Mechanical ventilation is a lifesaving treatment but can be associated with some complications such as ventilator-induced lung injury, ventilator associated pneumonia or ventilation induced diaphragm dysfunction. Although partial ventilatory support is preferred to limit some of the complications associated with controlled mechanical ventilation, there could be some problems like asynchrony between the patient and the ventilator. Asynchronies occur when the ventilator’s breath delivery does not match the patient’s ventilatory pattern or is inadequate to meet their flow demand. Asynchronies can lead to patient’s discomfort, prolong mechanical ventilation, intensive care unit stay and mortality. Early cycling occurs when the patient’s neural inspiratory time is longer than the inspiratory time imposed by the ventilator. It is a common cause of double trigger.
{"title":"Identifying asynchronies: Early cycling","authors":"Victor Perez, Jamille Pasco","doi":"10.53097/jmv.10073","DOIUrl":"https://doi.org/10.53097/jmv.10073","url":null,"abstract":"Mechanical ventilation is a lifesaving treatment but can be associated with some complications such as ventilator-induced lung injury, ventilator associated pneumonia or ventilation induced diaphragm dysfunction. Although partial ventilatory support is preferred to limit some of the complications associated with controlled mechanical ventilation, there could be some problems like asynchrony between the patient and the ventilator. Asynchronies occur when the ventilator’s breath delivery does not match the patient’s ventilatory pattern or is inadequate to meet their flow demand. Asynchronies can lead to patient’s discomfort, prolong mechanical ventilation, intensive care unit stay and mortality. Early cycling occurs when the patient’s neural inspiratory time is longer than the inspiratory time imposed by the ventilator. It is a common cause of double trigger.","PeriodicalId":73813,"journal":{"name":"Journal of mechanical ventilation","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41953878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Introduction Accurate measurements of parameters are essential during mechanical ventilation support. These measurements are achieved through sensors that monitor flows, volumes and pressures. External and internal flow sensors are both commonly used in mechanical ventilation systems to measure gas entering and leaving the lungs. The sensors could be located outside the ventilator (external or proximal) or inside the ventilator (internal or distal), each of which have their own respective advantages and disadvantages. There are differences in the way they function and the information they provide, which can affect their accuracy and usefulness in different clinical situations. The purpose of this study was to examine the differences between two critical care ventilators utilizing external sensors to two other ventilators utilizing internal sensors. Methods A bench study using a lung simulator was conducted using three passive, single compartment models: 1) compliance of 40 ml/cmH2O, resistance of 10 cmH2O, 2) compliance of 40 ml/cmH2O, resistance of 20 cmH2O, and 3) compliance of 20 ml/cmH2O, resistance of 10 cmH2O. In each study, two different modes of ventilation, volume controlled (tidal volume 400 ml, respiratory rate 20, PEEP 5 cmH2O, inspiratory time 0.7 seconds) and pressure controlled (inspiratory pressure 15 cmH2O, respiratory rate 20, PEEP 5 cmH2O, inspiratory time 0.7 seconds) were tested. We compared the inspiratory flow, inspiratory tidal volume, peak inspiratory pressures and PEEP in four commercially available critical care ventilators. Two use external flow sensors: G5 (Hamilton Medical), Bellavista 1000e (Vyaire Medical), and two use internal flow sensors: Evita Infinity 500 (Drager), and PB 980 (Medtronic). We also compared these parameters to a mathematical model. Results There were statistically significant differences (P < 0.001) in all four measured parameters: inspiratory flow, tidal volume, PIP and PEEP between all four ventilators, and between the mathematical model and all four ventilators in both modes, in all three clinical scenarios. The post-hoc Dunn test showed significant differences between each ventilator, except for a few parameters in PIP and PEEP, but not in flow or volume. There were variable but significant differences between some of the four parameters measured from the ventilator compared to those measured from the simulator of all four ventilators in both modes. The two ventilators using external sensors had more accurate differences between the delivered and measured tidal volumes (P < 0.001) and inspiratory flow (P < 0.001), however, the other two ventilators with internal sensors had more accurate differences between the delivered and measured PIP (P < 0.001) and PEEP (P < 0.001) levels. Conclusions All four ventilators performed differently from each other and from the mathematical model. The two ventilators using external sensors had more accurate differences between the delivered and measured tidal
