A tentative deal between Ottawa paramedics and their rural counterparts won't prevent the capital from running out of ambulances to respond to emergencies, senior officials say. In fact, it could make the situation worse.

According to documents obtained by CBC News through access to information, Ottawa paramedics were without a single available ambulance to transport patients to hospital more than 250 times in 2016.

Paramedics call it "level zero."

During a level zero alert, Ottawa paramedics using smaller vehicles may still respond to calls that don't require an ambulance. If the call involves cardiac arrest, police or firefighters may answer it to administer CPR.

In other cases, paramedics from neighbouring municipalities are called in to help. But the tentative agreement with paramedic services in Renfrew County, Prescott-Russell and Cornwall means those resources could soon be diminished.

Deal needs ministry's OK

​Anthony Di Monte, the city's general manager of emergency and protective services, said the agreement — which would see paramedics from neighbouring areas respond only to calls involving cardiac arrest and unconscious patients — still needs the approval of Ontario's Ministry of Health and Long-Term Care.

Asked whether he believed the agreement, if ratified by the province, would result in more level zero alerts in Ottawa, Di Monte agreed it would.

Myles Cassidy was hired as Ottawa's paramedic chief in June. Previously he oversaw emergency services in Cornwall, Ont. (Ashley Burke/CBC) "You're asking me a hypothetical situation because we haven't agreed," Di Monte said Wednesday. "But yes, it would. That's part of the complexity. That's why there's no agreement yet. We're exploring different avenues."

Councillors from at least one neighbouring township, Prescott-Russell, have already signed off on the agreement and are in the process of sending it to the province for approval.

Ottawa's chief paramedic, Myles Cassidy, has delegated authority to enter into such agreements, meaning he does not require the approval of Ottawa city council.

City hit level zero 256 times last year

Ottawa's paramedic service was without an available ambulance 256 times in 2016, according to the most recent figures available.

The frequency of level zero alarms we are hearing every shift are increasing. - Darryl Wilton, Professional Paramedic Association of Ottawa

Some days saw multiple level zero alerts. On Dec. 15, seven alerts were issued over the paramedic service's dispatch system. Last July there were 16 alerts in a single week.

The alerts lasted anywhere from a few minutes to two-and-a-half hours.

According to Darryl Wilton, president of the Professional Paramedic Association of Ottawa, the alerts are happening more and more frequently.

"It's worse," said Wilton. "The frequency of the [level zero] alarms we are hearing every shift are increasing."

Wilton said many of the alerts came this summer, when thousands of tourists crowded the city's downtown for Canada 150 events, further straining the paramedic service's resources.

Service can absorb volume, chief maintains

Paramedic Chief Myles Cassidy, who oversaw emergency services in Cornwall before coming to Ottawa in June, said the agreement with the three rural municipalities is aimed at taking the pressure off smaller paramedic services in surrounding communities, and won't have a significant impact on service levels in the capital, where paramedics receive approximately 137,000 calls for service per year.

La Machine was one of the Canada 150 events that kept Ottawa paramedics extra busy this summer. (Matthew Kupfer/CBC)

Paramedics from neighbouring municipalities are called in to respond to only a "very small percentage" of those emergencies, Cassidy said.

"The system will adjust and absorb those calls," he said.

Di Monte confirmed Ottawa paramedics have been under extra stress this summer, but said they've been able to keep up with the demand.

"There was no impact on patient care or outcome," said Di Monte. "But yeah, we're struggling a little bit."

New hires will help, GM says

Di Monte said the recent addition of new recruits will help Ottawa's paramedic service deal with the growing burden.

"We let volume and growth catch up with us, and we're correcting that," he said.

Ottawa city council approved the hiring of 12 paramedics in 2016 and another 24 this year, plus the addition of one ambulance.

Fourteen more paramedics and a second new ambulance are anticipated next year, pending budget approval.