The terrifying tale that an Alberta man shared last week of the 39 days he spent on a ventilator in an ICU battling COVID-19 included what he called severe hallucinations.
And according to Dr. Darren Markland, an Edmonton intensive care physician, that's something many patients experience as they fight for their lives in an ICU — whether with COVID-19 or some other critical illness.
It's called ICU delirium.
On Monday's CBC Calgary News at 6 with Rob Brown, Markland described the experience as a scrambling of one's ability to perceive time and to put things together in the usual ways.
"People with sleep deprivation can feel some of that," he said. "Multiply that by a factor of 10 or 20 and you get the idea of how bad it can be in the intensive care unit."
Markland said it's an "incredibly common" occurrence with patients in the ICU.
"It's probably because what really gets you into the intensive care unit, in most cases, is brain failure. So, when you are really sick, one of the last things to fail is your consciousness."
In Paul Hemsing's case, the Medicine Hat man told CBC News last week that it took about five days for him to emerge from the fog of sedation once doctors finally got him out of a medically induced coma.
"That was a really mentally scary time, because you were foggy and groggy, and you were seeing snakes and spiders. I was very panicked," he said.
According to Markland, the high amount of sedation often needed to treat patients in an ICU can contribute to delirium.
A study published in March in the academic journal The Lancet looked at data from 2,000 critically ill patients with COVID-19 from 69 ICUs across 14 countries. It found that greater than 50 per cent developed delirium that lasted for a median of two weeks.
That study concluded that the use of benzodiazepine infusion, for sedation, increased the risk by about 60 per cent.
Markland says the noisy, chaotic atmosphere of the ICU is also a big factor.
"Our intensive care unit is very busy, very loud. And that's the last thing you need when you're trying to get your wits about you," he said.
Becoming delirious while undergoing ICU care can increase the chance of death by 30 per cent, according to Markland.
A study in 2019 by the Indiana-based Regenstrief Institute published in the journal Critical Care Medicine said that each day with delirium in the ICU is associated with a 10 per cent increased likelihood of death.
"And that's probably because it correlates with the severity of disease. When your brain malfunctions, you know it's a bad situation," Markland said.
And ICU delirium can make the work of caring for the patient that much harder.
"Sometimes they fight the ventilator, they pull on tubes," he said.
"And that can go on for quite a long time. That requires a lot of extra nursing care."