{"title":"Mechanical ventilator flow and pressure sensors: Does location matter?","authors":"Shane Toma, Mia Shokry, Ehab Daoud","doi":"10.53097/jmv.10071","DOIUrl":"https://doi.org/10.53097/jmv.10071","url":null,"abstract":"Introduction Accurate measurements of parameters are essential during mechanical ventilation support. These measurements are achieved through sensors that monitor flows, volumes and pressures. External and internal flow sensors are both commonly used in mechanical ventilation systems to measure gas entering and leaving the lungs. The sensors could be located outside the ventilator (external or proximal) or inside the ventilator (internal or distal), each of which have their own respective advantages and disadvantages. There are differences in the way they function and the information they provide, which can affect their accuracy and usefulness in different clinical situations. The purpose of this study was to examine the differences between two critical care ventilators utilizing external sensors to two other ventilators utilizing internal sensors. Methods A bench study using a lung simulator was conducted using three passive, single compartment models: 1) compliance of 40 ml/cmH2O, resistance of 10 cmH2O, 2) compliance of 40 ml/cmH2O, resistance of 20 cmH2O, and 3) compliance of 20 ml/cmH2O, resistance of 10 cmH2O. In each study, two different modes of ventilation, volume controlled (tidal volume 400 ml, respiratory rate 20, PEEP 5 cmH2O, inspiratory time 0.7 seconds) and pressure controlled (inspiratory pressure 15 cmH2O, respiratory rate 20, PEEP 5 cmH2O, inspiratory time 0.7 seconds) were tested. We compared the inspiratory flow, inspiratory tidal volume, peak inspiratory pressures and PEEP in four commercially available critical care ventilators. Two use external flow sensors: G5 (Hamilton Medical), Bellavista 1000e (Vyaire Medical), and two use internal flow sensors: Evita Infinity 500 (Drager), and PB 980 (Medtronic). We also compared these parameters to a mathematical model. Results There were statistically significant differences (P < 0.001) in all four measured parameters: inspiratory flow, tidal volume, PIP and PEEP between all four ventilators, and between the mathematical model and all four ventilators in both modes, in all three clinical scenarios. The post-hoc Dunn test showed significant differences between each ventilator, except for a few parameters in PIP and PEEP, but not in flow or volume. There were variable but significant differences between some of the four parameters measured from the ventilator compared to those measured from the simulator of all four ventilators in both modes. The two ventilators using external sensors had more accurate differences between the delivered and measured tidal volumes (P < 0.001) and inspiratory flow (P < 0.001), however, the other two ventilators with internal sensors had more accurate differences between the delivered and measured PIP (P < 0.001) and PEEP (P < 0.001) levels. Conclusions All four ventilators performed differently from each other and from the mathematical model. The two ventilators using external sensors had more accurate differences between the delivered and measured tidal","PeriodicalId":73813,"journal":{"name":"Journal of mechanical ventilation","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41797033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
52-year-old female with COVID-19 pneumonia and ARDS was intubated and placed on a Servo-U ventilator using Volume Control mode aiming lung protective settings. However, three hours after intubation, the patient’s ventilator waveform showed significant inspiratory effort, triggering the flow adaptation feature and switching the ventilator from volume control with constant flow to pressure control with variable flow. This dual targeting mode, called Volume Control with Flow adaptation, resulted in twice the tidal volume delivered to the patient and increased the risk of volumotrauma. The flow adaptation was subsequently turned off, and the sedation was adjusted to prioritize lung protection for the patient. This case highlights the importance of monitoring patient-ventilator interaction and choosing appropriate ventilator settings to prevent lung injury in patients with ARDS. Keywords ARDS, IMV, Volumotrauma, Flow adaptation
