1
|
Chen Y, Yuan Y, Chang Q, Zhang H, Li F, Chen Z. Continuous estimation of respiratory system compliance and airway resistance during pressure-controlled ventilation without end-inspiration occlusion. BMC Pulm Med 2024; 24:249. [PMID: 38769572 PMCID: PMC11107031 DOI: 10.1186/s12890-024-03061-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 05/13/2024] [Indexed: 05/22/2024] Open
Abstract
BACKGROUND Assessing mechanical properties of the respiratory system (Cst) during mechanical ventilation necessitates an end-inspiration flow of zero, which requires an end-inspiratory occlusion maneuver. This lung model study aimed to observe the effect of airflow obstruction on the accuracy of respiratory mechanical properties during pressure-controlled ventilation (PCV) by analyzing dynamic signals. METHODS A Hamilton C3 ventilator was attached to a lung simulator that mimics lung mechanics in healthy, acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary disease (COPD) models. PCV and volume-controlled ventilation (VCV) were applied with tidal volume (VT) values of 5.0, 7.0, and 10.0 ml/kg. Performance characteristics and respiratory mechanics were assessed and were calibrated by virtual extrapolation using expiratory time constant (RCexp). RESULTS During PCV ventilation, drive pressure (DP) was significantly increased in the ARDS model. Peak inspiratory flow (PIF) and peak expiratory flow (PEF) gradually declined with increasing severity of airflow obstruction, while DP, end-inspiration flow (EIF), and inspiratory cycling ratio (EIF/PIF%) increased. Similar estimated values of Crs and airway resistance (Raw) during PCV and VCV ventilation were obtained in healthy adult and mild obstructive models, and the calculated errors did not exceed 5%. An underestimation of Crs and an overestimation of Raw were observed in the severe obstruction model. CONCLUSION Using the modified dynamic signal analysis approach, respiratory system properties (Crs and Raw) could be accurately estimated in patients with non-severe airflow obstruction in the PCV mode.
Collapse
Affiliation(s)
- Yuqing Chen
- Department of Respiratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, No.241, West Huaihai Road, Shanghai, 200030, China.
| | - Yueyang Yuan
- School of Mechanical and Electrical Engineering, Hunan City University, Yiyang, 413099, China
| | - Qing Chang
- Department of Respiratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, No.241, West Huaihai Road, Shanghai, 200030, China
| | - Hai Zhang
- Department of Respiratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, No.241, West Huaihai Road, Shanghai, 200030, China
| | - Feng Li
- Department of Respiratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, No.241, West Huaihai Road, Shanghai, 200030, China
| | - Zhaohui Chen
- College of Information Technology, Shanghai Jian Qiao University, Shanghai, 201306, China
| |
Collapse
|
2
|
Ilyas A, Kharadi N, Shafique M, Mehreen T, Habib M, Khan J, Akhtar A, Kiran F, Mehmood F. Incidence of Weaning Failure in Obese Patients in Intensive Care Unit. Cureus 2024; 16:e55881. [PMID: 38595891 PMCID: PMC11002967 DOI: 10.7759/cureus.55881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/08/2024] [Indexed: 04/11/2024] Open
Abstract
Background The escalating prevalence of obesity worldwide presents unique challenges in critical care management, especially in the context of mechanical ventilation and weaning processes in intensive care units (ICUs). The present study aimed to determine the incidence of weaning failure in obese patients in an ICU. Methods A prospective observational study was carried out to gather data on patients in the ICU of Shifa International Hospital located in Islamabad, Pakistan. The target population consisted of adult patients who were both male and female, ages 18 years and above. These individuals required intubation procedures as well as mechanical ventilation during their hospitalization. The researchers followed these patients prospectively and observed their medical conditions closely to gather data about how obesity might impact critical care interventions and outcomes. Results The sample size was 288 bearing a median age of 61.0 with an interquartile range of 19 years. Older age manifested a significantly higher frequency of failed extubation (p=0.065). Higher body mass index (BMI) was significantly associated with failed extubation among the study population. It was found that a higher significant difference was associated with BMI > 30 kg/m2 (obese) in failed and successful extubation. One-half of the patients with failed extubation and only 16 (5.9%) patients with successful extubation had end-stage renal disease (p<0.001). It was found that patients who underwent failed extubation had notably increased ICU mortality (p=0.108), 28-day mortality (p=0.067), as well as mean ICU (p<0.001) and hospital stay (p=0.007). Conclusion Our study revealed some insightful correlations between obesity, age, comorbidities, length of hospitalization, ICU stay, and mortality rate in terms of weaning failure among the study population.
Collapse
Affiliation(s)
- Anum Ilyas
- Critical Care Department, Shifa International Hospital Islamabad, Islamabad, PAK
| | - Nusrat Kharadi
- Critical Care Department, Shifa International Hospital Islamabad, Islamabad, PAK
| | | | - Tooba Mehreen
- Critical Care Department, Shifa International Hospital Islamabad, Islamabad, PAK
| | - Maria Habib
- Critical Care Department, Shifa International Hospital Islamabad, Islamabad, PAK
| | - Jaffar Khan
- Critical Care Department, Shifa International Hospital Islamabad, Islamabad, PAK
| | - Aftab Akhtar
- Internal Medicine Department, Shifa International Hospital Islamabad, Islamabad, PAK
| | - Fnu Kiran
- Internal Medicine Department, Liaquat National Hospital and Medical College, Karachi, PAK
| | - Farrukh Mehmood
- Internal Medicine Department, Liaquat National Hospital and Medical College, Karachi, PAK
| |
Collapse
|
3
|
Acicbe Ö, Özgür CY, Rahimi P, Canan E, Aşar S, Çukurova Z. The effect of inspiratory rise time on mechanical power calculations in pressure control ventilation: dynamic approach. Intensive Care Med Exp 2023; 11:98. [PMID: 38117345 PMCID: PMC10733269 DOI: 10.1186/s40635-023-00584-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 12/14/2023] [Indexed: 12/21/2023] Open
Abstract
BACKGROUND Mechanical power may serve as a valuable parameter for predicting ventilation-induced injury in mechanically ventilated patients. Over time, several equations have been developed to calculate power in both volume control ventilation (VCV) and pressure control ventilation (PCV). Among these equations, the linear model mechanical power equation (MPLM) closely approximates the reference method when applied in PCV. The dynamic mechanical power equation (MPdyn) computes power by utilizing the ventilatory work of breathing parameter (WOBv), which is automatically measured by the mechanical ventilator. In our study, conducted in patients with Covid-19 Acute Respiratory Distress Syndrome (C-ARDS), we calculated mechanical power using both the MPLM and MPdyn equations, employing different inspiratory rise times (Tslope) at intervals of 5%, ranging from 5 to 20% and compared the obtained results. RESULTS In our analysis, we used univariate linear regression at both I:E ratios of 1:2 and 1:1, considering all Tslope values. These analyses revealed that the MPdyn and MPLM equations exhibited strong correlations, with R2 values exceeding 0.96. Furthermore, our Bland-Altman analysis, which compared the power values derived from the MPdyn and MPLM equations for patient averages and all measurements, revealed a mean difference of -0.42 ± 0.41 J/min (equivalent to 2.6% ± 2.3%, p < 0.0001) and -0.39 ± 0.57 J/min (equivalent to 3.6% ± 3.5%, p < 0.0001), respectively. While there was a statistically significant difference between the equations in both absolute value and relative proportion, this difference was not considered clinically relevant. Additionally, we observed that each 5% increase in Tslope time corresponded to a decrease in mechanical power values by approximately 1 J/min. CONCLUSIONS The differences between mechanical power values calculated using the MPdyn and MPLM equations at various Tslope durations were determined to lack clinical significance. Consequently, for practical and continuous mechanical power estimation in Pressure-Controlled Ventilation (PCV) mode, the MPdyn equation presents itself as a viable option. It is important to note that as Tslope times increased, the calculated mechanical power exhibited a clinically relevant decrease.
