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Background: The COVID-19 pandemic in Latin America generated the need to develop low-cost, fast-manufacturing mechanical ventilators. The Universidad de La Sabana and the Fundacion Neumologica Colombiana designed and manufactured the Unisabana-HERONS (USH) ventilator. Here, we present the preclinical and clinical study results to evaluate its effectiveness and safety characteristics in an animal model (Yorkshire Sow) and five patients with acute respiratory failure receiving mechanical ventilatory support for 24 h. Methods: The effectiveness and safety outcomes included maintaining arterial blood gases and pulse oximetry saturation (SpO2), respiratory pressures and volumes (during continuous monitoring) in the range of ARDS and lung-protective strategy goals, and the occurrence of barotrauma. A significance level of 0.05 was used for statistical tests. This clinical trial was registered on Clinicaltrials.gov (NCT04497623) and approved by the ethics committee. Results: Among patients treated with the Unisabana-HERONS, the most frequent causes of acute respiratory failure were pneumonia in 3/5 (60 %) and ARDS in 2/5 (40 %). During the treatment, the ventilatory parameters related to lung protection protocols were kept within the safety range, and vital signs and blood gas were stable. The percentage of time that the respiratory pressures or volumes were out of safety range were plateau pressure >30 cm H2O: 0.00 %; driving pressure >15 cm H2O: 0.06 %; mechanical power >15 J/min: 0.00 %; and Tidal volume >8 mL/kg: 0.00 %. There were no adverse events related to the ventilator. The usability questionnaire retrieved a median score for all items between 9 and 10 (best score: 10), indicating great ease of use. Conclusion: The Unisabana-HERONS ventilator effectively provided adequate gas exchange and maintained the ventilatory parameters in the range of lung protection strategies in humans and an animal model. Furthermore, it is straightforward to use and is a low-cost medical device.

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Respiratory diseases are among the leading causes of death globally, with the COVID-19 pandemic serving as a prominent example. Issues such as infections affect a large population and, depending on the mode of transmission, can rapidly spread worldwide, impacting thousands of individuals. These diseases manifest in mild and severe forms, with severely affected patients requiring ventilatory support. The air-oxygen blender is a critical component of mechanical ventilators, responsible for mixing air and oxygen in precise proportions to ensure a constant supply. The most commonly used version of this equipment is the analog model, which faces several challenges. These include a lack of precision in adjustments and the inspiratory fraction of oxygen, as well as gas wastage from cylinders as pressure decreases. The research proposes a blender model utilizing only dynamic pressure sensors to calculate oxygen saturation, based on Bernoulli's equation. The model underwent validation through simulation, revealing a linear relationship between pressures and oxygen saturation up to a mixture outlet pressure of 500 cmH2O. Beyond this value, the relationship begins to exhibit non-linearities. However, these non-linearities can be mitigated through a calibration algorithm that adjusts the mathematical model. This research represents a relevant advancement in the field, addressing the scarcity of work focused on this essential equipment crucial for saving lives.

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BACKGROUND: Weeksella virosa pneumonia is an infection that has been described as a healthcare-associated infection. This is a rare gram-negative anaerobic bacterium associated with the use of mechanical ventilation for a long period of time and is more frequent in immunosuppressed patients. This is the first case reported in the state of Veracruz and the second in Mexico. CASE PRESENTATION: We present the case of a 64-year-old female from Veracruz, Mexico who developed an infectious process in the right pelvic limb after a transcatheter aortic valve replacement procedure and subsequently developed sudden cardiorespiratory arrest requiring mechanical ventilation, with subsequent imaging studies demonstrating a pneumonic process associated with a nosocomial infection. DISCUSSION AND CONCLUSIONS: We should take into consideration that this pathogen affects not only adults with multiple comorbidities but also children with renal, hepatic, or oncological pathologies, as well as immunocompromised patients, who should be considered high-risk populations for W. virosa infection.

