Design of a flow modulation device to facilitate individualized ventilation in a shared ventilator setup.

This study aims to resolve the unmet need for ventilator surge capacity by developing a prototype device that can alter patient-specific flow in a shared ventilator setup. The device is designed to deliver a predictable tidal volume (VT), requiring minimal additional monitoring and workload. The prototyped device was tested in an in vitro bench setup for its performance against the intended use and design criteria. The ventilation parameters: VT and airway pressures, and ventilation profiles: pressure, flow and volume were measured for different ventilator and device settings for a healthy and ARDS simulated lung pathology. We obtained VTs with a linear correlation with valve openings from 10 to 100% across set inspiratory pressures (IPs) of 20 to 30 cmH2O. Airway pressure varied with valve opening and lung elastance but did not exceed set IPs. Performance was consistent in both healthy and ARDS-simulated lung conditions. The ventilation profile diverged from traditional pressure-controlled profiles. We present the design a flow modulator to titrate VTs in a shared ventilator setup. Application of the flow modulator resulted in a characteristic flow profile that differs from pressure- or volume controlled ventilation. The development of the flow modulator enables further validation of the Individualized Shared Ventilation (ISV) technology with individualization of delivered VTs and the development of a clinical protocol facilitating its clinical use during a ventilator surge capacity problem.

Individualized mechanical ventilation in a shared ventilator setting: limits, safety and technical details.

The COVID-19 pandemic has resulted in an increased need for ventilators. The potential to ventilate more than one patient with a single ventilator, a so-called split ventilator setup, provides an emergency solution. Our hypothesis is that ventilation can be individualized by adding a flow restrictor to limit tidal volumes, add PEEP, titrate FiO2 and monitor ventilation. This way we could enhance optimization of patient safety and clinical applicability. We performed bench testing to test our hypothesis and identify limitations. We performed a bench testing in two test lungs: (1) determine lung compliance (2) determine volume, plateau pressure and PEEP, (3) illustrate individualization of airway pressures and tidal volume with a flow restrictor, (4a) illustrate that PEEP can be applied and individualized (4b) create and measure intrinsic PEEP (4c and d) determine PEEP as a function of flow restriction, (5) individualization of FiO2. The lung compliance varied between 13 and 27 mL/cmH2O. Set ventilator settings could be applied and measured. Extrinsic PEEP can be applied except for settings with a large expiratory time. Volume and pressure regulation is possible between 70 and 39% flow restrictor valve closure. Flow restriction in the tested circuit had no effect on the other circuit or on intrinsic PEEP. FiO2 could be modulated individually between 0.21 and 0.8 by gradually adjusting the additional flow, and minimal affecting FiO2 in the other circuit. Tidal volumes, PEEP and FiO2 can be individualized and monitored in a bench testing of a split ventilator. In vivo research is needed to further explore the clinical limitations and outcomes, making implementation possible as a last resort ventilation strategy.

Determinants of emergency physician wellness in Belgium.

OBJECTIVES: This cross-sectional study examines first whether emergency physicians differ from a comparison group of surgeons, more specifically general surgeons and orthopedic surgeons, in terms of job and organizational characteristics and second to what extent these characteristics are determinants of professional well-being outcomes in emergency physicians. METHODS: Belgian emergency physicians (n = 346) were invited to participate in this study. Forty-three percent of the eligible participants completed a questionnaire. The survey instrument contained 48 questions on determinants (personal characteristics, job conditions [Job Demand Control Support], organizational and environmental work conditions) as well as 39 questions on outcomes (job satisfaction, turnover intention, subjective fatigue, psychological distress, work-home interference, work engagement) by means of the Leiden Quality of Work Questionnaire for Medical Doctors, the Checklist Individual Strength, the Brief Symptom Inventory, and the Utrecht Work Engagement Scale. Hierarchical multiple regression analyses were used to examine the association between the determinants and each of the outcomes. RESULTS: Emergency physicians reported higher job demands, lower job control, and less adequate work conditions compared with the group of surgeons. High job demands increased turnover intention, subjective fatigue, psychological distress, work-home interference in emergency physicians, but lack of job control, lack of social support from the supervisor, and inadequate communication also contributed in an unfavorable way to some of these outcomes. CONCLUSION: Emergency medicine departments must reduce the constant exposure to high job demands by allowing emergency physicians to have enough time for both physical and mental recovery. Work motivation and work conditions might be improved by increasing job control over job demands by giving emergency physicians more decision latitude and autonomy, improving good communication and teamwork and adequate social support from the supervisor and providing good material resources. These interventions can improve professional well-being outcomes in emergency physicians.