{"title":"Set and don’t forget","authors":"M. Sameed, R. Chatburn","doi":"10.53097/jmv.10074","DOIUrl":"https://doi.org/10.53097/jmv.10074","url":null,"abstract":"52-year-old female with COVID-19 pneumonia and ARDS was intubated and placed on a Servo-U ventilator using Volume Control mode aiming lung protective settings. However, three hours after intubation, the patient’s ventilator waveform showed significant inspiratory effort, triggering the flow adaptation feature and switching the ventilator from volume control with constant flow to pressure control with variable flow. This dual targeting mode, called Volume Control with Flow adaptation, resulted in twice the tidal volume delivered to the patient and increased the risk of volumotrauma. The flow adaptation was subsequently turned off, and the sedation was adjusted to prioritize lung protection for the patient. This case highlights the importance of monitoring patient-ventilator interaction and choosing appropriate ventilator settings to prevent lung injury in patients with ARDS. Keywords ARDS, IMV, Volumotrauma, Flow adaptation","PeriodicalId":73813,"journal":{"name":"Journal of mechanical ventilation","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47277638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mechanical ventilation is currently the most widely used supportive therapy for the treatment of moderate and severe hypoxemia of any etiology. However, the decision of "when" is the right time to initiate the withdrawal of this support is currently a matter of debate worldwide. Many authors describe that the disconnection process should be gradual and in compliance with standards that provide safety to this process; while other authors report that it is not feasible to establish a universal standard since each patient would have a unique behavior that would be difficult to establish in a protocolized manner. The present review represents an extensive search for evidence in an attempt to clarify this issue, generating evidence from a consensus of experts at international level, based on a broad review of the literature. Keywords: Weaning, Spontaneous breathing trial, Rapid shallow breathing index, P0.1
{"title":"Mechanical ventilator liberation protocol. Recommendation based on review of the evidence","authors":"","doi":"10.53097/jmv.10072","DOIUrl":"https://doi.org/10.53097/jmv.10072","url":null,"abstract":"Mechanical ventilation is currently the most widely used supportive therapy for the treatment of moderate and severe hypoxemia of any etiology. However, the decision of \"when\" is the right time to initiate the withdrawal of this support is currently a matter of debate worldwide. Many authors describe that the disconnection process should be gradual and in compliance with standards that provide safety to this process; while other authors report that it is not feasible to establish a universal standard since each patient would have a unique behavior that would be difficult to establish in a protocolized manner. The present review represents an extensive search for evidence in an attempt to clarify this issue, generating evidence from a consensus of experts at international level, based on a broad review of the literature. Keywords: Weaning, Spontaneous breathing trial, Rapid shallow breathing index, P0.1","PeriodicalId":73813,"journal":{"name":"Journal of mechanical ventilation","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43992788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Introduction Orotracheal intubation becomes a challenge for the anesthesiologist when the glottis is not visualized with direct laryngoscopy. Videolaryngoscopes emerged as an alternative in these situations, but the costs of these devices restrict their popularization. Doubts remain as to whether low-cost devices would be safe and effective, such as the 3D printing Open-Source video laryngoscope. Aim To analyze the 3D printing Open-Source video laryngoscope for orotracheal intubation for general anesthesia in its the rate of achieving, glottis visualization time, intubation time and its correlation with the order of execution. Methods Clinical, prospective, analytical study of a questionnaire carried out after the procedure. Statistical analysis was performed using Spearman's correlation, Kruskal-Wallis test, and chi-square test. Results There was a total of 64 uncomplicated orotracheal intubation procedures with an overall success rate of 93.8%. Mean time for viewing the glottis (16.4”), mean times of endotracheal intubation with Mallampati I (26.5”), ll (33.7”), lll (57.3”), lV (38.5”) were obtained with no statistical significance (P 0.170) and overall mean time of orotracheal intubation (36.4”) with a moderate negative correlation of –0.36 across the orotracheal intubation execution order. Conclusion In the analysis of endotracheal intubation with the 3D printing Open-Source video laryngoscope a high success rate was demonstrated without any complications. The time to obtain endotracheal intubation tends to reduce with subsequent experiences and learning, but it is more than twice the time required to adequately visualize the glottis and the Mallampati classification was not a relevant time predictor. Keywords: Orotracheal intubation; Videolaryngoscopy, Airway management
{"title":"Analysis of the 3D printing open source video laryngoscope for orotracheal intubation","authors":"Isadora Opolski, Samuel da Rosa Souza, C. Franck","doi":"10.53097/jmv.10070","DOIUrl":"https://doi.org/10.53097/jmv.10070","url":null,"abstract":"Introduction Orotracheal intubation becomes a challenge for the anesthesiologist when the glottis is not visualized with direct laryngoscopy. Videolaryngoscopes emerged as an alternative in these situations, but the costs of these devices restrict their popularization. Doubts remain as to whether low-cost devices would be safe and effective, such as the 3D printing Open-Source video laryngoscope. Aim To analyze the 3D printing Open-Source video laryngoscope for orotracheal intubation for general anesthesia in its the rate of achieving, glottis visualization time, intubation time and its correlation with the order of execution. Methods Clinical, prospective, analytical study of a questionnaire carried out after the procedure. Statistical analysis was performed using Spearman's correlation, Kruskal-Wallis test, and chi-square test. Results There was a total of 64 uncomplicated orotracheal intubation procedures with an overall success rate of 93.8%. Mean time for viewing the glottis (16.4”), mean times of endotracheal intubation with Mallampati I (26.5”), ll (33.7”), lll (57.3”), lV (38.5”) were obtained with no statistical significance (P 0.170) and overall mean time of orotracheal intubation (36.4”) with a moderate negative correlation of –0.36 across the orotracheal intubation execution order. Conclusion In the analysis of endotracheal intubation with the 3D printing Open-Source video laryngoscope a high success rate was demonstrated without any complications. The time to obtain endotracheal intubation tends to reduce with subsequent experiences and learning, but it is more than twice the time required to adequately visualize the glottis and the Mallampati classification was not a relevant time predictor. Keywords: Orotracheal intubation; Videolaryngoscopy, Airway management","PeriodicalId":73813,"journal":{"name":"Journal of mechanical ventilation","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47664472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kimberly A Weil, Vanessa Baumann, Brittany Brown, Rebecca Nadeau, Brett Gerstenhaber, Edward P Manning
Purpose: Tracheostomy is a necessary procedure required for prolonged mechanical ventilation in long-term acute care hospitals (LTACH). Many factors influence successful decannulation, or tracheostomy removal, and it is unclear what factors are essential for determining decannulation. The purpose of this study was to determine retrospective performance of single prognostic variables for successful decannulation, like peak expiratory flow measurement, overnight oximetry testing, and blood gas analysis.
Methods: A retrospective analysis of a three-year period to investigate the association between peak flow (PF) measurements ≥160 L/min, successful overnight oximetry (ONO), sex, and decannulation success. Average PF measurements, arterial blood gas (ABG), days on mechanical ventilation, LTACH length of stay (LOS), and age were also investigated.
Results: We examined the records of 135 patients, 127 of which were successfully decannulated. PF measurements ≥160 L/min (p=0.16), sex (p<0.05) and passing ONO (p<0.05) were significantly different between successfully and unsuccessfully decannulated patients; mean ABG (pH, pCO2, pO2), mechanical ventilation days, LOS, and age were not significantly different (p>0.05).
Conclusions: These results suggest no single prognostic variable can predict decannulation outcomes. Rather, clinical judgment of experienced medical professionals appears sufficient to achieve a 94% decannulation success rate. Additional investigation is required to determine what metrics are necessary, or if clinical judgment alone can predict decannulation success.
