Mechanical ventilator as a shared resource for the COVID-19 pandemic / El ventilador mecánico como recurso divisible ante la pandemia de COVID-19

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.

A study of maternal and fetal outcomes in critically ill obstetric patients

Background: Pregnancy related morbidity is becoming a nightmare in Indian women. Some of these women end up in mortality and a few of them narrowly escape death. Critical care should be and is an authenticated part of obstetric practice. This study is an effort initiated to understand the risk of maternal morbidity, to investigate the contributing factors, foetal outcome, to study the adverse event, cause of maternal death and remedial measures.Methods: All the obstetric cases admitted in Intensive care unit in a government institute in Maharashtra during January 2018 to June 2019 were analyzed prospectively. The indications for transfer into intensive care, risk factors, co morbidities if any were studied. Maternal and fetal morbidity and mortality were included in the study.Results: During the study period, there were 10, 208 deliveries. There were 12 maternal deaths and 98 critically ill patients became morbid. Anemia is found to be a major pre-existing contributing factor (25.5%) and an important risk factor making pregnancy become critical. DIC is found to be a major reason for ICU admission (39.1%), 72.7% needed mechanical ventilator and 60.1% needed ionotropic support.Conclusions: Anemia is a major problem still existing in our country. Gestational hypertension is another leading cause of critical illness in pregnancy. Identification of patients who are going downhill, timely referral to higher centers and appropriate management can improve both the maternal and the fetal outcomes.

Mortality Outcome in Patients of Guillian Barre Syndrome. A single Center Study

Introduction: The Guillian Barre syndrome (GBS) is characterised by acute areflexic paralysis with albumincytological dissociation. Study was undertaken to analyze the electrophysiological studies, clinical profile and outcome of GBS at our institute. Material and Methods: This study was a hospital based descriptive and prospective study was conducted on patients admitted in the Medical intensive care unit. Patients with age more than 18 years, irrespective of their sex, diagnosed as GBS, fulfilling the criteria as modified by Asbury were included in the current study. Association between qualitative variables was assessed by Chi-Square test. Quantitative data was represented using mean ± SD, median. Results: Out of 50 enrolled, 21 patients belonged to age 21 to 40. 33 pts were male and 17 pts were female, 7 patients expired. Two peak of occurrence of GBS was found in age one in age group 21 to 41years and another in age more than 51 years.13 patients had history of antecedent infection. 35 patients had albumin-cytological dissociation. As per the results of nerve conduction study, patients were categorized in the following 3 groups AMAN-24, AIDP-14 and ASMAN-12. Conclusions: The independent predictors for the need of mechanical ventilation were history of breathlessness on admission, SBC of equal to or less than 10, upper or lower limb power of less than or equal to 2 (P valve <0.01). The predictors of poor outcome were presence of sepsis, need for mechanical ventilation, VAP, SBC of < 10 and lower limb power < 2.

Adult venovenous extracorporeal membrane oxygenation for severe respiratory failure: Current status and future perspectives.

Extracorporeal membrane oxygenation (ECMO) for severe acute respiratory failure was proposed more than 40 years ago. Despite the publication of the ARDSNet study and adoption of lung protective ventilation, the mortality for acute respiratory failure due to acute respiratory distress syndrome has continued to remain high. This technology has evolved over the past couple of decades and has been noted to be safe and successful, especially during the worldwide H1N1 influenza pandemic with good survival rates. The primary indications for ECMO in acute respiratory failure include severe refractory hypoxemic and hypercarbic respiratory failure in spite of maximum lung protective ventilatory support. Various triage criteria have been described and published. Contraindications exist when application of ECMO may be futile or technically impossible. Knowledge and appreciation of the circuit, cannulae, and the physiology of gas exchange with ECMO are necessary to ensure lung rest, efficiency of oxygenation, and ventilation as well as troubleshooting problems. Anticoagulation is a major concern with ECMO, and the evidence is evolving with respect to diagnostic testing and use of anticoagulants. Clinical management of the patient includes comprehensive critical care addressing sedation and neurologic issues, ensuring lung recruitment, diuresis, early enteral nutrition, treatment and surveillance of infections, and multisystem organ support. Newer technology that delinks oxygenation and ventilation by extracorporeal carbon dioxide removal may lead to ultra‑lung protective ventilation, avoidance of endotracheal intubation in some situations, and ambulatory therapies as a bridge to lung transplantation. Risks, complications, and long‑term outcomes and resources need to be considered and weighed in before widespread application. Ethical challenges are a reality and a multidisciplinary approach that should be adopted for every case in consideration.

