OSCE Flashcards
(57 cards)
What are the 5 types of shock?
(1) Cardiogenic (heart)
(2) Hypovolaemic (loss of volume)
(3) Anaphylaxis (vascular)
(4) Neurological (vascular)
(5) Toxic/septic (vascular)
Why do we do CPR?
To build up Coronary Perfusion Pressure (CPP). CPR cleans out the pooled blood in the right atrium and gives the heart a chance to restart if combined with early defibrillation.
What is chest recoil and why is it important?
Allowing the chest to rise in between compressions, as it allows the chest to fully expand, which creates negative pressure that pulls blood back into the chest and cardiac tissues
What is Coronary Perfusion Pressure (CPP)?
The pressure gradient that drives blood flow in the heart. There needs to be a +15mmHg difference between the left ventricle and right atrium for blood to flow through the coronary arteries.
What is the pathophysiology of VF?
- VF is a type of arrythmia where disorganised heart signals cause the ventricles to twitch uselessly.
- As a result, the heart does not pump blood to the rest of the body.
- It is caused by either a problem with the electrical system or a disruption of normal blood supply to the heart muscle.
A good analogy is thinking of the heart as a tube of toothpaste, if you squeeze the whole tube with your hand, the contents come out, whereas if you use fingers simultaneously, there is reduced output due to the irregularity.
What is the pathophysiology of pVT?
In pulseless ventricular tachycardia, the ventricles contract at a rate too rapid to allow for an adequate filling time during diastole, subsequently resulting in hemodynamic collapse from a diminished cardiac output causing insufficient blood supply to end organs.
What is the action of adrenaline?
- A sympathomimetic that stimulates alpha and beta adrenergic receptors. This causes variable effects on vascular resistance.
- During CPR , myocardial and cerebral flow is enhanced as it improves perfusion pressures.
- Increases cardiac output
- It stimulates the α1 receptors in vascular smooth muscle—causing vasoconstriction.
- This increases coronary perfusion pressure (CPP) and cerebral perfusion pressure (CePP). The CPP is strongly associated with ROSC.
What is the action of amiodarone?
An antiarrythmic - lengthens cardiac action potential. Causes a delay in repolarisation by blocking potassium currents. Reduces the cardiac muscle excitability and prevents abnormal heart rhythms.
Why is shock dangerous?
It can result in inadequate blood flow to the cells, and causes an inability to deliver O2 and nutrients around the body. Reduction in blood flow also creates failure to rid the body of waste materials from the process of cellular metabolism.
What is the targeted temperature after ROSC?
Between 32 and 36 degrees celcius
When would you withhold or discontinue resuscitation attempts?
- The presence of a DNR or advanced directive
- Where a death is expected due to terminal illness
- Submersion of an adult for >1hr, paediatric >1.5hrs
- If all of the following exist together:
- 15 minutes since the onset of collapse
- No bystander CPR prior to crew arrival
- Asystolic for >30 secs on ECG
- No suspicion of: drowning, hypothermia,
poisoning/toxins, pregnancy.
- Massive cranial and cerebral destruction - Hemicorporectomy
- Decapitation
- Decomposition
- Incineration
- Rigor mortis
- Hypostasis
- Foetal maceration in newborns
Drowning management
- Dry patient for defibrillation
- 5 rescue breaths (to reverse hypoxia) before CPR (BOTH ADULTS AND CHILDREN)
- CA will be secondary to hypoxia
- Consider early ET intubation - foam will be generated to make sure to suction
- Prolonged submersion will also likely be hypovolaemic due to cessation of hydrostatic pressure of water on body - fluid challenge
- Prolonged resus attempts required
Pregnancy arrest management:
- If over 20 weeks pregnant, manually displace the uterus to the left lateral position to relieve aortocaval compression
- Give a fluid bolus if there is hypotension or evidence of hypovolaemia
- Seek expert help early - obstetric, critical care etc
- Give IV tranexamic acid for PPH
- Consider early ET intubation by a skilled operator
Hypothermia management:
- Check for the presence of vital signs for up to 60secs
- If VF persists after 3 shocks, delay further shock attempts until core temp is >30
- Do not give any cardiac arrest drugs if core temp is <30
- Increase administration intervals for adrenaline to 6-10 minutes if the core temp is 30-34 (normothermia is >35 - normal drug intervals)
Describe and discuss when you would consider using fluids in a resuscitation and ROSC patient?
When BP is <90 systolic or when hypovolaemia is suspicious
What is the order of the stepwise airway management?
- Positioning
- Clear occlusion - forceps or suctioning
- HTCL/Jaw thrust
- OPA/NPA
- Supraglottic - iGel
- ET Intubation
- Needle cricothyroidotomy
What would your management be for an anaphylactic arrest?
- Remove trigger to stop any infusion.
- Establish IV or IO access
- Give rapid IV fluid bolus and either convey to hospital or get critical care to start adrenaline infusion
If a patient with anaphylaxis has a cardiac arrest, is it better to give IM adrenaline rather than wait until someone arrives who can obtain IV access and give IV adrenaline according to the ALS guidelines?
Once cardiac arrest occurs it is important to ensure expert help is coming and start CPR immediately. Good quality CPR with minimal interruption for other interventions improves the chances of survival from cardiac arrest. Once cardiac arrest has occurred, the absorption of adrenaline given by IM injection may not be reliable, therefore IM adrenaline is not likely to beneficial. Attempts to give IM adrenaline may also interrupt CPR. Advanced life support according to current guidelines should start as soon as possible.
What is refractory anaphylaxis?
No improvement in respiratory or cardiovascular symptoms despite 2 appropriate doses of IM adrenaline
According to SWAST guidelines, normal capnography reading during ROSC is ….
4.0 - 5.7 kPa
What ETCO2 reading could indicate a PE?
<1.7 kPa
Hyperkalaemia in CA:
- Consider hyperkalaemia or hypokalaemia in all patients with an arrythmia or CA
- Hyperkalaemia is the most common electrolyte disorder to cause CA
- Acute Hyperkalaemia is most likely to cause life-threatening cardiac arrythmias or CA
- Caused by increase in potassium release from cells or impaired excretions by the kidneys
- Main causes are renal failure and drugs, rhabdomyolisis, DKA or addison’s disorder
What normal BP would you like to see in ROSC?
> 90 systolic or a MAP of >65
What SpO2 reading would you like to see in ROSC?
Between 94% - 98%