Spinal Shock
- Article Author:
- Endrit Ziu
- Article Editor:
- Fassil Mesfin
- Updated:
- 9/5/2020 9:44:59 AM
- For CME on this topic:
- Spinal Shock CME
- PubMed Link:
- Spinal Shock
Introduction
Spinal shock is a result of severe spinal cord injury. It usually requires high-impact, direct trauma that leads to spinal cord injury and spinal shock. The initial encounter with a patient that has spinal shock is usually under a trauma scenario. Ischemia of the spinal cord can also produce a spinal shock, for example, a hypotensive patient in the medical intensive care unit (ICU) or a post-angiography patient with thrombotic occlusion of arteries that supply the cervical spine. Treatment of ischemic type spinal shock is different. The outcome expectations are also different from spinal shock achieved from a traumatic event. Spinal shock after a traumatic event affects mostly young; the average age is 29. It is more common in men (80%) than in women. Cord injury is often associated with fracture-dislocation, tearing of ligaments, rotational distraction, as well as tearing of the disc space. If the spinal shock is not associated with significant injury of the spinal column itself, then the prognosis for these patients is more favorable than when the fracture is present. The overall treatment of patients with significant spinal shock and injury presents a big challenge due to poor outcome, especially in patients that are in the prime of their youth. Two common mechanisms lead to spinal shock. Regarding the treatment of spinal cord injury, the best treatment for the primary spinal cord injury is prevention. The injury associated with the primary event is irreversible. However, secondary injuries such as hypotension and hypoxia are preventable. Aggressive medical management can reduce its effect on the overall functionality of the patient. This activity provides a concise introduction to the care of these patients.[1]
Etiology
The spinal shock has been described initially in a patient with a transected spinal cord and difficult to treat hypotension as a result of decreased sympathetic tone throughout the body and especially in the arterial wall. Initially, this process was described as permanent as the majority of these patients progressed to death. As clinical care started to improve, and the understanding of the pathologic mechanisms involved in the progression of deficits increased, survival also improved. Unfortunately, deficits after a spinal shock are still permanent, and we yet have to achieve the goal of improving those deficits. There are several definitions in the literature pertaining to spinal shock. Some definitions include the presence of hypotension, and some include the absence of reflexes below the level of the lesion with and without hypotension. Having a unique definition is important but what is more important is understanding the care of these patients.
In spinal shock, there is a transient increase in blood pressure due to the release of catecholamines. This is followed by a state of hypotension, flaccid paralysis, urinary retention, and fecal incontinence. The symptoms of spinal shock may last a few hours to several days/weeks.
Primary spinal cord injury may be due to transection, mechanical injury, gunshots, abscess, metastatic disease or distraction of the nerves. These injuries are usually associated with dislocation and/or fracture of the vertebral bodies. Secondary spinal cord injuries may be due to occlusion or disruption of arterial blood supply. The hypoperfusion leads to anoxic damage to the spinal cord.
Epidemiology
Young men in their second decades of life are prone to spinal cord injury and clinical diagnosis of spinal shock. Among cases of spinal shock, 45% are due to motor vehicle accidents (MVA), 34% domestic accidents such as falls, 15% sporting accidents, 6% self-harm. Intoxication due to alcohol or other drugs plays a major role, and often the initial neurological exam is not accurate due to intoxicant levels being very high. As one can imagine, the events before and after the event are very tragic for the patient, family, and society. The cost of care for these patients has spiraled out of control since they do require long-term care, which most often families are not equipped to provide.
Pathophysiology
Despite the fact that spinal shock has been described for many years, professionals continue to identify its pathophysiology. Animal models have been used to study the pathophysiology detail of spinal shock. From these studies, researchers have learned that at the point of the initial injury, the spinal cord appears normal, and no gross pathology can be identified. Within the first four hours of the initial injury, hemorrhagic foci appear more pronounced in the gray matter. In the first 24 hours, there is significant protein accumulation in the gray matter. Edema ensues and peaks at three to six days post-injury. On MRI, edema can be visualized up to two weeks after injury. The slow process of central cord necrosis and vacuolization ensues from this point on and continues for about two months. The characteristically thin rim of white matter surrounding the central core of necrosis remains intact throughout this process. Often it is observed that the patient starts losing neurologic function above the level of injury, which brings anxiety to an inexperienced provider prompting more imaging of the patient's spinal cord. Loss of function that happens several days post-injury above the level of the injury is mostly due to spinal cord pathways rearrangement. Once this process abates, the function above the injury returns to normal, although the exact time needed for this process is not precisely defined and could last from weeks to months. If a patient survives the initial injury but remains immobile, the area fills with gliotic tissue.[2]
History and Physical
Healthcare providers should obtain a detailed history of the accident. Often factors such as a rollover crash, ejection outside the car, or seat belt usage can give significant information on the severity and type of spinal cord injury that should be expected to an experienced physician. The presence of intoxication is important information, as it will confuse the physical exam. It is important to understand that the energy necessary to produce spinal shock and spinal fracture during a traumatic event is very high, and patients should be thoroughly examined for other tissue and organ injury. It is more appropriate to use the trauma activation code announced when a patient with spinal shock arrives at the emergency department, that way the trauma team can complete a full workup for the patient. The full spinal examination should include motor, sensory reflexes including bulbocavernosus reflex and anal wink reflex. Motor activity and strength decrease not only in the skeletal muscles but the motor activity of internal organs like bowel and bladder. This decrease leads to constipation and urinary retention. It is of utmost importance to record an American Spinal Injury Association (ASIA) score as prognostic long-term expectations can be made with fair accuracy before any discussion with family and the patient. While evaluating the patient, assume their spine is unstable and take all the necessary precautions to keep it stable until final imaging is obtained and stability is established.