{"title":"Prognostic variables and decannulation of tracheostomy in the long-term acute care environment: a case for clinician-driven decision-making.","authors":"Kimberly A Weil, Vanessa Baumann, Brittany Brown, Rebecca Nadeau, Brett Gerstenhaber, Edward P Manning","doi":"10.53097/jmv.10069","DOIUrl":"https://doi.org/10.53097/jmv.10069","url":null,"abstract":"<p><strong>Purpose: </strong>Tracheostomy is a necessary procedure required for prolonged mechanical ventilation in long-term acute care hospitals (LTACH). Many factors influence successful decannulation, or tracheostomy removal, and it is unclear what factors are essential for determining decannulation. The purpose of this study was to determine retrospective performance of single prognostic variables for successful decannulation, like peak expiratory flow measurement, overnight oximetry testing, and blood gas analysis.</p><p><strong>Methods: </strong>A retrospective analysis of a three-year period to investigate the association between peak flow (PF) measurements ≥160 L/min, successful overnight oximetry (ONO), sex, and decannulation success. Average PF measurements, arterial blood gas (ABG), days on mechanical ventilation, LTACH length of stay (LOS), and age were also investigated.</p><p><strong>Results: </strong>We examined the records of 135 patients, 127 of which were successfully decannulated. PF measurements ≥160 L/min (p=0.16), sex (p<0.05) and passing ONO (p<0.05) were significantly different between successfully and unsuccessfully decannulated patients; mean ABG (pH, pCO2, pO2), mechanical ventilation days, LOS, and age were not significantly different (p>0.05).</p><p><strong>Conclusions: </strong>These results suggest no single prognostic variable can predict decannulation outcomes. Rather, clinical judgment of experienced medical professionals appears sufficient to achieve a 94% decannulation success rate. Additional investigation is required to determine what metrics are necessary, or if clinical judgment alone can predict decannulation success.</p>","PeriodicalId":73813,"journal":{"name":"Journal of mechanical ventilation","volume":"4 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10328447/pdf/nihms-1884943.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9865785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A detailed understanding of respiratory mechanics during mechanical ventilation aids diagnostic accuracy and facilitates close monitoring of patient progress, allowing individualized ventilator adjustments aimed at minimizing ventilator induced lung injury. Respiratory mechanics can be described in terms of total respiratory, lung, and chest wall components and include compliance, resistance and are dependent on tidal volume, airway pressures, and flow for calculation. The interplay between the respiratory mechanics and ventilator delivered volume, flow, and pressure have an important role in the development of ventilator induced lung injury. The knowledge of alveolar dynamics and mechanics in the critically ill are lacking with much information originating mainly from bench and animal models of healthy and injured lungs. In this article we introduce the concept of alveolar compliance, resistance that depend on measuring the trans-alveolar pressure using esophageal balloon manometry and alveolar tidal volume using volumetric capnometry. This may have multiple implications in the understanding of components of ventilator induced lung injury specifically alveolar stress, strain, and mechanical power. Further studies are warranted to further understanding the monitoring and usefulness of alveolar mechanics. Keywords: Alveolar compliance and resistance, alveolar tidal volume, trans-alveolar pressure, alveolar stress and strain, alveolar mechanical power
