Inclusion criteria:
Glasgow Coma Scale (GCS) score ≥10
patients with stable hemodynamic
patients with out alcohol consumption ≥50 units per week or drug use(addiction) / narcotic or sedation drug order in icu
haven't been used of drugs that might alter melatonin secretion and decrease plasma levels of melatonin, such as benzodiazepines, NSAIDs, corticosteroids, beta-blockers, haloperidol and amiodarone / sedation with propofol, morphine, alfentanil and dexmedetomidine has been discontinued for a minimum of 36 hours (48 hours for lorazepam and midazolam) before enter to study
Apache II score < 35 and Estimated mortality < 75%
patients with out severe pain level (pain score > 7 on the numerical scale of pain) for one hour before the prescribe of melatonin
patients with out history of convulsions, psychiatric or neurological disease, deafness or blindness and the lack of any kind of sleep disorder such as sleep apnea, narcolepsy, chronic insomnia, restless legs syndrome (RLS)
patients with out liver insufficiency and renal insufficiency (requires dialysis)
patients with out severe heart failure (the New York Heart Association classification III/IV)
patients with out intestinal obstruction, ileus or other conditions likely to affect the enteral absorption of melatonin
Do not be pregnant or breast-feeding women
more than 24 hours have passed from general anesthesia or hospitalization
age ≥18 years old and ≤ 60 years old
Exclusion criteria:
The incidence of gastrointestinal failure that prevents the absorption of melatonin, including obstruction and ileus
The incidence of renal insufficiency (requires dialysis)
The incidence of any kind of sleep disorder such as sleep apnea, narcolepsy over night sleep
Pain scores above 7 on the numerical scale of pain during the intervention
Lack of willingness to cooperate in the study