New Canadian study tracks older adults to reduce postsurgery complications

As Canada’s population ages, improving surgical outcomes for older adults has become a growing priority for health researchers. A new study led by Hamilton-based scientists aims to identify early warning signs of serious complications such as infection, stroke, and heart problems — potentially allowing doctors to intervene sooner and save lives.

Researchers at McMaster University and affiliated institutions are preparing to follow 20,000 patients aged 65 and older to better understand what happens in the hours and days after surgery.

Older adults face higher surgical risks

While surgery is generally safe and often life-saving, older patients face higher risks, particularly if they have existing health conditions.

“Even though surgery is overwhelmingly safe and there are enormous benefits from it, complications can occur, particularly in much older patients with underlying comorbidities,” said Dr. Philip J. Devereaux, a cardiologist and professor at McMaster.

Previous Canadian research highlights the scale of the problem. A nationwide study published last year involving 2,007 older adults found that one in six developed a new disability or died within six months of major non-cardiac surgery. After one year, the number rose to one in five.

These findings underscore the need for earlier detection and prevention — especially in Canada, where seniors represent one of the fastest-growing segments of the population.

Continuous monitoring could reveal early warning signs

Through earlier work at the Population Health Research Institute, a joint institute of McMaster and Hamilton Health Sciences, researchers identified a key challenge: symptoms of complications are often missed or detected too late.

Pain medications commonly used after surgery, including opioids, can mask warning signs.

“That can result in substantial delays in recognizing and treating complications,” Devereaux said.

To address this, the team helped develop a wearable device known as the Vitaliti monitor. The device continuously tracks vital signs including:

• Heart rate and rhythm

• Blood pressure

• Body temperature

• Oxygen levels

• Breathing rate

• Movement and body position

• Sleep patterns

Participants in the new VISION-2 study will wear the monitor before surgery and again immediately afterward, continuing for 30 days during recovery.

AI to predict life-threatening infections

One major focus of the study is sepsis, a dangerous and potentially fatal response to infection.

Researchers expect about 800 participants to develop sepsis. They will compare those patients with similar individuals who do not develop the condition.

Using artificial intelligence, the team will analyze subtle changes in vital signs to identify patterns that appear hours before sepsis is diagnosed.

“The goal is to determine how these parameters change six, nine, and 12 hours before clinical diagnosis,” Devereaux explained.

Detecting these early warning signals could allow health-care teams to treat infections sooner and prevent serious harm.

The same approach will also be used to identify early signs of heart ischemia — when the heart muscle does not receive enough oxygen — as well as other major complications.

Hidden strokes also under investigation

Another key concern is the risk of so-called “silent” or covert strokes after surgery.

Using MRI scans, researchers previously discovered that about seven per cent of patients aged 65 and older experience these strokes following non-cardiac surgery.

Although patients may not notice immediate symptoms, these silent strokes significantly increase the risk of cognitive decline within a year.

MRI scans can detect these events, but widespread screening is not practical due to high costs and limited access — a challenge familiar to many Canadian hospitals facing resource constraints.

Blood protein analysis may unlock new clues

To overcome these limitations, the Hamilton research team will also analyze blood samples collected before and after surgery.

Using specialized technology available locally, researchers can measure up to 5,000 different proteins in a single sample.

This could help identify new biological markers — known as biomarkers — that signal when complications such as stroke or infection are developing.

These findings could eventually lead to blood tests capable of detecting complications much earlier than current methods allow.

Hamilton at the centre of international research effort

The study will begin in Hamilton, Ontario, with patients recruited from local hospitals as well as international sites.

Researchers hope the results will improve care not only in Canada but globally, helping physicians better monitor vulnerable patients during recovery.

Conclusion

As Canada’s health-care system adapts to an aging population, preventing postsurgical complications is becoming increasingly important. By combining wearable technology, blood analysis, and artificial intelligence, Hamilton researchers aim to detect life-threatening problems sooner — potentially transforming recovery and improving outcomes for thousands of older surgical patients.