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Cardiogenic shock continues to be a frustrating clinical
problem; the management of this
condition requires a rapid and well-organized approach. (See
Prognosis, Treatment, and
Medication.)
The diagnosis of cardiogenic shock can sometimes be made at the
bedside by observing
hypotension and clinical signs of poor tissue perfusion, which
include oliguria, cyanosis, coolextremities, and altered mentation.
These signs usually persist after attempts have been made to
correct hypovolemia, arrhythmia, hypoxia, and acidosis. (See
Presentation, DDx.)
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.
Neurogenic shockoccurs after an injury to the spinal cord.
Sympathetic outflow is
disrupted resulting in unopposed vagal tone.The major clinical
signs are
hypotension and bradycardia. Acute spinal cord injury is most
commonly seen with
blunt trauma accounting for approximately 85 to 90 percent of
cases. The most
commonly affected area is the cervical region, followed by the
thoracolumbar
junction, the thoracic region, and the lumbar region. Neurogenic
shockmust be
differentiated from spinal shock. Spinal shock is defined as
temporary loss of
spinal reflex activity occurring below a total or near-total
spinal cord injury.
Anaphylactic Shock
A sudden, severe allergic reaction characterized by a sharp drop
in blood pressure,
urticaria, and breathing difficulties that is caused by exposure
to a foreign
substance, such as a drug or bee venom, after a preliminary or
sensitizing
exposure. The reaction may be fatal if emergency treatment,
including epinephrine
injections, is not given immediately. Also called
anaphylaxis.
Anaphylactic shock is a particularly severe form of allergic
reaction, which may be fatal if not
rapidly and properly cared for. The allergens which may bring on
this condition are varied, andin some cases even a trace amount is
enough to trigger full anaphylaxis. Because of its extremely
quick action, this reaction is responsible for many deaths in
the United States and worldwide. Itis estimated that more than 400
people die each year in the United States from anaphylacticshock
brought on by insect stings, and more than 125 people die each year
as a result of food
allergies.
The symptoms of anaphylactic shock are varied, but often include
a constriction of the airway,
light-headedness and fainting, swelling of the neck and face,
itching, and low blood pressure. Aconstricted airway, caused by a
tightening of the bronchiole walls, is the most common cause of
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