Cardiac Arrest Flashcards
What is a cardiac arrest?
Arrest in the activity of the heart - stood beating
No contraction of the heart muscle, BUT there may still be electrical activity in the heart
What is PEA?
Most common cause?
Pulseless electrical activity
No contraction, but still electrical activity in the heart
any electrical activity that appears on an ECG like it should be producing a pulse, but it is not
Most common cause is hypovolemia
What is an irreversible consequence of cardiac arrest?
Irreversible brain damage can occur after <5 minutes of cardiac arrest
What are the reversible causes of cardiac arrest?
5 H’s and 4 T’s
H’s:
- Hypoxia
- Hypovolemia
- Hypokalaemia, (Hypoglycemia, Hypocalcemia, Acidemia and other metabolic disorders)
- Hyperkalaemia
- Hypothermia
T’s:
- Tension pneumothorax
- Tamponade (cardiac)
- Toxins
- Thrombosis (coronary or pulmonary)
What are reversible causes added to the list for pregnant patients?
Eclampsia
Intracranial haemorrhage
What is the prognosis of a cardiac arrest?
Medical emergency, poor prognosis
Out of hospital arrest has a survival rate of 2-8%
In hospital cardiac arrest has a 1-year survival rate of about 15%.
How does defibrillation work?
When you pass a large current through the heart, you can completely depolarise it. After this time, there will be a period of asystole, hopefully after which normal sinus mechanisms will restore sinus rhythm to the heart.
Defibrillators deliver a high-voltage, short duration DC shock, via two metal pads (coated in conducting gel or jelly) placed on the chest.
Where should the defibrillator pads be placed?
upper right sternal edge and the apex.
What is the difference between defibrillation vs cardioversion?
Defibrillation - unsynchronised shock given to the heart
Cardioversion - synchronised shock given to the heart (at a specific time in the ECG)
What can happen if you give a shock around the peak of the T wave?
You can induce unusual and dangerous rhythms eg. AF or VTach
When is a synchronised shock usually given?
Around 0.02s after the peak of the R wave
What can be said about shocks given in ventricular fibrillation?
Timing of the impulse/shock is not important
What is the initial management of cardiac arrest?
- On finding an unconscious individual - three SSS’s
- Safety - safe to approach?
- Shake - “are you alright?” while shaking their shoulder
- Shout - if pt responds, do ABCDE assessment. If doesn’t respond, shout for help and put out a cardiac arrest call. - Open airway with head tilt/chin lift manoeuvre (jaw thrust if risk of c-spine injury), palpate carotid, listen and feel for breathing for 10 seconds
- No pulse or no signs of life - begin CPR, 30:2 compressions:ventilation, to lower half of sternum to depth of 5-6cm at a rate of 100 per minute
Ventilation applied via bag-valve-mask (BVM)
- Attach defibrillator pads and pause CRP to analyse the rhythm - further management depends on whether rhythm is shockable or not
What are shockable rhythms?
Ventricular fibrillation
Pulseless Ventricular Tachycardia
What are Non-shockable rhythms?
PEA - pulseless electrical activity
Asystole - no rhythm present
How are shockable rhythms managed?
VF or Pulseless VT
- As individuals to stand clear and remove any oxygen delivery devices. After charged, deliver 1 shock with defibrillator
- Immediately resume CPR for 2 mins
- Assess rhythm - if shockable, resume compressions immediately. charge defibrillator again and deliver second shock. then do CPR for 2 mins.
Repeat until third shock
- After third shock, give adrenaline 1mg IV (10 ml of 1:10,000) and Amiodarone 300mg IV
Continue giving adrenaline after alternate shocks ie fifth, seventh, ninth, eleventh etc
- If organised electrical activity seen during rhythm check (step 3) - seek evidence of return of spontaneous circulation (ROSC)
- If present, commence post-resuscitation care
- If absent, resume CPR immediately and switch to non-shockable rhythm algorithm - If systole noticed at any point, switch to non-shockable algorithm
How are non-shockable rhythms managed?
