What is the equation for Mean Arterial Pressure?
MAP = Peripheral resistance x cardiac output
What is the equation for cardiac output
CO = HR x SV
What is the equation for stroke volume?
SV = end diastolic volume - end systolic volume
What are the 4 factors effecting perfusion?
- Blood volume
- Adequate pump
- Vessel tone
- Obstruction in CVS
What are 4 factors that lead to shock?
- Inadequate blood volume
- inadequate pump
- decreased vessel tone
- obstruction in CVS
What is shock?
Loss of fluid or disruption of the fluid flow around the circulatory system.
Imbalance between supply and demand of O2
What are the causes of shock?
- Trauma
- Blood loss
- Heart disease
- Burns
- Poisoning
- Infection
What are the classifications (types) of shock?
- Hypovolaemic
- Cardiogenic
- Distributive
- > Neurogenic
- > Septic
- > Anaphylactic
- Obstructive
What type of shock effects end diastolic volume?
Hypovolaemic & obstructive
What type of shock effects end systolic volume?
Cardiogenic
What type of shock effects Peripheral resistance?
Distributive
What is the average blood volume of a person?
70 - 80 mls/kg
What are Erythrocytes?
Red blood cells
What are Leucocytes?
White blood cells
What are thrombocytes?
Platelets
Whats is tPA and what does it do?
Tissue plasminogen activator
- Released from endothelial cells and converts plasminogen to plasmin
- plasmin breaks down fibrin in clots
What are the three types of bleeding?
- Capillary
- Venous
- Arterial
What are indications of capillary bleeding?
- dark red
- slowly ooze
- easily controlled
What are indications of venous bleeding?
- dark red
- steady flow
- non-pulsatile
What are indications of arterial bleeding?
- bright red
- spurting blood
How many classes of shock are there?
4
What categorises Class 1 of Shock?
- upto 15% blood loss (750mls)
- body compensates by constricting blood vessels
- Pt remains alert
- BP in normal limoits
- Pulse slightly elevated or normal and remains strongs
- RR and depths remain normal
- skin colour and temp remain normal
What categorises Class 2 of Shock?
- upto 30% blood loss (750 -1500mls)
- vasoconstriction continues to maintain BP
- blood flow shunted to vital organs
- Pt becomes confused and restless
- Skin turns pale, cool, dry
- Delayed capillary refill
- sympathetic response activates - increased HR, pulse quality weakens
- RR increases
What categorises Class 3 of Shock?
- upto 40% blood loss (1500 - 2000mls)
- Compensatory mechanisms begin to fail eg. vasoconstriction can no longer maintain BP which now falls
- Cardiac output and tissue perfusion continue to decrease
- Pt becomes more confused and restless and anxious
- Classic signs of shock present (rapid thready pulse, hypotension, elevated RR and depth, CPC skin)
- Oliguria (decreased urine output leading to renal failure)
- Thirst
