Drones could be used to deliver life-saving defibrillators to Scots who have suffered a cardiac arrest

Drones could soon be used to deliver life-saving defibrillators to people in Scotland who have suffered a cardiac arrest.

In a remarkable experiment that could revolutionise emergency responses, the Scottish Ambulance Service (SAS) is about to try flying autonomous aerial vehicles directly to casualties whose hearts have stopped.

The idea is that a high-speed drone can potentially drop a defibrillator right next to the stricken patient in far less time than it would take for a conventional ambulance to drive to the scene.

Given that every second counts after cardiac arrest, the quick arrival of a defibrillator from the sky could massively improve survival rates.

New figures show the ambulance service is failing to meet its ambitious target to respond to the most urgent calls-outs within six minutes.

But while a drone may be able to reach some casualties more quickly, the success of the scheme relies upon the willingness of bystanders to step in and use the machine to try to re-start the patient’s heart.

Although the technology has never been used in Scotland, it has previously been trialled in Sweden – where it been found to save lives.

The SAS plans to publish details of the plan in the coming months.

However, members of the public are being recruited to take part in an experiment in the Edinburgh area to test the drone scheme.

A recent online post said: “The Scottish Ambulance Service is exploring whether drones can be used to deliver life-saving equipment in medical emergencies.

“The service is looking for members of the public to take part in a simulated medical incident where a drone will deliver a defibrillator which is used to restart someone’s heart.”

Swedish trials

A similar scheme was pioneered in Sweden – and, in December 2021, the first ever life was saved by a defibrillator drone.

A 71-year-old man in the city of Trollhättan was shovelling snow from his driveway when he suddenly collapsed after suffering a cardiac arrest. Dr Mustafa Ali – a medic on his way to work at the local hospital – saw the man fall and immediately began CPR while asking another passer-by to dial emergency services for help.

Within three minutes, a drone had arrived and dropped off a lightweight defibrillator – which the doctor used to shock the man back to life.

The patient, who recovered fully, was later reported as saying: “I can’t put into words how thankful I am to this new technology and the speedy delivery of the defibrillator. If it wasn’t for the drone I probably wouldn’t be here.”

Swedish researchers have conducted a landmark study comparing response times and survival rates for defibrillator delivery by ambulance and by drone.

The results, published last November, showed that drones delivering defibrillators consistently out- performed ambulances in the race to get life-saving treatment to people whose hearts had stopped beating.

However the study concluded that while patients can get treatment faster by drone, there needs to be someone nearby trained in CPR.

Time is critical when it comes to reviving patients who have gone into cardiac arrest. Using a defibrillator to apply an electrical shock to a heart within three to five minutes of it stopping means up to 70% of patients survive.

To see whether drones could cut the time taken to get defibrillators to collapsed patients, Andreas Claesson, at the Karolinska Institute, and his colleagues launched a collaborative project with drone operator Everdrone and emergency services in western Sweden where drones and ambulances were dispatched to each suspected case of cardiac arrest.

Across the 55 test-cases, drones were quicker than ambulances 67% of the time, and by an average of three minutes and 14 seconds.

The study concluded: “Drones can deliver automated external defibrillators in daylight, non-daylight, summertime and wintertime, and before emergency services in a majority of cases.”

He added: “We have shown that the method of transportation is really effective. What happens after that is dependent on local conditions and CPR knowledge.”

999 response times

The potential value of the drones is highlighted by the latest statistics on 999 response times – which show that the ambulance service is missing its targets.

The SAS aims to respond to the most urgent call-outs within an average of just six minutes.

The most serious cases are classified as ‘purple’ and involve the most critically-ill patients – around half of whom have suffered cardiac arrest.

Figures for the week beginning March 4 show that the ambulance service responded to 477 “purple” incidents across Scotland – with an average response time of seven minutes and 25 seconds.

For “red” cases – where a patient is identified as having a likelihood of cardiac arrest between 1% and 10% – the target for response is seven minutes.

In the same week, the ambulance service attended 2,105 “red” incidents – with an average arrival time of eight minutes and 36 seconds.

For “amber” cases – where a patient is likely to need diagnosis and transport to hospital but where there is minimal risk of cardiac arrest – the target is 15 minutes.

Figures show that 4,208 such cases in the same week – with an average response time of 16 minutes and 44 seconds.

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How to use a defibrillator

Steps to using a defibrillator (as supplied by the British Heart Foundation)

Anyone can use a defibrillator. You do not need training. Once you turn it on, it will give clear step-by-step voice instructions

Step 1: Press the green button to switch on the defibrillator and follow the instructions.

Step 2: Remove the person’s clothing above the waist.

Step 3: Peel off the sticky pads and attach them to the person’s bare skin. Put one pad on each side of the chest (as shown in the picture on the defibrillator).

Step 4: Once you have attached the pads, stop CPR and do not touch the person. The defibrillator will then check the person’s heart rhythm.

Step 5: The defibrillator will decide whether a shock is needed. If so, it will tell you to press the “shock” button. An automatic defibrillator will shock the person without you needing to do anything. Do not touch the person while they’re being shocked.

Step 6: The defibrillator will tell you when the shock has been given and whether you need to continue CPR.

Step 7: If the defibrillator tells you to continue to do CPR, continue with chest compressions until the person shows signs of life, or the defibrillator tells you to stop so it can analyse the heartbeat again.