Patient Outcomes and Unit Composition With Transition to a High-Intensity ICU Staffing Model: A Before-and-After Study.

Provider staffing models for ICUs are generally based on pragmatic necessities and historical norms at individual institutions. A better understanding of the role that provider staffing models play in determining patient outcomes and optimizing use of ICU resources is needed. OBJECTIVES: To explore the impact of transitioning from a low- to high-intensity intensivist staffing model on patient outcomes and unit composition. DESIGN SETTING AND PARTICIPANTS: This was a prospective observational before-and-after study of adult ICU patients admitted to a single community hospital ICU before (October 2016-May 2017) and after (June 2017-November 2017) the transition to a high-intensity ICU staffing model. MAIN OUTCOMES AND MEASURES: The primary outcome was 30-day all-cause mortality. Secondary outcomes included in-hospital mortality, ICU length of stay (LOS), and unit composition characteristics including type (e.g., medical, surgical) and purpose (ICU-specific intervention vs close monitoring only) of admission. RESULTS: For the primary outcome, 1,219 subjects were included (779 low-intensity, 440 high-intensity). In multivariable analysis, the transition to a high-intensity staffing model was not associated with a decrease in 30-day (odds ratio [OR], 0.90; 95% CI, 0.61-1.34; p = 0.62) or in-hospital (OR, 0.89; 95% CI, 0.57-1.38; p = 0.60) mortality, nor ICU LOS. However, the proportion of patients admitted to the ICU without an ICU-specific need did decrease under the high-intensity staffing model (27.2% low-intensity to 17.5% high-intensity; p < 0.001). CONCLUSIONS AND RELEVANCE: Multivariable analysis showed no association between transition to a high-intensity ICU staffing model and mortality or LOS outcomes; however, the proportion of patients admitted without an ICU-specific need decreased under the high-intensity model. Further research is needed to determine whether a high-intensity staffing model may lead to more efficient ICU bed usage.

Efficacy of Losartan in Hospitalized Patients With COVID-19-Induced Lung Injury: A Randomized Clinical Trial.

Importance: SARS-CoV-2 viral entry may disrupt angiotensin II (AII) homeostasis, contributing to COVID-19 induced lung injury. AII type 1 receptor blockade mitigates lung injury in preclinical models, although data in humans with COVID-19 remain mixed. Objective: To test the efficacy of losartan to reduce lung injury in hospitalized patients with COVID-19. Design, Setting, and Participants: This blinded, placebo-controlled randomized clinical trial was conducted in 13 hospitals in the United States from April 2020 to February 2021. Hospitalized patients with COVID-19 and a respiratory sequential organ failure assessment score of at least 1 and not already using a renin-angiotensin-aldosterone system (RAAS) inhibitor were eligible for participation. Data were analyzed from April 19 to August 24, 2021. Interventions: Losartan 50 mg orally twice daily vs equivalent placebo for 10 days or until hospital discharge. Main Outcomes and Measures: The primary outcome was the imputed arterial partial pressure of oxygen to fraction of inspired oxygen (Pao2:Fio2) ratio at 7 days. Secondary outcomes included ordinal COVID-19 severity; days without supplemental o2, ventilation, or vasopressors; and mortality. Losartan pharmacokinetics and RAAS components (AII, angiotensin-[1-7] and angiotensin-converting enzymes 1 and 2)] were measured in a subgroup of participants. Results: A total of 205 participants (mean [SD] age, 55.2 [15.7] years; 123 [60.0%] men) were randomized, with 101 participants assigned to losartan and 104 participants assigned to placebo. Compared with placebo, losartan did not significantly affect Pao2:Fio2 ratio at 7 days (difference, -24.8 [95%, -55.6 to 6.1]; P = .12). Compared with placebo, losartan did not improve any secondary clinical outcomes and led to fewer vasopressor-free days than placebo (median [IQR], 9.4 [9.1-9.8] vasopressor-free days vs 8.7 [8.2-9.3] vasopressor-free days). Conclusions and Relevance: This randomized clinical trial found that initiation of orally administered losartan to hospitalized patients with COVID-19 and acute lung injury did not improve Pao2:Fio2 ratio at 7 days. These data may have implications for ongoing clinical trials. Trial Registration: ClinicalTrials.gov Identifier: NCT04312009.

Cinematic virtual reality for anxiety management in mechanically ventilated patients: a feasibility and pilot study.

BACKGROUND: Mechanically ventilated patients experience anxiety for many reasons. Pharmacological treatments such as benzodiazepines are commonly employed to manage anxiety; however, these therapies often cause undesired side effects. Additional therapies for anxiety management are needed. We sought to determine whether cell phone-based virtual reality therapy could feasibly be used for anxiety management in mechanically ventilated patients. METHODS: Mechanically ventilated subjects underwent at least one session of virtual reality therapy in which they were shown a cinematic video of an outdoor green space or blue space with 360° visual range of motion. Goal session duration was 5 minutes. The primary outcome was incidence of predefined patient safety events, including self-extubation and accidental removal of tubes or lines. RESULTS: Ten subjects underwent a total of 18 virtual reality sessions. Fifteen sessions lasted the planned 5 minutes, one session was extended at participant request, and two sessions were terminated early at participant request. There were no occurrences of the predefined safety events, and no occurrences of cybersickness. Use of a visual analog scale to measure anxiety level was feasible for this pilot study, demonstrating feasibility of this scale for future, larger scale studies. CONCLUSIONS: Virtual reality therapy shows potential as a means of managing anxiety in patients undergoing mechanical ventilation, and further rigorous exploration with this protocol is feasible.

