The CHARTER-Ireland trial: can nebulised heparin reduce acute lung injury in patients with SARS-CoV-2 requiring advanced respiratory support in Ireland: a study protocol and statistical analysis plan for a randomised control trial.

BACKGROUND: COVID-19 pneumonia is associated with the development of acute respiratory distress syndrome (ARDS) displaying some typical histological features. These include diffuse alveolar damage with extensive pulmonary coagulation activation. This results in fibrin deposition in the microvasculature, leading to the formation of hyaline membranes in the air sacs. Well-conducted clinical trials have found that nebulised heparin limits pulmonary fibrin deposition, attenuates progression of ARDS, hastens recovery and is safe in non-COVID ARDS. Unfractionated heparin also inactivates the SARS-CoV-2 virus and prevents entry into mammalian cells. Nebulisation of heparin may therefore limit fibrin-mediated lung injury and inhibit pulmonary infection by SARS-CoV-2. Based on these findings, we designed the CHARTER-Ireland Study, a phase 1b/2a randomised controlled study of nebulised heparin in patients requiring advanced respiratory support for COVID-19 pneumonia. METHODS: This is a multi-centre, phase 1b/IIa, randomised, parallel-group, open-label study. The study will randomise 40 SARs-CoV-2-positive patients receiving advanced respiratory support in a critical care area. Randomisation will be via 1:1 allocation to usual care plus nebulised unfractionated heparin 6 hourly to day 10 while receiving advanced respiratory support or usual care only. The study aims to evaluate whether unfractionated heparin will decrease the procoagulant response associated with ARDS up to day 10. The study will also assess safety and tolerability of nebulised heparin as defined by number of severe adverse events; oxygen index and respiratory oxygenation index of intubated and unintubated, respectively; ventilatory ratio; and plasma concentration of interleukin (IL)-1ß, IL6, IL-8, IL-10 and soluble tumour necrosis factor receptor 1, C-reactive protein, procalcitonin, ferritin, fibrinogen and lactate dehydrogenase as well as the ratios of IL-1ß/IL-10 and IL-6/IL-10. These parameters will be assessed on days 1, 3, 5 and 10; time to separation from advanced respiratory support, time to discharge from the intensive care unit and number tracheostomised to day 28; and survival to days 28 and 60 and to hospital discharge, censored at day 60. Some clinical outcome data from our study will be included in the international meta-trials, CHARTER and INHALE-HEP. DISCUSSION: This trial aims to provide evidence of potential therapeutic benefit while establishing safety of nebulised heparin in the management of ARDS associated with SARs-CoV-2 infection. TRIAL REGISTRATION: ClinicalTrials.gov NCT04511923 . Registered on 13 August 2020. Protocol version 8, 22/12/2021 Protocol identifier: NUIG-2020-003 EudraCT registration number: 2020-003349-12 9 October 2020.

Augmenting Critical Care Patient Monitoring Using Wearable Technology: Review of Usability and Human Factors.

BACKGROUND: Continuous monitoring of the vital signs of critical care patients is an essential component of critical care medicine. For this task, clinicians use a patient monitor (PM), which conveys patient vital sign data through a screen and an auditory alarm system. Some limitations with PMs have been identified in the literature, such as the need for visual contact with the PM screen, which could result in reduced focus on the patient in specific scenarios, and the amount of noise generated by the PM alarm system. With the advancement of material science and electronic technology, wearable devices have emerged as a potential solution for these problems. This review presents the findings of several studies that focused on the usability and human factors of wearable devices designed for use in critical care patient monitoring. OBJECTIVE: The aim of this study is to review the current state of the art in wearable devices intended for use by clinicians to monitor vital signs of critical care patients in hospital settings, with a focus on the usability and human factors of the devices. METHODS: A comprehensive literature search of relevant databases was conducted, and 20 studies were identified and critically reviewed by the authors. RESULTS: We identified 3 types of wearable devices: tactile, head-mounted, and smartwatch displays. In most cases, these devices were intended for use by anesthesiologists, but nurses and surgeons were also identified as potentially important users of wearable technology in critical care medicine. Although the studies investigating tactile displays revealed their potential to improve clinical monitoring, usability problems related to comfort need to be overcome before they can be considered suitable for use in clinical practice. Only a few studies investigated the usability and human factors of tactile displays by conducting user testing involving critical care professionals. The studies of head-mounted displays (HMDs) revealed that these devices could be useful in critical care medicine, particularly from an ergonomics point of view. By reducing the amount of time the user spends averting their gaze from the patient to a separate screen, HMDs enable clinicians to improve their patient focus and reduce the potential of repetitive strain injury. CONCLUSIONS: Researchers and designers of new wearable devices for use in critical care medicine should strive to achieve not only enhanced performance but also enhanced user experience for their users, especially in terms of comfort and ease of use. These aspects of wearable displays must be extensively tested with the intended end users in a setting that properly reflects the intended context of use before their adoption can be considered in clinical settings.

