CPR Flashcards
What do the RECOVER guidelines cover?
All important factors to be considered when carrying out CPR, such as:
How to assess the patient
How to perform effective CPR
How to communicate effectively
How to identify ROSC
How often do RECOVER recommend CPR drills to be carried out?
Every 3-6 months or whenever a new team member joins
As per the VMD, what is not allowed in a crash box?
Pre-drawn drugs
Controlled drugs
What are the 6 H’s that can predispose a patient to CPA?
Hypovolaemia
Hypoxia
Hydrogen ions (acidosis)
Hypokalaemia/Hyperkalaemia
Hypothermia
Hypoglycaemia
What are the 5 T’s that can predispose a patient to CPA?
Tamponade (cardiac)
Toxins
Trauma
Tension pneumothorax
Thrombosis
Name some warning signs of impending CPA
Change in heart rate or rhythm i.e. bradycardia
Decreasing responsiveness
Weakening pulses
Abnormal breathing patterns such as Cheyne-Stokes respiration
Regardless of the situation or staffing levels, what is the main priority for a patient with CPA?
Prompt re-establishment of a circulation through chest compressions
What are the three steps if there is suspected cardiac or respiratory arrest whilst the patient is under anaesthesia?
Call for assistance
Note time
Turn off anaesthetic agent
How does patient size affect where CPR takes place?
Small patients, if feasible, can be transported to the ‘arrest station’ as CPR effort continues
Large/anaesthatised patients should have CPR completed where they are, with any necessary people/equipment brought to them
In a large practice, name examples of places where crash boxes should be stored
Theatre
Prep
Kennels
In accordance with the CPR initial assessment algorithm, if a patient is found collapsed in a kennel, what should be done to determine if CPR is necessary?
Call for help
Stimulate patient vigorously (shake and shout)
If not response, determine if patient is breathing
If a patient is apnoeic and only one rescuer is available to initiate BLS, what should they do?
Evaluate patients airways, ensure is clear of obvious obstructions
Do not delay compressions
Why is it inadvisable to assess femoral pulse if CPA is suspected? and what should the rescuer do?
Can be unreliable and wastes time
If CPA suspected, patient not breathing and airway is clear then CPR should be started
At what ratio should compressions to ventilation be for a single-rescuer BLS?
30 compressions : 2 breaths
During single rescuer BLS, when would the cycle of 30:2 be ended?
Additional rescuers arrive
ROSC
Resuscitation efforts terminated
If CPA is suspected, and the patient is not intubated, how should ventilation be provided?
Tight fitting mask with oxygen if available
What would be considered a risk to a rescuer when completed mouth-to-nose ventilation?
Zoonotic disease
Narcotic overdose
What should be done if mouth-to-nose ventilation is the only option during CPA and there is a present risk to the rescuer?
Only chest compressions should be performed, no ventilation
In what position should the patients head and neck be when providing rescue breath? and why?
With patients head and neck in alignment with the spine to avoid obstructing the airway
If an obvious upper airway obstruction is identified and cannot be removed, what other method can be used to establish an airway?
Tracheostomy
If intubated, how many breaths should a patient be given during CPR every minute?
10 per minute i.e. 1 breath delivered every 6 second
How long should inspiration and expiration last during CPR ventilation?
Inspiration - 1 second
Expiration - 5 seconds
Who is often the CPR leader and why?
The Veterinary Surgeon due to the need to prescribe drugs throughout the arrest period
Name 5 roles that can be assigned during multi-rescuer CPR
Leader
Compressor
Ventilator
Assistant
Scribe
Describe the role of the compressor
Deliver uninterrupted high-quality chest compressions for two minutes
This is a rotating role with compressors swapping every two minutes to avoid fatigue and delivery of poor quality compressions
Describe the role of the ventilator
Responsible for initially managing the patient’s airway (ensuring airway clear and placing ETT)
May also be responsible for attaching capnograph is not already completed by assistant
Describe the role of the assistant during CPR
Attaching monitoring equipment (ECG/capnograph)
Securing IV access
Drawing up/administering drugs
Preparing defibrillator if needed
Describe the role of scribe during CPR
Timing the arrest
Record when and what drugs +/- defibrillation dose is administered
Alert the team at end of 2-minute cycles
Describe closed-loop communication
Message (instruction or information) is sent (often by leader) to the whole team or individual. Individuals receiving message repeat it back to ensure message has been understood. The sender then confirms they have heard the repeated message which then completes the loop
Explain why closed-loop communication is recommended during the arrest period
To ensure effective team communication
Ensures everyone is clear on what is required and helping to avoid mistakes i.e. drug doses
What is the main priority if a patient developed RA but CA has not yet developed?