Collapse
Affiliation(s)
- Özlem Acicbe
- Department of Anesthesiology and Reanimation, Şişli Hamidiye Etfal Training and Research Hospital, University of Health Sciences, Istanbul, Turkey
| | - Canan Yazıcı Özgür
- Department of Anesthesiology and Reanimation, Bakırköy Dr. Sadi Konuk Training and Research Hospital, University of Health Sciences, Istanbul, Turkey
| | - Payam Rahimi
- Department of Anesthesiology and Reanimation, Bakırköy Dr. Sadi Konuk Training and Research Hospital, University of Health Sciences, Istanbul, Turkey
| | - Emral Canan
- Department of Anesthesiology and Reanimation, Bakırköy Dr. Sadi Konuk Training and Research Hospital, University of Health Sciences, Istanbul, Turkey
| | - Sinan Aşar
- Department of Anesthesiology and Reanimation, Bakırköy Dr. Sadi Konuk Training and Research Hospital, University of Health Sciences, Istanbul, Turkey.
| | - Zafer Çukurova
- Department of Anesthesiology and Reanimation, Bakırköy Dr. Sadi Konuk Training and Research Hospital, University of Health Sciences, Istanbul, Turkey
| |
Collapse
|
4
|
Zeng C, Zhu M, Motta-Ribeiro G, Lagier D, Hinoshita T, Zang M, Grogg K, Winkler T, Vidal Melo MF. Dynamic lung aeration and strain with positive end-expiratory pressure individualized to maximal compliance versus ARDSNet low-stretch strategy: a study in a surfactant depletion model of lung injury. Crit Care 2023; 27:307. [PMID: 37537654 PMCID: PMC10401825 DOI: 10.1186/s13054-023-04591-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 07/26/2023] [Indexed: 08/05/2023] Open
Abstract
BACKGROUND Positive end-expiratory pressure (PEEP) individualized to a maximal respiratory system compliance directly implies minimal driving pressures with potential outcome benefits, yet, raises concerns on static and dynamic overinflation, strain and cyclic recruitment. Detailed accurate assessment and understanding of these has been hampered by methodological limitations. We aimed to investigate the effects of a maximal compliance-guided PEEP strategy on dynamic lung aeration, strain and tidal recruitment using current four-dimensional computed tomography (CT) techniques and analytical methods of tissue deformation in a surfactant depletion experimental model of acute respiratory distress syndrome (ARDS). METHODS ARDS was induced by saline lung lavage in anesthetized and mechanically ventilated healthy sheep (n = 6). Animals were ventilated in a random sequence with: (1) ARDSNet low-stretch protocol; (2) maximal compliance PEEP strategy. Lung aeration, strain and tidal recruitment were acquired with whole-lung respiratory-gated high-resolution CT and quantified using registration-based techniques. RESULTS Relative to the ARDSNet low-stretch protocol, the maximal compliance PEEP strategy resulted in: (1) improved dynamic whole-lung aeration at end-expiration (0.456 ± 0.064 vs. 0.377 ± 0.101, P = 0.019) and end-inspiration (0.514 ± 0.079 vs. 0.446 ± 0.083, P = 0.012) with reduced non-aerated and increased normally-aerated lung mass without associated hyperinflation; (2) decreased aeration heterogeneity at end-expiration (coefficient of variation: 0.498 ± 0.078 vs. 0.711 ± 0.207, P = 0.025) and end-inspiration (0.419 ± 0.135 vs. 0.580 ± 0.108, P = 0.014) with higher aeration in dorsal regions; (3) tidal aeration with larger inspiratory increases in normally-aerated and decreases in poorly-aerated areas, and negligible in hyperinflated lung (Aeration × Strategy: P = 0.026); (4) reduced tidal strains in lung regions with normal-aeration (Aeration × Strategy: P = 0.047) and improved regional distributions with lower tidal strains in middle and ventral lung (Region-of-interest [ROI] × Strategy: P < 0.001); and (5) less tidal recruitment in middle and dorsal lung (ROI × Strategy: P = 0.044) directly related to whole-lung tidal strain (r = 0.751, P = 0.007). CONCLUSIONS In well-recruitable ARDS models, a maximal compliance PEEP strategy improved end-expiratory/inspiratory whole-lung aeration and its homogeneity without overinflation. It further reduced dynamic strain in middle-ventral regions and tidal recruitment in middle-dorsal areas. These findings suggest the maximal compliance strategy minimizing whole-lung dynamically quantified mechanisms of ventilator-induced lung injury with less cyclic recruitment and no additional overinflation in large heterogeneously expanded and recruitable lungs.
Collapse
Affiliation(s)
- Congli Zeng
- Department of Anesthesiology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA.
| | - Min Zhu
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Gabriel Motta-Ribeiro
- Biomedical Engineering Program, Alberto Luiz Coimbra Institute for Graduate Studies and Research in Engineering, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - David Lagier
- Department of Cardiovascular Anesthesiology and Critical Care Medicine, University Hospital Timone, Marseille, France
| | | | - Mingyang Zang
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Kira Grogg
- Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Tilo Winkler
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Marcos F Vidal Melo
- Department of Anesthesiology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| |
Collapse
|
5
|
Chen Y, Yuan Y, Zhang H, Li F. Accuracy of the estimations of respiratory mechanics using an expiratory time constant in passive and active breathing conditions: a bench study. Eur J Med Res 2023; 28:195. [PMID: 37355638 DOI: 10.1186/s40001-023-01146-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 05/23/2023] [Indexed: 06/26/2023] Open
Abstract
BACKGROUND Respiratory mechanics monitoring provides useful information for guiding mechanical ventilation, but many measuring methods are inappropriate for awake patients. This study aimed to evaluate the accuracy of dynamic mechanics estimation using expiratory time constant (RCexp) calculation during noninvasive pressure support ventilation (PSV) with air leak in different lung models. METHODS A Respironics V60 ventilator was connected to an active breathing simulator for modeling five profiles: normal adult, restrictive, mildly and severely obstructive, and mixed obstructive/restrictive. Inspiratory pressure support was adjusted to maintain tidal volumes (VT), achieving 5.0, 7.0, and 10.0 ml/kg body weight. PEEP was set at 5 cmH2O, and the back-up rate was 10 bpm. Measurements were conducted at system leaks of 25-28 L/min. RCexp was estimated from the ratio at 75% exhaled VT and flow rate, which was then used to determine respiratory system compliance (Crs) and airway resistance (Raw). RESULTS In non-obstructive conditions (Raw ≤ 10 cmH2O/L/s), the Crs was overestimated in the PSV mode. Peak inspiratory and expiratory flow and VT increased with PS levels, as calculated Crs decreased. In passive breathing, the difference of Crs between different VT was no significant. Underestimations of inspiratory resistance and expiratory resistance were observed at VT of 5.0 ml/kg. The difference was minimal at VT of 7.0 ml/kg. During non-invasive PSV, the estimation of airway resistance with the RCexp method was accurately at VT of 7.0 ml/kg. CONCLUSIONS The difference between the calculated Crs and the preset value was influenced by the volume, status and inspiratory effort in spontaneously breathing.