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BACKGROUND: Ventilation configurations are of great clinical importance for adequate outcomes in mechanically ventilated patients, and they may even be used as specific physical therapy techniques. OBJECTIVES: To compare the effectiveness of lung hyperinflation through mechanical ventilation (HMV) with HMV plus flow bias optimization regarding respiratory mechanics, hemodynamics, and volume of secretion. METHODS: Patients mechanically ventilated > 24 h were included in this randomized crossover clinical trial. The following techniques were applied: HMV alone (control group) and HMV plus flow bias optimization (intervention group). RESULTS: The 20 included patients underwent both techniques, totaling 40 collections. A total of 52 % were women, the mean age was 60.8 (SD, 15.7) years, and the mean mechanical ventilation time was 4.3 (SD, 3.0) days. The main cause of mechanical ventilation was sepsis (44 %). Expiratory flow bias in optimized HMV was higher. than conventional HMV (p < 0.001). The volume of tracheal secretions collected was higher during optimized than conventional HMV. (p = 0.012). Significant differences in peak flow occurred at the beginning of the technique and a there was a significant decrease in respiratory system resistance immediately and 30 min after applying the technique in the intervention group. CONCLUSIONS: The volume of tracheal secretions collected was higher during optimized HMV, and, HMV with flow bias optimization resulted in lower respiratory system resistance and flow peaks and produced expiratory flow bias.

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Risk factors for COVID-19 death in high-altitude populations have been scarcely described. This study aimed to describe risk factors for COVID-19 death in three referral hospitals located at 3399 m in Cusco, Peru, during the first 14 months of the pandemic. A retrospective multicenter cohort study was conducted. A random sample of ~50% (1225/2674) of adult hospitalized patients who died between 1 March 2020 and 30 June 2021 was identified. Of those, 977 individuals met the definition of death by COVID-19. Demographic characteristics, intensive care unit (ICU) admission, invasive respiratory support (IRS), disease severity, comorbidities, and clinical manifestation at hospital admission were assessed as risk factors using Cox proportional-hazard models. In multivariable models adjusted by age, sex, and pandemic periods, critical disease (vs. moderate) was associated with a greater risk of death (aHR: 1.27; 95%CI: 1.14-1.142), whereas ICU admission (aHR: 0.39; 95%CI: 0.27-0.56), IRS (aHR: 0.37; 95%CI: 0.26-0.54), the ratio of oxygen saturation (ROX) index ≥ 5.3 (aHR: 0.87; 95%CI: 0.80-0.94), and the ratio of SatO2/FiO2 ≥ 122.6 (aHR: 0.96; 95%CI: 0.93-0.98) were associated with a lower risk of death. The risk factors described here may be useful in assisting decision making and resource allocation.

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The first anesthetic machines appeared following their public demonstration by Morton in 1846. These initial devices were simple inhalers based on the evaporation of the anesthetic agent. Their main problem was the loss of effectiveness with cooling. More complex inhalers were subsequently developed, in which the main difference was the possibility to provide more than one agent. Moreover, the concentration of the inhaled anesthetic was regulated for greater efficiency. At the beginning of the twentieth century, gas machines emerged, allowing the application of an anesthetic flow independent of the patient's inspiratory effort. These machines incorporated technological advances such as flow meters, carbon dioxide absorption systems and fine adjustment vaporizers. In this period, in the field of thoracic surgery, intraoperative artificial ventilation began to be employed, which helped overcome the problem of pneumothorax associated with open pleura by applying positive pressure. From the 1930s, the gas machines were fitted with a ventilator, and by the 1950s this had become a basic component of the anesthesia system. Later still, in the 1980s, alarm and monitoring systems were incorporated, giving rise to the current generation of workstations.

