The state of California, in the United States of America, has a population of nearly 40 million people and is the 5th largest economy in the world. During the coronavirus disease 2019 (COVID-19) pandemic in 2020-2021, the state experienced a medical surge that stressed its sophisticated health-care and public health system. During this period, ventilators, oxygen, and other equipment necessary for providing ventilatory support became a scarce resource in many health-care settings. When demand overwhelms supply, creative solutions are required at all levels of disaster management and health care. This study describes the disaster response by the state of California to mitigate the emergency demands for oxygen delivery resources.

The COVID-19 (Coronavirus disease of 2019) pandemic has led to intense conversations about ventilator allocation and reallocation during a crisis standard of care. Multiple voices in the media and multiple state guidelines mention reallocation as a possibility. Drawing upon a range of neuroscientific, phenomenological, ethical, and sociopolitical considerations, the authors argue that taking away someone’s personal ventilator is a direct assault on their bodily and social integrity. They conclude that personal ventilators should not be part of reallocation pools and that triage protocols should be immediately clarified to explicitly state that personal ventilators will be protected in all cases.

Innovation Concept: Ventilator management is an essential skill and a training objective for emergency medicine (EM) specialists in Canada. EM trainees obtain the majority of this training during off-service rotations. Previous attempts to strengthen ventilator knowledge include lectures and simulation – both of which are time and resource intensive. Given the unique features of ventilator management in the ED, we developed an ED-specific ventilator curriculum. The purpose of this study is to 1) identify resident needs regarding ventilator curricula and 2) assess resident response to this pilot curriculum. Methods: A needs-assessment survey administered to RCPSC- and CCFP-EM residents at The Ottawa Hospital (TOH) showed the majority of residents (87%, n = 31 respondents) believe there is a need for more ED-focused ventilator management training, and only 13% felt confident in ventilator management. Ten on-line modules were prepared by an EM-Critical Care attending, and distributed on-line to all EM trainees at TOH (n = 52). Mid- and post-implementation surveys are used to assess residents’ confidence in ventilator management, and perceived usefulness of the curriculum. User feedback from focus groups constitutes part of the curriculum evaluation. Curriculum, Tool or Material: Employing a flipped classroom approach, ten on-line modules were distributed to RCPSC- and CCFP-EM trainees at TOH. Each module requires less than ten minutes to complete and focuses on a single aspect of ventilation. The modules are available for residents to complete at their own pace and convenience. At curriculum completion, an EM-Critical Care attending physician facilitates an interactive session. Conclusion: Mid-implementation survey results demonstrate increased confidence in independently managing ventilated patients in the ED (13% pre- vs. 56% mid-implementation), and an increased perception of having sufficient ventilator training (26% pre- vs. 78% mid-implementation). All respondents felt the modules were of appropriate length, content was easy to follow, and that the modules should be part of the residency curriculum. Our ED-specific online ventilator modules area a viable tool to increase residents’ confidence in ventilator management. This novel curriculum could be adopted by other residency programs and continuing professional development initiatives. Future work will include post-implementation data-gathering, and formal curriculum evaluation.

Objectives: This study aimed to investigate the technical documentation of manufacturers on issues of safe use of their device in a home setting.

Methods: Three categories of equipment were selected: infusion pumps, ventilators, and dialysis systems. Risk analyses, instructions for use, labels, and post market surveillance procedures were requested from manufacturers. Additionally, they were asked to fill out a questionnaire on collection of field experience, on incidents, and training activities.

Results: Specific risks of device operation by lay users in a home setting were incompletely addressed in the risk analyses. A substantial number of user manuals were designed for professionals, rather than for patients or lay carers. Risk analyses and user information often showed incomplete coherence. Post market surveillance was mainly based on passive collection of field experiences.

Conclusions: Manufacturers of infusion pumps, ventilators, and dialysis systems pay insufficient attention to the specific risks of use by lay persons in home settings. It is expected that this conclusion is also applicable for other medical equipment for treatment at home. Manufacturers of medical equipment for home use should pay more attention to use errors, lay use and home-specific risks in design, risk analysis, and user information. Field experiences should be collected more actively. Coherence between risk analysis and user information should be improved. Notified bodies should address these aspects in their assessment. User manuals issued by institutions supervising a specific home therapy should be drawn up in consultation with the manufacturer.

