M101 Initial Assessment Flashcards
What is the order of the A – E Assessment of an acutely unwell patient?
Airway Breathing Circulation Disability Exposure
When is the A – E Assessment of an acutely unwell patient carried out in a different order?
military - patient usually bleeding out
What does a nasal cannulae provide?
small and unpredictable increase in inspired oxygen
Why is the oxygen supply from a nasal cannulae unpredictable?
mixed in with the air in the room
What is the maximum capacity of oxygen delivered per minute from a nasal cannulae?
5 litres per minute (L/min)—delivering an oxygen concentration of
What is the percentage of oxygen in the air delivered from a nasal cannulae?
28–44%
What is the percentage of oxygen in the air delivered from a Hudson Mask?
around 40%
What is the maximum capacity of oxygen delivered per minute from a non-rebreather mask?
flow rate of about 10 to 15 liters/minute (L/min)
What is the oxygen supply from a non-rebreather mask?
60 percent to 80 percent oxygen
Reservoir mask
Well fitting face mask
Reservoir bag to collect oxygen while patient is breathing out
One way valves to ensure inspiration draws oxygen from reservoir bag and expired breath is directed out of the sides of the mask
Can deliver 80-85% oxygen
Used widely in acutely unwell patients
Controlled oxygen administration
Accurate oxygen delivery achieved by high flow of gas, which exceeds patient’s peak inspiratory flow rate
Used for patients who are sensitive to oxygen eg those with severe COPD
pulse oximeter
can be blocked from nail varnish
What will circulatory compromise look like in a patient?
pale
peripheral capillary refill will be slow
might not be conscious due to lack of blood flow to the brain
increased inspiratory rate
What will circulatory compromise look like in a patient?
pale
peripheral capillary refill will be slow
might not be conscious due to lack of blood flow to the brain
increased inspiratory rate
physiology of shock
Cardiac Output = Stroke Volume x Heart Rate
If stroke volume is reduced (eg by bleeding) then tachycardia can partially compensate for this.
This is mediated by the sympathetic nervous system which also causes pallor, sweating and diversion of cardiac output towards vital organ systems
Intravenous volume replacement is vital in this situation. It’s also important to stop ongoing losses
What will circulatory compromise look like in a patient?
pale peripheral capillary refill will be slow might not be conscious due to lack of blood flow to the brain increased inspiratory rate cold peripherals
Starling curve
Explanation of preload improving cardiac output
Need to be cautious with fluid volume resuscitation in the context of poor cardiac function
Myocardial Contractility
Stroke volume requires good myocardial contractility. Contractility is impaired by sepsis and cardiac ischaemia amongst other things Improving contractility needs identification of the cause but treating hypoxia is important. Cautious intravenous fluid boluses usually help. Inotropic agents (eg adrenaline) may then be needed This requires central venous access and intensive care
Myocardial Contractility
Stroke volume requires good myocardial contractility. Contractility is impaired by sepsis and cardiac ischaemia amongst other things Improving contractility needs identification of the cause but treating hypoxia is important. Cautious intravenous fluid boluses usually help. Inotropic agents (eg adrenaline) may then be needed This requires central venous access and intensive care
Systemic Vascular Resistance
Blood pressure = cardiac output x systemic vascular resistance (V=IR)
A drop in SVR means that there is less resistance to ejection of blood. Even with a normal or high cardiac output, a low SVR (as seen in sepsis and anaphylaxis) will result in a low blood pressure
Intravenous fluid may help in situations of low SVR, but vasopressors may also be needed (eg noradrenaline) which also require central access and intensive care
Categories/Causes of Shock
Hypovolaemic Distributive Obstructive Cardiogenic Patients may be suffering from more than one kind of shock
Hypovolaemic Shock
Haemorrhagic (trauma/GI Bleeding/aortic aneurysm)
Non-haemorrhagic (burns/pancreatitis/GI losses)
Reduced circulating volume reduces ventricular filling, stroke volume and cardiac output
Distributive Shock
Severe Peripheral Vasodilatation Septic Shock Neurogenic Shock Anaphylactic Shock These cause hypotension via a reduction in systemic vascular resistance
Obstructive Shock
Pulmonary Embolism
Tension Pneumothorax
Cardiac Tamponade
These impair ventricular filling which reduces stroke volume and therefore cardiac output. Intravenous fluids may help but other specific treatment may also be necessary