{"title":"Alveolar mechanics: A new concept in respiratory monitoring","authors":"Ehab Daoud, C. Franck","doi":"10.53097/jmv.10065","DOIUrl":"https://doi.org/10.53097/jmv.10065","url":null,"abstract":"A detailed understanding of respiratory mechanics during mechanical ventilation aids diagnostic accuracy and facilitates close monitoring of patient progress, allowing individualized ventilator adjustments aimed at minimizing ventilator induced lung injury. Respiratory mechanics can be described in terms of total respiratory, lung, and chest wall components and include compliance, resistance and are dependent on tidal volume, airway pressures, and flow for calculation. The interplay between the respiratory mechanics and ventilator delivered volume, flow, and pressure have an important role in the development of ventilator induced lung injury. The knowledge of alveolar dynamics and mechanics in the critically ill are lacking with much information originating mainly from bench and animal models of healthy and injured lungs. In this article we introduce the concept of alveolar compliance, resistance that depend on measuring the trans-alveolar pressure using esophageal balloon manometry and alveolar tidal volume using volumetric capnometry. This may have multiple implications in the understanding of components of ventilator induced lung injury specifically alveolar stress, strain, and mechanical power. Further studies are warranted to further understanding the monitoring and usefulness of alveolar mechanics. Keywords: Alveolar compliance and resistance, alveolar tidal volume, trans-alveolar pressure, alveolar stress and strain, alveolar mechanical power","PeriodicalId":73813,"journal":{"name":"Journal of mechanical ventilation","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49406951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mechanical ventilation supports the work of breathing, improves gas exchange, and unloads the respiratory muscles, all of which require good synchronization between the patient and the ventilator. Asynchronies occur when the ventilator’s breath delivery does not match the patient’s neural ventilatory pattern or is inadequate to meet the patient’s flow demand. Patient–ventilator asynchrony can be easily detected by observing the patients in those extreme situations in which they fight the ventilator; nevertheless, the vast majority of asynchronies occur without major clinical signs and go undetected or corrected without measuring patient's respiratory effort (either esophageal pressure or electrical activity of the diaphragm). Synchrony problems are common, occurring in perhaps as many as 25% of patients receiving invasive ventilation and up to 80% of patients receiving noninvasive ventilation. In this concise review, we describe work shifting and double triggering asynchronies. Keywords: Patient-ventilator asynchronies, work shifting, double triggering
{"title":"Identifying asynchronies: work shifting and double triggering","authors":"Victor Perez, Jamille Pasco","doi":"10.53097/jmv.10066","DOIUrl":"https://doi.org/10.53097/jmv.10066","url":null,"abstract":"Mechanical ventilation supports the work of breathing, improves gas exchange, and unloads the respiratory muscles, all of which require good synchronization between the patient and the ventilator. Asynchronies occur when the ventilator’s breath delivery does not match the patient’s neural ventilatory pattern or is inadequate to meet the patient’s flow demand. Patient–ventilator asynchrony can be easily detected by observing the patients in those extreme situations in which they fight the ventilator; nevertheless, the vast majority of asynchronies occur without major clinical signs and go undetected or corrected without measuring patient's respiratory effort (either esophageal pressure or electrical activity of the diaphragm). Synchrony problems are common, occurring in perhaps as many as 25% of patients receiving invasive ventilation and up to 80% of patients receiving noninvasive ventilation. In this concise review, we describe work shifting and double triggering asynchronies. Keywords: Patient-ventilator asynchronies, work shifting, double triggering","PeriodicalId":73813,"journal":{"name":"Journal of mechanical