Background and objective Few and conflicting data are available regarding the changes of plasma potassium concentration during acute respiratory acidosis in human beings. This study compares the acute changes in plasma potassium concentration in acutely hypercapnic patients and in non–hypercapnic patients during general anaesthesia.

Methods Thirty-three patients undergoing interventional rigid bronchoscopy were studied. Ventilation of the lungs was randomly conducted using either spontaneous–assisted ventilation or intermittent negative–pressure ventilation. All patients received the same anaesthetic protocol. Arterial blood gases and osmolality, and plasma concentrations of glucose, sodium, potassium and chloride were measured.

Results Intraoperatively, PaCO2 was higher during spontaneous-assisted ventilation than during intermittent negative-pressure ventilation (9±1.8 vs. 5.4±1.2 kPa, P < 0.001) and the pH was also lower during spontaneous-assisted ventilation than during intermittent negative-pressure ventilation (7.24±0.07 vs. 7.4 ±0.08, P < 0.001). Plasma potassium concentration remained similar in both groups (3.8± 0.2mmolL−1 with spontaneous–assisted ventilation vs. 3.7± 0.4mmol L−1 with intermittent negativepressure ventilation).

Conclusion Acute respiratory acidosis does not affect plasma potassium concentration.

The VersaMed 201 is a lightweight, computer-controlled, electrically driven ventilator, designed for transport, home-ventilation and field use. We have evaluated the device in human beings with healthy and pathological lungs. In the first part of the study, the VersaMed was substituted for a standard operating room ventilator for 15–30 min during elective surgery in 20 subjects. In the second stage of the study, 20 patients with lung pathology who were being ventilated in the critical care department were transferred to the VersaMed for a 30-min period. In all the patients studied, arterial blood gases, haemodynamic parameters and other respiratory variables were maintained at similar values seen with the standard ventilators used. We conclude that the VersaMed 201 is suitable for use in human beings with healthy and pathological lungs as a reliable, portable ventilator.

There is a risk of regurgitation if a laryngeal mask airway is used with intermittent positive pressure ventilation. The lower the pressure gradient between airway and stomach, the less will be the likelihood of stomach insufflation with gas and consequent regurgitation. A flow generator ventilator, such as the Penlon Nuffield 200 which achieves a peak pressure at the end of inspiration at any given tidal volume, is likely to produce a higher peak airway pressure than a pressure generator. Replacing the expiratory valve by a venturi gives a preferable flow pattern with an inspiratory pressure plateau. At equal tidal volumes, the venturi modification provided a 10% lower inflation pressure (standard deviation 6%, P < 0.01) and a 1.8% smaller leak (P < 0.05) past the laryngeal mask airway. The same comparison but using identical inflation pressures, gave 8% larger tidal volumes (standard deviation 5.1%, P < 0.01) and a 2% smaller leak (P < 0.01) past the laryngeal mask airway.

The concentrations of nitrous oxide, sevoflurane and oxygen in the circle system of a closed-circuit anaesthesia machine, the PhysioFlex™, were measured in seven patients. During anaesthesia, the settings for each gas were changed and their concentrations recorded. At the induction of anaesthesia, it took 80– 510s (median 190 s) for the end-tidal sevoflurane concentration to reach 2.0%, and 920–2640 s (median 1500 s) for the oxygen in the breathing circuit to reach 30%. At this time, the nitrous oxide concentration was 60±3% (mean±SD). During anaesthesia, it took 90–480 s (median 140 s) for the end-tidal sevoflurane concentration setting to decrease from 3.0 to 1.0%, and 90–400 s (median 110 s) to return from 1.0 to 3.0%. When the inspired oxygen was increased from 30 to 50%, circuit concentrations reached equilibrium in 40–60 s (median 40 s), and when decreased from 50% back to 30%, equilibrium took 310–470 s (median 450 s). During recovery from anaesthesia, inspiratory sevoflurane concentration took 40–70 s (median 50 s) to decrease to 0.2%. The PhysioFlex™ provided adequate control of sevoflurane and oxygen concentrations, but not of increasing nitrous oxide concentrations.