Management of Ventilatory Insufficiency in Neuromuscular Patients Using Mechanical Ventilator Supported by the Korean Government

Since 2001, financial support has been provided for all patients with neuromuscular disease (NMD) who require ventilatory support due to the paralysis of respiratory muscles in Korea. The purpose of this study was to identify ventilator usage status and appropriateness in these patients. We included 992 subjects with rare and incurable NMD registered for ventilator rental fee support. From 21 February 2011 to 17 January 2013, ventilator usage information, regular follow-up observation, and symptoms of chronic hypoventilation were surveyed by phone. Home visits were conducted for patients judged by an expert medical team to require medical examination. Abnormal ventilatory status was assessed by respiratory evaluation. Chronic respiratory insufficiency symptoms were reported by 169 of 992 subjects (17%), while 565 subjects (57%) did not receive regular respiratory evaluation. Ventilatory status was abnormal in 102 of 343 home-visit subjects (29.7%). Although 556 subjects (56%) reported 24-hour ventilator use, only 458 (46%) had an oxygen saturation monitoring device, and 305 (31%) performed an airstacking exercise. A management system that integrates ventilator usage monitoring, counselling and advice, and home visits for patients who receive ventilator support could improve the efficiency of the ventilator support project.

A study of the use of home mechanical ventilator and medical insurance

PURPOSE: Use of a home mechanical ventilator can shorten the hospitalization duration of children with chronic respiratory failure requiring long-term use of a mechanical ventilator. In this study, the researchers analyzed patients who had used a home mechanical ventilator. METHODS: From January 2009 to July 2014, we retrospectively investigated 15 patients under 18 years of age, from 2 hospitals, and their use of home mechanical ventilators. RESULTS: The median age of the patients was 55 months. Ten children were male, and 5 were female. As for the type of mechanical ventilators, 10 used a pressure type, 3 used a volume type, and 2 used a volume-mask type. Analysis of underlying diseases revealed that 10 children had neuromuscular disease, 3 had pulmonary disease, and 2 suffered from hypoxic ischemic encephalopathy. The number of patients who were discharged from the hospital with a home mechanical ventilator was 13. One child died of sepsis irrespective of the mechanical ventilator. Six patients had health insurance. But 9 did not. The group with insurance had the possibility of being discharged earlier than the group without. On readmission, the length of hospitalization was also reduced in patients who had used a home mechanical ventilator. CONCLUSION: Use of a mechanical ventilator at home is helpful in patients who need long-term use of a mechanical ventilator due to neuromuscular disease, chronic pulmonary diseases, and accidents because complications are rare and insurance coverage is feasible.

A study on the overall management strategy of mechanical ventilations in the hospital / 中国医学装备

Objective:Now the mechanical ventilation has become the essential emergency or therapy equipment in the all sizes of hospitals. However with the widely application of ventilators, they are still the kind of high risk of medical instruments. In order to reduce various equipment failures, an overall management strategy based on traceability of two-dimension code is constructed in this article, which will provide a new direction for medical equipment management.Methods: Using the popular application of WiFi network and creating the only identified two-dimension code, the overall management strategy is established for the ventilators.Results: The centralized and decentralized management model is adopted in the preservation of ventilators. And all the operators of ventilators will be supported technology service about equipment failures and setting parameters by the respiratory department and engineering department. In addition to this, the two departments should organize the staff to learn the operation of ventilators in the hospital. All of those compose the structure of overall management.Conclusion: With the management of this method, the efficiency of ventilators is improved, and the rate of machine failures is dropped. The difficulty about technology service caused by space can be solved in time. Finally, the professional ability of the staff in hospital will be improved with the communication among the different departments.

Parameter estimation of an artificial respiratory system under mechanical ventilation following a noisy regime

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.

Costo-efectividad de linezolid comparado con vancomicina en el manejo de la neumonía asociada a ventilación mecánica en Colombia / Cost effectiveness of linezolid compared with vancomycin in the management of ventilator-associated pneumonia in Colombia

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.

Two Cases of Tension Pneumopericardium in Mechanically Ventilated Preterm Infants

Pneumopericardium is a rare form of neonatal air leakage. Tension pneumopericardium is much more infrequent, but can cause a cardiovascular deterioration with high mortality up to 80% and neurodevelopmental morbidity in half of the cases. We report two cases of preterm infants who successfully recovered from tension pneumopericardium that developed during mechanical ventilator assistance. The patients displayed a sudden increase in oxygen demand and subsequent cardiovascular deterioration. Immediate needle aspiration of the pneumopericardium performed after checking X-ray images rescued each of patient. Since the clinical symptoms are non-specific, clinicians' suspicion is most important when patients show sudden refractory cardiovascular collapse, especially in ventilator-assisted neonates. This life threatening complication demands instant diagnosis and intervention.

