Helicopter air ambulance transfers weren't readily available for days at a time, leading to fears patients could be harmed.
Improvements were ordered for the service covering Auckland and Northland and a review by independent experts is due early next year. Officials have reassured the public that problems have been fixed.
"The northern region now has four modern, large twin-engine helicopters which replace smaller helicopters," said Keriana Brooking, Ministry of Health deputy director-general for health system improvement. "The service gaps have been due to the complexity of bringing the new helicopters into service."
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Air ambulance crews demonstrated their crucial role in the emergency system by responding to last week's Whakaari/White Island eruption, including transfer of burns victims to hospitals across the country.
However, documents obtained by the Weekend Herald reveal services in Auckland and Northland struggled soon after a Government-initiated overhaul.
Chief executives from the country's 20 DHBs were so concerned they wrote to the Director General of Health, Dr Ashley Bloomfield, at the end of August and warned patients could come to harm.
There were numerous incidents since June when the DHBs had been told inter-hospital and pre-emergency transfers by helicopter air ambulance was "compromised and at times unavailable for a period ranging from eight hours to several days". Pre-emergency or hospital transfers include transport from an accident or medical event to hospital.
"The chief executives are concerned that patients will be harmed if this preventable resourcing issue is not resolved," the letter to Bloomfield warned.
A new agreement for air ambulance services was reached last year between the Ministry of Health, ACC and a new agency combining the long-standing Auckland Rescue Helicopter Trust and the Northland Emergency Services Trust.
Health Minister David Clark trumpeted the agreement in a press release as a "major step towards a better, safer service nationwide", and said upgrading aircraft and systems would make services "more effective and efficient".
However, problems emerged not long after the new combined operation - called Northern Rescue Helicopter Limited (NRHL) - took over. Between June and July the service was hit with four separate breach notices. On one occasion a helicopter from outside the region had to fly to Whangārei, meaning there could be no inter-hospital air transfers in Hawke's Bay DHB for 24 hours.
"The shifting of helicopters from one region to another without robust risk assessment and management planning intensifies the risk of harm being caused to patients and DHB workforce," the DHB chief executive letter to Bloomfield stated.
"The chief executives are concerned that NRHL continues to breach contracted service provision requirements. The risks associated with this ongoing disruption to service and lack of operational functionality compromises safety and may result in harm to patients."
Bloomfield responded on September 3, assuring the DHBs that action was being taken, with "active discussions with the provider about the current inadequate service provision and the ongoing extent of the gap between the current state and contracted service standards".
"We have been very clear that the current state is not acceptable and the gap needs to be addressed promptly and sustainably."
As a result, Auckland Rescue Helicopter Trust had considered outsourcing flight management, piloting and crewing to another organisation, Bloomfield wrote (the trust ultimately opted against this). Bloomfield recognised the problems "create significant additional pressure" for DHB teams.
The national ambulance sector office (Naso) is jointly funded by ACC and the Ministry of Health and plans and funds ambulance services. It told NRHL it wanted a range of changes made by December 1, including training, aircraft and equipment certification, operational procedures and aircraft maintenance. An assurance review by aeromedical experts was launched, with a report back in early 2020.
Michelle Boag, acting chief executive of the Auckland Rescue Helicopter Trust, said the trust and Northland Emergency Services Trust, the two partners in NRHL, would leave comment on the "very outdated" documents to the ministry. The DHBs and Health Minister David Clark also referred questions to the ministry.
Brooking said there were no reports of patients being harmed because of the issues, and the changes ordered by Naso had been made. The public could have confidence in the service, she said, and there was stricter monitoring in place than ever before.
The decision to buy the larger helicopters was made before the new air ambulance structure, she said, and the service gaps were a result of delays in bringing the new aircraft into service.
"There are now modern, larger and safer helicopters in service that meet all Civil Aviation Authority regulatory requirements. Clinical staff have more room to provide intensive care on board, ensuring patients needing urgent clinical attention get the right care at the right time.
"This is a significant upgrade which is transformational, impacting on crewing capacity, training and operational configurations, all while maintaining business as usual operations. Doing this while maintaining safety standards is paramount and implementation has taken longer than Northern Rescue Helicopter Limited had anticipated."
Rescue helicopters in New Zealand operate as trusts and charities, and must fundraise to cover just over half of their annual operating costs.