Two hospitals in Toronto are experimenting with dedicated teams that can administer a deep-freeze treatment for cardiac arrest patients, which is thought to improve the odds of those patients retaining healthy neurological function.
Therapeutic hypothermia reduces a patient’s body temperature by roughly five degrees Celsius for a 24-hour period. This technique, doctors say, can help a patient’s recovery after a cardiac-arrest induced coma. But therapeutic hypothermia isn’t popular at the bedside of Canadian hospitals, despite evidence from two separate 2002 medical trials in Europe and Australia.
Steven Brooks, at Toronto’s Sunnybrook Hospital, was inspired enough by those trials to create dedicated, on-call Post Arrest Consult Teams (PACT) last year at both Sunnybrook and St. Michael’s hospital, so that all cases of post-cardiac- arrest syndrome brought into those hospitals would have a shot at the treatment.
“The problem was that doctors weren’t familiar with how to do the treatment or they didn’t see these kinds of patients very often, so there wasn’t a lot of comfort and expertise,” Dr. Brooks said. Overcrowding in emergency rooms as well as continuity of care when patients are transferred to different hospital units are other challenges.
If these dedicated teams increase the incidence of patient treatment and save more lives, hospitals will be more inclined to try the treatment across Canada, he said.
Since the team was launched at St. Michael’s in February, the hospital has seen 46 cardiac arrest patients, of whom 20 were treated with therapeutic hypothermia, said Karen Wannamaker, the lead nurse of PACT. Although it’s too early in the study to say if PACT is working, Ms. Wannamaker and Dr. Brooks say they are confident eligible patients are now less likely to slip through the cracks.
Cardiac arrest kills about 16,000 Canadians a year, Dr. Brooks said. “Even after we start the heart again, about 60 per cent of people who get admitted to hospital will end up dying as a complication of the cardiac arrest. That’s because other important organs are injured when blood flow stops.”
In therapeutic hypothermia, the body’s core temperature is reduced from the norm of 37 to roughly 32 for a one-day period through various methods – ice packs around the major arteries of the head, groin and armpits; a chilled saline solution administered intravenously, and a blanket that circulates temperature-controlled water. Occasionally patients are also given paralytic drugs that stop shivering, the body’s involuntary method of getting warmer. The cooling helps preserve brain function as well as the recovery of other organs that would have been harmed by the lack of oxygen flow while the patient’s heart was stopped.
Dr. Brooks said this cooling treatment is significantly more effective than some other traditional treatment. It has an NNT (number needed to treat) of 6, which represents the average number of patients who need to be treated to prevent one additional bad outcome. In comparison, the NNT for using clot-busting medicine is somewhere between 37 and 91.
“It’s fairly easy, but it takes a co-ordinated effort to make it all happen,” Ms. Wannamaker said.
Kelvin Au credits his recovery from a heart attack to the treatment. The 33-year-old collapsed on a basketball court in 2009 and was rushed to a hospital in Toronto’s North York region. Doctors there were able to start his heart, but Mr. Au did not regain consciousness.
“The doctors had been pessimistic, but they said this cold treatment was the best shot at his recovery,” his wife, Liz Au, said in an interview.
He was transferred to St. Michael’s hospital, where a few medical professionals were practising therapeutic hypothermia, but without the dedicated team.
“This is definitely one of the things that saved my life,” Mr. Au said. “I now have my life almost back to normal, but I still can’t remember about two weeks of life around when the heart attack happened and I have short-term amnesia.”
American hospitals have also recently started experimenting with similar teams, such as teaching hospital at the University of Pittsburgh Medical Center.
Dr. Brooks said he hopes the trial runs of these teams at the two Toronto hospitals will eventually lead to application at more hospitals in Ontario, and possibly Canada.
“We think this PACT will allow us to treat more eligible patients with therapeutic hypothermia, and it should help with making the best decisions for the patients’ survival,” Dr. Brooks said.
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