ventilation","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43935449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background Most patients admitted to the intensive care unit with coronavirus disease (COVID-19) develop severe respiratory failure. Understanding lung mechanics helps to guide protective mechanical ventilation, improve oxygenation, and reduce the ventilator induce lung injury. This study aims to describe lung mechanics characteristics of patients with COVID -19 related acute respiratory distress syndrome (CARDS) and to compare them with non-COVID-19 associated ARDS. Methods We performed a retrospective observational study of lung mechanics: plateau pressure (Pplat), Driving pressure (DP), Mechanical power (MPw), Elastic (dynamic) power (EdPw), Total ventilatory power (TPw), and oxygenation parameters (ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2), the ratio of arterial oxygen partial pressure to fractional inspired oxygen multiplied by PEEP [PaO2/(FiO2 x PEEP)], arterial and venous carbon dioxide partial pressure (PaCO2, PvCO2), and Ventilation dead space (VD) were measured and compared between the two groups after initiation of mechanical ventilation. Results 30 CARDS and 10 ARDS patients fulfilled the study requirements. We observed a significant higher MPw in the CARDS group (29.17 ± 8.29 J/min vs 15.78 ± 4.45 J/min, P 0.007), similarly observed with EdPw (256.7 ± 84.06 mJ/min vs 138.1 ± 39.15 mJ/min, P 0.01) and TPw (289.1 ± 84.51 mJ/min vs 161.5 ± 45.51, P 0.007). Inside the CARDS group, we found 2 subgroups, a low shunt subgroup and a higher shunt (Qs/Qt (%): 6.61 ± 2.46 for vs 40.3 ± 20.6, P 0.0009), however, between these two subgroups we didn’t find statistical differences on lung mechanic parameters but only in oxygenation parameters (PaO2/FiO2 and PaO2/FiO2*PEEP). When comparing these two subgroups with ARDS patients, we found more similarity between the low shunt CARDS and the ARDS patients on MP (R2 0.99, P 0.001), EdPw (R2 0.89, P 0.05) and TPw (R2 0.99, P 0.0009). Conclusions: Our study suggests important differences between CARDS and ARDS regarding mechanical parameters that could lead to more complicated management of CARDS patients and a higher prevalence of VILI. However due to the study limitations, a bigger study is necessary to corroborate our findings. Keywords: COVID-19, CARDS, ARDS, lung mechanics, VILI.
大多数入住重症监护病房的冠状病毒病(COVID-19)患者会出现严重的呼吸衰竭。了解肺力学有助于指导保护性机械通气，改善氧合，减少呼吸机所致肺损伤。本研究旨在描述COVID-19相关急性呼吸窘迫综合征(CARDS)患者的肺力学特征，并将其与非COVID-19相关ARDS进行比较。方法回顾性观察肺力学:平台压(Pplat)、驱动压(DP)、机械功率(MPw)、弹性(动态)功率(EdPw)、总通气量(TPw)、氧合参数(动脉氧分压与分吸气氧之比(PaO2/FiO2)、动脉氧分压与分吸气氧之比乘以PEEP [PaO2/(FiO2 × PEEP)]、动脉和静脉二氧化碳分压(PaCO2、PvCO2)、并比较两组机械通气启动后的通气死空(VD)。结果30例CARDS患者和10例ARDS患者符合研究要求。我们观察到CARDS组的MPw(29.17±8.29 J/min vs 15.78±4.45 J/min, P 0.007)显著高于EdPw(256.7±84.06 mJ/min vs 138.1±39.15 mJ/min, P 0.01)和TPw(289.1±84.51 mJ/min vs 161.5±45.51,P 0.007)。在CARDS组中，我们发现了2个亚组，低分流亚组和高分流亚组(Qs/Qt(%): 6.61±2.46 vs 40.3±20.6,P 0.0009)，但在这两个亚组之间，我们没有发现肺力学参数的统计学差异，只有氧合参数(PaO2/FiO2和PaO2/FiO2*PEEP)的统计学差异。将这两个亚组与ARDS患者进行比较，我们发现低分流卡组与ARDS患者在MP (R2 0.99, P 0.001)、EdPw (R2 0.89, P 0.05)和TPw (R2 0.99, P 0.0009)上有更大的相似性。结论:我们的研究表明，CARDS和ARDS在力学参数上存在重要差异，这可能导致CARDS患者的管理更复杂，VILI的患病率更高。然而，由于研究的局限性，需要更大规模的研究来证实我们的发现。关键词:COVID-19，卡片，ARDS，肺力学，VILI
{"title":"Comparing lung mechanics of patients with COVID related respiratory distress syndrome versus non-COVID acute respiratory distress syndrome: a retrospective observational study","authors":"F. Chacon-Lozsan, P. Tamási","doi":"10.53097/jmv.10062","DOIUrl":"https://doi.org/10.53097/jmv.10062","url":null,"abstract":"Background Most patients admitted to the intensive care unit with coronavirus disease (COVID-19) develop severe respiratory failure. Understanding lung mechanics helps to guide protective mechanical ventilation, improve oxygenation, and reduce the ventilator induce lung injury. This study aims to describe lung mechanics characteristics of patients with COVID -19 related acute respiratory distress syndrome (CARDS) and to