Circadian rest-activity misalignment in critically ill medical intensive care unit patients

Circadian Rhythms, Immune Regulation, and the Risk for Sepsis: Circadian Rhythms and Neonatal Care

Circadian rhythms provide an anticipatory mechanism for organisms to adapt to environmental changes. Host response to infections is under robust circadian control. Most of the existing literature focuses on adults in epidemiologic and animal studies. Neonatal and early infancy represent critical windows in the consolidation of circadian rhythms. This review summarizes our understanding of the molecular clock, especially its relevance to immunity and adult sepsis. Further, using our knowledge of circadian biology in caring for a newborn host with emerging circadian rhythms represents a unique challenge and an opportunity for improving our approach and outcomes in neonatal sepsis.

Glucose circadian rhythm assessment in pregnant women for gestational diabetes screening

BACKGROUND

Gestational diabetes mellitus (GDM) is the most common complication during pregnancy, and it is associated with short- and long-term health impairments. Even with increasing incidence rates worldwide, to date, GDM lacks an international standard diagnosis criterion.

OBJECTIVE

To elucidate whether a chronobiological perspective may improve the identification of patients at risk for neonatal complications.

METHODS

We analyzed a dataset with 92 recruited pregnant patients with Continuous Glucose Monitoring (CGM) data obtained in a blinded study. The primary outcome consisted in evaluating whether the composite of adverse neonatal outcomes could be predicted by chronobiological variables derived from fitting glucose oscillation to a circadian rhythm. The secondary neonatal outcomes included preterm birth, neonatal intensive care unit admission, hypoglycemia, mechanical ventilation or continuous positive airway pressure, hyperbilirubinemia, and hospital length of stay. The secondary maternal outcomes included weight gain during pregnancy, hypertensive disorders of pregnancy, induction of labor, cesarean delivery, and postpartum complications. 87 subjects had enough data to study for glucose circadian rhythmicity.

RESULTS

We developed a 3-covariate model including two chronobiological metrics, the midline estimating statistic of rhythm (MESOR) and glucose M10 start-time, and age that was predictive of the primary outcome, and associated with maternal secondary outcomes (preeclampsia with severe features and weight gain during pregnancy), and newborn secondary outcomes (preterm delivery < 37 weeks, indicated preterm delivery, NICU admission, need for CPAP, and differences in length of hospital stay).

CONCLUSIONS

Chronobiological parameters might contribute to a better identification of the adverse outcomes associated with GDM in both the mother and newborn.

Sleep and Circadian Health of Critical Survivors: A 12-Month Follow-Up Study

OBJECTIVES

To investigate the sleep and circadian health of critical survivors 12 months after hospital discharge and to evaluate a possible effect of the severity of the disease within this context.

DESIGN

Observational, prospective study.

SETTING

Single-center study.

PATIENTS

Two hundred sixty patients admitted to the ICU due to severe acute respiratory syndrome coronavirus 2 infection.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The cohort was composed of 260 patients (69.2% males), with a median (quartile 1-quartile 3) age of 61.5 years (52.0-67.0 yr). The median length of ICU stay was 11.0 days (6.00-21.8 d), where 56.2% of the patients required invasive mechanical ventilation (IMV). The Pittsburgh Sleep Quality Index (PSQI) revealed that 43.1% of the cohort presented poor sleep quality 12 months after hospital discharge. Actigraphy data indicated an influence of the disease severity on the fragmentation of the circadian rest-activity rhythm at the 3- and 6-month follow-ups, which was no longer significant in the long term. Still, the length of the ICU stay and the duration of IMV predicted a higher fragmentation of the rhythm at the 12-month follow-up with effect sizes (95% CI) of 0.248 (0.078-0.418) and 0.182 (0.005-0.359), respectively. Relevant associations between the PSQI and the Hospital Anxiety and Depression Scale (rho = 0.55, anxiety; rho = 0.5, depression) as well as between the fragmentation of the rhythm and the diffusing lung capacity for carbon monoxide (rho = -0.35) were observed at this time point.

CONCLUSIONS

Our findings reveal a great prevalence of critical survivors presenting poor sleep quality 12 months after hospital discharge. Actigraphy data indicated the persistence of circadian alterations and a possible impact of the disease severity on the fragmentation of the circadian rest-activity rhythm, which was attenuated at the 12-month follow-up. This altogether highlights the relevance of considering the sleep and circadian health of critical survivors in the long term.

Phase I pilot safety and feasibility of a novel restraint device for critically ill patients requiring mechanical ventilation

Background

Mechanically ventilated Intensive Care Unit (ICU) patients often require wrist restraints, contributing to immobility and agitation, over-sedation, and delirium. The Exersides® Refraint® (Healthy Design, LLC), a novel restraint alternative, may be safe and facilitate greater mobility than traditional restraints.

Objective

This National Institutes of Health Small Business Technology Transfer (STTR) Program Grant-funded single-site Phase I feasibility study evaluated Exersides® safety and feasibility in anticipation of a multi-site Phase II randomized controlled trial (RCT).

