Basic life support from the nursing side
- Procedure
If a patient does not respond and is not breathing normally: call for help and the defibrillator, push hard and fast, and defibrillate as soon as you can.
What it is
Basic life support (BLS) is the first response to cardiac arrest: recognising it, calling for help, starting high-quality compressions, ventilating and using the automated external defibrillator (AED) as early as possible. In hospital, a nurse is often the one who finds the patient: they recognise the arrest, call the code, start CPR, bring the crash cart and organise the record. Compression quality and minimal pauses matter most. This page summarises BLS for study; it does not replace a certified course or the current AHA or ERC guidelines.
Indications
- A person who does not respond and is not breathing normally (or is only gasping).
- No definite pulse after a brief check (health professionals).
- Witnessed arrest, or a patient found unresponsive on the unit.
Contraindications and precautions
- Scene safety: make sure the surroundings are safe for you and the patient.
- Respect a valid do-not-resuscitate order under the law and the institutional protocol.
- Use personal protective equipment and barrier devices or a bag-mask to ventilate.
- Suspected spinal injury: log-roll the patient, keeping head and neck aligned.
- Firm surface: a CPR board or the bed in CPR mode so compressions are effective.
Equipment
- Automated external defibrillator or monitor-defibrillator with pads.
- Bag-mask with reservoir, oxygen source and suction equipment.
- CPR board and crash cart.
- Code record sheet and a clock or timer.
Step by step (and why)
- Check safety, call the patient and tap their shoulders — confirms they do not respond.
- Shout for help, call the code and ask for the crash cart and AED — early defibrillation saves lives.
- Look for breathing and feel the pulse together, within a few seconds — delay in starting compressions worsens the outcome.
- No definite pulse: heel of the hand on the centre of the chest, arms straight — so the force goes to the sternum.
- Compress at 100–120 per minute, about 5 cm deep, with full recoil — it creates blood flow to brain and heart.
- Open the airway and give 2 one-second breaths that make the chest rise, cycles of 30:2 — oxygenates without long pauses.
- Put the AED pads on as soon as it arrives and follow the prompts; nobody touches the patient during a shock — protects the team.
- Resume compressions right after each shock or analysis and rotate compressors — fatigue lowers quality.
- Assign roles (airway, compressions, AED, recorder, leader) — an organised team cuts pauses and errors.
- Record start time, shocks, drugs ordered by the doctor and changes — the timeline guides decisions.
Main differences by age (health professionals)
| Item | Adult | Child (1 year to puberty) | Infant (under 1 year) |
|---|---|---|---|
| Compressions:breaths | 30:2 | 30:2 with one rescuer; 15:2 with two | 30:2 with one rescuer; 15:2 with two |
| Depth | About 5 cm | About 5 cm | About 4 cm |
| Rate | 100–120 per minute | 100–120 per minute | 100–120 per minute |
| If alone | Call for help and the AED, then start | About 2 minutes of CPR before leaving to call | About 2 minutes of CPR before leaving to call |
Complications
- Rib or sternal fractures from compressions.
- Gastric distension and vomiting from excessive or too-fast breaths.
- Shallow, slow or interrupted compressions, which reduce survival.
- Shock risk for the team if anyone touches the patient during defibrillation.
Next step: when to call for help
- Continue until the resuscitation team arrives and takes over, the patient shows signs of life or the leader says to stop.
- If circulation returns, watch airway, breathing and pulse and prepare transfer as directed.
- Give the team a short report: time of arrest, rhythm, shocks and what was done.
- After the code, restock the crash cart and take part in the case review.
Test yourself
Think of the answer, then tap the question to see it.
For how long, at most, do you check the pulse before starting compressions?
A few seconds, looking at breathing at the same time, without delaying compressions. If there is no definite pulse, compressions are started.
At what rate and depth is an adult's chest compressed?
At 100–120 compressions per minute, about 5 cm deep, letting the chest recoil fully.
What is the compression-to-breath ratio in a child with two rescuers?
15 compressions and 2 breaths. With one rescuer, 30:2 is used.
When is the AED used during CPR?
As soon as it is available: the pads are applied, its prompts are followed and compressions resume right afterwards.
Why are compressors rotated during a code?
Because fatigue reduces depth and rate. Rotating keeps compressions at high quality.
Connections
Educational content for students; it does not replace your institution's protocols, supervised clinical training or a prescriber's order. Dose-calculation examples use made-up numbers: they are educational, not a clinical order.
Sources: CPR - adults and children after onset of puberty (MedlinePlus, U.S. National Library of Medicine, 2026); CPR - young child (age 1 year to onset of puberty) (MedlinePlus, U.S. National Library of Medicine, 2026); CPR - infant (MedlinePlus, U.S. National Library of Medicine, 2026).
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Representative model, for educational purposes only.