High-quality compressions, minimal pauses (<5 s for shocks) and early defibrillation come first.
RCUK 2025 made no major ALS changes from 2021 but puts more weight on effective ventilation.
Act now
- 1
Check pad position — poor placement is common. Consider antero-posterior pads after 3 failed shocks.
- 2
Shockable (VF/pVT): shock, then resume CPR for 2 minutes immediately without a pulse check.
- 3
Non-shockable (PEA/asystole): CPR for 2 minutes, give adrenaline as soon as IV/IO access is available.
- 4
Once an advanced airway is in, give continuous compressions; use waveform capnography.
Assess
- Unresponsive with absent or abnormal breathing = cardiac arrest. Agonal gasps are not signs of life.
- Call the resuscitation team (2222), start CPR 30:2, attach the defibrillator.
Investigations
- Blood gas during the arrest for K⁺, glucose, Hb and pH.
- Point-of-care ultrasound only if it does not interrupt compressions.
Manage
- Work through the reversible causes: hypoxia, hypovolaemia, hyper/hypokalaemia and other metabolic causes, hypo/hyperthermia, thrombosis (coronary or pulmonary), tension pneumothorax, toxins, tamponade.
- After ROSC: ABCDE, SpO₂ 94–98%, normal PaCO₂, systolic BP above 100 mmHg, 12-lead ECG, treat the cause, temperature control.
Escalate when
- From the outset — this is a team emergency. Check the patient's resuscitation status (DNACPR/ReSPECT) as soon as the team arrives.
- Consider ECPR or coronary angiography/PCI with the senior team where available.
Doses and prescribing
Adrenaline
1 mg IV/IO (10 mL of 1 in 10,000). Non-shockable: as soon as possible. Shockable: after the 3rd shock. Then every 3–5 minutes (alternate cycles).
Amiodarone
300 mg IV/IO after the 3rd shock; a further 150 mg after the 5th shock.
Lidocaine
100 mg IV is an alternative if amiodarone is unavailable or locally preferred.
Flush each drug with 20 mL 0.9% sodium chloride.
Check the BNF and your local formulary before prescribing.
Written to current guidance · sources checked 14 Nov 2026. We watch NICE for updates weekly.
Sources (1)
Reviewed by Aboodee Alhasso, MPharm MRCPharm IP on 14 Nov 2026
For healthcare professionals, as an aid to clinical judgement — not a substitute for it. Follow your local policy and ask a senior when in doubt.