Download spinal shock - S3 amazonaws com

SPINAL SHOCK
When a spinal cord injury is caused due to trauma, the body goes into a state known as spinal
shock. While spinal shock begins within a few minutes of the injury, it make take several hours
before the full effects occur. During spinal shock the nervous system is unable to transmit
signals, some of which may return once spinal shock has subsided, the time spinal shock lasts
for is approximately 4-6 weeks following the injury. In some rare cases spinal cord shock can
last for several more months. The loss of these signals will effect the persons movement,
sensation and how well the body’s systems function. Often the persons loss of movement and
sensation below the level of the spinal cord injury may appear complete soon after the injury.
This may mask the real extent of the damage. Usually, over the first few weeks the some of
body systems adjust to the effects of the injury and their function improves. Therefore, during
this time and the early stage of ANY new injury it is unlikely that an accurate prediction of any
recovery or permanent paralysis can be made.
Treatment begins with the emergency medical personnel who make an initial evaluation and
immobilise the patient for transport. Immediate medical care within the first 8 hours following
injury is critical to the patient's recovery. Nowadays there is much greater knowledge about
the moving and handling of spinal injury patients. Incorrect techniques used at this stage
could worsen the injuries considerably.
When injury occurs and for a period of time thereafter, the spinal cord responds by swelling.
Treatment starts with steroid drugs, these can be administered at the scene by an air
ambulance Doctor or trained paramedic. These drugs reduce inflammation in the injured area
and help to prevent further damage to cellular membranes that can cause nerve death.
Sparing nerves from further damage and death is crucial.
Each patient's injury is unique. Some patients require surgery to stabilise the spine, correct a
gross misalignment, or to remove tissue causing cord or nerve compression. Spinal
stabilisation often helps to prevent further damage. Some patients may be placed in traction
and the spine allowed to heal naturally. Every injury is unique as is the course of post injury
treatment that follows.
When a spinal cord is damaged by trauma, it also causes a concussion like injury to
spinal cord which leads to total sensory and motor power loss and loss of all reflexes for
initial some period which is followed by then gradual recovery of reflexes.
This state of sensory and motor loss along with total loss of reflexes following trauma
is known as spinal shock.
Spinal shock begins within a few minutes of the injury, it make take several hours before
the full effects occur. During spinal shock the nervous system is unable to transmit
signals from brain to end organs as they are not routed by the spinal cord.
Usually the spinal shock recovers within 24 hours but may last over few weeks in less
common cases. In some rare cases spinal cord shock can last for several more months.
Significance of Spinal Shock
The loss of these signals will result in loss of movements, sensations other body function.
Complete loss of movement and sensation below the level of the spinal cord injury makes
it difficult to assess the exact quantum of injury. Thus it is not possible to find the level,
extent and severity of injury as patients would show compete neural loss.
The only way to find that is to wait for spinal shock to recover. Over the first few weeks
the some of body systems adjust to the effects of the injury and their function improves.
Therefore, during this time it is unlikely that an accurate prediction of any recovery or
permanent paralysis can be made.
Pathophysiology of spinal Shock
Exact cause of the spinal shock is not known. It is thought that acute injury causes
depolarization of axons due to transfer of kinetic energy.
There are three phases of spinal shock
Phase 1
A complete loss or weakening of all reflexes below the level of spinal cord injury. This
phase lasts for a day. The neurons involved in various reflex arcs the neural input from
the brain due to spinal concussion become hyperpolarized and less responsive.
Phase 2
It occurs over the next two days, and is characterized by the return of some, but not all,
reflexes. The first reflexes to reappear are polysynaptic in nature, such as the
bulbocavernosus reflex.
Bulbocavernosus reflex can be checked by noting anal sphincter contraction in response
to squeezing the glans penis or tugging on the Foley. It involves the S1, S2, S3 nerve
roots and is spinal cord mediated reflex. Its presence signals the end of spinal shock.
Monosynaptic reflexes, such as the deep tendon reflexes, are not restored until Phase 3.
The reason reflexes return is the hypersensitivity of reflex muscles following denervation
— more receptors for neurotransmitters are expressed and are therefore they are easier to
stimulate.
Phases 3 and 4
are characterized by hyperreflexia, or abnormally strong reflexes usually produced with
minimal stimulation following sprouting of interneurons and lower motor neurons below
the injury begin to attempt to reestablishment of synapses.
Identification of Spinal Shock
Paralysis, hypotonia & areflexia, and at its conclusion there may be hyperreflexia,
hypertonicity, and clonus.
Return of reflex activity below level of injury (such as bulbocavernosus) indicates end of
spinal shock.
Spinal shock does not occur in the lesions that occur below the cord, and therefore, lower
lumbar injuries should not cause spinal shock . If bulbocaveronsus reflex in such cases
may indicate a cauda equina injury
Return of the of bulbocavernous reflex signifies the end of spinal shock, and if injury is
complete, any further neurological improvement will be minimal. Complete absence of
distal motor function or perirectal sensation, together with recovery of the
bulbocavernosus reflex, indicates a complete cord injury, and in such cases it is highly
unlikely that significant neurologic damage will return.
Neurogenic shock
Neurogenic shock is a type of shock caused by the sudden loss of the autonomic nervous
system signals to the smooth muscle in vessel walls.
This results in loss of background sympathetic stimulation, which is responsible for
maintenence of tone of blood vessels. As a result of loss of vascular tone, the vessels
suddenly relax resulting in a sudden decrease in peripheral vascular resistance and
decreased blood pressure.
Causes
Failure of the autonomic nervous system can arise from



Regional anesthetics
Injuries to the spinal cord (cervical spine and upper thoracic spine)
Administration of autonomic blocking agents.
Pathophysiology
The cardiac output decreases because the venule and small veins lose tone. Blood pools
in the periphery and blood pressure falls. In the normal situation, a reflex increase in
heart rate will occur to compensate for the peripheral pooling of blood. However, in
neurogenic shock, the sympathetic pathways to the heart are blocked or damaged by
trauma, resulting in a bradycardia.
Symptoms and Signs
The surroundings leading to shock are very important in making the diagnosis.
Diagnosis of neurogenic shock rests on knowledge of the history surrounding the onset of
shock. The features suggesting neurogenic shock are






Hypotensio
Bradycardia
Warm, dry extremities
Peripheral vasodilation and venous pooling
Poikilothermia ( Cold Body)
Decreased cardiac output (with cervical or high thoracic injury)
Treatment




Fluid challenge
Vasopressors
Beta-blockers can be implemented.
Phenylephrine or norepinephrine can be used