Cardiopulmonary Resuscitation

Question 1

1. what is the chain of survival?

2. what are the aspects making up the chain of survival?

Answer 1

1. Four key, inter-related steps which when delivered effectively optimise survival from out of hospital cardiac arrest
2. early recognition and call for help, early bystander CPR, early defibrillation, early advanced life support and standardised post resuscitation care

Question 2

what can be done to improve out of hospital cardiac arrest survival? (6)

Answer 2

All school children taught CPR and AED use

Everyone who can should learn CPR

Availability of defibrillators in places with large number of people

Owners of defibrillators should register location and availability with ambulance services

Systems to enable ambulance service to identify and deploy nearest defib to scene of suspected cardiac arrest

All out of hospital cardiac arrest resuscitation attempts reported to national out of hospital cardiac arrest audit

Question 3

what is the algorithm for cardiac arrest out of hospital?

Answer 3

1. safety
2. response
3. airway
4. breathing - look, feel, listen for 10 secs
5. call for help/ambulance
6. send for AED
7. circulation - 30 chest compressions
8. 2 rescue breaths
9. continue 30:2
   [if AED arrives follow instructions]
10. if they start breathing - recovery position

Question 4

describe the resuscitation of children

Answer 4

5 initial rescue breaths before chest compressions
If on your own perform CPR for 1 minute before going for help
Compress chest by 1/3 depth
Use 2 fingers for an infant under 1 year
Use one or 2 hands as needed for a child over 1 year

Question 5

what are the signs of cardiac arrest?

Answer 5

Unconscious

Unresponsive

Not breathing or not breathing normally (gasping noises)

Question 6

what are the causes of cardiac arrest?

Answer 6

Ventricular fibrillation
Heart attack
Cardiomyopathy
Congenital heart disease
Heart valve disease
Acute myocarditis
Electrocution
Drug overdose
Severe haemorrhage (hypovolaemic shock)
Hypoxia

Question 7

what is the difference between a cardiac arrest and a heart attack?

Answer 7

Heart attack occurs when the blood supply to the heart muscle is cut off due to a clot in one of the coronary arteries. The heart is still pumping and they will be conscious and breathing. A heart attack can lead to a cardiac arrest. A cardiac arrest is an electrical issue and the patient will be unconscious

Question 8

describe the immediate recovery management following cardiac arrest?

Answer 8

Coronary care or ICU

May need induced coma

Question 9

describe the mid term recovery following cardiac arrest?

Answer 9

Pacemaker, ICD, cardiac rehabilitation

Question 10

describe long term recovery following cardiac arrest?

Answer 10

Practical matters eg driving, work
Lifestyle changes
Long term effects of hypoxia during cardiac arrest; personality changes, problems with memory, fatigue, dizziness or balance issues, aphasia/dysphasia, myoclonus, permanent brain injury

Question 11

describe the first stages of the ALS algorithm if a patient has a cardiac arrest in hospital?

Answer 11

1. patient unresponsive and not breathing normally
2. call resuscitation team
3. CPR 30:2 / attach defib, monitor
4. assess rhythm

Question 12

what are the reversible causes of cardiac arrest?

Answer 12

hypoxia, hypovolaemia, hypo-/hyperkalaemia/metabolic, hypothermia

thrombosis, tension pneumothorax, tamponade, toxins

Question 13

what are the shockable rhythms?

Answer 13

ventricular fibrillation

pulseless VT

Question 14

what are the non shockable rhythms?

Answer 14

PEA

asystole

Question 15

what other interventions should be performed during CPR?

Answer 15

• high quality chest compressions
• minimise interruptions to compression
• give oxygen
• use waveform capnography
• continuous compressions when airway in place
• vascular access
• adrenaline every 3-5mins
• amiodarone after 3 shocks

Question 16

describe the ALS algorithm for a shockable rhythm?

Answer 16

1. Confirm cardiac arrest
2. Call resuscitation team
3. Uninterrupted chest compressions / apply defib pads
4. Plan actions before pausing CPR for rhythm analysis
5. Stop compressions – confirm VF/pVT from ecg (<5 seconds)
6. Resume chest compressions immediately
7. Select at least 150J for first shock
8. When defib charged tell rescuer to stand clear and then give shock
9. Immediately restart CPR and continue for 2 mins
10. Pause to check monitor if still shockable repeat
11. repeat
12. Give adrenaline 1mg IV and then further dose every 3-5 mins until ROSC achieved
13. and 300mg IV amiodarone after 3 defibrillation attempts, condsider another 150mg IV after 5 defib attempts (lidocaine 1mg/kg may be used as alternative)

Question 17

describe the ALS algorithm for non shockable rhythms?

