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

Pharmacologic Sleep Aids in the Intensive Care Unit: A Systematic Review

Background: Patients in the intensive care unit (ICU) often experience poor sleep quality. Pharmacologic sleep aids are frequently used as primary or adjunctive therapy to improve sleep, although their benefits in the ICU remain uncertain. This review aims to provide a comprehensive assessment of the objective and subjective effects of medications used for sleep in the ICU, as well as their adverse effects. Methods: PubMed, Web of Science, Scopus, Embase, and Cochrane Central Register of Controlled Trials were systematically searched from their inception until June 2023 for comparative studies assessing the effects of pharmacologic sleep aids on objective and subjective metrics of sleep. Results: Thirty-four studies with 3498 participants were included. Medications evaluated were melatonin, ramelteon, suvorexant, propofol, and dexmedetomidine. The majority of studies were randomized controlled trials. Melatonin and dexmedetomidine were the best studied agents. Objective sleep metrics included polysomnography (PSG), electroencephalography (EEG), bispectral index, and actigraphy. Subjective outcome measures included patient questionnaires and nursing observations. Evidence for melatonin as a sleep aid in the ICU was mixed but largely not supportive for improving sleep. Evidence for ramelteon, suvorexant, and propofol was too limited to offer definitive recommendations. Both objective and subjective data supported dexmedetomidine as an effective sleep aid in the ICU, with PSG/EEG in 303 ICU patients demonstrating increased sleep duration and efficiency, decreased arousal index, decreased percentage of stage N1 sleep, and increased absolute and percentage of stage N2 sleep. Mild bradycardia and hypotension were reported as side effects of dexmedetomidine, whereas the other medications were reported to be safe. Several ongoing studies have not yet been published, mostly on melatonin and dexmedetomidine. Conclusions: While definitive conclusions cannot be made for most medications, dexmedetomidine improved sleep quantity and quality in the ICU. These benefits need to be balanced with possible hemodynamic side effects.

Effect of prolonged sedation with dexmedetomidine, midazolam, propofol, and sevoflurane on sleep homeostasis in rats

BACKGROUND

Sleep disruption is a common occurrence during medical care and is detrimental to patient recovery. Long-term sedation in the critical care setting is a modifiable factor that affects sleep, but the impact of different sedative-hypnotics on sleep homeostasis is not clear.

METHODS

We conducted a systematic comparison of the effects of prolonged sedation (8 h) with i.v. and inhalational agents on sleep homeostasis. Adult Sprague-Dawley rats (n=10) received dexmedetomidine or midazolam on separate days. Another group (n=9) received propofol or sevoflurane on separate days. A third group (n=12) received coadministration of dexmedetomidine and sevoflurane. Wakefulness (wake), slow-wave sleep (SWS), and rapid eye movement (REM) sleep were quantified during the 48-h post-sedation period, during which we also assessed wake-associated neural dynamics using two electroencephalographic measures: theta-high gamma phase-amplitude coupling and high gamma weighted phase-lag index.

RESULTS

Dexmedetomidine-, midazolam-, or propofol-induced sedation increased wake and decreased SWS and REM sleep (P<0.0001) during the 48-h post-sedation period. Sevoflurane produced no change in SWS, decreased wake for 3 h, and increased REM sleep for 6 h (P<0.02) post-sedation. Coadministration of dexmedetomidine and sevoflurane induced no change in wake (P>0.05), increased SWS for 3 h, and decreased REM sleep for 9 h (P<0.02) post-sedation. Dexmedetomidine, midazolam, and coadministration of dexmedetomidine with sevoflurane reduced wake-associated phase-amplitude coupling (P≤0.01). All sedatives except sevoflurane decreased wake-associated high gamma weighted phase-lag index (P<0.01).

CONCLUSIONS

In contrast to i.v. drugs, prolonged sevoflurane sedation produced minimal changes in sleep homeostasis and neural dynamics. Further studies are warranted to assess inhalational agents for long-term sedation and sleep homeostasis.

Intensive care unit interventions to promote sleep and circadian biology in reducing incident delirium: a scoping review

RATIONALE/OBJECTIVES

Despite plausible pathophysiological mechanisms, research is needed to confirm the relationship between sleep, circadian rhythm and delirium in patients admitted to the intensive care unit (ICU). The objective of this review is to summarise existing studies promoting, in whole or in part, the normalisation of sleep and circadian biology and their impact on the incidence, prevalence, duration and/or severity of delirium in ICU.

METHODS

A sensitive search of electronic databases and conference proceedings was completed in March 2023. Inclusion criteria were English-language studies of any design that evaluated in-ICU non-pharmacological, pharmacological or mixed intervention strategies for promoting sleep or circadian biology and their association with delirium, as assessed at least daily. Data were extracted and independently verified.

RESULTS

Of 7886 citations, we included 50 articles. Commonly evaluated interventions include care bundles (n=20), regulation or administration of light therapy (n=5), eye masks and/or earplugs (n=5), one nursing care-focused intervention and pharmacological intervention (eg, melatonin and ramelteon; n=19). The association between these interventions and incident delirium or severity of delirium was mixed. As multiple interventions were incorporated in included studies of care bundles and given that there was variable reporting of compliance with individual elements, identifying which components might have an impact on delirium is challenging.