Systole or PEA
- On recognition - resume chest compressions immediately for 2 mins
- On recognising organised electrical activity, seek evidence of ROSC and if absent (PEA), resume chest compressions immediately for 2 minutes
- After first rhythm check, give adrenaline 1 mg IV (10 ml of 1:10,000)
- After two minutes, pause CPR to check the rhythm; on recognising asystole, resume chest compressions immediately and continue for 2 minutes; on recognising organised electrical activity, seek evidence of ROSC and if absent (PEA), resume chest compressions immediately and continue for 2 minutes
Repeat until third rhythm check
- After 3rd rhythm check, given adrenaline 1 mg IV (10 ml of 1:10,000); continue giving adrenaline after alternate rhythm checks i.e. 5th, 7th, 9th etc
- If shockable rhythm is identified during a rhythm check, switch to the shockable algorithm but continue giving adrenaline after alternate rhythm checks: do not withhold until after the third shock
What is the defibrillator usually charged to?
150J
When is cardioversion usually used?
Often pre-planned
Used to treat significant, but not immediately life-threatening arrhythmias eg. narrow complex tachycardias, AF, Atrial flutter
Do patients receive sedation in cardioversion?
Emergency - pt usually unconscious due to cariogenic shock, so no anaesthesia given
Awake / planned - pt may get sedation to make tx more tolerable
What are contraindications and complications?
Digoxin - increases risk of arrhythmias after cardioversion, so in elective cases this is withheld for 24hrs before tx
Systemic embolus risk increased in pts with longstanding atrial arrhythmias who get elective cardioversion – these pts given 4 weeks anticoagulant therapy either before/after cardioversion
What are the main points of ALS?
Chest compressions
Defibrillation
Drug delivery
Adrenaline
Amiodarone
Thrombolytic Drugs
Chest compressions as part of ALS
- Ratio of chest compressions to ventilation is 30:2
- Chest compressions are continued while defibrillator is charged
Defibrillation in ALS
- Single shock for VF/pulseless VT followed by 2 minutes of CPR
- If cardiac arrest is witnessed in a monitored patients (eg. in a coronary care unit), give up to 3 successive (stacked) shocks (rather than 1 shock) followed by CPR
Drug delivery in ALS
1st line - attempt IV access
If IV access can’t be obtained - Intraosseous route (IO)
What is no longer recommended in terms of delivery of drugs?
Delivery via tracheal tube
Adrenaline as part of ALS
- Non-shockable rhythms: Adrenaline 1mg asap
- During VF/VT cardiac arrest, Adrenaline 1mg given after chest compressions have restarted after 3rd shock (from defibrillator)
- Repeat adrenaline 1mg every 3-5 minutes while ALS continues
Amiodarone as part of ALS
- Give Amiodarone 300mg to patients in VF/Pulseless VT after 3 shocks have been administered
- Further dose of Amiodarone 150mg given to patients in VF/pulseless VT after 5 shocks have been administered
- Lidocaine used as alternative if amiodarone unavailable or use lidocaine instead
Thrombolytic drugs as part of ALS?
- Consider if pulmonary embolus suspected
- If given, CPR should be continued for extended period of 60-90 minutes
ALS diagram
What drug is no longer recommended for routine use?
atropine is no longer recommended for routine use in asystole or pulseless electrical activity (PEA)
What can be said about O2?
following successful resuscitation oxygen should be titrated to achieve saturations of 94-98%.
This is to address the potential harm caused by hyperoxaemia
What can be considered during CPR?
Coronary angio or PCI
Mechanical chest compressions to facilitate transfer/tx
Extracorporeal CPR
How should patients be managed after ROSC?
ABCDE approach
SpO2 of 94-98% and normal PaCO2
12-lead ECG
Identify and treat cause
Targeted temperature management
What are the major causes of cardiac arrest in pregnancy?
Obstetric haemorrhage
Pulmonary embolism
Sepsis leading to metabolic acidosis and septic shock
What is obstetric haemorrhage a major cause of?
Severe hypovolemia and cardiac arrest
What are the causes of massive obstetric haemorrhage?
Ectopic pregnancy (early pregnancy)
Placental abruption (including concealed haemorrhage)
Placenta praevia
Placenta accreta
Uterine rupture
How does aortocaval compression lead to a cardiac arrest?
- After 20 weeks gestation, uterus is a significant size.
- When a pregnant woman lies supine, the mass of the uterus can compress the IVC and aorta.
