St John was called to the Warepa-Romahapa area near Balclutha last Monday morning but had to use a police four-wheel-drive vehicle to reach the patient while waiting for the rescue helicopter.
Ambulance staff performed CPR on the patient, a 22-year-old woman, until the rescue helicopter arrived to transport her to Dunedin Hospital.
St John district operations manager coastal Otago Dave Jasperse said the ambulance had been "out and about" in the snow earlier that day without any issues, but staff were advised to fit chains before responding to the rural call-out.
"I think the snow caught everyone out and it was decided a police four-wheel-drive [vehicle] would be faster."
Ambulance staff had tried to think proactively and it was a "good call" to use the rescue helicopter, he said.
Others have raised concerns about the lack of a 4WD ambulance in South Otago and the wider Clutha district, due its size and the number of rural roads. In the Owaka, Clinton and Lawrence areas snow and ice often closed roads, making access difficult.
Last Monday, the Lawrence-based ambulance also had trouble on an icy State Highway 8 between Lawrence and Milton while attending a car crash in Manuka Gorge.
None of the five ambulances in South Otago - at Balclutha, Clinton, Lawrence, Milton or Owaka - are 4WD. They carry chains instead.
Milton's 4WD Chevrolet ambulance was replaced with a 2WD Mercedes in June 2009 due to fleet rotation and rarely was used outside the area.
"A Mercedes [ambulance] with chains will get to most places a 4WD can. Because we have the rescue helicopter, if we know a job is off-road or anywhere in questionable areas we will call for an air-ambulance. It's sort of negated the need for 4WD ambulances," Mr Jasperse said.
In Otago there were two 4WD ambulances, one each in Wanaka and Queenstown due to the skifields, he said.
The Otago Daily Times understands the woman in the Warepa-Romahapa call-out had an asthma attack and recovered.
South Otago police have two 4WD vehicles, one based at Owaka and the other at Lawrence.
