Cardiac Arrest Flashcards
What type of rhythms do most in hospital cardiac arrests have?
Non shockable.
What are the most common antecedents to cardiac arrest?
Hypoxia and hypotension.
What requirements must a doctor fulfil when managing cardiac arrest?
Early recognition of abnormal physiology.
Identifying at risk patients.
Must identify when proper resus is appropriate e.g. DNAR.
What is the ideal time frame for initiating defibrillation?
Within 3 mins.
What facets of physiology are most cardiac arrests associated with?
Airway, breathing and circulation.
What are the 6 main factors involved in oxygen delivery that can go wrong and cause cardiac arrest?
Oxygen saturation. Hb. HR. Preload. Contractility afterload.
What is the gold standard for measuring oxygen saturation?
Arterial blood gasses.
What blood test gives us HB amounts?
FBC, ABG and hemocue.
What is a blood reassure change always due to?
Changes in HR, preload, contractility, afterload change. E.g. TPR.
How can we improve SaO2?
FiO2, clear airway and ensure adequate breathing.
How can we ensure appropriate HB levels?
Set a transfusion trigger, treat anaemia, group and save, cross match, get IV access.
How can we help BP through preload?
IV fluids and raise the legs.
How can we help BP through contractility?
Treat the cause e.g. PCI for MI.
How can we help BP through afterload?
For excess afterload, use vasodilators.
If reduced afterload then use vasoconstrictors e.g. In septic shock.
What must we reassess ABCDE?
Whenever the patients condition changes.
After an intervention is made.
Periodically when looking after a patient.
What are the steps when approaching an in hospital critically ill patient?
Personal safety. Check responsiveness. Vital signs. Get help. Assess Treat
How can we recognise an airway obstruction?
Dyspnoea, unable to speak, distress, choking, SOB, noises, use of accessory muscles and see saw breathing.
How can we treat airway obstruction?
Airway manoeuvres.
Adjuncts.
Intubation.
FiO2.
How can we assess breathing?
Look - for accessory muscles, Cyanosis. Respiratory rate. Consciousness level. Chest deformity.
Listen - noisy breathing and breath sounds.
Feel - expansion, percussion and tracheal position.
How do we treat breathing problems?
Oxygen, open airway, treat underlying cause and support breathing e.g. Bag and mask.
What is a fissuring plaque?
Lipid rich stable eccentric plaque causing luminal obstruction.
How do we assess circulatory issues in relation to cardiac arrest?
Look at the patient.
Vital signs.
Cap refill time, peripheral colour and temp.
Organ perfusion - chest pain, mental state, urine output etc.
Blood and fluid losses.
How do we treat circulatory problems in the critically ill patient?
Airway, breathing, O2, IV access, bloods, fluid challenge, haemorrhagic monitoring, into ropes or vasopressors, O2, aspirin, GTN, analgesia etc.
What two ways can we assess disability in patients?
AVPU or GCS. And always blood glucose!!!
What must we be mindful of during exposure of the critically ill patient?
Heat loss and dignity.
How do we manage an out of hospital critically ill patient initially?
Personal safety, responsiveness, help, check airway and look, listen, feel for vitals. Start management.
What four group can initial assessment of a critically ill patient lead to and how do we manage them?
1 - responsive - leave and get help.
2 - breathing but unconscious - recovery position and help.
3 - not breathing - respiratory arrest- help and ventilation.
4 - no pulse - cardiac arrest - help/CPR.
How do clinically diagnose a cardiac arrest?
Unresponsive and not breathing properly e.g. Agonal breaths.
How long do we assess breathing for in the unconscious patient?
No more than 10 seconds.
What should we do if we doubt an unconscious patients breathing is normal?
Take it as being not normal. For and ask for AED. Get help.
How many chest compressions should we do in CPR, what depth do we use and what speed?
30 for 2 breaths. 5-6 cms. 100-120 bpm.
How long should we blow into a victims mouth during CPR?
1 second.
How long maximum should the 2 rescue breaths take?
No more than 5 seconds.
Where should chest compressions be done?
Middle of lower half of sternum in the centre of the chest.
What are the two shockable rhythms?
VF and VT.
What two rhythms are not shockable?
Asystole and PEA.
What must we make sure we exclude from ECG tracings before we diagnose VF?
Artifacts from muscle movement etc.
What does a VF wave look like?
Bizarre, irregular waveform. No recognisable QRS complexes. Random frequency and amplitude. Uncoordinated electrical activity.
What two types of VF wave do we get?
Coarse and fine.
What does a ventricular tachycardia rhythm look like?
Monomorphic VT - Broad complex rhythm, rapid rate and constant QRS morphology.
Polymorphic VT - torsade de pointes.
What does torsade de pointes look like?
QRS amplitude varies and the QRS complexes appear to twist around the baseline. Looks like a big squiggle then a small then repeat.
When should we use a precordial thump and what is its efficacy?
Only used if defib not available in a witnessed VF/VT arrest. De-emphasised now as it is rarely effective.
When should we apply AED pads during CPR?
While CPR is going on so we don’t interrupt it.
What are the steps in manual defibrillation?
