CPR - Advanced Life Support Flashcards
What are the components of advanced life support?
- Monitoring
- Obtain Vascular Access
- Administer Reversals
What are the different methods of monitoring in CPR?
Capnography - EtCO2
ECG
SPO2%
Blood gas analysis (movement error)
Blood pressure (movement error)
What is the most important method of monitoring in CPR?
Capnography - EtCO2
Measures perfusion - movement of CO2 from tissues to lungs
>18mmHg = good compressions
Big jump in mmHg = heart is pumping blood
What clinical changes should you be monitoring during CPR?
Pulses – but difficult to palpate!
Mucous membrane colour
Eye position changes
Pupil changes size
Palpebral, corneal, gag reflex may be noticed
Breathing or chest movements (twitches) resume
Lacrimation (production of tears)
Animal regains consciousness
What does the ECG tell you during CPR?
The heart rhythm - whether the animal is shockable or not
What are the different routes of vascular access during CPR?
IV - Cephalic, saphenous or jugular
Intraosseous
Intratracheal
Describe IV vascular access in CPR
Route of choice for drugs & fluids
Tricky during CPCR because of the movement
Jugular venous canula is ideal for administration but risk of thrombophlebitis, other veins not as effective but you can ‘flush’ the drug centrally
Describe intraosseous vascular access in CPR
As rapid as peripheral veins
Useful in small animals, very collapsed animals and birds
Sites used include the greater tubercle of the humerus, tibial crest or trochanteric fossa of the femur
In neonates can be achieved with a needle, however, in older patients with a mature cortex, a drill is often needed.
Describe intratracheal vascular access in CPR
Dilute and use urinary catheter inserted beyond carina
Chest inflations will distribute the drugs
Higher doses are needed
Which drug is the antagonist of alpha-2-agonists (e.g., medetomidine)?
atipamezole
Which drug is the antagonist of opioids (e.g., methadone)
naloxone
Which drug is the antagonist of benzodiazepines (e.g., midazolam)?
flumazenil
What is this? is it shockable?
Ventricular Fibrillation - Yes it is shockable
What are the options for trying to convert ventricular fibrillation and pulseless ventricular tachycardia into asystole or PEA?
Defibrillation
Pre-cordial thump
Medical conversion:
- Sodium channel blocker – lidocaine
- Potassium channel blocker – amiodarone
- Beta blocker - esmolol
Why do we want to convert a VF or pulseless VT into asystole or PEA?
Animals in VF or pulseless VT are more likely to die that asystole and PEA
An animal has no palpable pulse, and a rate lower that 200bpm. What is happening and is it shockable?
PEA
Not shockable
An animal has no palpable pulse, and a rate greater that 200bpm. What is happening and is it shockable?
Pulseless ventricular tachycardia - shockable
An animal has no palpable pulse, and the ECG shows a flatline. What is happening and is it shockable?
asystole - not shockable
An animal has no palpable pulse, and the ECG does not show a flatline. What is happening and is it shockable?
Ventricular fibrillation - shockable
What is PEA?
Pulseless electrical activity - can look normal on ECG
What drugs can be given to an asystolic or PEA patient?
Adrenaline/epinephrine
Vasopressin
Atropine
Others (less common) - Fluid therapy, Bicarbonate, Calcium, glucocorticoids
Describe the use of adrenaline/epinephrine on an asystolic or PEA patient
Adrenergic agonist – α and β receptors.
Increases myocardial oxygen demand.
α adrenergic effects include peripheral vasoconstriction (vasopressor) - ‘Shunts’ blood from the periphery to the heart, brain and lungs.
Low dose adrenaline is recommended (0.01mg/kg)
Given every 3-5 minutes i.e. every other 2-minute cycle
Pro-arrythmic so avoid initially in VFib/VTach.
Describe the use of vasopressin in asystolic or PEA patients
Causes peripheral vasoconstriction without deleterious effects on myocardial oxygen demand
Therefore, may be preferable to adrenaline in VFib/VTach
Adrenaline preferable as vasopressin is more expensive
Describe the use of atropine in asystolic or PEA patients
Parasympatholytic/vagolytic (breaks down vagal tone)
Theoretically good for patients with high vagal tone – common in veterinary patients (esp. cats)
Rabbits can have atropinase as a naturally occurring enzyme so not recommended.
One off dose
Describe the use of fluid therapy in CPR
Only considered in patients with known hypovolaemia
Describe the use of bicarbonate in CPR
Metabolic acidosis is a common occurrence in CPA (lots of lactate produced)
considered only in prolonged CPA
Suggested for administration in known hyperkalaemia
Describe the use of Ca (calcium gluconate/chloride) in CPR
Recommended for use in patients with known or suspected hyperkalaemia
Suggested for use in patients with known hypocalcaemia
Describe the use of glucocorticoids in CPR
Not recommended in CPR – may worsen perfusion e.g. cerebral perfusion
What is ROSC?
Return of Spontaneous Circulation
What are the signs of ROSC?
Capnography – sudden increases in ETCO2 are associated with ROSC
ECG – Return of a normal rhythm is not necessarily supportive – PEA
Return of consciousness/movement/reflexes
Describe post-ROSC care
Many patients re-arrest
Respiratory optimisation:
- Supportive oxygen +/- ventilation if required
- Target PaO2 80-100mmHg or SpO2 94-98%
- Beware hyperoxia and oxidative damage with reperfusion
Cardiovascular optimisation:
- If hypotensive – beware fluid overload, so use of vasopressor therapy is sensible
Hypothermia:
- Can be beneficial to cardiac and neurologic outcomes – re-warm slowly 0.5oC/h
