Excessive daytime sleepiness may raise risk of cognitive problems after surgery, reveals study
People 60 and older who are excessively sleepy during the day may have more problems with memory and thinking after surgery, suggests a study presented at the ANESTHESIOLOGY® 2025 annual meeting. Daytime sleepiness is a symptom of sleep deficiency that affects up to 20% of adults and may increase the risk of perioperative neurocognitive disorders (PNDs), researchers found.
“Asking patients, their family or caregivers if they doze frequently during the day or have trouble staying alert might provide an important clue to brain health after surgery,” said Jeffry Takla, M.D., lead author of the study and a postdoctoral associate in anesthesiology at Duke University School of Medicine, Durham, North Carolina. “Excessive daytime sleepiness is often overlooked in preoperative evaluations, but it can elevate the risk of PNDs. PNDs have been associated with worse postoperative quality of life and increased hospital length of stay. In some cases, patients may not fully recover their previous level of independence and may need extra help from caregivers or even transition to assisted living.”
A PND is a problem with thinking and awareness that can affect up to 40% of older patients after surgery. It often appears as delirium, a sudden state of confusion that can come and go within days after surgery and include symptoms like being disoriented, having trouble focusing or not following instructions. In some cases, it can continue for weeks or months as a longer-term neurocognitive disorder and include confusion, memory problems and difficulty concentrating, which can reduce quality of life.
In the study, 96 patients aged 60 or older scheduled for non-cardiac surgery completed the Epworth Sleepiness Scale, a short questionnaire that measures daytime sleepiness based on how likely the person is to fall asleep during common activities such as reading or watching TV. They also underwent home sleep apnea testing and had cognitive and delirium assessments before and after surgery. Of that group, 11 (11.5%) had experienced moderate to severe daytime sleepiness. Six weeks after surgery, 82 patients returned for cognitive and delirium tests and 14 of them (17.1%) experienced postoperative neurocognitive disorder. The eight patients with moderate to severe excessive daytime sleepiness who completed follow up testing were found to have greater global cognitive decline — meaning worse problems with memory and thinking — six weeks after surgery.
Families and caretakers can help reduce the likelihood of PNDs by spending time with the patient. They should alert the health care team if they notice the patient is showing new signs of memory problems, trouble paying attention or agitation. This alerts the care team to check for possible causes of PNDs, while also focusing on supportive steps like re-orienting the patient, getting them moving early and ensuring they are eating and drinking enough.
“Excessive daytime sleepiness isn’t a normal part of aging,” said Dr. Takla. “It often stems from poor or fragmented sleep, sleep disorders such as sleep apnea, medication side effects, or other health or mental health conditions.”
Good sleep habits can help. They include regular bed and wake times, getting natural sunlight and daily activity, limiting evening caffeine and alcohol and a quiet, comfortable bedroom. If sleepiness continues, people should see their primary care doctor or sleep specialist to determine the cause and find treatment.
“Future studies should examine whether excessive daytime sleepiness is linked to the incidence of PND. If such a relationship exists, researchers should explore whether detecting and treating excessive daytime sleepiness can lower the risk of PNDs, such as delirium, in older patients after surgery,” said Dr. Takla. “People who have this problem may consider having a sleep study or sleep hygiene counseling, especially if their symptoms continue or interfere with daily function.”
