Shock Flashcards
What is Shock ?
Acute failure of the circulatory system to supply
the peripheral tissues and organs of the body with an adequate blood supply resulting in cellular hypoxia.
All characterised by Circulatory failure
Causing an Imbalance of oxygen supply and demand
What is the main energy source form cells ?
ATP is the primary energy form in cells
Aerobic respiration (usual)
If you don’t have enough, switch to anaerobic respiration and produce lactate.
Lactate is a direct result of tissue hypofusion which is why we give oxygen to reperfuse.
How many litres of blood do we have within the body ?
5L
What is the equation for BP
BP = CO x sys VR
BP = Cardiac Output x Systemic Vascular Resistance
What symptoms will occur if the body cant compensate ?
Tachycardia
Poor peripheral perfusion
Prolonged CRT
Feel cool/clammy
Pallor of skin
What are the 4 types of shock ?
Hypovolemic
Cardiogenic
Distributive
Obstructive
What will likely been seen on bloods/ ABG ?
Metabolic acidosis
Acute renal failure (raised creatinine and urea)
Liver failure- poor clotting, raised transaminases
What is hypovolemic shock?
Loss of circulating volume
whether it be blood, plasma or extracellular fluid.
What are the causes of Hypovolemic shock ?
Bleeding- external or internal
Femoral/pelvis fractures, ectopic pregnancy, ruptured organ e.g. spleen/liver
Burns- “leaky” capillaries and evaporation from burn surface
Severe loss of sodium and water- Diarrhoea and vomiting, dehydration
What is cardiogenic shock ?
What is its causes ?
The heart fails as a pump: poor CO, poor organ perfusion & hypoxia
Causes:
Myocardial damage from infarction, myocarditis, cardiomyopathy
Sustained arrhythmias, valvular damage eg endocarditis
What is obstructive shock?
What are the causes ?
Caused by a Mechanical obstruction to flow of blood
into or out of the heart
May be obstruction to cardiac filling
or
obstruction to cardiac outflow
Causes: Pulmonary Embolism (PE), tension pneumothorax, cardiac tamponade
What is distributive shock ?
What are the three common types?
Here, there is a normal blood volume, its just not in the right placed.
Cause–
loss of sympathetic tone or release of excessive vasodilator substances
3 common types- anaphylaxis, sepsis, neurogenic
How does anaphylactic shock occur ?
Severe systemic allergic reaction
Immunologically mediated
This leads to the release of histamine, resulting in vasodilator and leading to angioedema.
How does neurogenic shock occur ?
Loss of sympathetic inhibition of vasodilation
Massive vasodilation occurs
- Here there is a normal volume of blood does not fill circulatory system
Rarest form of shock - Occurs with spinal injuries at and above T6
- Remember that injuries may cause neurogenic shock
may - hypovolaemic shock
What are some clinical features of anaphylactic shock ?
Clinical features:
Laryngeal oedema can be life threatening.
Bronchospasm
Circulatory collapse/hypotension
Contraction of GI and Uterine smooth muscle
Urticaria/hives
Angioedema
DEATH CAN OCCUR IN MINUTES
Stridor
Cough
Wheeze
Chest tightness
Shortness of breath
Abdominal pain (cramping)
Skin burning/itching
“My face is swelling”
“My throat is closing”
Anxiety
Feeling of impending doom
What happens in septic shock ?