Answer 17

1. CPR 30:2
2. Adrenaline 1mg IV ASAP
3. Continue CPR 30:2 until airway is secured then continue compressions without pausing during ventilation
4. Recheck rhythm after 2 mins
5. If electical activity compatible with pulse start post resuscitation care

Question 18

describe how you would go about treating the 4 H’s

Answer 18

Hypoxia- ensure patient is ventilated, adequate chest rise and bilateral breath sounds

Hypovolaemia- usually due to severe haemorrhage which may be due to trauma, GI bleeding or AAA. Stop haemorrhage and restore intravascular fluid with bloods

Hyperkalaemia, hypokalaemia, hypoglycaemia, hypocalcaemia, acideamia/metabolic -detect by biochemical tests or history eg renal failure. Give IV calcium chloride in presence of hyperkalaemia, hypocalcaemia and calcium channel blocker

Hypothermia -suspect based on history eg cardiac arrest associated with drowning

Question 19

describe how you would go about treating the 4T’s

Answer 19

Thrombosis – coronary thrombosis: associated with ACS or ishcaemic heart disease. Most common cause of sudden cardiac arrest. Consider urgent coronary angiography and percutaneous coronary intervention.
Thromboembolic or mechanical circulatory obstruction: massive PE, if this is considered the cause consider fibrinoytic drug immediately. If this is done consider performing CPR for 60-90 mins before termination of resuscitation

Tension pneumothorax – can be primary cause of PEA, associated with trauma. Diagnosis cinically or via ultrasound

Tamponade – cardiac – difficult to diagnose. Cardiac arrest after penetrating chest trauma is suggestive of tamponade – resuscitative throacotomy

Toxins – laboratory investigations may be needed. Antidotes should be used. Treatment is supportive and follow standard ALS

Question 20

what imaging would you consider during ALS?

Answer 20

Echocardiography/ultrasound may help diagnosis and treatment

Placement of sub-xiphid probe before chest compressions are pausd for planned rhythm assessment

Ultrasound – identify cardiac tamponade, PE, hypovolaemia, pneumothorax

Question 21

when should CPR be stopped?

Answer 21

it is generally accepted that asystole for more than 20 minutes in the absence of a reversible cause and with ongoing ALS constitutes a reasonable ground for stopping further resuscitation attempts.

Question 22

what is the purpose of post resuscitation care?

Answer 22

Short term mortality from cardiac arrest is high. The aim in post resuscitation care is to manage post cardiac arrest syndrome which comprises of brain injury, myocardial dysfunction, ishcaemic/reperfusion response, precipitating pathology.

Question 23

describe airway assessment in immediate post resuscitation care?

Answer 23

if post arrest patient is not waking 5-10 mins after ROSC intubation should be planned

Question 24

describe breathing assessment in immediate post resuscitation care?

Answer 24

nasogastric/orogastric tube will relieve gastric distension which can improve ventilatory status. Aim for 94-98% O2 sats

Question 25

describe circulation assessment in immediate post resuscitation care?

Answer 25

patients usually haemodynamically unstable. Target mean arterial pressure should take into account; normal BP, estimated cardiac function, cause of cardiac arrest. Fluid challenges of 125-500mls to optimise patient perfusion and preload. Invasive circulatory monitoring – arterial line provides continuous BP to track response to therapy. Echo can give visual guide to filling status and cardiac index. Non invasive cardiac output monitoring may be useful and can be rapidly established. Inotropes and vasopressors to maintain BP and cardiac output

Question 26

describe disability assessment in immediate post resuscitation care?

Answer 26

GCS prior to sedation, short acting sedating agents such as propofol preferred control seizures
Glucose control¬ – tight glycaemic control not recommended as comatose patient is a greater risk of undiagnosed hypoglycaeia yet it must be controlled but not unless it is more than 8mmol/l

Question 27

what investigations are important post resuscitation?

Answer 27

CXR – confirms line and tube position, rules out iatrogenic complications

12 lead ECG – if ischaemia/infarction or arrythmia suspected

Potassium – maintained at 4-4.5mmol/l to limit arrythmias

Improving lactate post arrest demonstrates reducing tissue ischaemia

Ultrasonography – diagnose cause of cardiac arrest

Question 28

what is post arrest hypothermia?

Answer 28

May suppress chemical reactions associated with reperfusion injury post arrest. ALS group recommend cooling to 32-34 degrees for 12-24 hours after out of hospital VF arrest. Complications include infection, arrythmias, diuresis, electrolye abnormalities and coagulopathy. Pyrexia must be prohibited post cardiac arrest, common in first 48 hours and risk of poor neurological outcome increases each degree rise over 37 degrees

Question 29

how can clinical neurological findings post arrest inform prognosis?

Answer 29

retention of function is a good predictor of good functional outcome. Myoclonic epilepsy is poor prognostic indicator. Pathophysiological factors eg hypoglycaemia and interventions will affect neurological exam and should be considered

Question 30

how can comorbidities and age post arrest inform prognosis?

Answer 30

increased age increases short term mortality but doesn’t predict neurological outcome. Increased age and PEA rhythm combined are significant predictors of poor outcome. Poor outcome associated with diabetes, sepsis, cancer, sroke or being housebound before cardiac arrest

Question 31

can the type of arrest help inform post arrest prognosis?

Answer 31

Non cardiac cause, asystole are unreliable as predictors of poor outcome

Question 32

how can downtime/delay to start of CPR and quality of CPR influence prognosis?

Answer 32

Poor outcome associated with increasing time interval between collapse and start of CPR and/or from start of CPR to return of spontaneous circulation. Increasing number of shocks or adrenaline doses correlate with poorer neurological outcome. Low ETCO2 of less than 10mmHg during resuscitation is associated with poor outcome

Question 33

can early ABG interpretation post arrest inform post arrest prognosis?

Answer 33

pH on initial ABG not correlated with survical, high lactate associated with severe neurological impairment