Collapse
Affiliation(s)
- Yuqing Chen
- Department of Respiratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, 200030, China.
| | - Yueyang Yuan
- School of Mechanical and Electrical Engineering, Hu Nan City University, Yi Yang, 413099, China
| | - Hai Zhang
- Department of Respiratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Feng Li
- Department of Respiratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, 200030, China
| |
Collapse
|
6
|
Tingay DG, Naidu H, Tingay HD, Pereira-Fantini PM, Kneyber MCJ, Becher T. Is mechanical power an under-recognised entity within the preterm lung? Intensive Care Med Exp 2023; 11:28. [PMID: 37211573 DOI: 10.1186/s40635-023-00511-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 04/11/2023] [Indexed: 05/23/2023] Open
Abstract
BACKGROUND Mechanical power is a major contributor to lung injury and mortality in adults receiving mechanical ventilation. Recent advances in our understanding of mechanical power have allowed the different mechanical components to be isolated. The preterm lung shares many of the same similarities that would indicate mechanical power may be relevant in this group. To date, the role of mechanical power in neonatal lung injury is unknown. We hypothesise that mechanical power maybe useful in expanding our understanding of preterm lung disease. Specifically, that mechanical power measures may account for gaps in knowledge in how lung injury is initiated. HYPOTHESIS-GENERATING DATA SET To provide a justification for our hypothesis, data in a repository at the Murdoch Children's Research Institute, Melbourne (Australia) were re-analysed. 16 preterm lambs 124-127d gestation (term 145d) who received 90 min of standardised positive pressure ventilation from birth via a cuffed endotracheal tube were chosen as each was exposed to three distinct and clinically relevant respiratory states with unique mechanics. These were (1) the respiratory transition to air-breathing from an entirely fluid-filled lung (rapid aeration and fall in resistance); (2) commencement of tidal ventilation in an acutely surfactant-deficient state (low compliance) and (3) exogenous surfactant therapy (improved aeration and compliance). Total, tidal, resistive and elastic-dynamic mechanical power were calculated from the flow, pressure and volume signals (200 Hz) for each inflation. RESULTS All components of mechanical power behaved as expected for each state. Mechanical power increased during lung aeration from birth to 5 min, before again falling immediately after surfactant therapy. Before surfactant therapy tidal power contributed 70% of total mechanical power, and 53.7% after. The contribution of resistive power was greatest at birth, demonstrating the initial high respiratory system resistance at birth. CONCLUSIONS In our hypothesis-generating dataset, changes in mechanical power were evident during clinically important states for the preterm lung, specifically transition to air-breathing, changes in aeration and surfactant administration. Future preclinical studies using ventilation strategies designed to highlight different types of lung injury, including volu-, baro- and ergotrauma, are needed to test our hypothesis.
Collapse
Affiliation(s)
- David G Tingay
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
- Department of Neonatology, The Royal Children's Hospital, Parkville, Australia
| | - Hannah Naidu
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Australia
| | - Hamish D Tingay
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Australia
| | - Prue M Pereira-Fantini
- Neonatal Research, Murdoch Children's Research Institute, Parkville, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Martin C J Kneyber
- Division of Paediatric Critical Care Medicine, Department of Paediatrics, Beatrix Children's Hospital, University Medical Center Groningen, Groningen, The Netherlands
- Critical Care, Anaesthesiology, Peri-Operative and Emergency Medicine, The University of Groningen, Groningen, The Netherlands
| | - Tobias Becher
- Department of Anesthesiology and Intensive Care Medicine, University Medical Centre Schleswig-Holstein, Campus Kiel, Arnold-Heller-Straße 3, Haus R3, 24105, Kiel, Germany.
| |
Collapse
|
7
|
van Diepen A, Bakkes THGF, De Bie AJR, Turco S, Bouwman RA, Woerlee PH, Mischi M. Evaluation of the accuracy of established patient inspiratory effort estimation methods during mechanical support ventilation. Heliyon 2023; 9:e13610. [PMID: 36852019 PMCID: PMC9958297 DOI: 10.1016/j.heliyon.2023.e13610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/13/2022] [Accepted: 02/06/2023] [Indexed: 02/12/2023] Open
Abstract
There is a clinical need for monitoring inspiratory effort to prevent lung- and diaphragm injury in patients who receive supportive mechanical ventilation in an Intensive Care Unit. Different pressure-based techniques are available to estimate this inspiratory effort at the bedside, but the accuracy of their effort estimation is uncertain since they are all based on a simplified linear model of the respiratory system, which omits gas compressibility of air, and the viscoelasticity and nonlinearities of the respiratory system. The aim of this in-silico study was to provide an overview of the pressure-based estimation techniques and to evaluate their accuracy using a more sophisticated model of the respiratory system and ventilator. The influence of the following parameters on the accuracy of the pressure-based estimation techniques was evaluated using the in-silico model: 1) the patient's respiratory mechanics 2) PEEP and the inspiratory pressure of the ventilator 3) gas compressibility of air 4) viscoelasticity of the respiratory system 5) the strength of the inspiratory effort. The best-performing technique in terms of accuracy was the whole breath occlusion. The average error and maximum error were the lowest for all patient archetypes. We found that the error was related to the expansion of gas in the breathing set and lungs and respiratory compliance. However, concerns exist that other factors not included in the model, such as a changed muscle-force relation during an occlusion, might influence the true accuracy. The estimation techniques based on the esophageal pressure showed an error related to the viscoelastic element in the model which leads to a higher error than the occlusion. The error of the esophageal pressure-based techniques is therefore highly dependent on the pathology of the patient and the settings of the ventilator and might change over time while a patient recovers or becomes more ill.
