiography, flexion, extension, fluoroscopy, computed tomography, computed scanning, and magnetic resonance imaging. The selected search results were then classified into levels of evidence.

RESULTS

From among a total of 10,000 publications, 137 relevant publications were stringently reviewed. The level of evidence is on the whole limited due to deficit data; therefore, only class II-III recommendations are possible. We developed an algorithm for the diagnostic approach to suspected trauma of the cervical spine. This clinical algorithm displays the complex diagnosis of cervical spine injury in a clear and logically structured process.

CONCLUSIONS

The diagnostic algorithm for cervical spine injury meets the presently required standards and maximizes care for the newly injured. The development, which can be followed using evidence-based medicine, is transparent and therefore aids the decision process when choosing an adequate diagnostic procedure.

Neurologic deterioration secondary to unrecognized spinal instability following trauma--a multicenter study

STUDY DESIGN

A retrospective study was undertaken that evaluated the medical records and imaging studies of a subset of patients with spinal injury from large level I trauma centers.

OBJECTIVE

To characterize patients with spinal injuries who had neurologic deterioration due to unrecognized instability.

SUMMARY OF BACKGROUND DATA

Controversy exists regarding the most appropriate imaging studies required to "clear" the spine in patients suspected of having a spinal column injury. Although most bony and/or ligamentous spine injuries are detected early, an occasional patient has an occult injury, which is not detected, and a potentially straightforward problem becomes a neurologic catastrophe.

METHODS

The study was designed as a retrospective review of patients who had neurologic deterioration as a direct result of an unrecognized fracture, subluxation, or soft tissue injury of the cervical, thoracic, or lumbar spine from 8 level I trauma centers. Demographics, injury information, and neurologic outcome were collected. The etiology and incidence of the missed injury were determined.

RESULTS

A total of 24 patients were identified who were treated or referred to 1 of the participating trauma centers and had an adverse neurologic outcome as a result of the missed injury. The average age of the patients was 50 years (range 18-92), and average delay in diagnosis was 19.8 days. Radiculopathy developed in 5 patients, 16 had spinal cord injuries, and 3 patients died as a result of their neurologic injury. The most common reason for the missed injury was insufficient imaging studies (58.3%), while only 33.3% were a result of misread radiographs or 8.3% poor quality radiographs. The incidence of missed injuries resulting in neurologic injury in patients with spine fractures or strains was 0.21%, and the incidence as a percentage of all trauma patients evaluated was 0.025%.

CONCLUSIONS

This multicenter study establishes that missed spinal injuries resulting in a neurologic deficit continue to occur in major trauma centers despite the presence of experienced personnel and sophisticated imaging techniques. Older age, high impact accidents, and patients with insufficient imaging are at highest risk.

Exclusion of Unstable Cervical Spine Injury in Obtunded Patients with Blunt Trauma: Is MR Imaging Needed when Multi–Detector Row CT Findings Are Normal?

PURPOSE

To retrospectively determine what information, if any, magnetic resonance (MR) imaging of the cervical spine in obtunded and/or "unreliable" patients with blunt trauma adds to multi-detector row computed tomography (CT) of the entire cervical spine (including routine multiplanar sagittal and coronal reformations) when the CT findings are normal.

MATERIALS AND METHODS

The study was HIPAA compliant and institutional review board approved. Informed consent was not required. From April 2001 to November 2003, 1400 trauma patients underwent MR imaging of the cervical spine to evaluate potential cervical spine injuries. Multi-detector row CT of the cervical spine was performed with a four- or 16-detector row scanner. MR imaging of the cervical spine was performed with transverse gradient-echo, sagittal intermediate-weighted, sagittal short inversion time inversion-recovery, and sagittal T1- and T2-weighted fast spin-echo sequences. Many MR examinations were performed to exclude soft-tissue injuries in the cervical spine of obtunded patients with blunt trauma in whom cervical spine injury could not be excluded with physical examination. Complete cervical spine MR studies were obtained to evaluate soft-tissue injuries in 366 obtunded patients with blunt trauma (281 male and 85 female patients; age range, 13-92 years; mean age, 42.1 years). The patients had previously undergone total cervical spine multi-detector row CT with normal findings. The results obtained with these two modalities were compared.

RESULTS

MR images were negative for acute injury in 354 of the 366 patients and negative for cervical spine ligamentous injury in 362. Seven of the 366 patients had cervical cord contusions, four patients had ligamentous injuries, three patients had intervertebral disk edema, and one patient had a cord contusion, a ligamentous injury, and an intervertebral disk injury. Four patients had ligamentous injuries; however, all of these patients had ligament injuries limited to only one of the three columns of cervical spine ligament support. Multi-detector row CT had negative predictive values of 98.9% (362 of 366 patients) for ligament injury and 100% (366 of 366 patients) for unstable cervical spine injury.

