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Respiratory Care Aug 2019There have been many innovations to the standard endotracheal tube over the years, many of which were intended to reduce the incidence of ventilator-associated pneumonia... (Review)
Review
There have been many innovations to the standard endotracheal tube over the years, many of which were intended to reduce the incidence of ventilator-associated pneumonia (VAP). Ventilator-associated events are associated with the objective outcomes of increased duration of mechanical ventilation, length of ICU and hospital stay, and increased risk of mortality. Many specialty tubes have been associated with a reduction in the clinical diagnosis of VAP, but studies have failed to show differences in objective outcomes. This article reviews the evidence related to specialty tubes and discusses their role in improving objective outcomes associated with ventilator-associated events.
Topics: Humans; Iatrogenic Disease; Intubation, Intratracheal; Pneumonia, Ventilator-Associated; Respiration, Artificial; Ventilators, Mechanical
PubMed: 31346072
DOI: 10.4187/respcare.07048 -
Respiratory Care Sep 2006Although life-saving, mechanical ventilation is associated with numerous complications. These include pneumonia, cardiovascular compromise, barotrauma, and... (Review)
Review
Although life-saving, mechanical ventilation is associated with numerous complications. These include pneumonia, cardiovascular compromise, barotrauma, and ventilator-induced lung injury. Recent data from animal studies suggest that controlled mechanical ventilation can cause dysfunction of the diaphragm, decreasing its force-generating capacity--a condition referred to as ventilator-induced diaphragmatic dysfunction (VIDD). The decrease in diaphragmatic contractility is time-dependent and worsens as mechanical ventilation is prolonged. Evidence supporting the occurrence of comparable diaphragmatic dysfunction in critically ill patients is scarce, although most patients receiving mechanical ventilation display profound diaphragmatic weakness. Atrophy, fibers remodeling, oxidative stress, and structural injury have been implicated as potential mechanisms of VIDD. The decrease in diaphragmatic force that occurs during controlled mechanical ventilation is attenuated during assisted modes of ventilation. Whether the decrease in diaphragmatic contractility observed during controlled ventilation contributes to failure to wean from the ventilator is difficult to ascertain. Weaning-failure patients have reasons other than VIDD for respiratory-muscle weakness. Until we have further data, it seems prudent to avoid the use of controlled mechanical ventilation in patients with acute respiratory failure.
Topics: Critical Illness; Diaphragm; Humans; Lung Injury; Respiration, Artificial; Respiratory Insufficiency; Ventilators, Mechanical
PubMed: 16934168
DOI: No ID Found -
Respiratory Care May 2021Dual-patient, single-ventilator protocols (ie, protocols to ventilate 2 patients with a single conventional ventilator) may be required in times of crisis. This study... (Observational Study)
Observational Study
BACKGROUND
Dual-patient, single-ventilator protocols (ie, protocols to ventilate 2 patients with a single conventional ventilator) may be required in times of crisis. This study demonstrates a means to titrate peak inspiratory pressure (PIP), PEEP, and [Formula: see text] for test lungs ventilated via a dual-patient, single-ventilator circuit.
METHODS
This prospective observational study was conducted using a ventilator connected to 2 test lungs. Changes in PIP, PEEP, and [Formula: see text] were made to the experimental lung, while no changes were made to the control lung. Measurements were obtained simultaneously from each test lung. PIP was titrated using 3D-printed resistors added to the inspiratory circuit. PEEP was titrated using expiratory circuit tubing with an attached manual PEEP valve. [Formula: see text] was titrated by using a splitter added to the ventilator tubing.
RESULTS
PIP, PEEP, and [Formula: see text] were reliably and incrementally titratable in the experimental lung, with some notable but manageable changes in pressure and [Formula: see text] documented in the control lung during these titrations. Similar results were measured in lungs with identical and different compliances.
