The crash call came from a general surgery Ward. A woman in her mid-sixties had collapsed and gone into cardiac arrest. What made this case immediately striking was the timeline: nursing staff reported she had been ambulatory just minutes before, walking around the ward as normal. There had been no obvious warning. No dramatic deterioration. One moment upright and independent; the next, in full arrest on the floor.

On arrival, the team was already in motion. CPR (cardiopulmonary resuscitation) had been commenced by ward staff before we reached the bedside, which is exactly as it should be. Every second without chest compressions is a second the brain goes without oxygen. The ward team had responded fast and done the right thing.

A non-rebreather mask had been placed over the patient's face even while compressions were ongoing. This high-concentration oxygen mask, with its one-way valve system, delivers close to 60 to 80% oxygen and was the best available option at that immediate moment to maximise oxygen delivery to whatever circulation the compressions were generating.

The anaesthetist took charge of the airway without hesitation. An iGel supraglottic airway device was inserted. The iGel is a remarkable piece of kit: a soft, gel-like supraglottic airway that sits above the vocal cords and creates a seal around the larynx without needing a cuff to be inflated. It can be inserted quickly, requires no laryngoscope, and is far easier to place under the chaotic conditions of a cardiac arrest than a full endotracheal tube. Crucially, it allows ventilation to continue without interrupting chest compressions.

With the iGel in place, ventilation was delivered using an Ambu bag (bag-valve-mask device), a self-inflating resuscitation bag that forces oxygen into the lungs with each manual squeeze. Meanwhile, I set up a Waters circuit, a specialised anaesthetic breathing system that allows more controlled delivery of anaesthetic gases and oxygen and gives the team greater flexibility once the immediate crisis is managed.

Effective CPR is exhausting. Chest compressions must be delivered at the correct depth (at least 5 to 6 centimetres into the sternum), at the correct rate (100 to 120 per minute), and with full chest recoil between each compression so the heart can refill. Doing this for even two minutes to a high standard is physically demanding. Rotating the person performing compressions every two minutes is best practice, and that rotation happened here.

I took over compressions and completed six full rounds of the standard 30:2 ratio: thirty compressions followed by two ventilation breaths. This ratio is the cornerstone of Basic and Advanced Life Support protocols, designed to balance perfusion of the vital organs with adequate oxygenation of the blood. Six rounds. Focused, rhythmic, deliberate.

At approximately six minutes into the resuscitation, the patient achieved ROSC — Return of Spontaneous Circulation. This is the moment every person in that room is working towards. The heart restarted. A strong, palpable pulse returned. Most remarkably, spontaneous breathing followed almost immediately.

Neurological assessment was carried out rapidly. The patient's pupils were reactive to light, a hugely encouraging sign. Reactive pupils indicate that the brainstem is functioning and that oxygen deprivation has not caused irreversible damage to the central nervous system. She was also slightly responsive, showing early signs of consciousness returning. The brain had been protected.

With spontaneous breathing re-established, my role shifted to supporting rather than controlling ventilation. I maintained a jaw thrust to keep the airway open. This is a simple but effective manoeuvre: with two hands positioned at the angle of the jaw, the mandible is lifted forward, pulling the tongue away from the back of the throat without moving the neck. It requires no equipment and is one of the most important basic airway skills in emergency care.

The patient was breathing for herself. The iGel was carefully removed and she was placed back on a non-rebreather mask to maintain high-flow oxygen delivery. Post-arrest patients require aggressive oxygenation during the immediate recovery period to support a heart and brain that have been under enormous physiological stress.

Despite the encouraging recovery, a venous blood gas (VBG) was taken and returned a carbon dioxide level of 10. To put this into context: normal venous CO₂ sits between approximately 4.1 and 6.0 kilopascals. A reading of 10 is severely elevated, indicating that the body was failing to adequately expel CO₂ and that ventilation, despite spontaneous breathing, was grossly insufficient. This is known as hypercapnia, and at these levels it represents a serious threat to neurological recovery.

The senior clinician reviewed the blood gas result and made the call to proceed with intubation — to pass an endotracheal tube through the vocal cords into the trachea and take full control of the patient's breathing. This was the right decision. The Outreach team, who had attended the arrest and brought their own advanced equipment, provided the kit needed to perform the intubation safely. The procedure was carried out without complication.

Once intubated and stable, the patient was transferred to CT imaging. The scan of her chest revealed the presence of small clots within the pulmonary vasculature — in other words, a pulmonary embolism (PE). A pulmonary embolism occurs when a blood clot (or multiple clots) travels through the venous system and becomes lodged in the arteries supplying the lungs, obstructing blood flow and placing acute strain on the right side of the heart.

The clots identified in this case were described as small. Whether they were directly responsible for triggering the cardiac arrest remains uncertain. Small PEs do not typically cause arrest on their own, though in the context of a patient with underlying vulnerabilities, even a modest clot burden can precipitate a catastrophic event. The finding raised important questions for the clinical team managing her ongoing care.

The patient was transferred to the Intensive Care Unit without incident. Intubated, ventilated, and monitored. Alive, when she might very easily not have been.

These cases are shared to educate, reflect, and honour the seriousness of the work we do every day. All identifying details have been removed to fully protect patient privacy and dignity. If you found this helpful or have questions, get in touch via www.skillfullscrubs.co.uk — new episodes every week.