Evaluating Vitamin C in Septic Shock: A Randomized Controlled Trial of Vitamin C Monotherapy.

OBJECTIVES: To determine whether IV vitamin C therapy reduces 28-day mortality in patients with septic shock. DESIGN: Multicenter, double-blinded, randomized controlled trial. SETTING: One academic medical ICU and four community ICUs. PATIENTS: Of 167 adult patients within 24 hours of vasopressor initiation for septic shock, 126 consented to participation, and 124 received study drug and were included in analysis. INTERVENTIONS: IV vitamin C (10 mg/mL in normal saline) administered as a 1,000-mg bolus over 30 minutes followed by continuous infusion of 250 mg/hr for 96 hours or placebo of equal volumes of normal saline. MEASUREMENTS AND MAIN RESULTS: Of 124 subjects receiving study drug and included in analysis, 60 received vitamin C and 64 placebo. The primary outcome of all-cause 28-day mortality (vitamin C, 26.7%; placebo, 40.6%; p = 0.10) was lower in the vitamin C arm but did not reach statistical significance. Initiation of renal replacement therapy was higher in the vitamin C arm (vitamin C, 16.7%; placebo, 3.3%; p = 0.015), as was volume of fluid administration within 6 hours of study drug initiation (vitamin C, 1.07 L; placebo, 0.76 L; p = 0.03). There were no statistically significant differences in other secondary outcomes. In post hoc subgroup analysis, there was a decrease in 28-day mortality in the vitamin C arm among patients requiring positive-pressure ventilation at the time of enrollment (vitamin C, 36.3%; placebo, 60.0%; p = 0.05). This trial is registered at clinicaltrials.gov under identifier NCT03338569. CONCLUSIONS: Vitamin C monotherapy failed to significantly reduce mortality in septic shock patients as hypothesized. Our findings do not support its routine clinical use for this purpose.

A multi-center phase II randomized clinical trial of losartan on symptomatic outpatients with COVID-19.

BACKGROUND: The SARS-CoV-2 virus enters cells via Angiotensin-converting enzyme 2 (ACE2), disrupting the renin-angiotensin-aldosterone axis, potentially contributing to lung injury. Treatment with angiotensin receptor blockers (ARBs), such as losartan, may mitigate these effects, though induction of ACE2 could increase viral entry, replication, and worsen disease. METHODS: This study represents a placebo-controlled blinded randomized clinical trial (RCT) to test the efficacy of losartan on outpatients with COVID-19 across three hospital systems with numerous community sites in Minnesota, U.S. Participants included symptomatic outpatients with COVID-19 not already taking ACE-inhibitors or ARBs, enrolled within 7 days of symptom onset. Patients were randomized to 1:1 losartan (25 mg orally twice daily unless estimated glomerular filtration rate, eGFR, was reduced, when dosing was reduced to once daily) versus placebo for 10 days, and all patients and outcome assesors were blinded. The primary outcome was all-cause hospitalization within 15 days. Secondary outcomes included functional status, dyspnea, temperature, and viral load. (clinicatrials.gov, NCT04311177, closed to new participants). FINDINGS: From April to November 2020, 117 participants were randomized 58 to losartan and 59 to placebo, and all were analyzed under intent to treat principles. The primary outcome did not differ significantly between the two arms based on Barnard's test [losartan arm: 3 events (5.2% 95% CI 1.1, 14.4%) versus placebo arm: 1 event (1.7%; 95% CI 0.0, 9.1%)]; proportion difference -3.5% (95% CI -13.2, 4.8%); p = 0.32]. Viral loads were not statistically different between treatment groups at any time point. Adverse events per 10 patient days did not differ signifcantly [0.33 (95% CI 0.22-0.49) for losartan vs. 0.37 (95% CI 0.25-0.55) for placebo]. Due to a lower than expected hospitalization rate and low likelihood of a clinically important treatment effect, the trial was terminated early. INTERPRETATION: In this multicenter blinded RCT for outpatients with mild symptomatic COVID-19 disease, losartan did not reduce hospitalizations, though assessment was limited by low event rate. Importantly, viral load was not statistically affected by treatment. This study does not support initiation of losartan for low-risk outpatients.

Boundary Associated Long Noncoding RNA Mediates Long-Range Chromosomal Interactions.