Collapse
Affiliation(s)
- A van Diepen
- Department of Electrical Engineering, Technische Universiteit Eindhoven, De Zaale, Eindhoven, 5612AZ, Noord-Brabant, the Netherlands
| | - T H G F Bakkes
- Department of Electrical Engineering, Technische Universiteit Eindhoven, De Zaale, Eindhoven, 5612AZ, Noord-Brabant, the Netherlands
| | - A J R De Bie
- Catharina Hospital, Michelangelolaan 2, Eindhoven, 5623 EJ, Noord-Brabant, the Netherlands
| | - S Turco
- Department of Electrical Engineering, Technische Universiteit Eindhoven, De Zaale, Eindhoven, 5612AZ, Noord-Brabant, the Netherlands
| | - R A Bouwman
- Department of Electrical Engineering, Technische Universiteit Eindhoven, De Zaale, Eindhoven, 5612AZ, Noord-Brabant, the Netherlands.,Catharina Hospital, Michelangelolaan 2, Eindhoven, 5623 EJ, Noord-Brabant, the Netherlands
| | - P H Woerlee
- Department of Electrical Engineering, Technische Universiteit Eindhoven, De Zaale, Eindhoven, 5612AZ, Noord-Brabant, the Netherlands
| | - M Mischi
- Department of Electrical Engineering, Technische Universiteit Eindhoven, De Zaale, Eindhoven, 5612AZ, Noord-Brabant, the Netherlands
| |
Collapse
|
8
|
Trinkle CA, Broaddus RN, Sturgill JL, Waters CM, Morris PE. Simple, accurate calculation of mechanical power in pressure controlled ventilation (PCV). Intensive Care Med Exp 2022; 10:22. [PMID: 35644896 PMCID: PMC9148680 DOI: 10.1186/s40635-022-00448-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 05/12/2022] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Mechanical power is a promising new metric to assess energy transfer from a mechanical ventilator to a patient, which combines the contributions of multiple parameters into a single comprehensive value. However, at present, most ventilators are not capable of calculating mechanical power automatically, so there is a need for a simple equation that can be used to estimate this parameter at the bedside. For volume-controlled ventilation (VCV), excellent equations exist for calculating power from basic ventilator parameters, but for pressure-controlled ventilation (PCV), an accurate, easy-to-use equation has been elusive. RESULTS Here, we present a new power equation and evaluate its accuracy compared to the three published PCV power equations. When applied to a sample of 50 patients on PCV with a non-zero rise time, we found that our equation estimated power within an average of 8.4% ± 5.9% (mean ± standard deviation) of the value obtained by numerical integration of the P-V loop. The other three equations estimated power with an error of 19.4% ± 12.9% (simplified Becher equation), 10.0% ± 6.8% (comprehensive Becher equation), and 16.5% ± 14.6% (van der Meijden equation). CONCLUSIONS Our equation calculates power more accurately than the other three published equations, and is much easier to use than the only previously published equation with similar accuracy. The proposed new mechanical power equation is accurate and simple to use, making it an attractive option to estimate power in PCV cases at the bedside.
Collapse
Affiliation(s)
- Christine A. Trinkle
- grid.266539.d0000 0004 1936 8438Department of Mechanical Engineering, College of Engineering, University of Kentucky, 277 Ralph G. Anderson Building, Lexington, KY 40506 USA
| | - Richard N. Broaddus
- grid.266539.d0000 0004 1936 8438Division of Pulmonary, Critical Care and Sleep Medicine, College of Medicine, University of Kentucky, Lexington, KY USA
| | - Jamie L. Sturgill
- grid.266539.d0000 0004 1936 8438Division of Pulmonary, Critical Care and Sleep Medicine, College of Medicine, University of Kentucky, Lexington, KY USA
| | - Christopher M. Waters
- grid.266539.d0000 0004 1936 8438Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY USA ,grid.266539.d0000 0004 1936 8438Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY USA
| | - Peter E. Morris
- grid.266539.d0000 0004 1936 8438Division of Pulmonary, Critical Care and Sleep Medicine, College of Medicine, University of Kentucky, Lexington, KY USA
| |
Collapse
|
9
|
Widing H, Chiodaroli E, Liggieri F, Mariotti PS, Hallén K, Perchiazzi G. Homogenizing effect of PEEP on tidal volume distribution during neurally adjusted ventilatory assist: study of an animal model of acute respiratory distress syndrome. Respir Res 2022; 23:324. [PMID: 36419132 PMCID: PMC9685871 DOI: 10.1186/s12931-022-02228-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 10/26/2022] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The physiological response and the potentially beneficial effects of positive end-expiratory pressure (PEEP) for lung protection and optimization of ventilation during spontaneous breathing in patients with acute respiratory distress syndrome (ARDS) are not fully understood. The aim of the study was to compare the effect of different PEEP levels on tidal volume distribution and on the ventilation of dependent lung region during neurally adjusted ventilatory assist (NAVA). METHODS ARDS-like lung injury was induced by using saline lavage in 10 anesthetized and spontaneously breathing farm-bred pigs. The animals were ventilated in NAVA modality and tidal volume distribution as well as dependent lung ventilation were assessed using electric impedance tomography during the application of PEEP levels from 0 to 15 cmH20, in steps of 3 cmH20. Tidal volume distribution and dependent fraction of ventilation were analysed using Wilcoxon signed rank test. Furthermore, airway, esophageal and transpulmonary pressure, as well as airway flow and delivered volume, were continuously measured during the assisted spontaneous breathing. RESULTS Increasing PEEP improved oxygenation and re-distributed tidal volume. Specifically, ventilation distribution changed from a predominant non-dependent to a more even distribution between non-dependent and dependent areas of the lung. Dependent fraction of ventilation reached 47 ± 9% at PEEP 9 cmH20. Further increasing PEEP led to a predominant dependent ventilation. CONCLUSION During assisted spontaneous breathing in this model of induced ARDS, PEEP modifies the distribution of ventilation and can achieve a homogenizing effect on its spatial arrangement. The study indicates that PEEP is an important factor during assisted spontaneous breathing and that EIT can be of valuable interest when titrating PEEP level during spontaneous breathing, by indicating the most homogeneous distribution of gas volumes throughout the PEEP spectrum.
