Perioperative plasma melatonin concentration in postoperative critically ill patients: Its association with delirium

Abstract

Purpose: Delirium is a common complication in postoperative critically ill patients. Although abnormal melatonin metabolism is thought to be one of the mechanisms of delirium, there have been few studies in which the association between alteration of perioperative plasma melatonin concentration and postoperative delirium was assessed. Materials:We conducted a prospective observational study to assess the association of perioperative alteration of plasma melatonin concentration with delirium in 40 postoperative patients who required intensive care for more than 48 hours. We diagnosed postoperative delirium using CAM-ICU and measured melatonin concentration 4 times (before the operation as the preoperative value, 1 hour after the operation, POD 1 and POD 2).Results: Postoperative delirium occurred in 13 (33%) of the patients. Although there was no significant difference in preoperative melatonin concentration, delta melatonin concentration at 1 hour after the operation was significantly lower in patients with delirium than in those without delirium (-1.1 vs. 0 pg/ml, p=0.036). After adjustment of relevant confounders, delta melatonin concentration was independently associated with risk of delirium (odds ratio; 0.50, p=0.047). Conclusions:Delta melatonin concentration at 1 hour after the operation has a significant independent association with risk of postoperative delirium.

Assessment of the Relationship between Hypnotics and Delirium Using the Japanese Adverse Drug Event Report (JADER) Database

“…20) The risk of delirium in preoperative patients has been reported to increase when the melatonin concentration is low and to decrease with prophylactic oral administration of ramelteon. 21,22) The fact that no signal was seen for ramelteon in the present study also suggested that ramelteon is not involved in the onset of delirium.…”

Exogenous Melatonin for Delirium Prevention: a Meta-analysis of Randomized Controlled Trials

“…Recent studies measured the postoperative plasma concentration of melatonin and the urinary excretion of 6-sulfatoxymelatonin (6-Sheng Chen and LiGen Shi contributed equally to this work. SMT) as the chief metabolite of melatonin, where it was found that plasma melatonin was significantly lower in elderly patients with delirium [14][15][16], and urinary 6-SMT was higher in hypoactive delirium and lower in hyperactive delirium [17]. Several studies have also shown that elderly individuals tend to have an age-related suppression in the amplitude of nocturnal peak level of melatonin, which puts them at a higher risk of developing delirium [2,15,18].…”

Are Melatonin and its Agonist the Natural Solution for Prevention of Delirium in Critically Ill Patients? A Review of Current Studies

“…According to the association between delirium and irregular patterns of melatonin secretion, which has been described by several studies, irregular melatonin secretion could be one of the mechanisms of delirium (10,23,30,31,(50)(51)(52) as well as the presence of sleep deprivation in hospitalized delirious patients at the ICU, as it has been indicated that melatonin and its agonists could be an effective supplement for prevention and management of delirium (38,53,54). Furthermore, several studies have reported the marked improvement of delirium in delirious patients without side effects due to the use of melatonin and ramelteon (6,45,46).…”