Serum melatonin concentration in critically ill patients randomized to sedation or non-sedation

Melatonin: A potential protective multifaceted force for sepsis-induced cardiomyopathy

Sepsis is a life-threatening condition manifested by organ dysfunction caused by a dysregulated host response to infection. Lung, brain, liver, kidney, and heart are among the affected organs. Sepsis-induced cardiomyopathy is a common cause of death among septic patients. Sepsis-induced cardiomyopathy is characterized by an acute and reversible significant decline in biventricular both systolic and diastolic function. This is accompanied by left ventricular dilatation. The pathogenesis underlying sepsis-induced cardiomyopathy is multifactorial. Hence, targeting an individual pathway may not be effective in halting the extensive dysregulated immune response. Despite major advances in sepsis management strategies, no effective pharmacological strategies have been shown to treat or even reverse sepsis-induced cardiomyopathy. Melatonin, namely, N-acetyl-5-methoxytryptamine, is synthesized in the pineal gland of mammals and can also be produced in many cells and tissues. Melatonin has cardioprotective, neuroprotective, and anti-tumor activity. Several literature reviews have explored the role of melatonin in preventing sepsis-induced organ failure. Melatonin was found to act on different pathways that are involved in the pathogenesis of sepsis-induced cardiomyopathy. Through its antimicrobial, anti-inflammatory, and antioxidant activity, it offers a potential role in sepsis-induced cardiomyopathy. Its antioxidant activity is through free radical scavenging against reactive oxygen and nitrogen species and modulating the expression and activity of antioxidant enzymes. Melatonin anti-inflammatory activities control the overactive immune system and mitigate cytokine storm. Also, it mitigates mitochondrial dysfunction, a major mechanism involved in sepsis-induced cardiomyopathy, and thus controls apoptosis. Therefore, this review discusses melatonin as a promising drug for the management of sepsis-induced cardiomyopathy.

Prophylactic Melatonin for Delirium in Intensive Care Unit: An Updated Systematic Review and Meta-analysis of Randomized Controlled Trials

Introduction

Delirium, being a common disorder among critically ill patients, has a reported incidence ranging 45-83% in the intensive care unit (ICU) population. The prophylactic use of melatonin and melatonergics has been shown to have a positive effect in reducing the incidence of delirium in many clinical trials. Our study was thus proposed to find out the role of melatonin on the incidence and severity of ICU delirium, ICU and hospital length of stay (LOS), requirement, duration of mechanical ventilation, and ICU mortality.

Methodology

A systematic search of various databases was performed to find out the trials which compare melatonin with a placebo or standard therapy for delirium prevention with the results conveyed as mean differences (MDs) or risk ratios. The statistical software, Review Manager (RevMan, version 5.4), was used for data synthesis.

Results

Twelve studies were included in the meta-analysis. Prophylactic administration of melatonin or ramelteon was not associated with a statistically significant reduction in the incidence of delirium (odds ratio [OR] 0.63; confidence interval [CI]: 0.60, 1.32; p = 0.22), the severity of delirium (MD: 0.22; 95% CI: From -1.36 to 1.81; p = 0.78), ICU LOS (MD: 0.05; 95% CI: From -0.65 to 0.75; p = 0.89), hospital LOS (MD: -1.46; 95% CI: From -4.50 to -1.59; p = 0.35), need for mechanical ventilation (OR: 0.74, 95% CI: 0.38-1.44; p = 0.37), and ICU mortality (MD: 0.78; 95% CI: 0.56; 1.11; p = 0.62). However, a significant reduction in the duration of mechanical ventilation (MD: -0.85; 95% CI: From -1.64 to -0.06; p = 0.03) was found.

Conclusion

Our meta-analysis suggests that melatonin when given prophylactically has no significant role in reducing the incidence and severity of delirium, ICU and hospital LOS, need for mechanical ventilation, duration of mechanical ventilation, and ICU mortality. Further studies are warranted.