Airway management and ventilation
Describe cardiac pump theory
Direct external compression of the ventricles results in forward blood flow
Describe the thoracic pump theory
Changes in intrathoracic pressure during compressions generate blood flow i..e external chest compressions over the widest part of the thorax lead to increased overall intrathoracic pressure which forces blood from the thoracic vessels into the circulation
What is the recommended compression rate during CPR?
100-120/minute
By how much is the stroke volume reduced during CPR in comparison to the normal heartbeat?
20%
Why do compressions need to performed at a higher rate than a patients normal heart rate?
Due to a 20% reduction in stroke volume
Why would a rate exceeding 120 compressions/minute not be beneficial during CPR?
Reduces effectiveness of compressions
It would prevent full recoil of the thorax leading to decreased cardiac filling and therefore a reduced stroke volume
Why should a fatigued compressor be changed, even if a 2 minute cycle has not been completed?
The compressions could be ineffective despite an adequate rate
What happens to the stroke volume if compressions are stopped?
Drops to almost zero
What is the maximum time that a compression pause should last for?
10 seconds
Describe how ECG evaluation should be carried out, considering the short compression pause
The ECG should be viewed during the pause, each member shouts their interpretation and then it is discussed during the next cycle of compressions
Describe the necessary form of the compressor during medium-giant breed CPR
Should lock elbows in extension and their wrists through flexion
Shoulders should be positioned vertically
Abdominal core muscles should be used to perform compressions whilst keeping elbows locked
Describe the method of providing compressions to medium-giant breed keel chested dogs
Heels of compressors hands should overlap, with heel of hand in contact with the chest over the compression point
Fingers may be interlaced or held together but should NOT fan out across the thorax
The compression point is directly over the dog’s heart
Cardiac pump theory
Where is a dog’s heart located in lateral recumbency?
Humerus is rotated caudally so that caudal point of elbow lies approximately one-third of the distance between the sternum and the spine
The heart lies under the point of the elbow in this position
Describe the method of providing compressions in round-chested medium to giant breed dogs
Compressors overlapping hands should be placed with heels over the widest part of the thorax
Thoracic pump theory
Describe the method of providing compressions in barrel-chested medium to giant breed dogs
If the patient is stable in dorsal recumbency, the compressors overlapping hands should be placed with the heels over the mid-sternum
Describe the circumferential method of providing chest compressions to cats and small dogs
two-thumb technique compresses the heart between the thumbs and the opposing flat fingers of the ipsilateral hands
Describe the one-handed technique of providing chest compressions to a cats and small dogs
Compress the heart between thumb and flat fingers of the dominant hand which is wrapped around he sternal portion of the thorax whilst the non-dominant hand braces the dorsal thorax
Describe the one-handed heel technique of providing chest compressions to cats and small dogs
Compresses the heart under the heel of the dominant hand while the non-dominant hand braces the dorsal thorax
What is the correct compression depth is a patient is in lateral recumbency?
1/3 to 1/2 the width of the thorax at the compression point
What is the correct compression depth if the patient is in dorsal recumbency?
1/4 of the thoracic depth at the compression point
What should not be delayed when attempting to intubate?
Compressions
Why should suction apparatus be kept at the arrest station?
Fluid from airways may need to be suctioned if obscuring visualisation of the larynx
If a patient has narrow airways, what can be utilised as a guidewire/stylet?
Urinary catheter
How can you confirm correct ETT placement?
Direct visualisation
Capnography
The ETT is likely to be placed properly if the EtCO2 is over…
12mmHg
What is the minimum EtCO2 necessary to confirm high quality compressions?
> 18mmHg
What peak airway pressure should be applied during chest compressions?
30-40cm H20
What should the peak airway pressure be between pauses of compression cycles?
Less than 20cm H20
How can you assess ventilation quality (visually)?
Each breath should result in a visible but not excessive chest rise when evaluated during the ‘pause and check’
What tidal volume should you aim to ventilate for?
10ml/kg
What is the maximum inspiratory pressure that should be applied and when can this not be measured?