Methods

In two academic ICUs, mechanically ventilated adults ⩾25 years old who were non-comatose, required restraints and had an expected stay of ⩾2 days were enrolled to wear Exersides® and traditional wrist restraints for 4 h on day 1, in a randomized order, and in the reverse order on day 2. Main outcomes were Exersides® safety (i.e., patient/clinician lacerations/injuries), feasibility (i.e., ⩾90% of required data collected), and patient/family/clinician feedback.

Results

Eight patients were enrolled; one no longer required restraints at initiation, yielding seven subjects (median [interquartile range (IQR)] age 65 [55, 70] years, 86% men). All seven wore Exersides®, averaging (SD) 2.5 (1.0) hours per session, with no safety events reported. Across restraint time periods, 92% and 100% of Richmond Agitation-Sedation Scale (RASS) and wrist actigraphy data, respectively, were collected. Feedback was positive (more movement and comfortable than traditional restraints) and constructive (bulky, intimidating to apply).

Conclusions

This pilot study provided key safety and feasibility data for a Phase II RCT evaluating Exersides® versus traditional wrist restraints. Feedback motivated minor device modifications before RCT initiation.

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.

Actigraphy-based sleep and activity measurements in intensive care unit patients randomized to ramelteon or placebo for delirium prevention

Patients in the ICU often sleep poorly for various reasons, which may predispose to delirium. We previously conducted a clinical trial in which we tested the efficacy of ramelteon, a melatonin-receptor agonist used to treat insomnia, versus placebo, in preventing ICU delirium in patients who underwent elective pulmonary thromboendarterectomy (PTE) surgery. Here we examine sleep, activity, and circadian patterns, measured with actigraphy, to understand changes in these metrics with our intervention and in those with and without delirium. Participants wore wrist actigraphy devices while recovering post-operatively in the ICU. For sleep analysis, we extracted total sleep time and sleep fragmentation metrics over the 22:00 to 06:00 period nightly, and daytime nap duration from the daytime period (0:600 to 22:00) for each participant. For activity analyses, we extracted the following metrics: total daytime activity count (AC), maximum daytime AC, total nighttime AC, and maximum nighttime AC. Next, we performed a nonparametric circadian analysis on ACs over each 24-h day and extracted the following: interdaily stability (IS), intra-daily variability (IV), relative amplitude (RA), and low and high periods of activity (L5 and M10) as well as their start times. These metrics were compared between patients who received ramelteon versus placebo, and between patients who became delirious versus those who did not develop delirium. We additionally made comparisons between groups for daytime and nighttime light levels. No differences in sleep, activity, circadian metrics or light levels were found between drug groups. Delirious patients, when compared to those who were never delirious, had a lower IS (0.35 ± 0.16 vs. 0.47 ± 0.23; P = 0.006). Otherewise, no differences in IV, L5, M10, or RA were found between groups. L5 and M10 activity values increased significantly over the post-extubation for the whole cohort. No differences were found for daytime or nighttime light levels between groups. Overall, ramelteon did not impact sleep or circadian metrics in this cohort. Consistent with clinical experience, delirious patients had less inter-daily stability in their rest-activity rhythms. These data suggest that actigraphy might have value for individual assessment of sleep in the ICU, and for determining and detecting the impact of interventions directed at improving sleep and circadian activity rhythms in the ICU.Trial registration: REGISTERED at CLINICALTRIALS.GOV: NCT02691013. Registered on February 24, 2016 by principal investigator, Dr. Robert L. Owens.

The Circadian Biology of Heart Failure

Driven by autonomous molecular clocks that are synchronized by a master pacemaker in the suprachiasmatic nucleus, cardiac physiology fluctuates in diurnal rhythms that can be partly or entirely circadian. Cardiac contractility, metabolism, and electrophysiology, all have diurnal rhythms, as does the neurohumoral control of cardiac and kidney function. In this review, we discuss the evidence that circadian biology regulates cardiac function, how molecular clocks may relate to the pathogenesis of heart failure, and how chronotherapeutics might be applied in heart failure. Disrupting molecular clocks can lead to heart failure in animal models, and the myocardial response to injury seems to be conditioned by the time of day. Human studies are consistent with these findings, and they implicate the clock and circadian rhythms in the pathogenesis of heart failure. Certain circadian rhythms are maintained in patients with heart failure, a factor that can guide optimal timing of therapy. Pharmacologic and nonpharmacologic manipulation of circadian rhythms and molecular clocks show promise in the prevention and treatment of heart failure.

Probiotics: A gut response to the COVID-19 pandemic but what does the evidence show?

Since the global outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), research has focused on understanding the etiology of coronavirus disease 2019 (COVID-19). Identifying and developing prophylactic and therapeutics strategies to manage the pandemic is still of critical importance. Among potential targets, the role of the gut and lung microbiomes in COVID-19 has been questioned. Consequently, probiotics were touted as potential prophylactics and therapeutics for COVID-19. In this review we highlight the role of the gut and lung microbiome in COVID-19 and potential mechanisms of action of probiotics. We also discuss the progress of ongoing clinical trials for COVID-19 that aim to modulate the microbiome using probiotics in an effort to develop prophylactic and therapeutic strategies. To date, despite the large interest in this area of research, there is promising but limited evidence to suggest that probiotics are an effective prophylactic or treatment strategy for COVID-19. However, the role of the microbiome in pathogenesis and as a potential target for therapeutics of COVID-19 cannot be discounted.