Effects of Web-based Multimedia Contents for Mechanical Ventilator Practice on Knowledge and Clinical Competence of Nursing Students / 성인간호학회지

PURPOSE: The purpose of this study was to identify the effect of web-based learning for ventilator practice on the knowledge and clinical competence of nursing students. METHOD: The research design was a non-equivalent control group pre-post non-synchronized design. Twenty five nursing students were collected for the experimental group from August 23 to November 26, 2004 and nineteen nursing students for the control group from August 22 to November 25, 2005. All subjects experienced clinical practices in an intensive care unit of a hospital in G city for 2 weeks. The web-based learning for ventilator practice was conducted in the experimental group only. The data were analyzed with t-test and ANCOVA using SPSS 10.1 program. RESULT: The 2 week web-based clinical practice learning significantly improved the knowledge scores for the experimental group, however, there was no significant differences in the score for the clinical competence between experimental and control group. CONCLUSION: These findings suggest that a self-directed web-based learning for ventilator practice of nursing students can facilitate the knowledge of care for a ventilated patient. Therefore, faculties should develop a variety of web-based multimedia content programs for clinical instruction based on clinical situation.

A Study on the Physiological and Psychological Factors related to Successful Weaning from a Mechanical Ventilator / 간호학회지

This study was performed to identify the physiological and psychological variables related to successful weaning from a mechanical ventilator. The subjects of this study were 22 patients who received mechanical ventilation therapy for more than 3 days in intensive care units. Before the weaning trial, baseline data for following physiologic variables were obtained: spontaneous respiration rate, blood pressure, pulse rate, PaO2, PaCO2, PEEP, static compliance, minute ventilation, tidal volume, rapid shallow breathing index(f/VT), SaO2, PaO2/FiO2 and mean arterial pressure. During spontaneous breathing, physiologic and psychologic variables such as vital signs, ABG, perspiration, chest retraction, paradoxical respiration, dyspnea, anxiety, confidence and efficacy were measured. Successful weaning was defined as sustaining spontaneous respiration over 24 hours after extubation. Weaning failure was defined as the development of more than one of following signs: (1) hypoxemia, (2) CO2 retention or (3) perspiration, tachypnea, chest retraction, tachycardia, arrhythmia, hypotension or hypertension. Subjects (N=18) who successfully weaned from mechanical ventilator were compared with subjects (N=4) who failed. The results are as follows; Eighteen percents of the subjects failed during the weaning trial. Most subjects in the failed group were mechanically ventilated for long-time. This result shows that the success of weaning is more difficult in long-term ventilation patients. In the baseline data that was measured before weaning trial, the mean score of PaO2 in the successfully weaned group was 121mmHg. This is significantly higher than the mean score of PaO2 in the failed group(95mmHg). However, the scores of pH, tidal volume, f/VT, pulse rates, blood pressure, mean airway pressure, SaO2, and PaCO2 were similar between the two groups. Specially the scores of f/VT index as a predominant predictor for successful weaning were not significant (f/VT=44.4) and (f/VT=47). During spontaneous breathing, the scores of dyspnea and anxiety level in the successfully weaned group were less than those of the failed group. On the contrary, the scores of confidence and efficacy in the successful group were greater than those of the failed group. In conclusion, the baseline data that were measured before weaning trial were similar between the both groups, therefore future studies are needed to focus on searching other variables besides physiological parameters related to weaning outcome.

A Microbiological Study in the Humidifiers of the Mechanical Ventilators / 대한마취과학회지

Nosocomial infection represent a significant cause of patient morbidity and mortality, especially in the ICU and nosocomial pneumonia that cause high mortality may arise from contaminated respiratory equipments. This study was done to investigate the relationship of micro-organisms in upper respiratory tract and ventilatory equipment, especially humidifier. The total number of cases in this study was 20 and the specimen for bacteriologic culture were taken from the pharynx, the distilled water and the inner wall of humidifier and toilet of trachea at the 0, 4, 8, 12, 24, 48 hours after initiation of mechanical ventilation. The results obtained from the bacteriologic culture were as follows. 1) The most frequently found organism at the pharynx was Pseudomonas aeruginosa and next was Coagulase Negative Staphylococcus, followed by Streptococcus viridans, Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus group D, Enterobacter agglomerans, Acinetobacter spp. 2) The most frequently found organism at the trachea was Pseudomonas aeruginosa and next was Klebsiella pneumoniae followed by Coagulase Negative Staphylococcus, Streptocoecus viridans, Pseudomonas picketti, Staphylococcus aureus and no growth in 5 cases. 3) The most frequently found organism in the fluid of humidifier was Pseudomonas aeruginosa and next was Pseudomonas picketti, Klebsiella pneumoniae, Streptococcus group D and no growth in 2 cases. 4) The most frequently found organism at the pharynx was Pseudomonas aeruginosa and next was Pseudomonas picketti, Klebsiella pneumoniae, Streptococcus group D, Serratia liquefacines, Acinetobacter spp and no growth in 3 cases. 5) The number of isolated organisms in the fluid of humidifier was 3 at 0 hour and 18 after 48 hours and at the wall 2 at 0 hour and 15 after 48 hours. 6) The number of same organism that was isolated between the pharynx and trachea was 13 among 15 cases and between the wall and fluid of humidifier was 15 among 16 cases and between trachea and fluid of humidifier was 10 among 14 cases.