16
Spinal Injury
Neil Buxton
348
Introduction
A spinal cord injury can be devastating to the victim. The management of spinal cord injury secondary to gunshot wounds or other ballistic injuries is still controversial. In the United States of America, a gunshot wound is the second most common cause of spinal cord injury. In one civilian series, up to 25% of all spinal cord injuries were secondary to gunshot wounds.
This is a condition affecting mainly young people under 30 years of age, more than 90% of whom are males. Over a third will be under the influ- ence of alcohol or drugs, and nearly half will be shot from behind. Over half of such injuries will present with complete paraplegia. By the nature of the inflicting injury, more than one quarter will have associated injuries. The majority of the gunshot wounds affect the thoracic spine, with the lumbar spine being second most common.
History
In World War I, only patients with incomplete injuries survived. Overall mortality rate was 71.8%, with urinary sepsis being the main cause of death.
At this time there was also a 62.2% operative mortality rate. Complete injuries were only treated with wound debridement. Laminectomy was reserved for incomplete injuries that were experiencing further neurologi- cal deterioration.
In World War II, surgery was offered to all, but the mortality rate had been reduced to 11.4%. In the Korean War, operative mortality was only one percent. Improved casualty evacuation times seen in the Vietnam War did nothing to further improve neurological recovery.
Civilian series have been even less encouraging. Stabbings have been found no less devastating than gunshot wounds to the spine.
Pathophysiology
A complete spinal cord injury is one whereby there is no function below the level of the injury. Some spinal cord reflexes may return. A physiolog- ically complete injury does not require complete transection of the spinal cord.
With modern high-velocity weapons, it is not necessary to hit the spinal cord directly to cause a spinal cord injury; hitting the bony components of the spine can cause microscopically detectable spinal cord injury up to 15 centimeters from the level of the primary injury. There is usually intramedullary hemorrhage and more rarely extradural or subdural haem- orrhage, even with a direct cord injury.
Initial Management and Assessment
Each victim of such an injury should undergo a full normal resuscitation protocol with appropriate management of life-threatening injuries along Advanced Trauma Life Support/Battlefield Advanced Trauma Life Support (ATLS/BATLS) guidelines. In such an injury, it is important to remember that, until proven otherwise, hypotension is due to blood loss and not spinal cord shock.
Having resuscitated the patient, stabilized them, and treated the other life-threatening injuries, the patient is then ready to be assessed by the neu- rosurgeon, and, in times of conflict, this may take many hours to days to achieve. However, it generally is agreed that early assessment of the neu- rological status is deemed vital and ideally should be carried out within 24 hours of the injury, always after the resuscitation. This is important because the presenting neurological and autonomic status have considerable impli- cations for the prognosis. Therefore, the first medical attendant who sees the casualty after resuscitation needs to fully examine them from a neuro- logical point of view, and, of course, this should be recorded with care. This is of paramount importance for prognostication, as 90% of presenting neu- rological deficits are permanent.
The neurological examination needs to record the sensory status, strength of muscle groups, tone in the limbs, reflexes, and sphincter status.
Simple measures such as nasogastric tube, bladder catheterization, and nursing management to prevent decubitus ulcers and deep venous throm- bosis are vital for the overall care of such an injured patient. For the medical attendant, the neurological examination should be repeated periodically in order to document recovery and/or deterioration.
Spinal Shock
This results in flaccid paralysis distal to the injury. The reflexes and tone return to become hyperactive by six to twelve weeks. The more rapid the return of the reflexes, the poorer the prognosis for neurological recovery in patients with complete injuries.
Neurogenic shock with bradycardia, hypotension, and hypothermia is due to autonomic paralysis and is managed with fluid replacement and active warming. Atropine may even be required, especially if the pulse rate drops below 40 beats per minute.
Investigations
Plain X-ray
This will demonstrate the bony anatomy and the presence and position of any retained foreign bodies.
Computed Tomography (CT)
Computed tomography provides good bony detail, but in the presence of metal fragments will have significant artifact. Computed tomography is excellent for three-dimensional reconstruction of the bony anatomy, but in the face of a fragment injury, the radiological artifact may be too great to make the pictures meaningful.
Magnetic Resonance Imaging (MRI)
Magnetic resonance imaging is extremely useful for the soft tissues, in par- ticular spinal cord anatomy. This is a particularly important modality, as early realization that complete transection of the cord has occurred is extremely useful for prognostication. The problem with MRI scanning is that there is a theoretical risk of the magnetic field causing foreign body movement, as well as artifact, even though there are records of the MRI being used safely in patients with fragmentation injuries. Magnetic reso- nance imaging is essential to investigate delayed deterioration (see chapter 23).
Myelography
This may be necessary where metal fragments and metal artifact prevent the use of CT or MRI.
Angiography
With respect to penetrating neck injuries, it is recommended that cervical angiography be undertaken before any surgical exploration. Late dete- rioration in some penetrating spinal cord injuries may need spinal ang- iography as the deterioration may be due to the development of an arteriovenous fistula.