How to cite this article

Mukundarajan R, Soni KD, Trikha A. Prophylactic Melatonin for Delirium in Intensive Care Unit: An Updated Systematic Review and Meta-analysis of Randomized Controlled Trials. Indian J Crit Care Med 2023;27(9):675-685.

Circadian rhythm disturbance and delirium in ICU patients: a prospective cohort study

BACKGROUND

Patients treated in the intensive care unit (ICU) may experience a reversal of day and night. The circadian rhythm in ICU patients can be disturbed.

METHODS

To explore the relationship between ICU delirium and the circadian rhythms of melatonin, cortisol and sleep. A prospective cohort study was carried out in a surgical ICU of a tertiary teaching hospital. Patients who were conscious during the ICU stay after surgery and were scheduled to stay in the ICU for more than 24 h were enrolled. Serum melatonin and plasma cortisol levels were measured three times a day by drawing arterial blood on the first three days after ICU admission. Daily sleep quality was assessed by the Richard-Campbell Sleep Questionnaire (RCSQ). The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) was performed twice a day to screen for ICU delirium.

RESULTS

A total of 76 patients were included in this study, and 17 patients developed delirium during their ICU stay. Melatonin levels were different at 8:00 (p = 0.048) on day 1, at 3:00 (p = 0.002) and at 8:00 (p = 0.009) on day 2, and at all three time points on day 3 (p = 0.032, 0.014, 0.047) between delirium and non-delirium patients. The plasma cortisol level in the delirium patients was significantly lower than that in the non-delirium patients at 16:00 on day 1 (p = 0.025). The changes in melatonin and cortisol secretion levels exhibited obvious biological rhythmicity in non-delirium patients (p < 0.001 for melatonin, p = 0.026 for cortisol), while no rhythmicity was found in melatonin and cortisol secretion levels in the delirium group (p = 0.064 for melatonin, p = 0.454 for cortisol). There was no significant difference in RCSQ scores in the first three days between the two groups.

CONCLUSIONS

The disturbance of the circadian rhythm of melatonin and cortisol secretion was associated with the development of delirium in ICU patients. Clinical staff should pay more attention to the importance of maintaining patients' normal circadian rhythms in the ICU.

TRIAL REGISTRATION

The study was registered with the US National Institutes of Health ClinicalTrials.gov(NCT05342987) (25/04/2022).

Sleep quality and quantity determined by polysomnography in mechanically ventilated critically ill patients randomized to dexmedetomidine or placebo

BACKGROUND

Abnormal sleep is commonly observed in the ICU and is associated with delirium and increased mortality. If sedation is necessary, it is often performed with gamma-aminobutyric acid agonists such as propofol or midazolam leading to an absence of restorative sleep. We aim to evaluate the effect of dexmedetomidine on sleep quality and quantity.

METHODS

Thirty consecutive patients were included. The study was conducted as a double-blinded, randomized, placebo-controlled trial with two parallel groups: 20 patients were treated with dexmedetomidine, and 10 with placebo. Two 16 h of polysomnography recordings were done for each patient on two consecutive nights. Patients were randomized to dexmedetomidine or placebo after the first recording, thus providing a control recording for all patients. Dexmedetomidine was administered during the second recording (6 p.m.-6 a.m.).

OBJECTIVE

To compare the effect of dexmedetomidine versus. placebo on sleep - quality and quantity.

PRIMARY OUTCOME

Sleep quality, total sleep time (TST), Sleep efficiency (SE), and Rapid Eye Movement (REM) sleep determined by Polysomnography (PSG).

SECONDARY OUTCOME

Delirium and daytime function determined by Confusion Assessment Method of the Intensive Care Unit and physical activity. Alertness and wakefulness were determined by RASS (Richmond Agitation and Sedation Scale).

RESULTS

SE were increased in the dexmedetomidine group by; 37.6% (29.7;45.6 95% CI) versus 3.7% (-11.4;18.8 95% CI) (p < .001) and TST were prolonged by 271 min. (210;324 95% CI) versus 27 min. (-82;135 95% CI), (p < .001). No significant difference in REM sleep, delirium physical activity, or RASS score was found except for RASS night two.

