what is the thoracic pump theory?
STATES:
AS CPR IS BEING PERFORMED THis COMPRESSES STERNUM - DECREASING SPACE ON CAVITY THUS INCREASING PRESSURE
when it recoils and returns the amount of space in the cavity increases, thus decreasing pressure in cavity
the change in pressure creates a vacuum effect pulling blood into heart.
What does the thoracic pump rely on to work?
Pressure gradients
- It relies on the difference in pressure between arterial and venous systems.
- blood flows forwards because of the pressure gradient
What happens to the papillary muscles in the thoracic pump?
They stop working, hence valves stop being an issue
How much difference blood (in mmHG) do we need between the left ventricle and right atrium for blood to flow through the coronary arteries
15mmHG
- often referred to as Coronary perfusion pressure
What is Coronary perfusion pressure?
15mmHG is required between the LV and RA for blood to flow through the coronary arteries
What happens if you do not allow adequate recoil on chest compressions?
results in worse hemodynamics, including decreased cardiac perfusion, cerebral perfusion and cardiac output.
What are the reversible causes of cardiac arrest?
(4H’s & 4T’s)
- Hypoxaemia (lack of oxygen in blood)
- Hypovolemia (lack of blood volume)
- Hypo/hyperthermia (low/high temp)
- Hypo/hyperkalemia (inadequate or excess of potassium)
- Tamponade; Cardiac (fluid building around the heart in pericardium)
- Tension pneumothorax (a collapsed lung)
- Thrombosis/clot (pulmonary or coronary)
- Toxins/poisons/drugs
A sudden spike in end tidal CO2 (ETCO2) is a sign of what?
ROSC
Return of spontaneous circulation
ECO2 below 10mmgh for 10 mins has what percentage mortality rate?
100%
What is defribrillation attempting?
attempt to cause depolarisation of all cardiac cells. IN hope that the pacemaker cells will take over