Instability
Battlefield gunshot wounds to the neck causing neurological deficit have a high fatality rate. In those surviving, it generally is accepted that the neck injury is not unstable.
It is important that the mechanism of injury be elicited during the history as, especially during the transition to war phase, there are many motor- vehicle accidents and those injured in them would be expected to have potentially unstable spinal injuries. It is essential to treat any person so injured who has reduced or impaired levels of consciousness due to intox- ication or the injury as having a spinal injury until positively proven other- wise. In such an instance, where practical, full ATLS-type management should be initiated. In a mass casualty situation, or where the tactical situ- ation is unsafe, the expediency of life-saving treatment may necessitate reduced diligence with respect to spinal immobilization.
It is important to remember that some penetrating injuries, if treated as unstable, may actually be to the detriment of the casualty as, for example, putting on a cervical collar for a penetrating neck injury has in some instances been found to mask significant deteriorations. Indeed, in these casualties, subsequent investigation have found that the spinal injury was, in fact, not unstable after all. Quite clearly, if an unstable injury is missed, the consequences for the casualty are potentially devastating; this is why the mechanism of injury is important in the history. In fact, in a purely pen- etrating injury of the neck, it is recommended that a supportive collar not be used at all (see Chapter 7 and Chapter 11).
Operation?
There is considerable controversy regarding whether or not to decompress the spinal cord or theca. The initial neurological status remains the most important factor for overall expected outcomes. Initial military experience from the major wars of the twentieth century suggested that highly aggres- sive surgical therapy should be the approach; however, in recent years, with increasing civilian experience, a more conservative approach has been
adopted. With regard to incomplete spinal cord injuries alone, it has been found that removal of the penetrating fragment, if impinging upon the spinal cord, does improve overall motor function in some reported series.
In some published studies where surgery was undertaken in nearly all cases, there have been some instances where the neurological status has actually been made worse by surgery.
For foreign bodies present in or around the cauda equina, many studies have supported the removal of the foreign body, but this can be a techni- cal challenge at operation because the foreign bodies can move. Having the patient positioned slightly head up and using fluoroscopy to aid identifica- tion of the foreign body position is recommended.
There is considerable agreement that where there is cerebrospinal fluid leakage, progressive neurological deficit, or spinal instability, surgery should be undertaken, although surgery for instability may be controversial to some authorities. In war, if casualty evacuation is needed, the spinal injury casualty will need to be made stable by surgical fixation so transfer can be made more easily and safely. The removal of the foreign body to prevent later sepsis remains controversial, as many studies have indicated that foreign body retention does not actually increase the risks. In cases were the penetrating fragment traverses the abdominal cavity, and therefore pos- sibly the bowels, prior to entering the spinal canal, the life-threatening injuries are recommended to be dealt with first, followed by thorough wash out from anteriorly with a prolonged high-dose usage of antibiotics. It is hardly surprising that penetration of the colon is associated with the highest risks of infection, although some studies have suggested that transoral is higher still. Retained foreign bodies can cause problems in other areas, in particularly plumbism (lead poisoning), but this is an infrequent complica- tion of lead fragments. It has been recognized that lead fragments in joint spaces or disc spaces should be removed, as toxicity is likely. Of more concern are copper-jacketed projectiles, as these are particularly toxic and it is recommended that, whatever the situation, any copper-jacketed pro- jectile be removed at surgery as soon as possible.
Role of Antibiotics and Other Drugs
It is recommended that high-dose broad-spectrum antibiotics be adminis- tered intravenously for seven to ten days, especially if there is a retained foreign body or if the projectile has traversed a hollow viscous.
Antacids are recommended to minimize the risk of stress ulceration.
Methylprednisolone has been advocated in the management of blunt spinal cord injury, but a number of studies have not found methylpred- nisolone to be of any clinical benefit in gunshot-wound–induced spinal cord injury. Indeed, in one series, increased rate of complications was found and attributed to the use of steroids. There is currently ongoing controversy
regarding the use of steroids, even in the previously advocated blunt spinal cord injury; therefore, at this moment in time, the use of steroids in pene- trating spinal cord injury cannot be recommended.
General Nursing Care/Postoperative Care
The management of a spinally injured patient, whether it be due to pene- trating injury or blunt, are virtually identical from the nursing and post- operative management aspects. The casualty needs a nasogastric tube, bladder management, aseptic management of catheters, careful pressure area care, and early physiotherapy and rehabilitation. Careful fluid man- agement and catheter management needs to be maintained with avoidance of urinary tract infections and catheter blockage in the long-term care.
With increasing sophistication in the management, these patients are living significant lengths of time and represent a considerable nursing challenge.
Care of such a casualty needs to be addressed at identifying missed injuries, such as peripheral fractures, but with emphasis on ruling out a second spinal injury. Other severe injuries, such as abdominal trauma and head injury, should have been recognized in the primary or secondary survey and dealt with accordingly. A low threshold for investigating for other injuries should be maintained throughout the care of such a patient.