Collapse
Affiliation(s)
- Hannes Widing
- grid.8993.b0000 0004 1936 9457Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Akademiska Sjukhuset, Ing 40, 3 Tr, 751 85 Uppsala, Sweden ,grid.1649.a000000009445082XDepartment of Anaesthesiology and Intensive Care Medicine, Region Västra Götaland, Sahlgrenska University Hospital/Östra, Gothenburg, Sweden
| | - Elena Chiodaroli
- grid.8993.b0000 0004 1936 9457Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Akademiska Sjukhuset, Ing 40, 3 Tr, 751 85 Uppsala, Sweden ,grid.415093.a0000 0004 1793 3800Department of Anesthesia and Intensive Care, ASST Santi Paolo e Carlo, San Paolo University Hospital, Via Di Rudinì 8, Milan, Italy
| | - Francesco Liggieri
- grid.8993.b0000 0004 1936 9457Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Akademiska Sjukhuset, Ing 40, 3 Tr, 751 85 Uppsala, Sweden ,Division of Anesthesia and Intensive Care, San Martino Policlinic University Hospital, 16132 Genoa, Italy
| | - Paola Sara Mariotti
- grid.8993.b0000 0004 1936 9457Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Akademiska Sjukhuset, Ing 40, 3 Tr, 751 85 Uppsala, Sweden ,grid.10796.390000000121049995Department of Medical and Surgical Sciences, Anesthesia and Intensive Care Unit, University of Foggia, Foggia, Italy
| | - Katarina Hallén
- grid.1649.a000000009445082XDepartment of Anaesthesiology and Intensive Care Medicine, Region Västra Götaland, Sahlgrenska University Hospital/Östra, Gothenburg, Sweden
| | - Gaetano Perchiazzi
- grid.8993.b0000 0004 1936 9457Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Akademiska Sjukhuset, Ing 40, 3 Tr, 751 85 Uppsala, Sweden ,grid.412354.50000 0001 2351 3333Department of Anesthesia, Operation and Intensive Care, Uppsala University Hospital, Uppsala, Sweden
| |
Collapse
|
10
|
Flow Index accurately identifies breaths with low or high inspiratory effort during pressure support ventilation. Crit Care 2021; 25:427. [PMID: 34911541 PMCID: PMC8672539 DOI: 10.1186/s13054-021-03855-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 12/03/2021] [Indexed: 01/19/2023] Open
Abstract
Background Flow Index, a numerical expression of the shape of the inspiratory flow-time waveform recorded during pressure support ventilation, is associated with patient inspiratory effort. The aim of this study was to assess the accuracy of Flow Index in detecting high or low inspiratory effort during pressure support ventilation and to establish cutoff values for the Flow index to identify these conditions. The secondary aim was to compare the performance of Flow index,of breathing pattern parameters and of airway occlusion pressure (P0.1) in detecting high or low inspiratory effort during pressure support ventilation. Methods Data from 24 subjects was included in the analysis, accounting for a total of 702 breaths. Breaths with high inspiratory effort were defined by a pressure developed by inspiratory muscles (Pmusc) greater than 10 cmH2O while breaths with low inspiratory effort were defined by a Pmusc lower than 5 cmH2O. The areas under the receiver operating characteristic curves of Flow Index and respiratory rate, tidal volume,respiratory rate over tidal volume and P0.1 were analyzed and compared to identify breaths with low or high inspiratory effort. Results Pmusc, P0.1, Pressure Time Product and Flow Index differed between breaths with high, low and intermediate inspiratory effort, while RR, RR/VT and VT/kg of IBW did not differ in a statistically significant way. A Flow index higher than 4.5 identified breaths with high inspiratory effort [AUC 0.89 (CI 95% 0.85–0.93)], a Flow Index lower than 2.6 identified breaths with low inspiratory effort [AUC 0.80 (CI 95% 0.76–0.83)]. Conclusions Flow Index is accurate in detecting high and low spontaneous inspiratory effort during pressure support ventilation. Supplementary Information The online version contains supplementary material available at 10.1186/s13054-021-03855-4.
Collapse
|
11
|
Ceylan G, Topal S, Atakul G, Colak M, Soydan E, Sandal O, Sari F, Ağın H. Randomized crossover trial to compare driving pressures in a closed-loop and a conventional mechanical ventilation mode in pediatric patients. Pediatr Pulmonol 2021; 56:3035-3043. [PMID: 34293255 DOI: 10.1002/ppul.25561] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 06/17/2021] [Accepted: 06/22/2021] [Indexed: 11/10/2022]
Abstract
INTRODUCTION In mechanically ventilated patients, driving pressure (ΔP) represents the dynamic stress applied to the respiratory system and is related to ICU mortality. An evolution of the Adaptive Support Ventilation algorithm (ASV® 1.1) minimizes inspiratory pressure in addition to minimizing the work of breathing. We hypothesized that ASV 1.1 would result in lower ΔP than the ΔP measured in APV-CMV (controlled mandatory ventilation with adaptive pressure ventilation) mode with physician-tailored settings. The aim of this randomized crossover trial was therefore to compare ΔP in ASV 1.1 with ΔP in physician-tailored APV-CMV mode. METHODS Pediatric patients admitted to the PICU with heterogeneous-lung disease were enrolled if they were ventilated invasively with no detectable respiratory effort, hemodynamic instability, or significant airway leak around the endotracheal tube. We compared two 60-min periods of ventilation in APV-CMV and ASV 1.1, which were determined by randomization and separated by 30-min washout periods. Settings were adjusted to reach the same minute ventilation in both modes. ΔP was calculated as the difference between plateau pressure and total PEEP measured using end-inspiratory and end-expiratory occlusions, respectively. RESULTS There were 26 patients enrolled with a median age of 16 (9-25 [IQR]) months. The median ΔP for these patients was 10.4 (8.5-12.1 [IQR]) and 12.4 (10.5-15.3 [IQR]) cmH2O in the ASV 1.1 and APV-CMV periods, respectively (p < .001). The median tidal volume (VT) selected by the ASV 1.1 algorithm was 6.4 (5.1-7.3 [IQR]) ml/kg and RR was 41 (33 50 [IQR]) b/min, whereas the median of the same values for the APV-CMV period was 7.9 (6.8-8.3 [IQR]) ml/kg and 31 (26-41[IQR]) b/min, respectively. In both ASV 1.1 and APV-CMV modes, the highest ΔP was used to ventilate those patients with restrictive lung conditions at baseline. CONCLUSION In this randomized crossover trial, ΔP in ASV 1.1 was lower compared to ΔP in physician-tailored APV-CMV mode in pediatric patients with different lung conditions. The use of ASV 1.1 may therefore result in continued, safe ventilation in a heterogeneous pediatric patient group.
