Two people have reportedly died because of ambulances getting to them too late due to outdated GPS maps, NHS admitted.
The failure to update satnav maps as well as computer systems in control centres could have cost further three lives of patients with cardiac arrests as ambulance drivers struggled to find their addresses after changes to road layouts.
A total of 66 cases of late arrivals due to not updated maps have been reported in the past 18 months including new locations not being uploaded at all to the ambulance satnav systems.
"Ambulance vehicles should have satellite navigation systems that assist crews to identify the location of the emergency,” NHS said in a statement. “However, reports to the National Reporting and Learning System (NRLS) suggest some ambulance satellite navigation systems may not be up-to-date with new locations, resulting in delays."
It further called on ambulance operators to make sure their satnav systems are updated frequently enough to provide the timeliest possible help, which could determine the chances of the patients.
In the case of one of the two reported deaths, the ambulance arrived about ten minutes later than it would have arrived, had its GPS been updated with the map of the new estate where the accident happened.
The ambulance, unable to reach the location reportedly contacted its control centre, which also didn’t have its maps up-to-date
"If the latest maps were programmed into the satnav, then the patient may have received Advanced Life Support sooner with earlier defibrillation," the incident report said.
There have been many incidents of satnavs causing problems for ambulances in recent years.
In 2006 a London Ambulance Service crew transferring a patient to hospital was sent 200 miles in the wrong direction by a faulty satnav instead of on a 12 mile journey that should have taken about 30 minutes.
A spokesman for the ambulance service said the crew had not been to Mascalls Park Hospital near Brentwood in Essex before, and only realised they had gone the wrong way when they reached the outskirts of Manchester.
In 2012 an inquest heard that a satnav delayed an ambulance getting to the home of a nine-year-old boy who died after a severe asthma attack in Bromsgrove, Worcestershire.
An ambulance took 24 minutes to reach the schoolboy and he was pronounced dead shortly after arrival at hospital. It later emerged that the ambulance's satnav had sent the crew in the wrong direction, but it was found that it would have made no difference to his death.