Novel Interface Designs for Patient Monitoring Applications in Critical Care Medicine: Human Factors Review.

BACKGROUND: The patient monitor (PM) is one of the most commonly used medical devices in hospitals worldwide. PMs are used to monitor patients' vital signs in a wide variety of patient care settings, especially in critical care settings, such as intensive care units. An interesting observation is that the design of PMs has not significantly changed over the past 2 decades, with the layout and structure of PMs more or less unchanged, with incremental changes in design being made rather than transformational changes. Thus, we believe it well-timed to review the design of novel PM interfaces, with particular reference to usability and human factors. OBJECTIVE: This paper aims to review innovations in PM design proposed by researchers and explore how clinicians responded to these design changes. METHODS: A literature search of relevant databases, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, identified 16 related studies. A detailed description of the interface design and an analysis of each novel PM were carried out, including a detailed analysis of the structure of the different user interfaces, to inform future PM design. The test methodologies used to evaluate the different designs are also presented. RESULTS: Most of the studies included in this review identified some level of improvement in the clinician's performance when using a novel display in comparison with the traditional PM. For instance, from the 16 reviewed studies, 12 studies identified an improvement in the detection and response times, and 10 studies identified an improvement in the accuracy or treatment efficiency. This indicates that novel displays have the potential to improve the clinical performance of nurses and doctors. However, the outcomes of some of these studies are weakened because of methodological deficiencies. These deficiencies are discussed in detail in this study. CONCLUSIONS: More careful study design is warranted to investigate the user experience and usability of future novel PMs for real time vital sign monitoring, to establish whether or not they could be used successfully in critical care. A series of recommendations on how future novel PM designs and evaluations can be enhanced are provided.

Critical care nurses' knowledge of alarm fatigue and practices towards alarms: A multicentre study.

OBJECTIVES: To determine critical care nurses' knowledge of alarm fatigue and practices toward alarms in critical care settings. RESEARCH METHODOLOGY/DESIGN: A cross-sectional survey using an adaptation of The Health Technology Foundation Clinical Alarms Survey. SETTING: A sample of critical care nurses (n = 250) from 10 departments across six hospitals in Ireland. RESULTS: A response rate of 66% (n = 166) was achieved. All hospital sites reported patient adverse events related to clinical alarms. The majority of nurses (52%, n = 86) did not know or were unsure, how to prevent alarm fatigue. Most nurses (90%, n = 148) agreed that non-actionable alarms occurred frequently, disrupted patient care (91%, n = 145) and reduced trust in alarms prompting nurses to sometimes disable alarms (81%, n = 132). Nurses claiming to know how to prevent alarm fatigue stated they customised patient alarm parameters frequently (p = 0.037). Frequent false alarms causing reduced attention or response to alarms ranked the number one obstacle to effective alarm management; this was followed by inadequate staff to respond to alarms. Only 31% (n = 50) believed that alarm management policies and procedures were used effectively. CONCLUSION: Alarm fatigue has the potential for serious consequences for patient safety and answering numerous alarms drains nursing resources.

Lateral phase separation gives multiple lamellar phases in a "binary" surfactant/water system: the phase behavior of sodium alkyl benzene sulfonate/water mixtures.

We have examined the structure of the lamellar phase (Lalpha) that coexists with a micellar solution (L1) for a commercial sodium alkyl benzene sulfonate (LAS) mixed with water. The surfactant is a mixture containing C10-C13 alkyl chains, having all positional isomers of the benzene sulfonate group present except the 1-isomer. Unusually for ionic surfactants, the difference in compositions between the coexisting L1 and Lalpha phases is large (L1 = approximately 20 wt % LAS; Lalpha = approximately 65 wt %). The main technique employed was X-ray diffraction, supplemented by optical microscopy and differential scanning calorimetry (DSC). At ambient temperatures, the lamellar phase gives a single diffraction pattern with the main reflection (d) at approximately 32.5 A, whatever the composition. However, above 40 degrees C, the diffraction peak becomes broader and moves to higher d values. At higher temperatures still, several distinct and different diffraction peaks are observed, differing in detail according to composition. The largest d values (approximately 42-4 A) are observed for the lowest LAS concentrations, while the largest number of separate reflections (five) occurs for samples with approximately 44-50% LAS, both at the highest temperatures. Although there are some differences in the data between heating and cooling cycles, the d values return to the original value at low temperature. There are no observable transitions in DSC, nor is there any heterogeneity in the lamellar phase observable by microscopy. The data clearly indicate that there is some lateral separation of the different LAS isomers within the bilayers, which results in the formation of local lamellar regions having different surfactant compositions. This lateral phase separation may arise from the presence of an (electrostatic) attractive interaction, which gives rise to an upper consolute loop within the lamellar phase region of a pure LAS isomer. Similar mechanisms may occur in biological membranes and could be responsible for the occurrence of membrane lipid patches.