Other important considerations include hypovolemia; ruling out active bleeding may be difficult, but is vital. Once a sinister cause is excluded, then fluid resuscitation to maintain a blood pressure between 80 and 100 millimeter Hg systolic is appropriate. Adequate urine output is the best marker.
Hypothermia due to sympathetic failure causing peripheral vasodilata- tion should be actively managed.
Bradycardia due to decreased sympathetic drive can be so severe as to lead to asystolic arrest. Atropine may be necessary. Hypoxia and tracheal toilet can be enough to exacerbate the bradycardia to produce arrest.
Autonomic dysreflexia (mass reflex) can occur in over 50% of those with injuries higher than T6. There is an uncontrolled sympathetic reflex to usually only mildly noxious stimuli such as a full bladder or bowel. There is flushing, headache, sweating, anxiety, and hypertension with bradycardia.
Removal of the stimulus and elevation of the head of the bed are needed.
Failure to resolve the hypertension may require drug therapy such as hydralazine. Untreated, this hypertension can be fatal. Therefore, preven- tion by nursing diligence is necessary.
Prophylaxis for DVT and PE is essential.
Care to prevent chest problems due to reduced chest excursions, poor cough reflex, etc., is important. Chest infections are common. Breathing control is impaired.
There may be ileus, constipation, gastric reflux, and gastric stress ulcers.
All need appropriate management and, in the case of bowel motility and ulcers, prophylaxis. Nutritional advice and support is required early to min- imize the effects of posttraumatic catabolism.
Improved urological care has reduced the long-term death rate.
Improved catheter technology and the introduction of intermittent self- catheterization have brought about significant improvements. There should be a low threshold for treating urinary tract infections and periodic renal tract ultrasound to assess bladder capacity and any ureteric reflux.
Pressure area care and prevention of ulcers can make the difference between a relatively normal life and a prolonged hospital stay. The worst cases end up with osteomyelitis and major plastic and reconstructive surgery.
Pain can be a long-term problem. It may be due to spasm, or it can be neurogenic or analogous to phantom limb pain. Multidisciplinary pain team management is recommended.
Delayed deterioration should always prompt urgent investigation for posttraumatic syringomyelia, arachnoid adhesions, etc.Appropriate therapy is indicated to preserve function above the original level of injury. There- fore, any complaint of neurological change no matter how bizarre or minor must be taken seriously, and ideally, periodic complete physical examina- tion of the patient is needed.
Early physiotherapy and transfer to a dedicated spinal injury facility is essential for their optimal rehabilitation. This will include psychosocial, sexual, vocational, educational, and recreational rehabilitation in a multi- disciplinary setting.
Evacuation/Transfer
The patients having such an injury in an austere military environment will need careful and well-managed nursing care in order to facilitate their safe evacuation and transfer. As previously mentioned, they should be trans- ferred to a dedicated spinal unit at the earliest opportunity for appropriate rehabilitation and management. It is reasonable to suggest that in the pres- ence of a spinal fracture that an operative fixation will facilitate the early and easier transfer of such an injured patient, as less emphasis would need to be placed on prevention of further injury in the presence of an unstable spine.
Summary
The management of penetrating spinal cord injuries due to gunshot wounds or fragment injuries is, in the initial phase, as for any ATLS/BATLS proto- col. In the battlefield, the chances of the injury being unstable in survivors
due to a penetrating injury is very small. It is important to recognize the mechanism of injury and manage the patient accordingly. For example, a casualty involved in a motor-vehicle accident will be at higher risk of an unstable spinal injury than one who has just been shot by a 5.56-millime- ter round. Surviving casualties who have such penetrating neck injuries are extremely unlikely to have an unstable neck, and therefore the application of a stabilizing collar may in fact be detrimental to their care. As with the majority of spinal cord injuries and spinal injuries in general, other life- threatening injuries always take priority. North Atlantic Treaty Organiza- tion (NATO) guidelines are specific regarding the management of spinal injuries; they state that complete injuries do not require surgery, surgery being indicated for progressive neurological deficit and spinal instability. To this recommendation should be added that surgery should be applied in the presence of CSF leaks, delayed infections or foreign body reactions, and/or the presence of copper-jacketed rounds or lead foreign bodies in a joint or disc space. In addition, if there is radicular pain where the foreign body can clearly be demonstrated to be compromising a root on appropriate imaging, then this also should be removed. Decompressive laminectomy and foreign body removal for the sake of it is no longer justified. The use of steroids is not recommended at this time. High-dose antibiotics for at least seven to ten days are indicated.
Overall, the most important factor for a prognosis is the presenting neu- rological status. In 90% of casualties, the presenting neurological deficit is permanent. However, the mortality from a spinal cord injury alone is low, and with the best long-term care available, life expectancy can be virtually normal and that life can be fruitful and useful to society.
Further Reading
Tator CH, Benzel EC, eds. Contemporary Management of Spinal Cord Injury: From Impact to Rehabilitation. Park Ridge, IL: AANS; 2000.