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BACKGROUND: Prolonged use of mechanical ventilation is associated with some complications as high mortality and high morbidities as bronchopulmonary dysplasia, ventilator-associated pneumonia, and pneumothorax. However, extubation failure in preterm infants is still high (40-60%) in very low birth weight infants (VLBW). Noninvasive neurally adjusted ventilatory assistance (NIV-NAVA) is triggered by the diaphragmatic electrical activity through a nasogastric tube that synchronizes patient/ventilator respiration, cycle by cycle effectively shortening the assisted cycle trigger and the degree of ventilatory assistance, optimizing the effects of intermittent inspiratory pressure on nasal continuous positive airway pressure (NCPAP). This study aims to compare reintubation rates until 72 h after extubation in preterm infants of high risk for reintubation using NIV-NAVA or NCPAP. METHODS: A retrospective study of chart review data collection was performed in a private tertiary hospital. The study was approved by the local institutional Ethics Committee. We included infants considered at high risk of reintubation (BW < 1000 grams; use of invasive mechanical ventilation (IMV) for at least 7 days; or previous extubation failure episode) and compared the two groups according to the type of respiratory support after extubation: (1) NCPAP (n = 32); or (2) NIV-NAVA (n = 17). Demographics data were collected, the primary outcome was reintubation rate until 72 h after extubation. Secondary outcome was time to reintubation, BPD rate, IVH grade ≥ III, pneumothorax and death. RESULTS: There was no difference between both groups in demographic data. The reintubation rate decreased significantly in the NIV-NAVA group compared to NCPAP (50.0-11.7, p < .02) despite the significantly higher length of invasive mechanical ventilation (IMV) before extubation attempt in NIV-NAVA group (12.4 versus 5.5 days, p < .04). There was no difference between both groups in secondary outcomes. CONCLUSIONS: In this small retrospective cohort study, the use of NIV-NAVA as postextubation strategy was effective in reducing extubation failure within 72 h in preterm infants when compared to traditional NCPAP.

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COVID-19, the causative agent of which is a new type of coronavirus called SARS-CoV-2, has caused the most severe pandemic in the last 100 years. The condition is mainly respiratory, and up to 5% of patients develop critical illness, a situation that has put enormous pressure on the health systems of affected countries. A high demand for care has mainly been observed in intensive care units and critical care resources, which is why the need to redistribute resources in critical medicine emerged, with an emphasis on distributive justice, which establishes the provision of care to the largest number of people and saving the largest number of lives. One principle lies in allocating resources to patients with higher life expectancy. Mechanical ventilator has been assumed to be an indivisible asset; however, simultaneous mechanical ventilation to more than one patient with COVID-19 is technically possible. Ventilator sharing is not without risks, but the principles of beneficence, non-maleficence and justice prevail. According to distributive justice, being a divisible resource, mechanical ventilator can be shared; however, we should ask ourselves if this action is ethically correct.

COVID-19, cuyo agente causal es un nuevo tipo de coronavirus denominado SARS-CoV-2, ha provocado la pandemia más grave en los últimos 100 años. La afección es principalmente respiratoria y hasta 5 % de los pacientes desarrolla enfermedad crítica, lo cual ha producido una enorme presión sobre los sistemas de salud de los países afectados. Principalmente se ha observado alta demanda de atención en las unidades de cuidados intensivos y de recursos de atención vital. De ahí la necesidad de redistribuir los recursos en medicina crítica, con énfasis en la justicia distributiva, la cual establece atender al mayor número de personas y salvar el mayor número de vidas. Un principio estriba en asignar los recursos a pacientes con mayores expectativas de vida. Se ha dado por hecho que el ventilador mecánico es un bien indivisible; sin embargo, técnicamente es posible la ventilación mecánica simultánea a más de un paciente con COVID-19. La acción de compartir el ventilador no está exenta de riesgos, pero prevalecen los principios de beneficencia, no maleficencia y justicia. Conforme la justicia distributiva, al ser un bien divisible, el ventilador mecánico puede ser compartido, sin embargo, cabe preguntarse si esta acción es éticamente correcta.

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Abstract COVID-19, the causative agent of which is a new type of coronavirus called SARS-CoV-2, has caused the most severe pandemic in the last 100 years. The condition is mainly respiratory, and up to 5 % of patients develop critical illness, a situation that has put enormous pressure on the health systems of affected countries. A high demand for care has mainly been observed in intensive care units and critical care resources, which is why the need to redistribute resources in critical medicine emerged, with an emphasis on distributive justice, which establishes the provision of care to the largest number of people and saving the largest number of lives. One principle lies in allocating resources to patients with higher life expectancy. Mechanical ventilator has been assumed to be an indivisible asset; however, simultaneous mechanical ventilation to more than one patient with COVID-19 is technically possible. Ventilator sharing is not without risks, but the principles of beneficence, non-maleficence and justice prevail. According to distributive justice, being a divisible resource, mechanical ventilator can be shared; however, we should ask ourselves if this action is ethically correct.