Collapse
Affiliation(s)
- Gokhan Ceylan
- Department of Pediatric Intensive Care Unit, Dr Behcet Uz Children's Disease and Surgery Training and Research Hospital, Health Sciences University, Izmir, Turkey.,Department of Medical Research, HamiltonMedical AG, Bonaduz, Switzerland
| | - Sevgi Topal
- Department of Pediatric Intensive Care Unit, Dr Behcet Uz Children's Disease and Surgery Training and Research Hospital, Health Sciences University, Izmir, Turkey
| | - Gulhan Atakul
- Department of Pediatric Intensive Care Unit, Dr Behcet Uz Children's Disease and Surgery Training and Research Hospital, Health Sciences University, Izmir, Turkey
| | - Mustafa Colak
- Department of Pediatric Intensive Care Unit, Dr Behcet Uz Children's Disease and Surgery Training and Research Hospital, Health Sciences University, Izmir, Turkey
| | - Ekin Soydan
- Department of Pediatric Intensive Care Unit, Dr Behcet Uz Children's Disease and Surgery Training and Research Hospital, Health Sciences University, Izmir, Turkey
| | - Ozlem Sandal
- Department of Pediatric Intensive Care Unit, Dr Behcet Uz Children's Disease and Surgery Training and Research Hospital, Health Sciences University, Izmir, Turkey
| | - Ferhat Sari
- Department of Pediatric Intensive Care Unit, Dr Behcet Uz Children's Disease and Surgery Training and Research Hospital, Health Sciences University, Izmir, Turkey
| | - Hasan Ağın
- Department of Pediatric Intensive Care Unit, Dr Behcet Uz Children's Disease and Surgery Training and Research Hospital, Health Sciences University, Izmir, Turkey
| |
Collapse
|
12
|
Pan Q, Pan J, Zhang Z, Fang L, Ge H. Assessment of respiratory system compliance under pressure control ventilation without an inspiratory pause maneuver. Physiol Meas 2021; 42. [PMID: 34384069 DOI: 10.1088/1361-6579/ac1d3b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 08/12/2021] [Indexed: 02/07/2023]
Abstract
Objective. The measurement of the static compliance of the respiratory system (Cstat) during mechanical ventilation requires zero end-inspiratory flow. An inspiratory pause maneuver is needed if the zero end-inspiratory flow condition cannot be satisfied under normal ventilation.Approach. We propose a method to measure the quasi-static respiratory compliance (Cqstat) under pressure control ventilation mode without the inspiratory pause maneuver. First, a screening strategy was applied to filter out breaths affected strongly by spontaneous breathing efforts or artifacts. Then, we performed a virtual extrapolation of the flow-time waveform when the end-inspiratory flow was not zero, to allow for the calculation ofCqstatfor each kept cycle. Finally, the outputCqstatwas obtained as the average of the smallest 40Cqstatmeasurements. The proposed method was validated against the gold standardCstatmeasured from real clinical settings and compared with two reported algorithms. The gold standardCstatwas obtained by applying an end-inspiratory pause maneuver in the volume-control ventilation mode.Main results. Sixty-nine measurements from 36 patients were analyzed. The Bland-Altman analysis showed that the bias of agreement forCqstatversus the gold standard measurement was -0.267 ml/cmH2O (95% limits of agreement was -4.279 to 4.844 ml/cmH2O). The linear regression analysis indicated a strong correlation (R2 = 0.90) between theCqstatand gold standard.Significance. The results showed that theCqstatcan be accurately estimated from continuous ventilator waveforms, including spontaneous breathing without an inspiratory pause maneuver. This method promises to provide continuous measurements compliant with mechanical ventilation.
Collapse
Affiliation(s)
- Qing Pan
- College of Information Engineering, Zhejiang University of Technology, Liuhe Rd. 288, Hangzhou 310023, People's Republic of China
| | - Jie Pan
- College of Information Engineering, Zhejiang University of Technology, Liuhe Rd. 288, Hangzhou 310023, People's Republic of China
| | - Zhongheng Zhang
- Department of Emergency Medicine, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Qingchun East Rd. 3, Hangzhou 310016, People's Republic of China
- Key Laboratory of Emergency and Trauma, Ministry of Education, College of Emergency and Trauma, Hainan Medical University, Haikou 571199, People's Republic of China
| | - Luping Fang
- College of Information Engineering, Zhejiang University of Technology, Liuhe Rd. 288, Hangzhou 310023, People's Republic of China
| | - Huiqing Ge
- Department of Respiratory Care, Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Qingchun East Rd. 3, Hangzhou 310016, People's Republic of China
| |
Collapse
|
13
|
Chen Y, Yuan Y, Zhang H, Li F, Wang X. Continuous estimation of airway resistance in non-invasive ventilation. Respir Physiol Neurobiol 2021; 294:103738. [PMID: 34242813 DOI: 10.1016/j.resp.2021.103738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/18/2021] [Accepted: 07/03/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND This study aimed to evaluate the accuracy of expiratory time constant (RCexp) to continuously calculate the airway resistance (Raw). MATERIAL AND METHODS A Respironics V60 ventilator was connected to a lung simulator for modeling different profiles of respiratory mechanics. RESULTS During assisted ventilation, the respiratory system compliance (Crs) calculation was always overestimated in most lung models. The Raw estimation using the expiratory resistance (Rexp) method was close to the calculated value with the occlusion method during volume-controlled ventilation (VCV). In expiratory flow limitation (EFL) lung models, similar results were obtained in the estimation of inspiratory resistance (Rinsp), but different variations were observed in the calculation of the Rexp. The results estimated with RCexp and with dynamic signal analysis had significant variation and accuracy (p < 0.001). CONCLUSION The RCexp method is a robust approach to provide real-time assessments of Rinsp and Rexp in spontaneously breathing patients during noninvasive ventilation. An underestimation of Rexp was observed in EFL lung models.
Collapse
Affiliation(s)
- Yuqing Chen
- Department of Respiratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China.
| | - Yueyang Yuan
- School of Mechanical and Electrical Engineering, Hu Nan City University, Yi Yang 413099, Hunan, China
| | - Hai Zhang
- Department of Respiratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Feng Li
- Department of Respiratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Xiaohui Wang
- Department of Pharmaceutical Science, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China
| |
Collapse
|
14
|
Albani F, Pisani L, Ciabatti G, Fusina F, Buizza B, Granato A, Lippolis V, Aniballi E, Murgolo F, Rosano A, Latronico N, Antonelli M, Grasso S, Natalini G. Flow Index: a novel, non-invasive, continuous, quantitative method to evaluate patient inspiratory effort during pressure support ventilation. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2021; 25:196. [PMID: 34099028 PMCID: PMC8182360 DOI: 10.1186/s13054-021-03624-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 05/31/2021] [Indexed: 02/08/2023]
Abstract
Background The evaluation of patient effort is pivotal during pressure support ventilation, but a non-invasive, continuous, quantitative method to assess patient inspiratory effort is still lacking. We hypothesized that the concavity of the inspiratory flow-time waveform could be useful to estimate patient’s inspiratory effort. The purpose of this study was to assess whether the shape of the inspiratory flow, as quantified by a numeric indicator, could be associated with inspiratory effort during pressure support ventilation. Methods Twenty-four patients in pressure support ventilation were enrolled. A mathematical relationship describing the decay pattern of the inspiratory flow profile was developed. The parameter hypothesized to estimate effort was named Flow Index. Esophageal pressure, airway pressure, airflow, and volume waveforms were recorded at three support levels (maximum, minimum and baseline). The association between Flow Index and reference measures of patient effort (pressure time product and pressure generated by respiratory muscles) was evaluated using linear mixed effects models adjusted for tidal volume, respiratory rate and respiratory rate/tidal volume. Results Flow Index was different at the three pressure support levels and all group comparisons were statistically significant. In all tested models, Flow Index was independently associated with patient effort (p < 0.001). Flow Index prediction of inspiratory effort agreed with esophageal pressure-based methods. Conclusions Flow Index is associated with patient inspiratory effort during pressure support ventilation, and may provide potentially useful information for setting inspiratory support and monitoring patient-ventilator interactions. Supplementary Information The online version contains supplementary material available at 10.1186/s13054-021-03624-3.
