Ambulance delays due to out of date satellite navigation systems could have contributed to two patient deaths, according to incidents reported to the National Reporting and Learning System.

Two reports “suggest the delay contributed to the patient’s death” while three other reports described delays attending cardiac arrests, “suggesting the patient was not given the best chance of survival”.

NHS England has sent out a patient safety alert to ambulance trusts after 66 reports were submitted between April 2012 and September 2013 relating to satellite navigation systems.

Systems should be up to date with the latest road layouts, addresses and new build information.

However, nine reports indicated new locations had not been uploaded onto the navigation system.

One of the reports into a patient death said that the device had not been updated with the new road layouts to include new estates built in the last few years. This caused a 10 minute delay to arriving on the scene of a cardiac arrest.

The ambulance crew contacted its central control team but it “also seemed their maps were not up to date either”.

The report concluded that if the latest maps were programmed into the device, the patient may have received life support sooner.

Every six weeks digital updates are provided by the Ordnance Survey to ambulance trusts and detail all new addresses but the NRLS reports suggest the ambulance dispatch systems “were not always promptly updated”.

Ambulance trusts have been told to completely update their systems by 20 August.

An NHS England spokeswoman said: “It is vital that these ambulance systems remain up to date to prevent unnecessary delays in providing emergency care.”