CONCLUSIONS
Pressures and [Formula: see text] can be reliably adjusted when utilizing a dual-patient, single-ventilator circuit with simple, low-cost modifications to the circuit. This innovation could potentially be lifesaving in a resource-limited or crisis setting. Understanding the interactions of these circuits is imperative for making their use safer.
Topics: Humans; Lung; Positive-Pressure Respiration; Respiration; Respiration, Artificial; Ventilators, Mechanical
PubMed: 33298622
DOI: 10.4187/respcare.08446 -
British Journal of Anaesthesia Jul 2003
Review
Topics: Feedback; Humans; Lung Diseases; Respiration, Artificial; Respiratory Mechanics; Ventilators, Mechanical
PubMed: 12821570
DOI: 10.1093/bja/aeg129 -
Respiratory Care Apr 2019Different brands of volume-targeted modes may vary the location of tidal volume (V) monitoring and whether peak inspiratory pressure is adjusted based on inspiratory,...
BACKGROUND
Different brands of volume-targeted modes may vary the location of tidal volume (V) monitoring and whether peak inspiratory pressure is adjusted based on inspiratory, expiratory or leak-compensated V. These variables may result in different levels of support provided to patients, especially when an endotracheal tube (ETT) leak is present. We hypothesized that there would be no differences in gas exchange, triggering, or work of breathing between volume-targeted modes of 3 different brands of equipment in a surfactant-deficient, spontaneously breathing animal model with and without an ETT leak.
METHODS
Twelve rabbits (mean ± SD 1.61 ± 0.20 kg) were sedated, anesthetized, intubated, lavaged with 0.9% saline solution, and randomized in a crossover design so that each animal was supported by 3 different volume-targeted modes at identical settings with and without an ETT leak. After 30 min, arterial blood gas, V, and esophageal and airway pressure were recorded for each condition, and pressure-rate product and percentage of successfully triggered breaths were calculated.
RESULTS
Gas exchange and the pressure-rate product were not different between the ventilators in the absence of an ETT leak. When an ETT leak was introduced, volume-guarantee modes allowed a higher percentage of triggered breaths and peak inspiratory pressure, which resulted in higher minute ventilation, pH, and lower P than the pressure-regulated volume control mode ( < .05).
CONCLUSIONS
When a moderate ETT leak was present, volume-targeted modes that used proximal V monitoring and triggering with adaptive leak compensation capabilities appeared more effective in providing ventilation support than did a ventilator that used measurements obtained from the back at the ventilator and does not have leak compensation.
Topics: Animals; Animals, Newborn; Blood Gas Analysis; Intubation, Intratracheal; Materials Testing; Models, Animal; Monitoring, Physiologic; Pulmonary Gas Exchange; Pulmonary Surfactants; Rabbits; Respiration, Artificial; Respiratory Function Tests; Respiratory Mechanics; Tidal Volume; Ventilators, Mechanical
PubMed: 30723169
DOI: 10.4187/respcare.06271 -
PloS One 2022The Covid-19 outbreak challenged health systems around the world to design and implement cost-effective devices produced locally to meet the increased demand of...
The Covid-19 outbreak challenged health systems around the world to design and implement cost-effective devices produced locally to meet the increased demand of mechanical ventilators worldwide. This study evaluates the physiological responses of healthy swine maintained under volume- or pressure-controlled mechanical ventilation by a mechanical ventilator implemented to bring life-support by automating a resuscitation bag and closely controlling ventilatory parameters. Physiological parameters were monitored in eight sedated animals (t0) prior to inducing deep anaesthesia, and during the next six hours of mechanical ventilation (t1-7). Hemodynamic conditions were monitored periodically using a portable gas analyser machine (i.e. BEecf, carbonate, SaO2, lactate, pH, PaO2, PaCO2) and a capnometer (i.e. ETCO2). Electrocardiogram, echocardiography and lung ultrasonography were performed to detect in vivo alterations in these vital organs and pathological findings from necropsy were reported. The mechanical ventilator properly controlled physiological levels of blood biochemistry such as oxygenation parameters (PaO2, PaCO2, SaO2, ETCO2), acid-base equilibrium (pH, carbonate, BEecf), and perfusion of tissues (lactate levels). In addition, histopathological analysis showed no evidence of acute tissue damage in lung, heart, liver, kidney, or brain. All animals were able to breathe spontaneously after undergoing mechanical ventilation. These preclinical data, supports the biological safety of the medical device to move forward to further evaluation in clinical studies.