15cm H20
Not during manual ventilation
Why should over vigorous ventilation be avoided during CPR?
It causes decreased cardiac filling/output and can damage the pulmonary parenchyma through barotrauma
What does ALS include?
ALS monitoring
Securing IV access
Administration of reversal agents
What is the correct order of the ALS monitoring steps?
Attach ECG
Start waveform capnography
Vascular access
Reversal agents (if required)
What should be considered if IV access cannot be obtained and when should it be considered?
IO if suitable, after two minutes of attempting to gain IV access
IV access can still be attempted whilst IO is being placed
Intratracheal can also be used if vascular access not possible
Why is ECG beneficial during CPR?
Allows identification of the arrest rhythm during the pause and check
When should surgical spirit be avoided when attempting to get good contact for ECG clips/pads?
If defibrillation is a possibility
Why is it not advisable to assess ECG rhythm during compressions?
Due to movement, trace will look similar to ventricular fibrillation
What two checks should be performed during each ‘pause and check’?
Palpation for a femoral pulse
ECG check
What is advisable when assessing femoral pulse during the ‘pause and check’?
Individual assessing pulse should be in place and start to palpate shortly before the ‘pause and check’
What should be done once the ECG has been viewed during the ‘pause and check’?
Chest compressions started with new compressor within 10 seconds
Each team member states aloud their interpretation
The team can then discuss, during compressions, which pathway of the CPR algorithm to follow
What are the two pathways of the CPR algorithm?
Left - Shockable
Right - non-shockable
Describe asystole
Flat line
Non-shockable rhythm
Describe Pulseless Electrical Activity
Looks like regular ECG but >200bpm
No palpable pulses
Non-shockable rhythm
Describe ventricular fibrilattion
Disorganised cardiac electrical activity
Fine and coarse chaotic deflections with no p waves
Shockable rhythm
Describe pulseless ventricular tachycardia
Rapid, tall/wide, bizarre complexes with no p waves
Shockable rhythm
If ROSC is suspected, what should be assessed to confirm?
Patient responsiveness
Palpable pulse
Significant increase in EtCO2 >35mmHg
How can you differentiate between ventricular tachycardia and pulseless ventricular tachycardia?
VT is likely to have a HR <200bpm, where as PVT is likely >200bpm
What is the physiological difference between ventricular tachycardia and pulseless ventricular tachycardia?
VT is still serious but patient will have some blood circulating and likely to be rousable - May require anti-arrhythmic medication
PVT has no cardiac output due to decreased cardiac filling, leading to no circulating and the patient requiring BLS + defibrillation
What is the initial dose for a biphasic defibrillator?
2J/kg
What is the initial dose for a monophasic defibrillator?
4J/kg
Describe a refractory shock rhythm?
Where VF or PVT persists after a full cycle of compressions and defibrillation
What are the next steps once a refractory shock rhythm has been identified?
Compressions resume within 10 seconds
Initial defibrillation dose is doubled
Compressions start again without an ECG check
Over how long should antiarrhythmic drugs be administered?
2-4 minutes
If CPR is prolonged (>15 minutes), what else can be considered?
IV/IO sodium bicarbonate
Especially if blood pH is <7.0
If a refractory rhythm persists after a double dosage, what are the next advisable steps?
Two further shocks but dose should NOT be increased further
What does an EtCO2 below 18mmHG indicate?
Technique needs to be reviewed
How should the CPR technique be reviewed if the EtCO2 remains below 18mmHg?
Are compressions at appropriate rate (100-120bpm) and appropriate depth?
Is the compressor fatigued? Do they need to be changed?
Should an alternative technique be tried? I.e. thoracic pump instead of direct cardiac compressions
Are too many IPPB breaths being delivered?
Is there an underlying issue affecting perfusion of the lungs? i.e. pneumo/haemothorax, pulmonary parenchymal damage?
What should be done after administering IV medication during CPR and why?
Catheter fluids with isotonic fluid
Ensures the drug reaches central circulation
In which type of patients would an IO catheter be considered?
Neonates
Small animals
Exotic species
In which bones may an IO catheter be placed?
Femur
Humerus
Wing of the ilium
Tibial tuberosity
Why might IO placement in an adult dog/cat be difficult?
May take longer as need a drill due to bone density
Which drugs can be administered intratracheally?
