Nav: Home

Many ICU patients trade critical illness for new illness, ICU-acquired weakness

April 08, 2016

TORONTO, April 8, 2016--A growing number of patients are being discharged from intensive care units, cured of the critical illness that put them there but facing a new and potentially debilitating condition -- ICU-acquired weakness.

Intensive care patients are known to lose muscle mass and function for many reasons, ranging from prolonged immobilization, to the effects of ICU treatments such as mechanical ventilation to the critical illness itself.

While the mechanisms of muscle atrophy (loss) and function during an ICU stay have been studied well, little research has been conducted into the cellular and molecular mechanisms responsible for recovering muscle strength over the long-term.

A new study published today in the American Journal of Respiratory and Critical Care Medicine found that some patients who continue to suffer from weakness six months after they were discharged from the ICU, demonstrate persistent muscle wasting, even when the biologic functions that commonly cause muscles to atrophy have returned to normal such as inflammation or the breakdown of proteins in muscle tissue.

Furthermore, there is no guarantee that reconstitution of muscle size, normalizes strength; patients who managed to regrow muscle remained weak. In some cases, this muscle weakness causes profound disability and reduced quality of life, and can last a lifetime, said the study's lead author, Dr. Jane Batt, a respirologist at St. Michael's Hospital.

"We know ICU patients lose muscle mass and function. Critical illness literally causes their muscles to dissolve," said Dr. Batt, a scientist in the hospital's Keenan Research Centre for Biomedical Science. "Some people grow it back and some don't. Some people can regrow the muscle, but it doesn't function properly."

Dr. Batt said the novel finding of her study was that sustained muscle atrophy in the long term is the result of impaired regrowth and is associated with a decrease in the number of satellite cells, the precursors to muscle cells.

"While satellite cells are not required for existing muscle fibres to grow in size, they are essential for the regeneration of injured muscle," she said. Decreased number of satellite cells also contribute to age-related muscle loss, she noted.

"Critical illness appears to permanently change muscle biology so your regenerative capacity seems to be lost," she said.

Dr. Batt said ICU-acquired weakness can be a profound disability.

"You may not be able to bathe yourself, feed yourself, go to the toilet yourself, dress yourself," she said. "This can be a very difficult life to live."

Dr. Batt's study looked at critically ill patients who had spent at least one week on a ventilator in an ICU. The study is the first phase of the MEND ICU research program, spearheaded by Dr. Batt and Dr. Claudia dos Santos, an intensivist at St. Michael's. It is part of the RECOVER program, a multi-centre study that evaluates patient and caregiver outcomes after prolonged mechanical ventilation with a goal of developing a family-centred rehabilitation program after severe critical illness.

The number of patients in the study was small, Dr Batt acknowledged. She said this reflected the difficulty in completing long-term mechanistic studies with people who experience critical illness, as many of those who wanted to take part in the study, died, had to return to the ICU, or developed other serious medical problems necessitating treatment that precluded safe continuation in the study.

A companion study was published in the American Journal of Respiratory and Critical Care Medicine in March by the RECOVER program lead, Dr. Margaret Herridge of Toronto General Hospital. That study found that critically ill patients who spend more than one week on ventilation can be divided into four risk groups and that the degree of disability seven days after discharge will determine the one-year mortality and recovery trajectory, including ICU and hospital readmission. The older the patient, the worse the disability, this study found, although the first risk group was patients in their early 40s.

Dr. Batt's study received funding from the Canadian Institutes of Health Research, Physician Services Incorporated Foundation and the Ontario Thoracic Society.
-end-
About St. Michael's Hospital

St. Michael's Hospital provides compassionate care to all who enter its doors. The hospital also provides outstanding medical education to future health care professionals in more than 23 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, and care of the homeless are among the Hospital's recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing International Healthcare Education Center, which make up the Li Ki Sheng Knowledge Institute, research and education at St. Michael's Hospital are recognized and make an impact around the world. Founded in 1892, the hospital is fully affiliated with the University of Toronto.

Media contact:

For more information or to arrange an interview with Dr. Batt, please contact:
Leslie Shepherd
Manager, Media Strategy,
St. Michael's Hospital
Phone: 416-864-6094 or 416-200-4087
shepherdl@smh.ca
http://www.stmichaelshospital.com

St. Michael's Hospital

Related Disability Articles:

How gene mutation causes autism and intellectual disability
Scientists have discovered why a specific genetic mutation causes intellectual disability and autism spectrum disorder in children.
Is disability a risk factor for miscarriage?
A new study compared the proportion of women with any cognitive, physical, or independent living disability who experienced a miscarriage during the previous 5-year period to women without disabilities.
'Climate change is a disability rights issue'
In a high-profile Letter in Science, University of Konstanz climate scientist and ecologist Dr Aleksandra Kosanic, an Associate Fellow of the University of Konstanz's Zukunftskolleg, draws attention to the fact that disabled populations have, until now, been absent from international conversations about climate change and its impact.
Predicting frailty, disability and death
In a study led by investigators from Brigham and Women's Hospital, researchers analyzed patterns of movement among elderly study participants and found that irregular, spontaneous fluctuations could predict a person's risk of frailty, disability and death years later.
Movement patterns predict frailty and disability in the elderly
Elderly people who show more random changes in daily movement tend to be at greater risk of frailty, disability and death, according to a large study involving 1,275 individuals over the course of 13 years.
IQSEC1 gene mutations cause new intellectual disability syndrome
Researchers identify gene causing intellectual disability syndrome that is common in countries where consanguineous marriages are prevalent.
Best medications to reduce drooling for those with developmental disability
A new study has revealed the most effective medications to reduce drooling in young people with a developmental disability, which can affect their socialisation, relationships and community life.
Obesity worsens disability in multiple sclerosis
Obesity is an aggravating factor in relapsing-remitting multiple sclerosis, the most common form of the disease.
Musculoskeletal conditions now second global cause of years lived with disability
Musculoskeletal (MSK) conditions, which affect the body's joints, bones, muscles, tendons and ligaments, now rank as the second leading global cause of years lived with a disability, reveals an analysis of international data, published online in the Annals of the Rheumatic Diseases.
Rehabilitation psychologists: #SayTheWord disability
A group of female rehabilitation psychologists with disabilities highlight the need for clinicians, educators and disability allies to normalize the word 'disability.'
More Disability News and Disability Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

In & Out Of Love
We think of love as a mysterious, unknowable force. Something that happens to us. But what if we could control it? This hour, TED speakers on whether we can decide to fall in — and out of — love. Guests include writer Mandy Len Catron, biological anthropologist Helen Fisher, musician Dessa, One Love CEO Katie Hood, and psychologist Guy Winch.
Now Playing: Science for the People

#542 Climate Doomsday
Have you heard? Climate change. We did it. And it's bad. It's going to be worse. We are already suffering the effects of it in many ways. How should we TALK about the dangers we are facing, though? Should we get people good and scared? Or give them hope? Or both? Host Bethany Brookshire talks with David Wallace-Wells and Sheril Kirschenbaum to find out. This episode is hosted by Bethany Brookshire, science writer from Science News. Related links: Why Climate Disasters Might Not Boost Public Engagement on Climate Change on The New York Times by Andrew Revkin The other kind...
Now Playing: Radiolab

An Announcement from Radiolab