CONCLUSION

A normal multi-detector row CT scan of the total cervical spine in obtunded and/or "unreliable" patients with blunt trauma enabled the authors to exclude unstable injuries on the basis of findings at follow-up cervical spine MR imaging.

Cervical Spine Assessment in the Unconscious Trauma Patient: A Major Trauma Service???s Experience with Passive Flexion-Extension Radiography

BACKGROUND

There is no consensus on the most appropriate method of cervical spine assessment in unconscious trauma patients. Passive flexion-extension imaging is one option for further investigating unconscious patients whose plain cervical radiographs are normal. This study examines the usefulness of this passive imaging in investigating for occult cervical injury.

METHODS

All unconscious patients admitted to The Alfred Trauma Intensive Care Unit over 1 year (January 1-December 31, 1998), who could not be clinically assessed within 48 hours in regard to their cervical spine, were identified. Results of passive flexion-extension radiography were compared with final injury status and clinical outcome as determined by retrospective review of the imaging reports, radiographic films, and case notes.

RESULTS

One hundred twenty-three patients with normal three-view plain radiographs proceeded to passive functional investigation. These were false-negative in four of the seven patients with cervical spine injuries at presentation. No patients suffered any adverse neurologic events from their delayed diagnoses or from the flexion-extension procedure.

CONCLUSION

Passive flexion-extension imaging has inadequate sensitivity for detecting occult cervical spine injuries. Although no patients suffered adverse neurologic complications, the potential for devastating consequences from missed cervical injury has resulted in the removal of passive flexion-extension imaging from the screening protocol.

Clearing the cervical spine of paediatric trauma patients

OBJECTIVES

To review the evidence available for clearance of the cervical spine in children under 16 years of age after trauma, and to provide guidance to enable this to be practised safely.

METHODS

A comprehensive literature review was carried out, and combined with a review of standard texts and liaison with experts.

RESULTS

241 papers were identified, of which 71 papers were thought possibly relevant. These were obtained and appraised. Children in whom there is concern about possible cervical spine injury may be divided into three groups. Alert, asymptomatic children with a normal examination may be clinically cleared without need for radiology. Children with cervical spine symptoms or signs require plain radiology in the first instance. Those areas that are poorly visualised or suspicious should be discussed with a paediatric radiologist and are likely to undergo computed tomography. Children with impaired conscious level require careful evaluation. Plain radiology, if normal, can be usefully complemented by early magnetic resonance imaging to exclude ligamentous and spinal cord damage.

CONCLUSIONS

There is limited evidence to guide clinicians on how to clear the paediatric cervical spine. The approach suggested is similar to adult recommendations made elsewhere, and the differences are highlighted.

Cervical spine clearance: a review

Ethical concerns have hindered any randomised control blinded studies on the imaging required to assess the cervical spine in an unconscious trauma patient. The issue has been contentious for many years and has resulted in burgeoning but inconclusive guidance. MRI and multislice CT technology have made rapid advances, but the literature is slower to catch up. Never the less there appears to be an emerging consensus for the multiply injured patient. The rapid primary clinical survey should be followed by lateral cervical spine, chest and pelvic radiographs. If a patient is unconscious then CT of the brain and at least down to C3 (and in the USA down to D1) has now become routine. The cranio-cervical scans should be a maximum of 2 mm thickness, and probably less, as undisplaced type II peg fractures, can be invisible even on 1 mm slices with reconstructions. If the lateral cervical radiograph and the CT scan are negative, then MRI is the investigation of choice to exclude instability. Patients with focal neurological signs, evidence of cord or disc injury, and patients whose surgery require pre-operative cord assessment should be imaged by MRI. It is also the investigation of choice for evaluating the complications and late sequela of trauma. If the patient is to have an MRI scan, the MR unit must be able to at least do a sagittal STIR sequence of the entire vertebral column to exclude non-contiguous injuries, which, since the advent of MRI, are now known to be relatively common. Any areas of oedema or collapse then require detailed CT evaluation. It is important that cases are handled by a suitably skilled multidisciplinary team, and avoid repeat imaging due to technical inadequacies. The aim of this review is to re-examine the role of cervical spine imaging in the context of new guidelines and technical advances in imaging techniques.

