Melatonin Supplementation Linked to Better Sleep Quality in ICU Patients

By Marilynn Larkin

October 26, 2020

NEW YORK (Reuters Health) - In intensive care unit (ICU) patients taking analgesics and/or sedatives, a melatonin supplement improved sleep quality in a placebo-controlled trial, suggesting a possible role for the hormone in critically ill patients.

"Improving opportunities for quality rest time and sleep should be a fundamental part of patient care in the ICU," Dr. Suzana Lobo of San Jose do Rio Preto Medical School, Brazil, told Reuters Health by email. "Alarms, monitors, bright lights and other factors will certainly be disruptive for patients at a time of extreme vulnerability. In our study, melatonin administration, without environmental interventions, showed positive effects on improving the quality of sleep."

"In view of the positive effects observed, without adverse events and at a low cost, it is likely that the use of melatonin to improve sleep in the ICU will be expanded, along with other strategies aimed at patients' comfort," she said.

As reported in Critical Care Medicine, Dr. Lobo and colleagues enrolled 203 patients (mean age, 60) in medical or surgical ICUs who were taking analgesics and/or sedatives. Participants were randomized to 10 mg melatonin or placebo (10 mg microcrystalline cellulose) for up to seven consecutive nights. The treatment was administered orally or via nasogastric tube at 8 pm, two hours after dinner.

The number of observed sleeping hours at night was assessed by the bedside nurse and sleep quality was evaluated using the Richards Campbell Questionnaire Sleep (RCSQ).

Sleep quality was better in the melatonin group than in the placebo group (69.7% vs. 60.7%). About 45.8% of those taking melatonin and 34.4% of those on placebo had very good sleep (risk ratio, 1.33); 3.1% and 14.6% had very poor sleep (RR, 0.21).

No significant differences were seen with respect to days free of analgesics or sedatives; night sleep duration; or the occurrence of delirium, pain, and anxiety.

Plasma melatonin concentrations were analyzed in nine patients: serum peak levels at 2 am were 150 pg/mL for melatonin and 32.5 pg/mL for placebo.

Sixty-three patients experienced an adverse event. Seven in the placebo group and one in the melatonin group asked to be discontinued from the study medication due to poor sleep.

Dr. Joanna Stollings, Clinical Pharmacy Specialist in the Medical ICU and part of the Critical Illness Brain Dysfunction Survivorship Center at Vanderbilt University Medical Center in Nashville, told Reuters Health by email, "In this study, the nurse accounted for the number of hours of sleep that the patient got at night. Unfortunately, quantity does not always equal quality. The investigators did use the RCQS. However, sleep studies would need to be assessed to obtain a more objective measure of sleep quality."

Few patients in the study had comorbidities that are common in U.S. patients, such as diabetes, chronic obstructive pulmonary disease, obesity, and kidney disease, all of which can "cause sleep impairments and are major risk factors for delirium," she noted.

In addition, she said, "only six patients were receiving mechanical ventilation and (they) had very low severity of illness scores," spending a mean number of four nights in the ICU. "This makes application to... patients with high acuity that are mechanically ventilated with prolonged ICU stays difficult."

"Further studies are needed to determine the effects of melatonin on use of analgesia and sedation and on the prevalence of pain, anxiety, and delirium in patients with higher acuity with more objective measures," she added. "Given the differences in the patients in this study and the many patients commonly seen daily in the ICU in the U.S., I do not think we can clearly say if melatonin would make an appreciable difference in routine care."

She added that melatonin is not regulated by the U.S. Food and Drug Administration, "which has led to concerns about the product's quality and consistency."

SOURCE: Critical Care Medicine, online October 13, 2020.