CPR - Advanced Life Support Flashcards
What are the next steps in the CPR algorithm after basic life support?
- Monitoring
- Obtaining vascular access
- Administer reversals
When do you start advanced life support?
After the first 2 minutes of basic life support
What is involved in monitoring?
Electrocardiography gram - ECG
Capnography
Clinical changes
What does capnography tell you?
End tidal CO2 (ETCO2)
Most useful tool for monitoring
Measure perfusion
○ Movement of carbon dioxide from the tissues to the lungs
○ i.e. measures movement of blood
>15-20mmHg = Good compressions
What does ECG tell you?
Heart rate/rhythm
Does NOT tell you about perfusion/cardiac output
Can assess if it is shockable rhythm or not (use defibrillator?)
* Ventricular Fibrillation
* Pulseless Ventricular Tachycardia
What clinical changes can you assess?
- Pulses – difficult to palpate
- Mucous membrane colour
- Eye position changes
○ central -> ventromedial - Pupil changes size
- Palpebral, corneal, gag reflex may be noticed
- Breathing or chest movements (twitches) resume
- Lacrimation
- Animal regains consciousness
How can you establish vascular access?
Intravascular (IV)
Intraosseous (IO)
Intratracheal (IT)
What are the options for IV route?
Cephalic
Saphenous
Jugular
Central so doesn’t need flushing
Dirty procedure - risk of infection
Pros and Cons of using IV route
Ideal route of choice for drugs and fluids
Tricky during CPR because of movement
Jugular venous cannula is ideal for administration but risk of thrombophlebitis
Other veins not as effective but can ‘flush’ drug centrally
Pros and cons of intraosseous route
As rapid as using peripheral veins
Would need to use drill in adult patients
Not common in first opinion practice
Useful in small animals and birds
Methods of intraosseous route
Greater tubercle of humerus
Tibial crest or trochanteric fossa of femur
Pros and cons of intratracheal route
Chest inflations will distribute drugs
Higher doses needed
Dilute and use urinary catheter inserted beyond carina
Reversals/Antagonists examples
Atipamezole
Naloxone
Flumazenil
Atipamezole use
Reverses Alpha-2 agonists (medetomidine)
Naloxone use
Reverses opioids (methadone)
Flumazenil use
Reverses Benzodiazepines (midazolam)
When is it appropriate to administer a reversal agent?
After checking patient hospital drug records
Making sure you know why the patient is in
Make sure you know which drugs have been given
When should you check the ECG?
AFTER the first compression cycle (2 mins)
Not possible to asses during compressions
What does ventricular Fibrillation/Pulseless Ventricular Tachycardia mean?
Patient will be less responsive to basic life support (CPR)
Need to convert them
Defibrillator - need training, can be dangerous
Pre-cordial thump - need training
Medical conversion
Amiodarone/lidocaine
Carry on with basic life support after conversion
What is asystole?
Flatline
No electrical or mechanical activity
What is Pulseless Electrical Activity (PEA)
Can look normal on ECG
Electrical activity but no mechanical activity
More responsive to CPR than ventricular fibrillation
Can use drug therapy to augment
Drug therapy examples
Adrenaline/epinephrine
Vasopressin/ADH
Atropine
Adrenaline Use
Adrenergic agonist (a and b receptors)
Directs blood flow to heart by causing constriction of peripheral vessels and dilation of central ones
Positive inotrope - increases contraction of heart (increases CO)
Positive chronotrope - Increases heart rate
Pros and cons of using adrenaline
‘shunts’ blood to heart from periphery
Increases myocardial oxygen demand
Low dose is recommended to reduce this
Vasopressin/ADH use
Causes peripheral vasoconstriction - increasing blood pressure
Pros and cons of vasopressin/ADH
Does not have deleterious effects on myocardial oxygen demand
Similar efficacy to adrenaline - no better
Expensive
Atropine use
Inhibits the muscarinic actions of acetylcholine
(parasympatholytic - preventing parasympathetic innervation)
Removes suppression rather than stimulating
Pros and cons of atropine
Parasympatholytic - different action to adrenaline
Evidence doesn’t show clear benefit
Theoretically good for patients with high vagal tone
Not recommended in rabbits (due to atropinase)
Controversies examples
High dose adrenaline
Fluid therapy
Bicarbonate
Open-chest CPR
Controversies examples
High dose adrenaline
Fluid therapy
Bicarbonate
Open-chest CPR
Why is high dose adrenaline controversial?
Increased myocardial oxygen demand
Increased rate of ROSC
No increased survival rates
Can be considered in prolonged arrest (>10 minutes)
What is ROSC and how can you assess it?
Return of Spontaneous Circulation
Use capnography - sudden increase in ETCO2
Use ECG - return of normal rhythm (careful could be PEA)
Return of consciousness/movement/refexes
Why is fluid therapy controversial?
Administration to euvolemic patients is associated with reduced coronary perfusion
(can make them hypovolaemic)
ONLY consider in patients with KNOWN hypovolaemia
Why is bicarbonate controversial?
Basic - used to alkalise blood
Metabolic acidosis is a common occurrence in CPA
Mixed results in experimental studies
Only consider when prolonged CPA
Why is open-chat CPR controversial?
More effective than external compressions BUT
requires significant resources during and in recovery
Can be considered for intra-thoracic pathology
Post-ROSC care
Many patients re-arrest so keep going until fully conscious
Provide respiratory and cardiovascular optimisation
Prevent hypothermia
How do you provide respiratory optimisation?
○ Supportive oxygen +/- ventilation if required
○ Target PaO2 80-100mmHg or SpO2 94-98%
○ Beware hyperoxia and oxidative damage with reperfusion
How do you provide cardiovascular optimisation?
If hypotensive
Beware fluid overload, so use of vasopressor therapy is sensible
How do you prevent hypothermia
Re-warm slowly
Cover extremities
Use heat pads