Topics: Animals; Automation; Blood Gas Analysis; COVID-19; Cardiopulmonary Resuscitation; Female; Hemodynamics; Male; Respiration; Respiration, Artificial; SARS-CoV-2; Swine; Ventilators, Mechanical
PubMed: 35239740
DOI: 10.1371/journal.pone.0264774 -
Respiratory Care Oct 2021The growing number of patients on home mechanical ventilation has driven considerable progress in the performance and functionality of ventilators, with features...
BACKGROUND
The growing number of patients on home mechanical ventilation has driven considerable progress in the performance and functionality of ventilators, with features comparable with those used in the ICU. However, a publication gap exists in the evaluation and comparison of their performance and each ventilator choice depends on machine characteristics defined by manufacturers.
METHODS
We bench tested 8 home-care ventilators that are currently available: Monnal T50, EOVE EO-150, Puritan Bennet 560, Weinmann, PrismaVent 50, Trilogy Evo, Astral 150, and Vivo 60 by using an active lung model. These devices were tested under 18 experimental conditions that combined 3 variables: respiratory mechanics, ventilatory mode, and inspiratory muscle effort. The volume delivered, trigger response, pressurization capacity, and synchronization were analyzed.
RESULTS
Significant differences were observed in the performance among the devices. Decreased inspiratory muscle effort caused changes in the delivered volume, which worsened the response-to-trigger time, pressurization capacity, and synchronization. Increased pressure support favored the development of asynchronies. All the ventilators developed asynchronies under at least 1 set of conditions, but the EOVE and Trilogy Evo ventilators showed the fewest asynchronies during the experimental conditions studied.
CONCLUSIONS
Great variability in terms of technical performance was observed among the 8 home-care ventilators analyzed. Asynchronies became a major issue when home mechanical ventilation was used under higher pressure-support values and lower muscle efforts. Our results may prove to be useful in helping choose the best suited machine based on a patient's clinical therapy needs.
Topics: Humans; Intensive Care Units; Positive-Pressure Respiration; Respiration, Artificial; Respiratory Mechanics; Ventilators, Mechanical
PubMed: 34552013
DOI: 10.4187/respcare.08650 -
Minerva Anestesiologica Dec 2012Continuous positive airway pressure (CPAP) is the application in the airways of continuous positive pressure, close to the positive end expiratory pressure. The two... (Meta-Analysis)
Meta-Analysis Review
Continuous positive airway pressure (CPAP) is the application in the airways of continuous positive pressure, close to the positive end expiratory pressure. The two common available systems are by a continuous (high/low) flow system and by a mechanical ventilator. Aim of this study was to compare the mechanical performance of the CPAP systems in intubated and not intubated patients. Medical literature databases (MEDLINE and EMBASE) were searched for articles on "clinical trials" and "randomized controlled trials". The key words "continuous positive airway pressure" and "CPAP", were combined with any of these key words: adult, work of breathing, continuous flow, mechanical valve, water valve, balloon reservoir, mechanical ventilator, pressure triggering, flow triggering, lung model, demand valve, equipment. Thirty-two articles (18 human and 14 bench studies) met the inclusion criteria. The continuous flow systems are able to maintain acceptable airway pressure variations during normal breathing. The most recent mechanical ventilators equipped with flow by systems compared to the first one, presented a similar or better work of breathing compared to the continuous flow systems due to the application of a little amount of pressure support. Although the use of a continuous flow is cheaper compared to mechanical ventilators, it does not allow a continuous respiratory monitoring.