It is important to know that spinal shock usually occurs when the injury to the spinal cord is above T6. If the patient has hypotension and shock with spinal cord injury below T6, one should look for hemorrhage as a cause.
Evaluation
Patients with spinal cord injury need to be evaluated in a timely fashion to minimize secondary injuries. Preferably, these patients should be evaluated at level one trauma centers due to the extent of injuries. After the initial trauma, evaluation is completed, and if the patient is stable enough to undergo imaging, a complete spinal computed tomogram (CT) should be the initial imaging obtained. MRI spine imaging is very helpful but should not be the initial imaging modality. Myelogram would be helpful if the spinal shock is associated with canal compromise after fracture and would be the imaging of choice if the patient cannot obtain an MRI.
Other studies that are always done include:
- Levels of lactate
- Arterial blood gas to assess ventilation and oxygenation
- Complete blood count to assess hemoglobin levels
Treatment / Management
The cause of hypotension has to be treated. Hemorrhage may be due to injury in the chest or abdomen. Fluid resuscitation is vital. Crystalloid is often used to reverse the hypotension. The goal should be to bring the blood pressure at 90-100 mm Hg systolic. Oxygenation should be maintained and bradycardia managed with atropine. A Foley should be inserted and the output monitored. Some patients may benefit from low dose dopamine.
Spinal shock patients should be treated in an ICU setting, as many complications should be expected to arise due to the injury. Methylprednisone treatment is controversial with some trials showing modest benefit and some other showing more negative side effects than benefits. We recommend, if the patient is young and does not have any underlying diseases that could be exacerbated by steroid use, a short trial of methylprednisone should be initiated starting with a loading dose of 30 mg/kg followed by a maintenance dose of 5 mg/kg/h for the next 24 hours. Neurogenic shock usually ensues with lesions above the T6 level. Norepinephrine drip and judicious use of atropine for bradycardia should be part of the initial treatment. Eventually, within few days hypotension improves, and intravenous (IV) drips should be gradually decreased.
With high cervical injuries, the diaphragmatic function will be compromised, and these patients will necessitate early tracheotomy since they will be ventilator dependent. Deep vein thrombosis is excessively high in these patients. Prophylaxis should be initiated as soon as possible within days of the injury. Long-term management of spinal shock injury patients always requires multidisciplinary team treatment between different services. Approximately 60% of these patients will require spine stabilization with surgical intervention, and neurosurgery or orthopedic professionals should be consulted early. Lastly, maintain high suspicion, but constant movement of the patient on a regular basis should help the patient not to develop a pressure ulcer. [3][4][5][6]
Differential Diagnosis
The differential diagnoses of spinal shock include:
- Cardiogenic shock
- Sepsis
- Spinal abscess
- Vertebral fracture
Pertinent Studies and Ongoing Trials
Current guidelines on managing spinal cord injury
- Immobilize the patient. A sandbag and tape are not sufficient. Spinal immobilization in patients with penetrating trauma is not recommended.
- Perform imaging studies with CT scan
- The use of steroids is not recommended in all patients.
- Administration of GM-1 ganglioside is also not recommended.
Prognosis
The outlook for spinal shock is guarded and depends on comorbidity, level of spinal cord injury, associated injuries, patient age and type of injury. If the condition does not reverse within 24 hours, most patients have a prolonged recovery and will require extensive rehabilitation.
Complications
- Neurological deterioration
- Pressure sores
- Fecal incontinence
- Urinary retention
- Deep vein thrombosis
- Aspiration pneumonitis
Enhancing Healthcare Team Outcomes
Spinal shock carries very high morbidity if not immediately treated, thus, these patients must be managed by an interprofessional team that includes a trauma surgeon, neurologist intensivist, neurosurgeon, ICU nurses and the emergency department physician. These patients should be admitted to the ICU and closely monitored by nurses. Besides fluids, these patients may require a variety of treatments depending on which organ is affected. These patients also require DVT prophylaxis, pressure sore prevention, and adequate nutrition.[7][8]
Pulmonary complications like aspiration are common and need to be prevented. Patients need a foley catheter and thus are at risk for bacteremia. Besides physical therapy is necessary to prevent contractures and muscle atrophy. The dietitian should assess the patient for nutrition. Depression and anxiety are common and hence a mental health nurse should counsel the patient. The social worker should be involved to ensure that the patient has adequate facilities at home and finances to seek medical care. Only through open communication between the team members can the outcomes of spinal shock be improved.
Outcomes
The outcomes for most patients depends on the presence of neurological deficit at presentation. For those who do respond to fluids and steroids, the prognosis is good, but those who fail to respond usually have a protracted ICU course and prolonged recovery.[9][10] (Level V)