Collapse
Affiliation(s)
- Filippo Albani
- Department of Anesthesia and Intensive Care, Fondazione Poliambulanza, Brescia, Italy
| | - Luigi Pisani
- Department of Anesthesia and Intensive Care, Miulli Regional Hospital, Acquaviva Delle Fonti, Bari, Italy.,Mahidol Oxford Clinical Research Unit (MORU), Bangkok, Thailand
| | - Gianni Ciabatti
- Department of Anesthesiology, Neurointensive Care Unit, Azienda Ospedaliera Universitaria Careggi, Firenze, Italy
| | - Federica Fusina
- Department of Anesthesia and Intensive Care, Fondazione Poliambulanza, Brescia, Italy.
| | - Barbara Buizza
- Department of Anesthesia and Intensive Care, Spedali Civili, Brescia, Italy
| | - Anna Granato
- Department of Anesthesia and Intensive Care, Fondazione Poliambulanza, Brescia, Italy
| | - Valeria Lippolis
- Department of Anesthesia and Intensive Care, Mater Dei Hospital, Bari, Italy
| | - Eros Aniballi
- Department of Anesthesia, I.R.C.C.S. MultiMedica, Sesto San Giovanni, Milano, Italy
| | - Francesco Murgolo
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Antonio Rosano
- Department of Anesthesia and Intensive Care, Fondazione Poliambulanza, Brescia, Italy
| | - Nicola Latronico
- Department of Anesthesia and Intensive Care, Spedali Civili, Brescia, Italy.,Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Massimo Antonelli
- Department of Intensive Care and Anesthesiology, Fondazione Policlinico, Universitario A. Gemelli, Roma, Italy
| | - Salvatore Grasso
- Department of Emergency and Organ Transplantation, University of Bari, Bari, Italy
| | - Giuseppe Natalini
- Department of Anesthesia and Intensive Care, Fondazione Poliambulanza, Brescia, Italy
| |
Collapse
|
15
|
Chen Y, Yuan Y, Zhang H, Li F, Zhou X. Accuracy of the dynamic signal analysis approach in respiratory mechanics during noninvasive pressure support ventilation: a bench study. J Int Med Res 2021; 49:300060521992184. [PMID: 33626940 PMCID: PMC7925949 DOI: 10.1177/0300060521992184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE To evaluate the accuracy of respiratory mechanics using dynamic signal analysis during noninvasive pressure support ventilation (PSV). METHODS A Respironics V60 ventilator was connected to an active lung simulator to model normal, restrictive, obstructive, and mixed obstructive and restrictive profiles. The PSV was adjusted to maintain tidal volumes (VT) that achieved 5.0, 7.0, and 10.0 mL/kg body weight, and the positive end-expiration pressure (PEEP) was set to 5 cmH2O. Ventilator performance was evaluated by measuring the flow, airway pressure, and volume. The system compliance (Crs) and airway resistance (inspiratory and expiratory resistance, Rinsp and Rexp, respectively) were calculated. RESULTS Under active breathing conditions, the Crs was overestimated in the normal and restrictive models, and it decreased with an increasing pressure support (PS) level. The Rinsp calculated error was approximately 10% at 10.0 mL/kg of VT, and similar results were obtained for the calculated Rexp at 7.0 mL/kg of VT. CONCLUSION Using dynamic signal analysis, appropriate tidal volume was beneficial for Rrs, especially for estimating Rexp during assisted ventilation. The Crs measurement was also relatively accurate in obstructive conditions.
Collapse
Affiliation(s)
- Yuqing Chen
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Yueyang Yuan
- School of Mechanical and Electrical Engineering, Hu Nan City University, Yi Yang, China
| | - Hai Zhang
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Feng Li
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Xin Zhou
- Department of Pulmonary and Critical Care Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
16
|
[Patient self-inflicted lung injury (P-SILI) : From pathophysiology to clinical evaluation with differentiated management]. Med Klin Intensivmed Notfmed 2021; 116:614-623. [PMID: 33961061 PMCID: PMC8103432 DOI: 10.1007/s00063-021-00823-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 02/08/2023]
Abstract
Die Etablierung der unterstützten Spontanatmung gilt allgemein als eine vorteilhafte und wenig gefährdende Phase der Beatmungstherapie. Allerdings geben neuere Erkenntnisse Hinweise auf eine potenzielle Schädigung durch exzessive Spontanatembemühungen vor allem bei akuter Lungenschädigung. Das Syndrom wird unter dem Begriff „patient self-inflicted lung injury“ zusammengefasst. Ärzte, Pflegepersonen und Atmungstherapeuten sollten für diese Thematik sensibilisiert werden. Parameter, die mittels Ösophagusdruckmessung oder einfacher Manöver am Respirator bestimmt werden können, sind bei der Entscheidung zur Durchführung und zur Überwachung von Spontanatmung auch in den akuten Phasen der Lungenschädigung hilfreich. Weiterhin gibt es im Umgang mit hohem Atemantrieb oder erhöhter Atemanstrengung therapeutische Möglichkeiten, diesen zu begegnen.
Collapse
|
17
|
Abstract
PURPOSE OF REVIEW Accurate monitoring of the mechanical properties of the respiratory system is crucial to understand the pathophysiological mechanisms of respiratory failure in mechanically ventilated patients, to optimize mechanical ventilation settings and to reduce ventilator-induced lung injury. However, although the assessment of respiratory mechanics is simple in patients undergoing fully controlled ventilation, it becomes quite challenging in the presence of spontaneous breathing activity. Aim of the present review is to describe how the different components of respiratory mechanics [resistance, static compliance, and intrinsic positive end-expiratory pressure (PEEP)] can be measured at the bedside during assisted modes of ventilation. RECENT FINDINGS Available techniques for bedside measurement of resistance during assisted ventilation are complex and not commonly implemented. On the contrary, an increasing number of reports indicate that measurement of static compliance and intrinsic PEEP can be easily obtained, both with advanced monitoring systems (esophageal and gastric manometry, diaphragm electromyography, electrical impedance tomography) and, with some limitations, with simple airways occlusion maneuvers. SUMMARY Assessment of respiratory mechanics in spontaneously breathing patients, with some limitations, is feasible and should be included in everyday clinical practice; however, more data are needed to understand the clinical relevance of the measures obtained during assisted ventilation.