Topics: Continuous Positive Airway Pressure; Humans; Reference Values; Ventilators, Mechanical
PubMed: 23044739
DOI: No ID Found -
Respiratory Care Aug 2019Mechanical ventilation is a well-established and commonly employed modality of treatment for critically ill patients in the ICU. Pneumonia is a frequent complication in... (Review)
Review
Mechanical ventilation is a well-established and commonly employed modality of treatment for critically ill patients in the ICU. Pneumonia is a frequent complication in mechanically ventilated patients. Patients who develop ventilator-associated pneumonia (VAP) incur higher medical costs, have prolonged ICU and hospital stays, and have increased mortality risk. There is growing interest in finding new treatment modalities for this condition because the success rate for treating VAP with systemic antibiotics continues to be < 70%. Accordingly, clinicians are reevaluating the role of aerosolized antibiotics, either as a sole therapy or as adjuncts to systemic antibiotics, in an attempt to improve clinical outcomes in patients with VAP. There are several clinical settings in which aerosolized antibiotics could be used for treating pneumonia, including their use for prevention, as monotherapy, as adjunctive therapy with systemic antibiotics, and for treatment of extensively drug-resistant or pan drug-resistant pathogens. However, aerosolized antibiotics have not been uniformly effective for improving clinical outcomes of patients with VAP, and local and systemic side effects could complicate their use. Moreover, many questions about aerosolized antibiotics, such as optimal formulations and dosage and treatment regimens, remain unanswered and warrant future investigations.
Topics: Administration, Inhalation; Aerosols; Anti-Bacterial Agents; Humans; Pneumonia, Ventilator-Associated; Respiration, Artificial; Treatment Outcome; Ventilators, Mechanical
PubMed: 31346071
DOI: 10.4187/respcare.07024 -
BMC Research Notes Sep 2020The advent of new technologies has made it possible to explore alternative ventilator manufacturing to meet the worldwide shortfall for mechanical ventilators especially...
Increasing ventilator surge capacity in COVID 19 pandemic: design, manufacture and in vitro-in vivo testing in anaesthetized healthy pigs of a rapid prototyped mechanical ventilator.
OBJECTIVE
The advent of new technologies has made it possible to explore alternative ventilator manufacturing to meet the worldwide shortfall for mechanical ventilators especially in pandemics. We describe a method using rapid prototyping technologies to create an electro-mechanical ventilator in a cost effective, timely manner and provide results of testing using an in vitro-in vivo testing model.
RESULTS
Rapid prototyping technologies (3D printing and 2D cutting) were used to create a modular ventilator. The artificial manual breathing unit (AMBU) bag connected to wall oxygen source using a flow meter was used as air reservoir. Controlled variables include respiratory rate, tidal volume and inspiratory: expiratory (I:E) ratio. In vitro testing and In vivo testing in the pig model demonstrated comparable mechanical efficiency of the test ventilator to that of standard ventilator but showed the material limits of 3D printed gears. Improved gear design resulted in better ventilator durability whilst reducing manufacturing time (< 2-h). The entire cost of manufacture of ventilator was estimated at 300 Australian dollars. A cost-effective novel rapid prototyped ventilator for use in patients with respiratory failure was developed in < 2-h and was effective in anesthetized, healthy pig model.
Topics: Anesthesia, General; Animals; COVID-19; Coronavirus Infections; Equipment Design; Expiratory Reserve Volume; Female; Humans; Inspiratory Reserve Volume; Models, Biological; Pandemics; Pneumonia, Viral; Printing, Three-Dimensional; Respiration, Artificial; Respiratory Rate; Swine; Tidal Volume; Ventilators, Mechanical
PubMed: 32894167
DOI: 10.1186/s13104-020-05259-z