Assessing the Collapsed Athlete

The primary survey is <C>ABCDE: catastrophic haemorrhage, Airway, Breathing, Circulation, Disability, Exposure. Catastrophic external bleeding is controlled before the airway, which is why the sequence is written <C>ABCDE rather than ABCDE. A limb wound pouring blood is treated with direct pressure first, because an open airway will not help an athlete who is exsanguinating.

Safety and access come first: reach the athlete as soon as it is safe to do so. An unresponsive athlete triggers the emergency action plan. With help present, one person calls 999 and one fetches the defibrillator while you assess, so the call never delays compressions; a lone rescuer calls 999 first, before assessing breathing.

The airway is opened, using a jaw thrust with manual in-line stabilisation of the neck where spinal injury is suspected from the mechanism or the examination, rather than a head tilt and chin lift. The survey then reaches its decisive point at B. An unresponsive athlete with abnormal or uncertain breathing is assumed to be in cardiac arrest: compressions start immediately and the defibrillator is used, without a pulse check. When in doubt, start.

Only an athlete who is breathing normally continues down the survey, to Circulation, then Disability, assessed with AVPU (Alert, Voice, Pain, Unresponsive), the pupils and a capillary glucose, and then Exposure, finding the injury and covering the athlete. The survey is repeated whenever anything changes.

Recognising cardiac arrest is the hardest and most important call on the field, because the athlete does not always look the way clinicians expect. An unresponsive athlete with abnormal or uncertain breathing is in cardiac arrest until proven otherwise, and recognition does not depend on a pulse check.

The athlete-specific trap is breathing. Early after collapse, and particularly in athletes, breathing may appear near-normal or even panting, and regular respiratory movements with the eyes open and rolled back may follow cardiac arrest during exercise. Normal-looking breathing does not exclude arrest.

Brief seizure-like activity or myoclonic jerking can follow cardiac arrest and is routinely mistaken for a faint or a fit, which delays compressions. A known diagnosis of epilepsy does not change the response: assess responsiveness and breathing, and start compressions if the athlete is unresponsive with abnormal or uncertain breathing.

Contact does not exclude cardiac arrest. A blunt blow to the chest landing during vulnerable repolarisation can cause ventricular fibrillation, known as commotio cordis, a real risk in cricket, hurling and lacrosse and from a knee or elbow in collision sport. Any unexpected collapse in an athlete without rapid recovery is presumed cardiac arrest. Once recognised, the action is rehearsed and simple: start compressions, use the defibrillator, and follow the Sudden Cardiac Arrest pathway.

Only once an athlete has been established as not in arrest, breathing normally, does the structured secondary survey follow. It is a focused head-to-toe assessment with an AMPLE history (Allergies, Medications, Past medical history, Last meal, Events), a reassessment of disability using AVPU or the Glasgow Coma Scale with the pupils, and a capillary glucose. Glucose is checked once immediate life threats have been addressed, or concurrently by a second clinician; it must never delay resuscitation. The primary survey is repeated whenever anything changes, so an athlete who was talking and becomes drowsy with altered breathing is reassessed from the start.

The differential is sorted by contact and timing.

Collapse during exertion without contact points to a cardiac cause. Collapse after a blunt chest blow raises commotio cordis, and contact does not exclude cardiac arrest. Collapse with contact to the head or neck is treated as a head and neck injury, with the airway opened by a jaw thrust and in-line stabilisation where spinal injury is suspected. Collapse at or after the finish line may be exercise-associated collapse, but only as a diagnosis of exclusion reached after cardiac arrest, severe exertional heat illness, exercise-associated hyponatraemia and hypoglycaemia have been excluded, with reassuring observations and rapid improvement. It is not a benign default.

Two emergencies are held in mind while sorting. Anaphylaxis is treated with adrenaline 500 micrograms intramuscularly into the anterolateral thigh in an adult, repeated after five minutes if airway, breathing or circulation problems persist. Severe exertional heat illness is assessed on rectal temperature and cooled on site before transfer, with cold-water immersion where available and active cooling stopped at around 38.5 to 39 degrees Celsius to avoid overcooling.

Disposition follows the same conservative logic. Any unexpected collapse, even with rapid and complete recovery, means removal from sport and medical assessment, and exertional syncope needs a 12-lead electrocardiogram, urgent cardiac assessment, and no exercise pending it.

• •Resuscitation Council UK, 2025 Resuscitation Guidelines, adult basic life support (published October 2025): an unresponsive person with abnormal or uncertain breathing is treated as cardiac arrest and cardiopulmonary resuscitation is started immediately, without a pulse check, and early after collapse, particularly in athletes, breathing may appear near-normal or panting.
• •Resuscitation Council UK best-practice guideline on resuscitation on the field of play (2024): any unexpected collapse in an athlete without rapid recovery is presumed cardiac arrest, regular respiratory movements with the eyes open may follow arrest during exercise, and medical teams should reach a collapsed athlete without delay once it is safe.
• •Resuscitation Council UK anaphylaxis guidance: adrenaline 500 micrograms intramuscularly into the anterolateral thigh in an adult, repeated after five minutes if airway, breathing or circulation problems persist.
• •Faculty of Pre-Hospital Care exertional heat illness consensus statement (2024): severe exertional heat illness is assessed on rectal temperature and cooled on site before transfer, with cold-water immersion where available and active cooling stopped at around 38.5 to 39 degrees Celsius.

• •The primary survey exits at B: an unresponsive athlete with abnormal or uncertain breathing is in cardiac arrest, so start compressions and send for the defibrillator without a pulse check.
• •Early after collapse, and particularly in athletes, breathing can look near-normal or panting; normal-looking breathing does not exclude cardiac arrest.
• •Brief seizure-like activity or myoclonic jerking can follow cardiac arrest, so a known history of epilepsy does not change the response.
• •Contact does not exclude cardiac arrest: a blunt blow to the chest can cause ventricular fibrillation, known as commotio cordis.
• •Exercise-associated collapse is a diagnosis of exclusion, reached only after cardiac arrest, heat illness, hyponatraemia and hypoglycaemia are excluded.
• •Any unexpected collapse means removal from sport and assessment, and exertional syncope needs a 12-lead electrocardiogram before return.