Resumen COVID-19, cuyo agente causal es un nuevo tipo de coronavirus denominado SARS-CoV-2, ha provocado la pandemia más grave en los últimos 100 años. La afección es principalmente respiratoria y hasta 5 % de los pacientes desarrolla enfermedad crítica, lo cual ha producido una enorme presión sobre los sistemas de salud de los países afectados. Principalmente se ha observado alta demanda de atención en las unidades de cuidados intensivos y de recursos de atención vital. De ahí la necesidad de redistribuir los recursos en medicina crítica, con énfasis en la justicia distributiva, la cual establece atender al mayor número de personas y salvar el mayor número de vidas. Un principio estriba en asignar los recursos a pacientes con mayores expectativas de vida. Se ha dado por hecho que el ventilador mecánico es un bien indivisible; sin embargo, técnicamente es posible la ventilación mecánica simultánea a más de un paciente con COVID-19. La acción de compartir el ventilador no está exenta de riesgos, pero prevalecen los principios de beneficencia, no maleficencia y justicia. Conforme la justicia distributiva, al ser un bien divisible, el ventilador mecánico puede ser compartido, sin embargo, cabe preguntarse si esta acción es éticamente correcta.

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BACKGROUND: Nosocomial pneumonia has correlated to dental plaque and to oropharynx colonization in patients receiving mechanical ventilation. The interruption of this process, by preventing colonization of pathogenic bacteria, represents a potential procedure for the prevention of ventilator-associated pneumonia (VAP). METHODS: The study design was a prospective, randomized trial to verify if oral hygiene through toothbrushing plus chlorhexidine in gel at 0.12% reduces the incidence of ventilatior-associated pneumonia, the duration of mechanical ventilation, the length of hospital stay and the mortality rate in ICUs, when compared to oral hygiene only with chlorhexidine, solution of 0.12%, without toothbrushing, in adult individuals under mechanical ventilation, hospitalized in Clinical/Surgical and Cardiology Intensive Care Units (ICU). The study protocol was approved by the Ethical Committee of Research of the Health Sciences Center of the Federal University of Pernambuco - Certificate of Ethical Committee Approval (CAAE) 04300012500005208. Because it was a randomized trial, the research used CONSORT 2010 checklist criteria. RESULTS: Seven hundred sixteen patients were admitted into the ICU; 219 fulfilled the criteria for inclusion and 213 patients were included; 108 were randomized to control group and 105 to intervention group. Toothbrushing plus 0.12% chlorhexidine gel demonstrated a lower incidence of VAP throughout the follow up period, although the difference was not statistically significant (p = 0.084). There was a significant reduction of the mean time of mechanical ventilation in the toothbrushing group (p = 0.018). Regarding the length of hospital stay in the ICU and mortality rates, the difference was not statistically significant (p = 0.064). CONCLUSIONS: The results obtained showed that, among patients undergoing toothbrushing there was a significant reduction in duration of mechanical ventilation, and a tendency to reduce the incidence of VAP and length of ICU stay, although without statistical significance. TRIAL REGISTRATION: Retrospectively registered in the Brazilian Clinical Trials Registry (Registro Brasileiro de Ensaios Clínicos) - RBR-4TWH4M (4 September 2016).

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INTRODUCTION: Patients with hypoxemia and chronic respiratory failure may need to use oxygen therapy to correct hypoxemia and to use ventilatory support to augment alveolar ventilation, reverse abnormalities in blood gases (in particular hypercapnia) and reduce the work of breathing. Areas covered: This narrative review provides an overview on the use of oxygen therapy devices or portable ventilators for improved physical activity in daily life (PADL) as well as discusses the issue of lower mobility in daily life among stable patients with chronic respiratory disease who present indication for long-term oxygen therapy (LTOT) or home-based noninvasive ventilation (NIV). A literature review of these concepts was performed by using all related search terms. Expert commentary: Technological advances led to the development of light and small oxygen therapy devices and portable ventilators which aim to facilitate patients' mobility and ambulation. However, the day-by-day dependence of a device may reduce mobility and partially impair patients' PADL. Nocturnal NIV implementation in hypercapnic patients seems promising to improve PADL. The magnitude of their equipment-related physical inactivity is underexplored up to this moment and more long-term randomized clinical trials and meta-analysis examining the effects of ambulatory oxygen and NIV on PADL are required.