compare them with non-COVID-19 associated ARDS. Methods We performed a retrospective observational study of lung mechanics: plateau pressure (Pplat), Driving pressure (DP), Mechanical power (MPw), Elastic (dynamic) power (EdPw), Total ventilatory power (TPw), and oxygenation parameters (ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2), the ratio of arterial oxygen partial pressure to fractional inspired oxygen multiplied by PEEP [PaO2/(FiO2 x PEEP)], arterial and venous carbon dioxide partial pressure (PaCO2, PvCO2), and Ventilation dead space (VD) were measured and compared between the two groups after initiation of mechanical ventilation. Results 30 CARDS and 10 ARDS patients fulfilled the study requirements. We observed a significant higher MPw in the CARDS group (29.17 ± 8.29 J/min vs 15.78 ± 4.45 J/min, P 0.007), similarly observed with EdPw (256.7 ± 84.06 mJ/min vs 138.1 ± 39.15 mJ/min, P 0.01) and TPw (289.1 ± 84.51 mJ/min vs 161.5 ± 45.51, P 0.007). Inside the CARDS group, we found 2 subgroups, a low shunt subgroup and a higher shunt (Qs/Qt (%): 6.61 ± 2.46 for vs 40.3 ± 20.6, P 0.0009), however, between these two subgroups we didn’t find statistical differences on lung mechanic parameters but only in oxygenation parameters (PaO2/FiO2 and PaO2/FiO2*PEEP). When comparing these two subgroups with ARDS patients, we found more similarity between the low shunt CARDS and the ARDS patients on MP (R2 0.99, P 0.001), EdPw (R2 0.89, P 0.05) and TPw (R2 0.99, P 0.0009). Conclusions: Our study suggests important differences between CARDS and ARDS regarding mechanical parameters that could lead to more complicated management of CARDS patients and a higher prevalence of VILI. However due to the study limitations, a bigger study is necessary to corroborate our findings. Keywords: COVID-19, CARDS, ARDS, lung mechanics, VILI.","PeriodicalId":73813,"journal":{"name":"Journal of mechanical ventilation","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46540821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Daoud and Franck in this edition of the journal proffer an eloquent disquisition on alveolar compliance and resistance and describe ways in which we could make estimates of the effect of ventilation changes, using esophageal balloon manometry measure the trans alveolar pressure, and estimating the alveolar tidal volume using volumetric capnometry. 10 The article like the subject it addresses is complex and requires an active rather than passive read. It outlines the concepts clearly and highlights the need for accurate and exacting measurement. Complicating this is the need to provide simultaneous diaphragmatic and alveolar protective ventilation, which further complicates modelling of controlled ventilation strategies. 11 It remains something to be addressed in the future.
{"title":"Complex ventilation problems with no simple solution","authors":"R. C Freebairn","doi":"10.53097/jmv.10067","DOIUrl":"https://doi.org/10.53097/jmv.10067","url":null,"abstract":"Daoud and Franck in this edition of the journal proffer an eloquent disquisition on alveolar compliance and resistance and describe ways in which we could make estimates of the effect of ventilation changes, using esophageal balloon manometry measure the trans alveolar pressure, and estimating the alveolar tidal volume using volumetric capnometry. 10 The article like the subject it addresses is complex and requires an active rather than passive read. It outlines the concepts clearly and highlights the need for accurate and exacting measurement. Complicating this is the need to provide simultaneous diaphragmatic and alveolar protective ventilation, which further complicates modelling of controlled ventilation strategies. 11 It remains something to be addressed in the future.","PeriodicalId":73813,"journal":{"name":"Journal of mechanical ventilation","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70769254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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