- The compression on the vena cava is most significant - reduces blood returning to the heart (venous return) –> reduces cardiac output –> hypotension. In some instances, this can be enough to lead to the loss of cardiac output and cardiac arrest.
How is aortocaval compression treated?
- Vena cava is slightly to the right side of the body.
- The solution to aortocaval compression is to place the woman in the left lateral position, lying on her left side, with the pregnant uterus positioned away from the inferior vena cava.
- This should relieve the compression on the inferior vena cava and improve venous return and cardiac output.
What factors make resuscitation more complicated in pregnancy?
Aortocaval compression
Increased oxygen requirements
Splinting of the diaphragm by the pregnant abdomen
Difficulty with intubation
Increased risk of aspiration
Ongoing obstetric haemorrhage
What are the differences in terms of principles of resuscitation in pregnancy?
Follows same principles as standard ALS except:
- A 15 degree tilt to the left side for CPR, to relieve compression of the inferior vena cava and aorta
- Early intubation to protect the airway
- Early supplementary oxygen
- Aggressive fluid resuscitation (caution in pre-eclampsia)
- Delivery of the baby after 4 minutes, and within 5 minutes of starting CPR
When is an immediate c/s performed?
- When there is no response after 4 minutes to CPR performed correctly
- When CPR continues for more than 4 minutes in a woman more than 20 weeks gestation
What is the aim of a c/s?
- To deliver the baby and placenta within 5 minutes of CPR commencing.
- The operation is performed at the site of the arrest, for example, in A&E resus or on the ward.
- Done to improve survival of the mother - delivery improves venous return to the heart –> improves cardiac output –> reduces oxygen consumption
- Delivery helps with ventilation and chest compressions
- Delivery increases chances of baby surviving but this is secondary to survival of the mother
Paediatric ALS algorithm
How are paediatric patients resuscitated?
- Unresponsive - Commence BLS (oxygenate and ventilate), Call resus, CPR 15:2 until defibrillator/monitor attached
- Assess Rhythm – shockable vs non-shockable
3a - SHOCKABLE
- 1 shock (4 J/kg or AED)
- Resume CPR 15:2 for 2 mins
- Assess Rhythm and follow appropriate algorithm
3b - NON-SHOCKABLE
- CPR 15:2 for 2 min
- Assess Rhythm and follow appropriate algorithm
What should be done during paediatric CPR?
- Correct reversible causes
- Check electrode position and contact
- Attempt / verify: IV / IO access airway and oxygen
- Give uninterrupted compressions when trachea intubated
- Give adrenaline every 3-5 min
- Consider: amiodarone, atropine, magnesium
What is an infant and child defined as according tor Jesus council UK guidelines?
Infant - Under 1 year old
Child - between 1 year - 18 years
What is the most common cause of cardiorespiratory arrest in children and infants?
due to decompensated respiratory arrest (or circulatory failure causing hypoxia).
What is the initial management of cardiac arrest in children?
SSS
- Safe? - check for danger, put on gloves and PPE asap, careful with sharps
- Shake - for response (if respond, leave in same position and arrange urgent medical review)
- Shout (if no response to shake) - for help. Assess breathing and circulation and if no repose after 1 min, cardiac arrest call
- Airway - heal-tilt-chin-lift or jaw thrust if significant trauma suspected
- Asess for signs of life
- Look, listen and feel pt breathing for 10s
- Expose pt’s chest
- Movement?
- Infrequent and noisy gasps do not count as normal breathing (this may occur in the first few minutes after cardiac arrest).
- Pulse - femoral (infant), carotid (child)
- If breathing normally - recovery position
- If abnormal or absent breathing - BLS with 5 initial rescue breaths
How is the head-tilt chin-lift manoeuvre done?
- Place one hand on the patient’s forehead and gently tilt the head back.
- Place your fingertips under the child’s chin and lift.
How is the jaw thrust done?
- Identify the angle of the mandible.
- With the index and other fingers placed behind the angle of the mandible, apply steady upwards and forward pressure to lift the mandible.
- Using the thumbs, slightly open the mouth by downward displacement of the chin.
What pulse in a child is treated the same as no pulse?
< 60 bpm
What should you state when you call resus team (2222)
Your location (e.g. ward)
Type of cardiac arrest (e.g. infant or child)
What should you do if alone and paediatric resus?
commence one minute of CPR before calling for help
What should be done if child isn’t breathing?