Clearing the cervical spine in unconscious adult trauma patients: A survey of practice in specialist centres in the UK

A postal questionnaire survey of neurosurgery and spinal injury departments in the UK was conducted to determine how they assessed the cervical spine in unconscious, adult trauma patients, and at what point immobilisation was discontinued. Of the 32 units contacted, 27 responded (response rate, 84%). Most centres had no protocols to guide initial imaging or when immobilisation devices should be removed. Most responding centres performed fewer than three plain radiographs, and most did not use computerised tomography routinely. Routine use of magnetic resonance imaging or dynamic flexion-extension fluoroscopy was rare, and few units regarded the latter as safe in unconscious patients. There was no consensus on when immobilisation of the cervical spine should be discontinued. Most centres that terminated immobilisation immediately after imaging did so on the basis of plain radiographs alone. Unconscious adult trauma patients remain at risk of inadequate assessment of potential cervical spine injuries.

Clearing the cervical spine after polytrauma: implementing unified management for unconscious victims in the intensive care unit

Determining the best method for excluding cervical spine injury while a polytrauma victim is unconscious remains a controversial topic despite a number of published guidelines. A structured questionnaire demonstrated major differences between intensivists, neurosurgeons, orthopaedic surgeons and spinal surgeons with regard to the imaging modalities requested, the perception of their performance, the relative risks of missed injuries and the complications of immobilisation. Unconscious victims of polytrauma often come under the care of several subspecialties, with the direct consequence that management can be contradictory and lack standardisation. Advanced Trauma Life Support and Eastern Association for the Surgery of Trauma guidelines can reinforce and even contribute to non-standardised care. Having performed this clinician survey, we have now developed a multidisciplinary management protocol appropriate for Northern Ireland.

Prospective evaluation of computed tomographic scanning for the spinal clearance of obtunded trauma patients: preliminary results

BACKGROUND

Screening methods for detecting cervical spine injury in obtunded ventilated patients continue to evolve. This study compared the use of plain radiography to computed tomographic (CT) scanning of cervical spines in the obtunded blunt trauma patient. The accuracy of plain radiography and CT scanning in detecting clinically significant cervical spine injury in the obtunded blunt trauma patient was evaluated.

METHODS

We conducted a prospective cohort study with a 3-year convenience sample. The study population consisted of a high-risk subpopulation of severely injured patients, intubated or with a Glasgow Coma Scale score < 9 at presentation. Patients were assessed with a three-view cervical spine series and a CT scan of their cervical spines from the skull base to T1. Independent-blinded review of plain radiographs and CT scans was performed by two radiologists. Sensitivity, specificity, and accuracy of plain films were compared with CT scanning. Sensitivity of CT scanning was compared with discharge diagnosis of cervical spine or cord injury.

RESULTS

One hundred two patients were eligible and underwent three-view plain radiography and CT scanning. Sensitivity, specificity, and accuracy of plain films compared with CT scanning were 39%, 98%, and 88%, respectively. CT scanning was 100% sensitive in detecting cervical spine injury.

CONCLUSION

CT scanning in conjunction with plain films enhances the number of cervical spine injuries seen radiographically. Application of a protocol of plain radiographs and CT scanning may be used to clear cervical spines in the obtunded trauma patient. Ongoing evaluation of this protocol is required.

Clearing the cervical spine in unconscious polytrauma victims, balancing risks and effective screening

Cervical spine injury occurs in 5-10% of cases of blunt polytrauma. A missed or delayed diagnosis of cervical spine injury may be associated with permanent neurological sequelae. However, there is no consensus about the ideal evaluation and management of the potentially injured cervical spine and, despite the publication of numerous clinical guidelines, this issue remains controversial. In addition, many studies are limited in their application to the obtunded or unconscious trauma victim. This review will provide the clinician managing unconscious trauma victims with an assessment of the actual performance of clinical examination and imaging modalities in detecting cervical spine and isolated ligamentous injury, a review of existing guidelines in light of the available evidence, relative risk estimates and a proposed management scheme.

The emergency department: an appropriate referral rate for radiography

AIM

To evaluate the hypothesis that where there is good clinical practice in an emergency department (ED), there is a low uptake of plain radiography.

MATERIALS AND METHODS

Emergency notes and radiography records were reviewed over one week in January 1999, to determine the rate of radiography of first time attenders at the North Staffordshire NHS Trust. The clinical appropriateness of the imaging was assessed by pairs of radiology specialist registrars and casualty physicians. They judged the appropriateness of the imaging by the 1998 Royal College of Radiologists (RCR) guidelines and/or their clinical judgement, by consensus. Where there was no consensus or the data appeared incomplete, the radiology and ED consultant reviewed the notes.

RESULTS

A total of 1615 notes were found out of 1643 (98%). Of these, 147 (9%) return attenders were excluded and 32 patients left without being seen. The number of first time attenders was 1436 (87%), of whom 637 (44%) were radiographed; 95% of these radiography examinations were appropriate and 5% were inappropriate. Of the first time attenders who were not radiographed the decision was appropriate in 95% of cases, and inappropriate for 5%, i.e. 5% of those who had no radiography, should have been X-rayed. There were no disagreements between RCR guidelines and the clinical judgements, but in 16% there were no suitable RCR guidelines. Junior doctors were not always able to find the relevant RCR guideline (relevant clinical guideline found in 73% of cases) in the guideline book, compared to the consultants (relevant clinical guideline found in 84% of cases).

