Targeting drug safety in the ICU: An interview with Clinical Pharmacist Dr. Lisa Burry

by Natalie Osborne

In the intensive care unit (ICU), a multidisciplinary team of health care professionals must work in tandem to treat critically ill patients. This includes prescribing high-risk medications to severely ill patients while balancing efficacy, minimizing side effects and avoiding harmful drug interactions. Enter the Clinical Pharmacist; professionals trained in pharmacology and clinical medicine who make the rounds in the ICU everyday to ensure patients are receiving safe and efficacious drugs. 

It was this bedside interaction that drew Dr. Lisa Burry to the PharmD program at the University of Toronto (UofT). She had already completed a BSc in pharmacy and worked for four years as a hospital pharmacist in a small community hospital when her mentors encouraged her to pursue advanced clinical care training. She was accepted into one of just six spots in the post-doc PharmD program and hired in the Critical Care Clinical Pharmacy Specialist position at Mount Sinai Hospital even before graduation. Now, years later, Dr. Burry has decided to go back to school for yet another doctorate—this time a PhD at the Institute of Medical Science.

Lisa Burry, BSc Pharm, PharmD. Clinician Scientist & Clinical Pharmacy Specialist, Dept. of Pharmacy, Mount Sinai Hospital; Assistant Professor, Leslie Dan Faculty of Pharmacy, University of Toronto

As a Clinician-Scientist at Mount Sinai and Assistant Professor in the Leslie Dan Faculty of Pharmacy at UofT, Dr. Burry is already an accomplished researcher. She fully credits the clinical research-centric ICU she works in for involving her in as many projects as possible from the very start of her career, and eventually encouraging her to lead her own studies. Dr. Burry is particularly interested in sedation, delirium, and pain relief in critically ill patients. Due to their serious illness as well as invasive life-saving procedures, many ICU patients experience agitation, anxiety, sleep deprivation, and pain.

“My research has focussed on patient and drug safety, and symptom management. For example, if we’re giving a patient a drug to relieve their agitation, I want to determine; what’s the best option?  How long do we need to give it? And how can we wean them off it once they leave the ICU?” Dr. Burry further explains, “As patients’ symptoms evolve over time, the treatment plan is also going to evolve. We need a clear plan for when some of these drugs are going to stop, because there are consequences to many of these drugs in terms of prolonged hospitalization and long-term addiction potential.”

Delirium, associated with medications or severe acute infections, is a common symptom in the ICU. Dr. Burry and colleagues wanted to understand which common ICU drugs increased the risk of delirium, so they followed 550 ICU patients, quantifying every psychoactive drug they received and assessing them for delirium daily. Then, they ran models to assess if any of the drugs were independently associated with delirium, accounting for other potentially confounding predictors such as age and sex (e.g., older men are more likely to have delirium). 

They identified two classes of drugs—benzodiazepines and anti-cholinergic drugs—that were independently associated with delirium. They also determined the dose exposure of these drugs also increased delirium risk. 

 “We know these drugs were potentially problematic, so now we need to understand what to give our patients instead,” Dr. Burry says. “Offering no treatment is not an option, because the agitation, delirium, and pain management issues are still going to be there, so we need to find better alternatives.”

While Dr. Burry’s previous research has focussed on clinical practices within the ICU, she is now following patient outcomes after hospital discharge. For her thesis, Dr. Burry is focussing on geriatric patients (people over 65 years) who make up a large proportion of those admitted to Canadian ICUs. She is using the Institute for Clinical Evaluative Sciences (ICES) database to determine if patients discharged from the hospital after an episode of critical care are being sent home with benzodiazepines and antipsychotic drugs (e.g., to help with symptoms like sleep disturbances and agitation). She will identify risk factors associated with becoming an “acute user” (filling a prescription within a week of discharge) versus a “chronic user” (multiple prescription refills over six months). Dr. Burry will also track the outcomes of patients who are sent home with these drugs, such as emergency department visits, and rehospitalization.

“We know that some of these drugs are associated with falls in elderly people, but nobody has specifically looked at elderly patients who have survived an ICU stay—people we know had a major, severe illness and are more likely to be very frail,” explains Dr. Burry. “I’ll be looking at whether use of these drugs in this particular patient population is increasing the risk of falls, fractures, re-hospitalization, emergency visits and deaths.”

Her planned work will also help her identify which patients should be targeted to receive alternative treatments or weaning of newly initiated drugs; this could be either a different drug, or non-pharmacological strategies that offer comfort and care. One alternative treatment for delirium could be melatonin. Outside of her thesis work, Dr. Burry has recently completed a triple-blinded randomized controlled trial to assess the feasibility of using two different doses of melatonin versus placebo to prevent delirium in ICU patients. Since three quarters of delirium patients have sleep/wake abnormalities, melatonin may reduce delirium by improving patient’s sleep quality and reducing agitation at night (as well as exposure to drugs given to relieve agitation).

While returning to the classroom as a student after being out of school for a long time was a challenge, Dr. Burry believes that being a working adult with two degrees under her belt gave her a better understanding of what she needed. It also helped her target her learning a little better than she could have coming straight from her BSc in pharmacy. She encourages other health care practitioners with an interest in research to pursue advanced research training. 

“I think an MSc or PhD is extremely valuable, even for someone who has as much research experience as I do. The formalized training helps solidify what you do know and identify gaps,” says Dr. Burry “This program has not only given me new knowledge, it’s also reinforced previous learnings and provided the underlying reasons for ‘why things should be done a certain way’ when it comes to certain research methodologies, and I was missing that.”

“I think the fluidity and flexibility of the IMS facilitates people like me to come back and do more training, compared to other more rigidly structured graduate programs that are more of a ‘one-way’ pipeline,” says Dr. Burry. “The IMS allows people from many different disciplines to get extra training and meets the needs of adult learners.”