Cardiopulmonary resuscitation (CPR) Flashcards
Cardio-pulmonary arrest (CPA)
Cessation of ventilation and systemic perfusion
low survival rate, higher if already under GA
Equipment needed on resuscitation trolly
Drugs
Saline flush
ET tubes
Laryngoscope
IV catheters
Tape
Fluid therapy
Basic life support
Initiate CPR immediately
Chest compressions (100-120/min)
Ventilation (10/min)
C:V ratio = 30:2
Advanced life support
Initiate monitoring
- ECG
- End Tidal CO2
Obtain vascular access
Administer reversals
Reversal drugs
Opioids: naloxone
Alpha-2 agonists: atipamezole
Benzodiazepines: Flumazenil
How to recognise a CPA event?
Unresponsive patient
Absence of breathing/abnormal breathing
Absence of palpable pulse
Change in heart rhythm
Recognising a CPA event on End-tidal CO2
Decreasing or flatlines
CPA event on ECG
Ventricular fibrilation - not coordinated so no CO
Ventricular tachycardia - no P wave, usually higher than 180bpm
Asystole - no electrical activity
Pulse-less electrical activity - no peripheral pulse but electrical activity at the heart
Chest compressions
100-120/min
Compress 1/3 to 1/2 width of the chest
Allow full chest recoil
Minimise interruptions and delays in starting compressions
Rotate person every 2 min cycle - check for pulse/evaluate ECG
Cardiac pump theory
Direct compression of heart
For small dogs, cats, and keel chested dogs
Thoracic pump theory
Chest compression on widest portion of chest
For barrel chested dogs, and round chested dogs
Securing the airways
Remove any obstructions by suction or removal
Intubate
Ventilation
10 breaths/min
Before/without intubation - mouth to snout
Inspiratory time 1sec
Look at chest excursions
O2 100%
Avoid hyperventilation -> cerebral vasoconstriction
If high positive pressure administered -> decreased venous return and CO
Vascular access
IV - catheter, ideally cranial to heart
Intraosseus - often needed in puppies and kittens
Intratracheal (dilute and increase dose) - drug absorbed by tracheal mucosa
Drug therapy
Reversal agents
Vasopressors (epinephrine, vasopressin)
Anticholinergic (atropine)
Anti-arrhythmic (lidocaine, amiodarone)
Epinephrine/adrenaline
Low dose: 0.01mg/kg IV/IO every other cycle of CPR
High dose: 0.1 mg/kg IV/IO (long CPR)
Vasoconstriction and increased contractility
Less effective in acidotic environment
Cheap
Vasopressin
Not widely used in veterinary
0.8 U/kg IV/IO
Vasoconstriction, no ionotropic or chronotropic effects
Effective in acidotic environment
Expensive
Atropine
Anticholinergic - inhibits PS system
0.04 mg/kg IV/IO every other BLS cycle
Rapid onset of action
Increases HR and contractility
Can be alternated with adrenaline in cases of asystole of AV blocks
Amiodarone
Class III anti-arrhythmic, also with class I, II, and IV effects
For refractory Ventricular Fibrillation/ Pulseless Ventricular Tachycardia
Risk of anaphylactic reactions and hypotension
Lidocaine
Class I anti-arrhythmia, Na+ channels
For refractory Ventricular fibrillation/pulseless Ventricular Tachycardia (if amiodarone is not available)
Much cheaper
When is defibrillation possible?
Ventricular fibrillation
Pulseless ventricular tachycardia
When is defibrillation not possible?
Asystole
Pulseless electrical activity
How to carry out defibrillation
Dorsal recumbency: paddles placed on opposite sides of the chest
Conductive gel on both paddles (not US gel!!)
‘Check for clear’
Defibrillation
Monophasic or biphasic depending on direction of currect accross the myocardium
Newer defibrillators are usually biphasic
Joules provided by Biphasic defibrillation
2-4 J/kg
Joules provided by monophasic defibrillation
4-6 J/kg
Phases of ischaemia in CPA
Electrical phase - first 4 mins: minimal ischaemic damage - energy stores available - shock immediately
Circulatory phase - 4-10 mins: reversible ischaemic damage - ATP depletion - Shock after a full CPR cycle
Metabolic phase - >10 mins: irreversible ischaemic damage - shock after full CPR cycle
When to consider open chest CPR
CPA occurs intraoperatively
External compression might not be effective (pneumothorax, cardiac tampenade, diaphagmatic hernia)
XXL dogs
Acid/base and electrolytes therapy
Evaluation of blood gas analysis, electrolytes, glucose
Metabolic acidosis treated with SODIUM BICARBONATE
Hyperkalaemia
Hypokalaemia
Glucose administration is not recommended unless hypoglycaemic
Treatment of metabolic acidosis
Recommended if pH<7
Sodium bicarbonate 1mEq/kg dilutes IV over 15 mins
Normal end tidal CO2 values
35-45 mmHg
Return of spontaneous circulation (ROSC)
Respiratory rate and effort (should normalise - no gasping, agonal breathing etc.)
ECG (heart rate and rhythm)
Palpable pulse and blood pressure measurement
MM come back to normal
Pupil size and responsiveness, and other reflexes
Post CPR care
Re-arrest common monitoring is essential
Maintain perfusion and O2 supply to organs
Ventilation + O2 supplementation if required
Vasopressors, positive inotropes to maintain blood pressure and HR
Fluid therapy if haemorrhage/hypovolaemia
Avoid hyperthermia, slight hypothermia is better
Consider analgesia, but beware of side effects