Epinephrine
Vasopressin
Atropine
What should be done if drugs are administered intratracheally?
Diluted in saline first
Administered through catheter that is longer than the endotracheal tube
Why are intracardiac injections not advisable when administering medications during CPR?
Potential myocardial damage
What is the aim of vasopressor therapy?
Promote peripheral vasoconstriction
Increase cerebral and coronary perfusion during CPR
What is the standard dosing for epinephrine?
0.01mg/kg every 3-5 minutes (i.e. alternate BLS cycles)
Why is high dose (0.1mg/kg) epinephrine no longer recommended?
Whilst improves chances of ROSC, it worsens patient survival or neurological outcome in comparison to standard dose epinephrine
When should vasopressors be administered for a shockable rhythm?
If the rhythm persists beyond the first shock (refractory)
When and why would atropine be administered during CPR?
With a non-shockable rhythm where the belief is that high vagal tone may be contributing to CPA
It should NOT be repeated
Which patients would IV lidocaine be suitable for?
Dogs with refractory PVT or VF
NOT CATS
What bloods should be monitored during CPR and which medication should be administered if indicated by the bloods?
Plasma potassium and ionised calcium
Calcium gluconate if hypocalcaemic or hyperkalaemic
Define epinephrine
Catecholamine which is a non-specific adrenergic agonist
Why would epinephrine be used as a vasopressor?
Due to its a-1 adrenergic effects, to cause peripheral vasoconstriction and promote greater blood delivery to vital structures i.e. heart and brain
How might epinephrine be harmful to CPR and why?
It’s additional b-1 adrenergic activity (positive inotrope and chronotrope)
Increases myocardial oxygen demands and can exacerbate myocardial ischaemia
Predisposes to arrhythmias once ROSC is achieved
Define inotrope and chronotrope
Increase force of contraction
Increase rate of contraction
Define vasopression
Antidiuretic hormone
Why is vasopressin used as a vasopressor?
At higher doses, acts on peripheral V1 receptors present on vascular smooth muscle to cause peripheral vasoconstriction
Why might vasopressin be used as an alternative to epinephrine?
Different mode of action
No inotropic or chronotropic effects so unlikely to worsen myocardial ischaemia
Still active in an acidic pH - consideration where cells undergoing anaerobic respiration and producing lactic acid
Describe atropine and its uses
Anticholinergic/vagolytic
Has parasympathetic effects
Often administered for bradycardia resulting from high vagal tone
Name anti-arrhythmic drugs and state when they would be used
Lidocaine (dogs)
Amiodarone (cats)
Esmolol
Ventricular arrhythmias - shockable rhythm which has not responded to an initial defibrillation
What should be done regarding the anaesthetic agents if a CPA is suspected under anaesthesia?
Anaesthetic agents turned off immediately
System disconnected from patient and flushed with 100% oxygen
Why should the anaesthetic system be disconnected from the patient prior to flushing?
Flushing causes high pressures which can lead to increased airway pressures and barotrauma
What reversal agents may be administered?
Naloxone - for opiates
Flumazenil - for benzodiazepines
Atipamezole - for alpha-2 agonists
What fluid boluses should be administered to a patient during CPR if hypovolaemia is suspected?
isotonic crystalloid
20ml/kg - dog
10-15ml/kg cat
Why should IV fluids not be administered during CPR if a patient is euvolaemic or hypervolaemic?
May reduce myocardial blood flow or cause other complications such as pulmonary oedema
What is the aim of defibrillation?
Reset cardiac conduction system
Return normal cardiac rhythm by temporarily stopping hearts electrical activity
What should be turned off/removed if defibrillation is to be attempted?
Oxygen
Anything that could potentially conduct electricity i.e. dog collar
Describe the process of administering defibrillation
Charge appropriately
Pads covered with conductive electrode gel and applied to either side of the patients thorax over the area of the heart
All team members step away from table and associated equipment
Operator shouts clear and confirms no team member in contact with patient, table or any associated equipment
Shock dose administered
Without evaluating ECG rhythm, new compressor begins 2 minute cycle
What can be used as an alternative if a defibrillator is not available?
A single precordial thump
Give examples of monitoring during ROSC
ECG
BP
Pulse oximetry
Serial lactate, creatinine and blood glucose
Why are serial creatinine measurements taken once ROSC has occured?
To identify and rapidly treatment any acute kidney injury