CONCLUSION

The application of the RCR guidelines is taken as representing good clinical practice in determining when to refer a patient for radiography. Based on this assumption, a referral rate for radiography of 44% of first time attenders was found to be appropriate. This referral rate can be taken as a benchmark. A benchmark is necessary in order to allow departments to make a local assessment as to whether their local referral rate is likely to be too high or too low.

Cervical spine injury and airway management

Cervical spine injuries occur in 2-5% of blunt trauma patients, and 1-5% of these injuries are initially missed. Data from the large National Emergency X-Radiography Utilisation Study have helped to define the problem in some detail. There is a consensus on how to clear the cervical spine in patients who are alert, but in patients with altered mental status the choice of strategy for spinal clearance is more controversial. Despite obtaining extensive radiological studies, some clinicians will not clear the patient's cervical spine until full recovery of consciousness. As long as manual in-line neck stabilization is applied, rapid sequence induction of anaesthesia, followed by direct laryngoscopy and oral intubation appears to be safe in the patient with a cervical spine injury. If intubation is not urgent, an awake fibreoptic technique is a useful option. If intubation of the patient with a potential cervical spine injury fails, or appropriate experienced personnel are unavailable, the laryngeal mask airway or one of its various modifications are useful alternatives.

Radiographic assessment of the cervical spine in symptomatic trauma patients

STANDARDS

A three-view cervical spine series (anteroposterior, lateral, and odontoid views) is recommended for radiographic evaluation of the cervical spine in patients who are symptomatic after traumatic injury. This should be supplemented with computed tomography (CT) to further define areas that are suspicious or not well visualized on the plain cervical x-rays.

GUIDELINES

There is insufficient evidence to support treatment guidelines.

OPTIONS

It is recommended that cervical spine immobilization in awake patients with neck pain or tenderness and normal cervical spine x-rays (including supplemental CT as necessary) be discontinued after either a) normal and adequate dynamic flexion/extension radiographs, or b) a normal magnetic resonance imaging study is obtained within 48 hours of injury. Cervical spine immobilization in obtunded patients with normal cervical spine x-rays (including supplemental CT as necessary) may be discontinued a) after dynamic flexion/extension studies performed under fluoroscopic guidance, or b) after a normal magnetic resonance imaging study is obtained within 48 hours of injury, or c) at the discretion of the treating physician.

Flexion and extension views are not cost-effective in a cervical spine clearance protocol for obtunded trauma patients

BACKGROUND

Between 1994 and 1999, 837 flexion-extension cervical spine films (F/E) were ordered as part of a protocol to evaluate cervical stability in blunt trauma victims, particularly obtunded patients with otherwise normal films. After 5 years' experience with this protocol, a review of its efficiency and cost-effectiveness was performed.

METHOD

The radiology reports and charts were reviewed for positive or suggestive F/E series.

RESULTS

Nearly a third of all series were inadequate to rule out instability. Only four patients were identified who had decreased admission Glasgow Coma Scale score, normal plain films and/or CT, and positive or suggestive findings on F/E. One was felt to be a false positive, and the others had minor or borderline findings; all were treated with continuation of the cervical collar. Although one patient was lost to follow-up, none of the other three required subsequent surgery or developed deformity or neurologic injury.

CONCLUSION

Flexion-extension studies were not a cost-effective part of the protocol, and they were dropped.

Evaluation of the Oxford Protocol for Total Spinal Clearance in the Unconscious Trauma Patient

BACKGROUND

Prolonged use of spinal precautions in unconscious trauma patients is associated with significant morbidity. The trauma service of the John Radcliffe Hospital uses full-length radiography, computed tomographic scanning, and dynamic screening of the cervical spine to clear the spine at the earliest opportunity.

METHODS

The results in 210 consecutive patients were reviewed. Seventy-eight patients underwent dynamic screening of the cervical spine.

RESULTS

Five of these patients had a cervical fracture or instability. One patient had demonstrated minor changes only on plain radiography but gross instability on dynamic screening. There were no neurologic sequelae from dynamic screening and no fractures were missed. Collar removal was possible in all but one patient a median 3 days before extubation and 1 day after admission to the intensive care unit.

CONCLUSION

Full length spinal radiography and dynamic cervical screening may allow early and safe discontinuation of spinal precautions in the unconscious trauma patient in whom clinical signs are absent or unreliable.