CCCTC binding factor (CTCF) is involved in organizing chromosomes into mega base-sized, topologically associated domains (TADs) along with other factors that define sub-TAD organization. CTCF-Cohesin interactions have been shown to be critical for transcription insulation activity as it stabilizes long-range interactions to promote proper gene expression. Previous studies suggest that heterochromatin boundary activity of CTCF may be independent of Cohesin, and there may be additional mechanisms for defining topological domains. Here, we show that a boundary site we previously identified known as CTCF binding site 5 (CBS5) from the homeotic gene cluster A (HOXA) locus exhibits robust promoter activity. This promoter activity from the CBS5 boundary element generates a long noncoding RNA that we designate as boundary associated long noncoding RNA-1 (blncRNA1). Functional characterization of this RNA suggests that the transcript stabilizes long-range interactions at the HOXA locus and promotes proper expression of HOXA genes. Additionally, our functional analysis also shows that this RNA is not needed in the stabilization of CTCF-Cohesin interactions however CTCF-Cohesin interactions are critical in the transcription of blncRNA1. Thus, the CTCF-associated boundary element, CBS5, employs both Cohesin and noncoding RNA to establish and maintain topologically associated domains at the HOXA locus.

Shock.

Critically ill patients with undifferentiated shock are complex and challenging cases in the ED. A systematic approach to assessment and management is essential to prevent unnecessary morbidity and mortality. The simplified, systematic approach described in this article focuses on determining the presence of problems with cardiac function (the pump), intravascular volume (the tank), or systemic vascular resistance (the pipes). With this approach, the emergency physician can detect life-threatening conditions and implement time-sensitive therapy.

From sextant to GPS: twenty-five years of mapping the genome with ChIP.

Since its inception, ChIP technology has evolved immensely. Technological advances have improved its specificity and sensitivity, its scale has expanded to a genome-wide level, and its relative ease of use has made it a virtually ubiquitous tool. This year marks the 25th anniversary of the development of ChIP. In honor of this milestone, we briefly revisit its history, offer a review of recent articles employing ChIP on a genome-wide scale, and lay out our views for the future of ChIP.

The DNA binding and catalytic domains of poly(ADP-ribose) polymerase 1 cooperate in the regulation of chromatin structure and transcription.

We explored the mechanisms of chromatin compaction and transcriptional regulation by poly(ADP-ribose) polymerase 1 (PARP-1), a nucleosome-binding protein with an NAD(+)-dependent enzymatic activity. By using atomic force microscopy and a complementary set of biochemical assays with reconstituted chromatin, we showed that PARP-1 promotes the localized compaction of chromatin into supranucleosomal structures in a manner independent of the amino-terminal tails of core histones. In addition, we defined the domains of PARP-1 required for nucleosome binding, chromatin compaction, and transcriptional repression. Our results indicate that the DNA binding domain (DBD) of PARP-1 is necessary and sufficient for binding to nucleosomes, yet the DBD alone is unable to promote chromatin compaction and only partially represses RNA polymerase II-dependent transcription in an in vitro assay with chromatin templates (approximately 50% of the repression observed with wild-type PARP-1). Furthermore, our results show that the catalytic domain of PARP-1, which does not bind nucleosomes on its own, cooperates with the DBD to promote chromatin compaction and efficient transcriptional repression in a manner independent of its enzymatic activity. Collectively, our results have revealed a novel function for the catalytic domain in chromatin compaction. In addition, they show that the DBD and catalytic domain cooperate to regulate chromatin structure and chromatin-dependent transcription, providing mechanistic insights into how these domains contribute to the chromatin-dependent functions of PARP-1.

Regulation of chromatin structure and chromatin-dependent transcription by poly(ADP-ribose) polymerase-1: possible targets for drug-based therapies.

Poly(ADP-ribose) Polymerase-1 (PARP-1) is the prototypical and most abundantly expressed member of a family of PARPs that catalyze the polymerization of ADP-ribose (ADPR) units from donor NAD' molecules on target proteins. PARP-1 plays roles in a variety of genomic processes, including the regulation of chromatin structure and transcription in response to specific cellular signals. PARP-1 also plays important roles in many stress-induced disease states. In this chapter, we review the molecular and cellular aspects of PARP-1's chromatin-modulating activities, as well as the impact that these chromatin-modulating activities have on the regulation of gene expression. In addition, we highlight the potential therapeutic use of drugs that target PARP-1's enzymatic activity for the treatment of human diseases

Specific contributions of histone tails and their acetylation to the mechanical stability of nucleosomes.

The distinct contributions of histone tails and their acetylation to nucleosomal stability were examined by mechanical disruption of individual nucleosomes in a single chromatin fiber using an optical trap. Enzymatic removal of H2A/H2B tails primarily decreased the strength of histone-DNA interactions located approximately +/-36bp from the dyad axis of symmetry (off-dyad strong interactions), whereas removal of the H3/H4 tails played a greater role in regulating the total amount of DNA bound. Similarly, nucleosomes composed of histones acetylated to different degrees by the histone acetyltransferase p300 exhibited significant decreases in the off-dyad strong interactions and the total amount of DNA bound. Acetylation of H2A/H2B appears to play a particularly critical role in weakening the off-dyad strong interactions. Collectively, our results suggest that the destabilizing effects of tail acetylation may be due to elimination of specific key interactions in the nucleosome.