Postoperative delirium: does melatonin really work?

#Delirium  #Surgery  #Melatonin  #Prevention  #Cognition  #Sleep  #Geriatrics  #Anesthesia


Postoperative delirium (POD) is a common disorder in elderly patients following surgery. It manifests as attention, perception, and cognitive disturbances, potentially leading to severe complications. POD increases the risk of cognitive decline, loss of autonomy, and mortality.

Unfortunately, few effective treatments exist once delirium has set in. The medications used often have significant side effects, particularly in older adults. This makes prevention essential to reducing risks and improving patient recovery.

Among the approaches studied, melatonin could be a promising solution. This hormone, which regulates the sleep-wake cycle, also plays a role in cognition and mood. Sleep disturbances and circadian rhythm disruptions are frequently observed in patients with POD, suggesting that melatonin might help prevent this condition.

However, study results remain uncertain. Some research shows a beneficial effect in reducing POD, while others find no difference compared to a placebo. These discrepancies may stem from variations in dosage, treatment duration, or evaluation methods.

In this context, this study explores the effectiveness of melatonin in preventing postoperative delirium in elderly patients, analyzing its impact on POD incidence, sleep quality, and postoperative recovery.

Melatonin: miracle or mirage against POD?

This study included 120 patients over the age of 65 undergoing non-cardiac surgery. Participants were randomly assigned to two groups:

• Melatonin group: Administration of 3 mg of melatonin before surgery and for seven days postoperatively.
• Placebo group: Identical protocol without melatonin.

Patients were monitored during hospitalization and for three months after surgery. Evaluation criteria included POD incidence, sleep quality, length of hospital stay, and cognitive status at three months.

The findings indicate that POD incidence was similar between the two groups (16.3% in the melatonin group vs. 4.9% in the placebo group), with no statistically significant difference. No notable improvement in sleep quality or other clinical parameters was observed. Despite high adherence to treatment (92.9%), the study was prematurely discontinued due to recruitment difficulties and pandemic-related constraints.

A hope… or just a dream?

Postoperative delirium is a frequent complication in elderly patients, associated with increased morbidity, mortality, and prolonged hospital stays. Its management remains a challenge due to the lack of effective treatments, making prevention crucial. This study investigates the impact of perioperative melatonin administration on POD incidence by targeting sleep regulation and circadian rhythms.

Although melatonin was well tolerated, it did not demonstrate significant efficacy in preventing POD. No notable improvement was observed in sleep quality, cognitive status, or hospitalization rates between the melatonin and placebo groups.

However, the study’s early termination limits its statistical power and weakens the robustness of its conclusions. Additionally, pandemic-related constraints hindered patient recruitment and follow-up, potentially influencing the results. To definitively establish melatonin’s effectiveness in POD prevention, a larger-scale study (>1000 patients) is needed. This future research should incorporate methodological adjustments, including optimized patient selection, extended follow-up, and more precise evaluation criteria. Preventing POD remains a major challenge in anesthesia and geriatrics, requiring a combination of pharmacological and non-pharmacological strategies.