Regular physical activity at least seven times a week before cancer surgery was linked to a lower risk of developing postoperative delirium, according to research presented at the ANESTHESIOLOGY® 2026 annual meeting. In findings presented by Nader D. Nader at the ANESTHESIOLOGY 2026 annual meeting, cannabis consumers face an elevated probability of experiencing a heart attack close to their surgical window, alongside a surprising decrease in the likelihood of dangerous blood clots forming in their veins. Nader serves as both the lead author of that investigation and a professor of surgery and anesthesiology at the University at Buffalo, New York’s Jacobs School of Medicine and Biomedical Sciences.
Postoperative delirium is a sudden state of confusion that affects roughly 20% of patients undergoing surgery, posing particular risks for older adults by impairing attention, memory, and thinking while lengthening hospital stays and recovery times. In the context of cardiovascular safety, Nader D. Nader noted that cannabis can affect the heart, blood vessels, and how the body responds to anesthesia, making it vital to inform anesthesiologists before any procedure.
Melody Haratian, a medical student and lead author of the study at the University of South Florida Morsani College of Medicine in Tampa, noted the broader value of physical preparation. Jeffrey Huang, professor of oncological science and senior member of anesthesiology at Moffitt Cancer Center, emphasized that preparing for surgery starts before the day of the operation. Rose Berkun, associate professor of anesthesiology at the Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, New York, pointed out that contemporary cannabis items possess substantially greater potency than those from past decades, noting that elevated THC concentrations can trigger significant cardiovascular consequences.
Activity Frequency and Delirium Risk at Moffitt Cancer Center
The retrospective, matched, case-control study examined 258 patients who underwent cancer tumor removal surgery between 2024 and 2025. Among the cohort, 64 patients developed postoperative delirium, while 194 did not. Rather than counting active days, researchers evaluated the number of physical activity instances per week. In a different surgical context, reviewing five studies including data from 44,312 surgical patients, researchers found that cannabis use was associated with a 46% increased risk of myocardial infarction during or shortly after surgery compared to nonusers, alongside a 22% lower risk of venous thromboembolism.
Participants self-reported how frequently they walked or engaged in moderate or vigorous physical activity for at least 10 minutes at a time, along with the hours spent sitting on a typical day. Researchers identified postoperative delirium instances through positive results on the Confusion Assessment Method test, a standard screening tool used to detect delirium. Similarly, investigating acute aortic dissection surgery, researchers prospectively evaluated 67 patients and found that preoperative serum levels of C1q were predictive of postoperative delirium with an odds ratio of 1.379 (95% CI = 1.176–1.683, p < 0.001) and an area under the curve of 0.788.
Patients who reported a combined regimen of walking and moderate or vigorous physical activity at least seven times a week experienced a 50% lower risk of developing postoperative delirium compared to less active individuals. Conversely, patients who developed delirium reported less walking, lower levels of moderate, vigorous, and total physical activity, and more daily sitting time on average. Measurements of serum C1q showed significantly elevated concentrations in the delirium group relative to the patients without delirium, evaluated both before and after surgery.
Prehabilitation Strategies and Unresolved Questions
The results add to mounting evidence supporting prehabilitation, an approach that helps patients prepare for major operations through structured exercise, proper nutrition, and other supportive strategies to improve overall outcomes.