Warning over defibrillator batteries

Sports clubs have been urged to store automated external defibrillators (AEDs) with extreme care after the batteries in a diving club’s device went flat just days before a fatal diving accident.

Cork City Coroner’s court heard how an AED on one of Blackwater Sub Aqua Club’s dive boats failed to work as club members fought desperately to save John McNally after he got into difficulty off Roches’s Point.

Club member Liam Lacey said he checked the Zoll-made Class 2B AED, which was stored in a water-proof case in the club building, about 10 days before the dive and it indicated that everything was OK.

Tests on the machine, ordered after Mr McNally’s death and conducted in the US by Zoll, found that while the device was in working order and running self-diagnostics, its batteries had failed just five days before the tragic dive.

The inquest was told the device would have sounded an alarm for 24 hours and displayed a red X continuously on its screen.

Club members didn’t realise there was a problem until it was produced from its storage case on the dive boat mid-emergency.

Dr Joan Gilvarry of the Health Products Regulatory Authority, which oversaw the tests on the device, said the AED was powered by 10 regular Duracell batteries.

She said Zoll recommends that AED batteries are changed after five years, or when prompted by the device to do so.

But in this tragic case, she said: “The batteries failed four years and two days into their existence when they were needed for a patient.”

She told the inquest this was a rare event, with five similar cases recorded worldwide with some 500,000 such AEDs in service.

She said the authority issued guidance to sports clubs in 2011 about the storage of AEDs, advising that temperature, humidity, and storage practices can all have a bearing on battery life. Even if the AED had worked on this occasion, it probably wouldn’t have made any difference to Mr McNally, said Dr Margot Bolster, the assistant State pathologist.