CONCLUSIONS

This scoping review summarises the existing literature as it relates to ICU sleep and circadian disruption (SCD) and delirium in ICU. Further studies are needed to better understand the role of ICU SCD promotion interventions in delirium mitigation.

Sedation for Patients with Sepsis: Towards a Personalised Approach

This article looks at the challenges of sedoanalgesia for sepsis patients, and argues for a personalised approach. Sedation is a necessary part of treatment for patients in intensive care to reduce stress and anxiety and improve long-term prognoses. Sepsis patients present particular difficulties as they are at increased risk of a wide range of complications, such as multiple organ failure, neurological dysfunction, septic shock, ARDS, abdominal compartment syndrome, vasoplegic syndrome, and myocardial dysfunction. The development of any one of these complications can cause the patient's rapid deterioration, and each has distinct implications in terms of appropriate and safe forms of sedation. In this way, the present article reviews the sedative and analgesic drugs commonly used in the ICU and, placing special emphasis on their strategic administration in sepsis patients, develops a set of proposals for sedoanalgesia aimed at improving outcomes for this group of patients. These proposals represent a move away from simplistic approaches like avoiding benzodiazepines to more "objective-guided sedation" that accounts for a patient's principal pathology, as well as any comorbidities, and takes full advantage of the therapeutic arsenal currently available to achieve personalised, patient-centred treatment goals.

Sleep and critical illness: a review

Critical illness and stays in the Intensive Care Unit (ICU) have significant impact on sleep. Poor sleep is common in this setting, can persist beyond acute critical illness, and is associated with increased morbidity and mortality. In the past 5 years, intensive care clinical practice guidelines have directed more focus on sleep and circadian disruption, spurring new initiatives to study and improve sleep complications in the critically ill. The global SARS-COV-2 (COVID-19) pandemic and dramatic spikes in patients requiring ICU level care also brought augmented levels of sleep disruption, the understanding of which continues to evolve. This review aims to summarize existing literature on sleep and critical illness and briefly discuss future directions in the field.

Causes, Consequences, and Treatments of Sleep and Circadian Disruption in the ICU: An Official American Thoracic Society Research Statement

Background: Sleep and circadian disruption (SCD) is common and severe in the ICU. On the basis of rigorous evidence in non-ICU populations and emerging evidence in ICU populations, SCD is likely to have a profound negative impact on patient outcomes. Thus, it is urgent that we establish research priorities to advance understanding of ICU SCD. Methods: We convened a multidisciplinary group with relevant expertise to participate in an American Thoracic Society Workshop. Workshop objectives included identifying ICU SCD subtopics of interest, key knowledge gaps, and research priorities. Members attended remote sessions from March to November 2021. Recorded presentations were prepared and viewed by members before Workshop sessions. Workshop discussion focused on key gaps and related research priorities. The priorities listed herein were selected on the basis of rank as established by a series of anonymous surveys. Results: We identified the following research priorities: establish an ICU SCD definition, further develop rigorous and feasible ICU SCD measures, test associations between ICU SCD domains and outcomes, promote the inclusion of mechanistic and patient-centered outcomes within large clinical studies, leverage implementation science strategies to maximize intervention fidelity and sustainability, and collaborate among investigators to harmonize methods and promote multisite investigation. Conclusions: ICU SCD is a complex and compelling potential target for improving ICU outcomes. Given the influence on all other research priorities, further development of rigorous, feasible ICU SCD measurement is a key next step in advancing the field.

Effects of dexmedetomidine on postoperative sleep quality: a systematic review and meta-analysis of randomized controlled trials

STUDY OBJECTIVES

To assess the effect of dexmedetomidine (DEX) on postoperative sleep quality using polysomnography (PSG) to identify possible interventions for postoperative sleep disturbances.

METHODS

An electronic search of PubMed/MEDLINE, EMBASE, Cochrane Library and Web of Science was conducted from database inception to November 20, 2022. Randomized controlled trials (RCTs) on the effect of DEX administration on postoperative sleep quality using PSG or its derivatives were included. No language restrictions were applied. The sleep efficiency index (SEI), arousal index (AI), percentages of stage N1, N2 and N3 of non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep were measured in our meta-analysis.

RESULTS

Five studies, involving 381 participants were included. Administration of DEX significantly improved SEI, lowered AI, decreased the duration of stage N1 sleep and increased the duration of stage N2 sleep compared to placebo groups. There were no significant differences in the duration of stage N3 sleep and REM sleep. DEX administration lowered the postoperative Visual Analogue Scale (VAS) score and improved the Ramsay sedation score with no adverse effect on postoperative delirium (POD). However, high heterogeneity was observed in most of the primary and secondary outcomes.

CONCLUSIONS

Our study provides support for the perioperative administration of DEX to improve postoperative sleep quality. The optimal dosage and overall effect of DEX on postoperative sleep quality require further investigation using large-scale randomized controlled trials.