Mild Sedative May Prevent Post-Operative Delirium

The patients were admitted to the intensive care unit (ICU) after non-cardiac surgery in order to investigate if prophylactic low-dose dexmedetomidine--a highly selective α2 adrenoceptor agonist--could safely decrease the incidence of delirium in elderly patients following surgery.

The results showed that the incidence of postoperative delirium in the elderly patients was significantly lower in the dexmedetomidine group (9%) than in the placebo group (23%). On the other hand, the incidence of hypertension was higher with placebo (18%) than with dexmedetomidine (10%) group, as was incidence of tachycardia (14% versus 7%, respectively). Hypotension and bradycardia incidence did not differ among groups. The study was published on August 16, 2016, in The Lancet.

“Previous studies have shown that patients who struggle to sleep after their operation, perhaps because they are in pain or on a busy, noisy ward, are at increased risk of delirium,” said senior author Professor Daqing Ma, MD, of ICL. “The sedative dexmedetomidine seems to not only trigger sleep, but actually mimics the natural state the brain enters during sleep; although other sedatives induce sleep, they do not trigger the natural 'sleep state' the brain requires to rest, reset, and recover.”

Post-operative delirium usually strikes within the first two days of a person waking up from general anesthetic (GA), and the risk increases with age and time under anesthesia. Symptoms range from relatively mild ones, such as a person not knowing their name or where they are, to more severe ones, such as aggressive behavior, paranoia, or even hallucinations. The causes are unknown, but one theory is that major surgery can trigger inflammation throughout the body, which in some cases can spread to the brain.

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