Diagnose shockable rhythm from ECG. Select correct energy level. Charge paddles on patient. Shout - stand clear, O2 away! Visually check. Check monitor. Stand clear to CPR provider. Deliver shock Resume CPR immediately. Minimise pauses by planning and communicating actions.
How long do wait after delivering the first shock to do a second one?
2 mins.
What do we do after the third shock?
Maintain CPR and Give adrenaline 1mg IV then give this after alternate shocks.
When we check for signs of life after two mins of CPR and see organised electrical activity what do we do?
We check for signs of life and if there is return of spontaneous circulation, then start post resus care.
When we check for signs of life after two mins of CPR and there are no signs of resumption of life signs what do we do?
If no ROSC go to non VF/VT algorithm. If asystole go to non VF/VT algorithm.
What should we do if we see asystole on the monitors?
Check electrodes and give 1mg adrenaline IV as soon as possible and every 3-5 mins thereafter (every two cycles).
What is PEA?
Non shockable rhythm usually associated with an ECG output.
What should we do if we see PEA?
Exclude/treat reversible causes.
Adrenaline 1mg IV as soon as possible.
Every 3-5 mins 2 cycles thereafter.
What are the two drug mini jets we get?
Adrenaline 1mg.
Amiodarone 300mg.
What receptors does adrenaline work on?
Alpha vasoconstrictor and beta inotropic.
What are the possible causes of PEA?
4H's and T's. Hypoxia Hypovolaemia Hypo/hyperkaelaemia Hypothermia.
Thrombosis
Tamponade
Toxins
Tension pneumothorax.
What are the advantages and disadvantages of mouth to mask ventilation?
Avoids contact so decreases infection potential while allowing O2 enrichment.
Difficult to get an airtight seal and risk of gastric inflation.
What are the advantages and disadvantages of self inflating bag ventilation?
+ avoids contact, allows up to 85% O2 supplementation. Can be used with face masks, LMAs or tubes.
- risk of inadequate ventilation when used with a face mask. Risk of gastric inflation and needs two people for optimal use.
What are the advantages and disadvantages of supraglottic airway devices e.g. LMA?
+ Rapidly and easily inserted, variety of sizes, more efficient than face mask, avoids laryngoscopy.
- aspiration risk, not suitable for high ventilation pressures. Unable to aspirate airway.
When should we stop CPR?
When there is ROSC, it seems useless and if DNAR.
What are the four parts of post cardiac arrest syndrome?
- Post cardiac arrest brain injury.
- Post cardiac arrest myocardial dysfunction.
- Systemic ischaemia/reperfusion response.
- Persistent precipitating pathology.
What is the goal of post resus care?
To restore quality of life with normal cerebral perfusion/function. Normal other organ perfusion/function and stable cardiac rhythm.
What is the gold standard of airway management during an arrest?
ETT intubation.
What measures should we consider in patients with impaired cerebral function following a cardiac arrest?
Continued intubation, sedation and controlled ventilation.
Insert gastric tube to deflate stomach to improve lung compliance.
Secure the airway for transfer.
What examinations/investigations should we do for airway and breathing in a post cardiac arrest patient?
Inspection, palpating and percussion for pneumothorax, trauma, aspiration, pulmonary oedema etc.
CXR for all of above plus pneumoperitoneum, tracheal/gastric/chest drain placement.
ABG’s.
Capnography.
How should we optimise respiratory function post cardiac arrest?
Adjust fiO2 to achieve ideal SaO2/SpO2. Adjust minute volume to achieve ideal PaCO2/ETCO2. Alter pH Avoid excessive hyperventilation. Improve circulation to alter pH.
How do we look for signs of inadequate perfusion in post arrest patients?
Look for colouring, distended neck veins, urine volumes, pulmonary oedema, cap refill time.
What investigation should we do regarding circulation in post cardiac arrest patients?
FBC, U&Es, glucose, ABG's, LFTs. 12 lead. Standard ECG monitoring. CVP measurement. Echo.
What circulatory conditions should we monitor for post arrest?
Bp Systemic inflammatory response syndrome. Reperfusion injury. Arrhythmias Myocardial stunning.
What is myocardial stunning?
Section of the myocardium shows a contractile abnormality.
How steps can we take to improve circulation post arrest?
Fluids. Coronary reperfusion therapy. Inotropes. Diuretics and vasodilators. Maintain temperature if conscious, consider cooling if not.
What GCS score do we have if we get P or U on an AVPU?
8 or less.
What is the GCS range and what are we checking for?
3-15
Pupils, limb tone, movement and posture.
What are potential problems for optimising brain function post arrest?
Hyperaemia followed by hypoperfusion. No cerebral Autoregulation.
What is therapeutic hypothermia?
Unconscious adults after ROSC should be cooled to 32-34 deg asap and continued for 12-24 hours. Uses external or internal techniques.
What patients should we exclude from therapeutic hypothermia?
Severe sepsis and cardiogenic shock.
What are the complications of therapeutic hypothermia?
Infection, CVS instability, coagulopathy, hyperglycaemia and electrolyte imbalances.
When is the earliest we can predict a poor outcome following ROSC after arrest?
How do we predict this?
3 days. By absent pupil light reflexes and absent motor response to pain.
What type of rhythms do most out of hospital cardiac arrests have?
Shockable.
