Cardiac arrest Flashcards
What is the definition of cardiopulmonary arrest?
Cessation of cardiac function with the pt displaying no pulse, no breathing, and unresponsiveness
What are the possible primary causes of CA?
AMI/IHD/CHF
Cardiomyopathy
Pericarditis
Valvular stenosis
What are the possible secondary causes of CA?
Acute asthma Tension pneumothorax Drug OD Drowning Trauma Electrolyte imbalance Anaphylaxis Electrocution
List the steps in the chain of survival
Early intervention Access CPR Defibrillation ACLS Post-resus care
What is the compression to breaths ratio for paeds?
15:2
In paediatric arrests which is done first, ventilation or compressions? Justify your answer
Ventilation, as bradycardia is usually due to hypoxia
How does the QAS calculate paediatric body weight?
(age x 3) + 7
When is CPR indicated for a newborn (minutes/hours post birth)?
When HR is <60bpm despite ventilation for 30 seconds
How are compressions performed on a newborn?
Compress with two thumbs on lower third of the sternum
What is the ratio of compressions to breaths for a newborn?
3:1
When should an advanced airway be applied in CA?
After 6 minutes (3 cycles) unless traumatic (immediately in trauma settings)
How much adrenaline should be given when an adult pt is in a shockable rhythm and when?
1mg after the 2nd shock then every 3-5 minutes
List the H’s
Hypoxia
Hypovolaemia
Hyper/hypokalaemia/metabolic disorders
Hypo/hyperthermia
List the T’s
Tension pneumothorax
Tamponade
Toxins
Thrombosis (pulmonary/coronary/CVA)
What is included in post-resuscitative care?
- Reassess
- 12 lead ECG
- Rx precipitating causes
- Aim for SpO2 94-98% and normocapnia
- BGL mx
- Temp mx
How much adrenaline should be given when a paediatric pt is in a shockable rhythm and when?
10mcg/kg after 2nd shock then every 3-5 minutes
How much adrenaline should be given when a paediatric pt is in a non-shockable rhythm and when?
10 mcg/kg immediately then every 3-5 minutes
How much adrenaline should be given when an adut pt is in a non-shockable rhythm and when?
1mg immediately then every 3-5 minutes
Provide a rationale for defibrillation
Defibrillation produces simultaneous depolarisation of a critical mass of the myocardium and may enable the resumption of coordinated electrical activity
How much of the myocardium does defibrillation need to send into absolute refractory for it to be successful?
A critical mass of >70%
What are the indications for defibrillation?
VF and pulseless VT
What is the most desirable chest compression point on adults and why?
Lower half of the sternum - higher is not effective and lower risks abdominal organ damage
What is the ideal depth and rate of compressions on adults?
One third of the chest at a rate of 100/minute
Describe placement of defibrillation pads on adults
Para-sternal over the 2nd intercostal space, and mid-axillary over the 6th intercostal space
Where are defibrillation pads placed on paeds?
Centrally anterior and posterior
Is removal of oxygen from an LMA or ETT required for defibrillation? Explain your answer.
No - these are sealed units
What four things must be checked when confirming it is safe to defibrillate?
- Excess hair has been removed
- Pad placement is correct
- The pt is dry
- Everyone is clear
What is monophasic defibrillation?
Shock goes from one pad to the other
What is biphasic defibrillation?
Shock goes from one pad to the other then back again
Which is better, monophasic or biphasic defibrillation?
There is no definitive evidence in favour of either
Under QAS guidelines what are the energy levels of the first three shocks for adult pts using a LifePak12?
1 - 200j
2 - 300j
3 - 360j
At what energy level does the Corpuls3 deliver shocks for adults?
200j
What energy level does QAS recommend for paed defibrillation?
All shocks 4 joules/kg
What use is waveform capnography (ETCO2)?
- Confirm airway
- Assess adequacy of CPR
- Significant rise is an early sign of ROSC
What are some examples of CA in special circumstances?
Anaphylaxis Asthma Pregnancy Trauma Drug OD/poisoning Hypothermia
How is resuscitation altered in asthmastic CA?
