Anaesthesiology
Cardiopulmonary Resuscitation
CPR for MBBS and NEET-PG: basic life support sequence, chest compressions, shockable and non-shockable rhythms, adrenaline and amiodarone, and reversible causes, mapped to NMC codes AS2.
MedNext Academy | 3 min read
Cardiopulmonary Resuscitation
CPR for MBBS and NEET-PG: basic life support sequence, chest compressions, shockable and non-shockable rhythms, adrenaline and amiodarone, and reversible causes, mapped to NMC codes AS2.
This chapter teaches the systematic response to cardiac arrest, from bystander basic life support to hospital advanced cardiac life support. It covers high-quality chest compressions, the shockable and non-shockable rhythm algorithms, resuscitation drugs and the reversible causes that must be sought and treated.
High-yield: Cardiopulmonary Resuscitation
- The adult basic life support sequence follows the order chest compressions, airway then breathing (C-A-B), so compressions are started first.
- High-quality chest compressions are given at a rate of 100 to 120 per minute to a depth of 5 to 6 centimetres in an adult.
- Allow full chest recoil between compressions and keep interruptions to less than 10 seconds to maintain coronary perfusion.
- The compression to ventilation ratio is 30:2 for adults and for single-rescuer paediatric resuscitation.
- Shockable rhythms are ventricular fibrillation and pulseless ventricular tachycardia; the treatment is immediate defibrillation.
- Non-shockable rhythms are asystole and pulseless electrical activity, which are not defibrillated and are treated with adrenaline and CPR.
- Adrenaline 1 milligram intravenously is given every 3 to 5 minutes in cardiac arrest, immediately in non-shockable rhythms.
- Amiodarone 300 milligrams is given after the third shock in refractory ventricular fibrillation or pulseless ventricular tachycardia.
- The reversible causes are memorised as the four Hs and four Ts: hypoxia, hypovolaemia, hypo or hyperkalaemia, hypothermia, thrombosis, tamponade, tension pneumothorax and toxins.
- Defibrillation uses about 150 to 200 joules on a biphasic device, and CPR is resumed at once after each shock without a pulse check.
- Waveform capnography confirms tracheal tube placement and a sudden rise in the value can be the first sign of return of spontaneous circulation.
- Once an advanced airway is in place, compressions are continuous and ventilation is given at about 10 breaths per minute.
- Interruptions for pulse and rhythm checks are made every 2 minutes, aligned with a change of the person doing compressions to avoid fatigue.
- Early recognition, early CPR, early defibrillation and post-resuscitation care form the links of the chain of survival.
Adult ACLS at a glance
- **Compressions:** 100 to 120 per minute, depth 5 to 6 cm, full recoil, ratio 30:2 before an advanced airway.
- **Shockable rhythms:** Ventricular fibrillation and pulseless VT. Defibrillate, then resume CPR at once.
- **Drugs:** Adrenaline 1 mg every 3 to 5 minutes; amiodarone 300 mg after the third shock.
- **Reversible causes:** Four Hs and four Ts: hypoxia, hypovolaemia, hypo/hyperkalaemia, hypothermia, thrombosis, tamponade, tension pneumothorax, toxins.
NMC competencies in this chapter
- **AS2.1:** Basic life support
- **AS2.2:** Advanced cardiac life support
Frequently Asked Questions
Why does adult CPR start with compressions rather than breaths?
The current sequence is compressions, airway, breathing (C-A-B). Starting compressions first restores circulation to the heart and brain with the least delay, as most adult arrests are cardiac in origin.
Which rhythms are shockable?
Ventricular fibrillation and pulseless ventricular tachycardia are shockable and treated with immediate defibrillation. Asystole and pulseless electrical activity are non-shockable and treated with CPR and adrenaline.
When is adrenaline given in cardiac arrest?
Adrenaline 1 milligram is given every 3 to 5 minutes. In non-shockable rhythms it is given as soon as access is available, while in shockable rhythms it follows the first few shocks.
What are the reversible causes of cardiac arrest?
They are grouped as four Hs and four Ts: hypoxia, hypovolaemia, hypo or hyperkalaemia, hypothermia, thrombosis, tamponade, tension pneumothorax and toxins, and each should be actively sought.
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