CONCLUSION

Total sleep time and sleep efficiency were significantly increased, without elimination of REM sleep, in mechanically ventilated ICU patients randomized to dexmedetomidine, when compared to a control PSG recording performed during non-sedation/standard care.

The use of melatonin in Danish intensive care departments-A nationwide observational study

BACKGROUND

Melatonin is widely employed as a hypnotic in various patient groups. In intensive care patients, melatonin seems to be increasingly used due to potential clinical effects and a favourable safety profile.

OBJECTIVES

We aimed to investigate the extend of usage and clinical practice of melatonin therapy in intensive care departments in Denmark.

DESIGN

Data from regional hospital pharmacies and the Danish Intensive Care Database were used to estimate defined daily dose and defined daily dose per 1000 ICU admission days. Also, related expenses in the period 2015-2019. Finally, a questionnaire describing the clinical practice of melatonin therapy was provided to all Danish intensive care departments.

PRINCIPAL OBSERVATIONS

The usage of melatonin in intensive care departments in Denmark increased from 21,300 DDD (200.0 DDD per 1000 ICU admission days) in 2015 to 52,170 DDD (560.7 DDD per 1000 ICU admission days) in 2019. A total of 32 ICU departments participated in the study (97% of all Danish ICU departments). All included ICU departments employed melatonin as a hypnotic. Nineteen percent of included departments administered melatonin to all admitted patients, whereas 25% of departments rarely administered melatonin. Magistral melatonin 3-mg tablets was the most employed drug dose/formulation. Increased doses of melatonin were administered in selected patients. Melatonin was considered safe by prescribing clinicians.

CONCLUSIONS

Melatonin is widely and increasingly used in Danish intensive care departments. The more than doubled usage of melatonin in the study period advocates for further studies employing validated outcomes of sleep and other patient-relevant outcomes.

EDITORIAL COMMENT

This study documents that melatonin is frequently used as a hypnotic in Danish intensive care units during recent years despite a shortage of reliable evidence to support a recommendation to treat with melatonin in this context. These results support a need for conducting clinical trials to determine whether or not there is a beneficial effect of melatonin treatment in critically ill patients.

[Light Therapy for Prevention of Delirium in Critically Ill Patients: What's the Evidence?]

Circadian dysrhythmia affects the majority of ICU patients and has far-reaching effects on organ functioning. At the level of the central nervous system, circadian misalignment facilitates executive cognitive dysfunction and the development of ICU delirium. The pathophysiological mechanisms, especially in the cohort of critically ill patients, appear to be complex, multilayered and far from understood. Results from preliminary research indicate that multidimensional, patient-specific chronotherapeutic concepts developed specifically for the ICU setting may help improve the healing process of patients. Circadian lighting therapy might be a promising intervention in this context.

Influence of innate immune activation on endocrine and metabolic pathways in infancy

Prematurity is the leading cause of neonatal morbidity and mortality worldwide. Premature infants often require extended hospital stays, with increased risk of developing infection compared with term infants. A picture is emerging of wide-ranging deleterious consequences resulting from innate immune system activation in the newborn infant. Those who survive infection have been exposed to a stimulus that can impose long-lasting alterations into later life. In this review, we discuss sepsis-driven alterations in integrated neuroendocrine and metabolic pathways and highlight current knowledge gaps in respect of neonatal sepsis. We review established biomarkers for sepsis and extend the discussion to examine emerging findings from human and animal models of neonatal sepsis that propose novel biomarkers for early identification of sepsis. Future research in this area is required to establish a greater understanding of the distinct neonatal signature of early and late-stage infection, to improve diagnosis, curtail inappropriate antibiotic use, and promote precision medicine through a biomarker-guided empirical and adjunctive treatment approach for neonatal sepsis. There is an unmet clinical need to decrease sepsis-induced morbidity in neonates, to limit and prevent adverse consequences in later life and decrease mortality.