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.

Protocol for a scoping review of sepsis epidemiology.

INTRODUCTION: Sepsis is a common, life-threatening syndrome of physiologic, pathologic, and biochemical abnormalities that are caused by infection and propagated by a dysregulated immune response. In 2017, the estimated annual incidence of sepsis around the world was 508 cases per 100,000 (95% confidence interval [CI], 422-612 cases per 100,000), however, reported incidence rates vary significantly by country. A scoping review will identify knowledge gaps by systematically investigating the incidence of sepsis. METHODS AND ANALYSIS: This scoping review will be guided by the updated JBI (formerly Joanna Briggs Institute) methodology. We will search the following electronic databases: MEDLINE, EMBASE, CINAHL, and Cochrane Database of Systematic Reviews/Central Register of Controlled Trials. In addition, we will search websites of trial and study registries. We will review titles and abstracts of potentially eligible studies and then full-texts by two independent reviewers. We will include any study that is focused on the incidence of sepsis or septic shock in any population. Data will be abstracted independently using pre-piloted data extraction forms, and we will present results according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols Extension for Scoping Reviews. ETHICS AND DISSEMINATION: The results of this review will be used to create a publicly available indexed and searchable electronic registry of existing sepsis research relating to incidence in neonates, children, and adults. With input from stakeholders, we will identify the implications of study findings for policy, practice, and research. Ethics approval was not required given this study reports on existing literature.

Prophylactic acid suppressants in patients with primary neurologic injury: A systematic review and meta-analysis of randomized controlled trials.

PURPOSE: Neurocritical care patients are at risk of stress-induced gastrointestinal ulceration. We performed a systematic review and meta-analysis of stress ulcer prophylaxis (SUP) in critically ill adults admitted with a primary neurologic injury. MATERIALS AND METHODS: We included randomized controlled trials (RCTs) comparing SUP with histamine-2-receptor antagonists (H2RAs) or proton pump inhibitors (PPIs) to placebo/no prophylaxis, as well as to each other. The primary outcome was in-ICU gastrointestinal bleeding (GIB). Predefined secondary outcomes were all-cause 30-day mortality, ICU length of stay (LOS), nosocomial pneumonia, and other complications. RESULTS: We identified 14 relevant trials enrolling 1036 neurocritical care patients; 11 trials enrolling 930 patients were included in the meta-analysis. H2RAs resulted in a lower incidence of GIB as compared to placebo or no prophylaxis (Risk ratio [RR] 0.42, 95% CI 0.30-0.58; p < 0.001); PPIs with a lower risk of GIB compared to placebo/no prophylaxis (RR 0.37, 95% CI 0.23-0.59; p < 0.001). No significant difference was observed in GIB comparing PPIs with H2RAs (RR 0.53, 95% CI 0.26-1.06; p = 0.07; I2 = 0%). CONCLUSIONS: In neurocritical care patients, the overall high or unclear risk of bias of individual trials, the low event rates, and modest sample sizes preclude strong clinical inferences about the utility of SUP.

Long-Term Cognitive Outcomes and Sleep in Adults After Extracorporeal Life Support.

OBJECTIVES: To assess differences in cognitive outcomes and sleep in adult survivors of critical illness, managed with venovenous extracorporeal membrane oxygenation as compared to conventional mechanical ventilation only. DESIGN: Retrospective cohort study linked with data from the COGnitive outcomes and WELLness study. SETTING: A multisite study from five adult medical/surgical ICUs in Toronto. PATIENTS: Thirty-three ICU survivors including adult patients who received venovenous extracorporeal membrane oxygenation (n = 11) matched with patients who received mechanical ventilation only (n = 22) using specified covariates (e.g., age). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Baseline demographics and admission diagnoses were collected at enrollment. Cognitive outcome was evaluated using the Repeatable Battery for the Assessment of Neuropsychologic Status (global cognitive function) and Trail Making Test B (executive function), and sleep variables were estimated using actigraphy. Assessments occurred at 7 days post ICU discharge and again at 6- and 12-month follow-up. No statistically significant difference was seen between patients treated with or without venovenous extracorporeal membrane oxygenation in the mean daily Riker Sedation Agitation Score; however, patients in the venovenous extracorporeal membrane oxygenation group received greater amounts of fentanyl over their ICU stay as compared to patients receiving conventional mechanical ventilation only (p < 0.001). No significant differences were found in performance on either of the cognitive assessment tools, between survivors treated or not with venovenous extracorporeal membrane oxygenation at any of the time points assessed. Total sleep time estimated by actigraphy increased from approximately 6.5 hours in hospital to 7.5 hours at 6-month follow-up in all patients, regardless of treatment type. Total sleep time remained consistent in both groups from 6 to 12 months post ICU discharge. CONCLUSIONS: In this small retrospective case series, no significant differences were found in sleep or cognitive outcomes between extracorporeal life support and non-extracorporeal life support survivors. Further, in this hypothesis-generating study, differences in administered sedative doses during the ICU stay seen between the two groups did not impact 6- or 12-month cognitive performance or actigraphy-estimated sleep time.

Abnormal Sleep, Circadian Rhythm Disruption, and Delirium in the ICU: Are They Related?

Delirium is a syndrome characterized by acute brain failure resulting in neurocognitive disturbances affecting attention, awareness, and cognition. It is highly prevalent among critically ill patients and is associated with increased morbidity and mortality. A core domain of delirium is represented by behavioral disturbances in sleep-wake cycle probably related to circadian rhythm disruption. The relationship between sleep, circadian rhythm and intensive care unit (ICU)-acquired delirium is complex and likely bidirectional. In this review, we explore the proposed pathophysiological mechanisms of sleep disruption and circadian dysrhythmia as possible contributing factors in transitioning to delirium in the ICU and highlight some of the most relevant caveats for understanding the relationship between these complex phenomena. Specifically, we will (1) review the physiological consequences of poor sleep quality and efficiency; (2) explore how the neural substrate underlying the circadian clock functions may be disrupted in delirium; (3) discuss the role of sedative drugs as contributors to delirium and chrono-disruption; and, (4) describe the association between abnormal sleep-pathological wakefulness, circadian dysrhythmia, delirium and critical illness. Opportunities to improve sleep and readjust circadian rhythmicity to realign the circadian clock may exist as therapeutic targets in both the prevention and treatment of delirium in the ICU. Further research is required to better define these conditions and understand the underlying physiologic relationship to develop effective prevention and therapeutic strategies.