Slow ventilation rate to ~6/minute
Take the BVM off and allow the pt to exhale
What has CA in asthmatics been linked to?
- Severe bronchospasm and mucous plugging leading to asphyxia
- Arrhythmias due to hypoxia/stimulant drugs/electrolyte abnormalities
- Hyperinflation due to air trapping
- Tension pneumothorax
Explain the concept of air trapping in asthmatics
It is harder to for asthmatics expel air than take it in and ‘breath stacking’ occurs, gradually increasing pressure and eventually reducing BP and venous return.
What are some considerations in asthmatic CA?
- Consider early ETT
- If dynamic hyperinflation is suspected during CPR, compression of the chest wall and/or a period of apnoea (ETT disconnection after 2 minutes of CPR) may relieve gas trapping
- Consider possible co-existence of anaphylaxis
What are common causes of CA in pregnancy?
- Cardiac disease
- Pulmonary thrombo-embolism
- Haemorrhage
- Sepsis
- Hypertensive disorders of pregnancy
- Poisoning and self-harm
- Amniotic fluid embolism
- Pregnant women can also have the same causes of cardiac arrest as females of the same age group (e.g. anaphylaxis, drug OD, trauma)
What are the additional management points for CA in pregnancy?
- Manually displace the uterus to the left to remove caval compression: tilt woman’s uterus 15-30 degrees towards her left hip (if feasible). The angle of tilt used needs to allow high quality chest compressions and permit Caesarean delivery of the foetus if necessary.
- Urgent tx as an emergency Caesarean section may be performed at hospital: the fetus will need to be delivered if resuscitation efforts fail.
What are some common causes of CA in trauma?
Hypovolaemia
Tension pneumothorax
Pericardial tamponade
What are the additional management points for CA involving poisoning?
- Normal resuscitation guidelines for OD of beta blockers/calcium channel blockers/cocaine and stimulants/digoxin/carbon monoxide/TCAs
- Naloxone for opioid OD
- Be aware that carbon monoxide poisoning has high mortality
- Consider a hyperbaric chamber for carbon monoxide poisoning
- Sodium bicarbonate for TCA OD
How does CA mx change when the pt is hypothermic?
- Withhold resuscitation drugs if <30 degrees Celcius
- Shock three times at 360j if in VF/VT then no more until pt is over 30 degrees Celcius
- Double drug administration interval when pt is between 30 and 35 degrees Celcius
What is the rapid CPR discontinuation criteria?
CPR may be withdrawn before expiration of 20 continuous minutes if:
- Pt was observed to be unresponsive and pulseless for at least 10 minutes prior to paramedic arrival
- No CPR was provided during this period
- The pt is exhibiting signs of life extinct
- The pt’s cardiac rhythm is asystole
What is the general CPR discontinuation criteria?
CPR must be administered by the paramedic for 20 continuous minutes after which it may be withdrawn if:
- Pt is exhibiting signs of life extinct
- Pt’s cardiac rhythm is asytole or PEA at a rate <10bpm
What are the indications for ROLE?
No palpable carotid pulse No heart sounds for 30 seconds No breath sounds for 30 seconds Fixed dilated pupils No response to centralised stimuli
Describe ROSC mx
CCP backup (sedation, antidysrhythmics, seizure control)
Swap from defib pads to Lead II ECG
Posture as per LOC
Mx BGL
Describe ROSC mx
CCP backup (sedation, antidysrhythmics, seizure control)
Swap from defib pads to Lead II ECG
Posture as per LOC
Mx BGL
O2 depending on respiratory effort and SpO2 to minimise hypercapnia
Vigilant ABC monitoring
Urgent tx
Describe ROSC mx
CCP backup (sedation, antidysrhythmics, seizure control)
Swap from defib pads to Lead II ECG
Posture as per LOC
Mx BGL
O2 depending on respiratory effort and SpO2 to minimise hypercapnia
Vigilant ABC monitoring
Urgent tx
What are the signs of obvious death?
- Decomposition/putrefaction
- Hypostasis
- Rigor mortis
List the injuries incompatible with life
- Decapitation
- Cranial and cerebral destruction
- Hemicorporectomy (or similar massive injury)
- Incineration
- Foetal maceration