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Abstract Introduction: This work concerns the assessment of a novel system for mechanical ventilation and a parameter estimation method in a bench test. The tested system was based on a commercial mechanical ventilator and a personal computer. A computational routine was developed do drive the mechanical ventilator and a parameter estimation method was utilized to estimate positive end-expiratory pressure, resistance and compliance of the artificial respiratory system. Methods The computational routine was responsible for establishing connections between devices and controlling them. Parameters such as tidal volume, respiratory rate and others can be set for standard and noisy ventilation regimes. Ventilation tests were performed directly varying parameters in the system. Readings from a calibrated measuring device were the basis for analysis. Adopting a first-order linear model, the parameters could be estimated and the outcomes statistically analysed. Results Data acquisition was effective in terms of sample frequency and low noise content. After filtering, cycle detection and estimation took place. Statistics of median, mean and standard deviation were calculated, showing consistent matching with adjusted values. Changes in positive end-expiratory pressure statistically imply changes in compliance, but not the opposite. Conclusion The developed system was satisfactory in terms of clinical parameters. Statistics exhibited consistent relations between adjusted and estimated values, besides precision of the measurements. The system is expected to be used in animals, with a view to better understand the benefits of noisy ventilation, by evaluating the estimated parameters and performing cross relations among blood gas, ultrasonography and electrical impedance tomography.

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Objetivo: Estimar la costo-efectividad de linezolid versus vancomicina en el manejo de neumonía asociada a ventilación mecánica (NAV) causada por Staphylococcus aureus resistente a meticilina (SARM) en Colombia. Materiales y métodos: Se construyó un árbol de decisión para determinar la razón de costo-efectividad incremental de linezolid (600 mg iv/12 h) comparado con vancomicina (15 mg/kg iv/12 h) en el tratamiento de NAV por SARM. La perspectiva fue la del sistema de salud incluyendo solo costos directos. Todas las unidades monetarias se expresan en pesos colombianos del 2013 sin descuento (1 USD =$ 1.876,22). Se empleó un horizonte temporal de 30 días. Los resultados se midieron en proporción de pacientes curados. Los datos de eficacia y seguridad se tomaron de la literatura. Los costos de los procedimientos se obtuvieron del manual tarifario ISS del 2001, para medicamentos se utilizó el SISMED y la regulación de precios vigente. Se realizaron análisis de sensibilidad univariados y probabilísticos. Resultados: Los costos totales esperados por paciente curado fueron: $ 2.600.094 para linezolid y $ 1.992.753 para vancomicina. La proporción de pacientes curados fue: 53% con linezolid y 41%.con vancomicina. La razón de costo-efectividad de linezolid comparado con vancomicina fue $ 5.061.173 por paciente curado. Para cada alternativa, los resultados fueron sensibles a la probabilidad de éxito del tratamiento, a la probabilidad de presentar eventos adversos y al costo del tratamiento. Conclusión: En Colombia, linezolid sería una alternativa costo-efectiva en el tratamiento de NAV por SARM, para disponibilidades a pagar superiores a $ 5.061.173 por paciente curado.

Objective: To estimate the cost-effectiveness of linezolid versus vancomycin in the management of ventilator-associated pneumonia (VAP) caused by methicillin-resistant Staphylococcus aureus (MRSA) in Colombia. Materials and methods: We constructed a decision tree to determine the incremental cost effectiveness ratio (ICER) of linezolid (600 mg iv /12 h) compared to vancomycin (15 mg/kg iv/12 h) for the treatment of VAP caused for MRSA. The perspective is that of the Colombian health system, including only direct costs. All currency units are in Colombian pesos (COP, 2013) with no discount. (1 USD = $1,876.22). We used a time horizon of 30 days. The results were measured in the proportion of patients cured. The efficacy and safety data were taken from the literature. The costs of procedures were obtained of ISS tariff manual of 2001 and for drugs current price regulations and the SISMED database were used. Univariate and probabilistic sensitivity analyses were performed. Results: The total costs expected per patient cured were COP 2,600,094 for linezolid and COP 1,992,753 for vancomycin. The proportion of cured patients was 53% with linezolid and 41% with vancomycin. The ICER of linezolid compared with vancomycin was COP 5,061,173 per patient cured. For each alternative, the results were sensitive to the probability of the success of treatment, the probability of adverse events and the cost of treatment. Conclusion: Linezolid would be a cost-effective alternative in the treatment of VAP for MRSA in Colombia for willingness to pay above COP 5,061,173 per patient cured.

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