5 initial rescue breaths (ideally with bag valve mask)
How should a child’s head be positioned during rescue breaths?
Infant:
1. Place an infant’s head in the neutral position (avoid over-extension)
2. Take a breath, cover the mouth and nose of the infant with your mouth and blow steadily for 1 second (ensuring a good seal by looking for chest rise).
Child:
1. Place a child’s head in the ‘sniffing position’
2. Take a breath, cover the mouth of the child with your mouth and pinch the nose. Blow steadily for 1 second (ensuring a good seal by looking for chest rise).
How should chest compressions be delivered in paediatric patients?
15 compressions : 2 ventilations (15:2)
Infant and single rescuer
- Use two finger technique
- Compress the lower sternum with the tips of your two fingers (index and middle).
Infant and two rescuers
- Encircling technique
- Place both thumbs flat, side-by-side, on the lower half of the sternum, with the tips pointing towards the infant’s head.
- Spread the rest of both hands to encircle the infant’s ribcage; the tips of the fingers support the infant’s back.
- Press down on the lower sternum with your two thumbs to depress it. For very small infants, the thumbs may overlap.
Child >1 year
- Technique depends on size of child
- Small child: place the heel of one hand over the lower half of the sternum. Do not apply pressure over the child’s ribs; lift your fingers.
- Larger child: use two hands with your fingers interlocked (as per adult basic life support)
If more than one person is present, alternate the person performing chest compressions at 2-minute intervals.
What makes a high-quality chest compression?
- Position: on a flat, hard surface
- Rate: 100-120bpm
- Depth: depress 1/3 of the anterior-posterior dimension of the chest. In an infant, this is roughly 4cm and in a child is roughly 5cm.
- Location: lower ½ sternum
- Allow for adequate recoil of the chest after each compression
- It is essential to minimise interruptions to chest compressions.
How can paediatric patients be ventilated?
- Open airway using maneuvres
- If available, use a pocket mask or a bag-valve-mask (BVM) and place it over the child’s nose and mouth.
- If unavailable, place your mouth tightly over the patient’s mouth (and nose if an infant).
- Deliver 2 breaths.
- squeeze the bag or blow for ~ 1 second.
- Then perform the next cycle of 15 chest compressions.
- As soon as available, use supplementary oxygen.
Mouth-to-mouth ventilation
- If there are clinical reasons to avoid mouth-to-mouth ventilation (e.g. to avoid infectious disease transmission), perform chest compressions until help and airway equipment arrives.
- ALS would be commenced once the resuscitation team arrives.
How can an automated external defibrillator (AED) be used in paediatric patients?
- Attach AED
- Attach the 2 self-adhesive pads immediately to chest
- Positioning of pads different to adult (anterior-posterior)
- PAD 1: front of upper chest, between nipples (anterior)
- PAD 2: upper back, between shoulders (posterior) - Turn on AED
- Turn on and follow audio-visual instructions
- Typically, it will ask to pause chest compressions whilst it performs a rhythm check.
0 It will then indicate if the rhythm is shockable or non-shockable. If shockable, it will instruct you to deliver a shock.
- If a shock needs to be delivered, ensure you and no one else is in contact with the patient and press the deliver shock button on the AED.
- Re-commence CPR after the shock is delivered.
- Follow any further instructions from the AED.
- Advanced life support would be commenced once the resuscitation team arrives.
When is resuscitation stopped?
Continue resuscitation with 15:2 compressions and ventilation breaths until one of three things happen:
- There are signs of life (e.g. coughing, movement)
- The arrival of further qualified help
- You become exhausted
What is the shock of defibrillator in paeds?
4J / kg
What is the concentration of adrenaline used in cardiac arrest?
10ml 1:10,000 IV or 1ml of 1:1000 IV
What is the dose of adrenaline sued in anaphylaxis?
0.5ml 1:1,000 IM
Reversible causes of cardiac arrest?
5H’s and 4T’s
Hypoxia
Hypokalaemia/hyperkalaemia
Hypothermia/hyperthermia
Hypovolaemia
Hypotension
Tension pneumothorax
Tamponade
Thrombosis
Toxins
