Dr. Andrew McCallum's office did an initial review of some deaths and found that none of them appear to have been materially affected by issues involving transport by Ornge, which is currently under a criminal probe for financial irregularities.
Since then, other deaths have come to light, McCallum said in a statement Wednesday.
A panel comprising experts in air ambulance, pre-hospital care and emergency medicine is being established to "comprehensively review" all such cases and report back in late fall, he said.
"What we're doing is we're saying there's obviously a group of deaths where there's a common factor, and the factor is concerns about air ambulance transport," deputy chief coroner Dr. Dan Cass said in an interview with The Canadian Press.
"We wanted to ensure that we had the right knowledge and expertise around the table to be able to guide us in evaluating those deaths and coming up with themes and recommendations that might prevent deaths in the future."
The exact number of deaths that will be reviewed hasn't been determined, but 17 cases have already been identified for the panel to consider, Cass said.
It will be able to tap a number of sources, including the coroners' database, regional coroner's offices and cases flagged by the Ministry of Health, he said.
Ornge has also been asked to provide any information on cases that the coroner's office may not be aware of, he said.
Work is already underway, Cass said. Any findings and recommendations will be made public.
Dr. Craig Muir, the regional supervising coroner in Sudbury and a former chief of surgery, is chairman of the panel. It will also include Cass and two other emergency physicians, Dr. Jonathan Dreyer and Dr. John Tallon. All have expertise in emergency care and trauma management.
Premier Dalton McGuinty said he welcomes any advice they can provide.
"If the coroner's panel comes forward with any recommendations to enhance the safety measures then obviously we would be very interested in receiving those and putting those into place," he said.
It should be noted that the workers at Ornge, including paramedics and pilots, devote themselves to public safety, he added.
"I know they do the very best that they can, but if there's anything and all we could do to enhance safety conditions then we would like to do that."
Ornge released a statement saying it will co-operate fully with any requests for information and that patient safety remains its "top priority."
Both opposition parties say they welcome the review too. But the necessity of an expert panel to look into the deaths is another blow to Health Minister Deb Matthews, who failed to see the red flags at Ornge, said Conservative Frank Klees.
"I think that it was very apparent that the minister and the cabinet — including the premier — was well aware of the numerous incidents that involved patient deaths," he said.
"And yet, rather than support me in the calls I made on her to have this examined, she defended what was going on at Ornge."
In June, Klees released confidential cabinet documents which showed the government investigated 26 deaths involving its troubled air ambulance service over the past six years.
They related to 145 incidents involving Ornge since 2007 that were investigated by the Ministry of Health, including delays in dispatching air ambulances, paramedics unable to perform CPR due to cramped conditions in the helicopters, staff shortages and paramedics running out of supplies like oxygen and medication.
Klees said he's concerned that people who had a direct hand in these incidents are still working at Ornge.
A legislative committee spent months probing the controversy that's engulfed Ornge, including former CEO Chris Mazza's $1.4-million compensation.
The province's auditor general has already questioned Ornge's business dealings and slammed the government for failing to oversee an organization that received $730 million over five years and borrowed $300 million more.
The review into the deaths shouldn't be seen as an attack on front-line workers at Ornge who are trying their best to save lives, said New Democrat Gilles Bisson.
"This is a black eye for the government, if anything, not the employees of Ornge," he said.