shock Flashcards
What is shock?
a failure of the cardiovascular system to deliver enough oxygen and nutrient to meet cellular metabolic demand
Group of signs and symptoms that occur together in a pattern
to function normal the body requires 3 intact mechanims
An effective pump (heart)
adequate fluid volume (blood/body fluid)
Intact system of tubingmechanismof constriction and dilation (vessels)
types of shock
Cardiogenic shock
hypovalaemic shock
Neurogenic shock e.g. disruption in synapses
anaphylactic shock
Toxic shock
cardiogenic shock
Secondary to a cardiac episode
causes can include, acute MI, tension pneumothorax, cardiac tamponade
Neurogenic shock
occurs when nervous system loses control over the blood vessel tone I.e vasodilation
Causes include spinal injury, poisons, emotion
toxic shock
Caused by a local and generalised dilation of the blood vessels as a result of bacterial toxins.
the toxins damage tissue, including skin and organs.
Temp 38.9 or above, reduced BP, widespread fear red skin rash,
hypovolemic shock
Loss of circulating volume as a result of
haemorrhage due to trauma
Plasma loss due to burns
fluid loss through vomiting, diarrhoea and sweating
Stage 1 shock
up to 15% blood volume loss
Pallor of the skin
normal capillary refill - less than 2 seconds
Increase in pule rate - up to 100BPM
no change in systolic or diastolic pressure
At this stage, the systolic pressure is being maintained by compensatory mechanisms mediated through the autonomic nervous system.
stage 2 shock
15-30% blood loss Pallid, cool, clammy skin cap refill extending beyond the normal 2 seconds Pulse rate exceeding 100BPM increased Respiratory rate Narrower gap in BP
stage 3 shock
30-40%
Anxious and agitated as brain is being starved of oxygen
pulse rate greater than 120BPM
Systolic BP falling to 100mmHg or less
stage 4 shock
40%+ blood loss Central cyanosis moribund appearance (look dead) Altered level of consciousness marked tachycardia with weak pulse Respiratory distress systolic BP drops to below 70 or less
If in their house need to raise legs to push the blood back up to the heart
management of shock
Ensure open airway oxygen reassurance Respiratory and circulatory function assessment control external haemmorage Patient positioning immobilise fractures …
risk groups
haemorrhage Pregnant heart conditions elderly Trauma burns/scalds
Compensatory mechanism
if there is a drop in BP, the body will start to compensate.
Blood will be diverted from the extremities e.g. skin, limbs, organs within the abdominal cavity.
what is a drop in BP detected by?
Baroreceptors send signals to the brain to release norepinephrine …
renin-angiotensin-aldosterone system
Reduced blood flow stimulates the kidneys to release enzymes, renin and angiotensin II.
these enzymes cause vasoconstriction and they encourage secretion of the hormone vasopressin.
Vasopressin promotes water retention in the kidneys therefore, urine output is decreased (want to keep water) and blood volume decreases and blood pressure goes up.
anaphylactic shock
Exaggerated allergic reaction
histamine acts to deactivate the allergen and produce the immune response > more white cells summoned > vasodilation >
Antibodies contain records of allergens
effects on organs of anaphylactic shock
restriction in airway - pulmonary vasoconstriction
Spasm and oedema of the bronchi
Weakens cardiac contractions
peripheral vasodilation this may cause dizziness
Blood vessels become more permeable
signs and symptoms
Peripheral vasodilation produces flushed appearance
leak blood vessels produce oedema
Itching and hives
swelling around eyes
Difficulty breathing
etc