Collapse
|
18
|
Natalini G, Buizza B, Granato A, Aniballi E, Pisani L, Ciabatti G, Lippolis V, Rosano A, Latronico N, Grasso S, Antonelli M, Bernardini A. Non-invasive assessment of respiratory muscle activity during pressure support ventilation: accuracy of end-inspiration occlusion and least square fitting methods. J Clin Monit Comput 2020; 35:913-921. [PMID: 32617847 PMCID: PMC7330529 DOI: 10.1007/s10877-020-00552-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 06/26/2020] [Indexed: 12/01/2022]
Abstract
Pressure support ventilation (PSV) should be titrated considering the pressure developed by the respiratory muscles (Pmusc) to prevent under- and over-assistance. The esophageal pressure (Pes) is the clinical gold standard for Pmusc assessment, but its use is limited by alleged invasiveness and complexity. The least square fitting method and the end-inspiratory occlusion method have been proposed as non-invasive alternatives for Pmusc assessment. The aims of this study were: (1) to compare the accuracy of Pmusc estimation using the end-inspiration occlusion (Pmusc,index) and the least square fitting (Pmusc,lsf) against the reference method based on Pes; (2) to test the accuracy of Pmusc,lsf and of Pmusc,index to detect overassistance, defined as Pmusc ≤ 1 cmH2O. We studied 18 patients at three different PSV levels. At each PSV level, Pmusc, Pmusc,lsf, Pmusc,index were calculated on the same breaths. Differences among Pmusc, Pmusc,lsf, Pmusc,index were analyzed with linear mixed effects models. Bias and agreement were assessed by Bland-Altman analysis for repeated measures. The ability of Pmusc,lsf and Pmusc,index to detect overassistance was assessed by the area under the receiver operating characteristics curve. Positive and negative predictive values were calculated using cutoff values that maximized the sum of sensitivity and specificity. At each PSV level, Pmusc,lsf was not different from Pmusc (p = 0.96), whereas Pmusc,index was significantly lower than Pmusc. The bias between Pmusc and Pmusc,lsf was zero, whereas Pmusc,index systematically underestimated Pmusc of 6 cmH2O. The limits of agreement between Pmusc and Pmusc,lsf and between Pmusc and Pmusc,index were ± 12 cmH2O across bias. Both Pmusc,lsf ≤ 4 cmH2O and Pmusc,index ≤ 1 cmH2O had excellent negative predictive value [0.98 (95% CI 0.94-1) and 0.96 (95% CI 0.91-0.99), respectively)] to identify over-assistance. The inspiratory effort during PSV could not be accurately estimated by the least square fitting or end-inspiratory occlusion method because the limits of agreement were far above the signal size. These non-invasive approaches, however, could be used to screen patients at risk for absent or minimal respiratory muscles activation to prevent the ventilator-induced diaphragmatic dysfunction.
Collapse
Affiliation(s)
- Giuseppe Natalini
- Department of Intensive Care and Anesthesiology, Fondazione Poliambulanza, Brescia, Italy
| | - Barbara Buizza
- Department of Intensive Care and Anesthesiology, University of Brescia, Brescia, Italy
| | - Anna Granato
- Department of Intensive Care and Anesthesiology, Fondazione Poliambulanza, Brescia, Italy.,Department of Intensive Care and Anesthesiology, Fondazione Policlinico Universitario A.Gemelli IRCCS, Roma, Italy
| | - Eros Aniballi
- Department of Intensive Care and Anesthesiology, Fondazione Poliambulanza, Brescia, Italy.,Department of Intensive Care and Anesthesiology, Fondazione Policlinico Universitario A.Gemelli IRCCS, Roma, Italy
| | - Luigi Pisani
- Department of Intensive Care and Anesthesiology, Fondazione Poliambulanza, Brescia, Italy.,Department of Intensive Care, Amsterdam University Medical Centers - Location AMC, Amsterdam, Netherlands
| | - Gianni Ciabatti
- Department of Anesthesiology and Intensive Care, Neurointensive Care Unit, Azienda Ospedaliera Universitaria Careggi, Firenze, Italy.
| | - Valeria Lippolis
- Department of Intensive Care and Anesthesiology, Fondazione Poliambulanza, Brescia, Italy.,Department of Emergency and Organ Transplants (DETO), Anesthesiology and Intensive Care, Università Degli Studi Di Bari "Aldo Moro", Bari, Italy
| | - Antonio Rosano
- Department of Intensive Care and Anesthesiology, Fondazione Poliambulanza, Brescia, Italy
| | - Nicola Latronico
- Department of Intensive Care and Anesthesiology, University of Brescia, Brescia, Italy.,Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Salvatore Grasso
- Department of Emergency and Organ Transplants (DETO), Anesthesiology and Intensive Care, Università Degli Studi Di Bari "Aldo Moro", Bari, Italy
| | - Massimo Antonelli
- Department of Intensive Care and Anesthesiology, Fondazione Policlinico Universitario A.Gemelli IRCCS, Roma, Italy.,Catholic University of Sacred Heart, Roma, Italy
| | - Achille Bernardini
- Department of Intensive Care and Anesthesiology, Fondazione Poliambulanza, Brescia, Italy
| |
Collapse
|
19
|
Lung Recruitment in Obese Patients with Acute Respiratory Distress Syndrome. Anesthesiology 2020; 130:791-803. [PMID: 30844949 DOI: 10.1097/aln.0000000000002638] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Obese patients are characterized by normal chest-wall elastance and high pleural pressure and have been excluded from trials assessing best strategies to set positive end-expiratory pressure (PEEP) in acute respiratory distress syndrome (ARDS). The authors hypothesized that severely obese patients with ARDS present with a high degree of lung collapse, reversible by titrated PEEP preceded by a lung recruitment maneuver. METHODS Severely obese ARDS patients were enrolled in a physiologic crossover study evaluating the effects of three PEEP titration strategies applied in the following order: (1) PEEPARDSNET: the low PEEP/FIO2 ARDSnet table; (2) PEEPINCREMENTAL: PEEP levels set to determine a positive end-expiratory transpulmonary pressure; and (3) PEEPDECREMENTAL: PEEP levels set to determine the lowest respiratory system elastance during a decremental PEEP trial following a recruitment maneuver on respiratory mechanics, regional lung collapse, and overdistension according to electrical impedance tomography and gas exchange. RESULTS Fourteen patients underwent the study procedures. At PEEPARDSNET (13 ± 1 cm H2O) end-expiratory transpulmonary pressure was negative (-5 ± 5 cm H2O), lung elastance was 27 ± 12 cm H2O/L, and PaO2/FIO2 was 194 ± 111 mmHg. Compared to PEEPARDSNET, at PEEPINCREMENTAL level (22 ± 3 cm H2O) lung volume increased (977 ± 708 ml), lung elastance decreased (23 ± 7 cm H2O/l), lung collapse decreased (18 ± 10%), and ventilation homogeneity increased thus rising oxygenation (251 ± 105 mmHg), despite higher overdistension levels (16 ± 12%), all values P < 0.05 versus PEEPARDSnet. Setting PEEP according to a PEEPDECREMENTAL trial after a recruitment maneuver (21 ± 4 cm H2O, P = 0.99 vs. PEEPINCREMENTAL) further lowered lung elastance (19 ± 6 cm H2O/l) and increased oxygenation (329 ± 82 mmHg) while reducing lung collapse (9 ± 2%) and overdistension (11 ± 2%), all values P < 0.05 versus PEEPARDSnet and PEEPINCREMENTAL. All patients were maintained on titrated PEEP levels up to 24 h without hemodynamic or ventilation related complications. CONCLUSIONS Among the PEEP titration strategies tested, setting PEEP according to a PEEPDECREMENTAL trial preceded by a recruitment maneuver obtained the best lung function by decreasing lung overdistension and collapse, restoring lung elastance, and oxygenation suggesting lung tissue recruitment.
Collapse
|
20
|
Widing CH, Pellegrini M, Larsson A, Perchiazzi G. The Effects of Positive End-Expiratory Pressure on Transpulmonary Pressure and Recruitment-Derecruitment During Neurally Adjusted Ventilator Assist: A Continuous Computed Tomography Study in an Animal Model of Acute Respiratory Distress Syndrome. Front Physiol 2019; 10:1392. [PMID: 31824326 PMCID: PMC6882775 DOI: 10.3389/fphys.2019.01392] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 10/28/2019] [Indexed: 01/22/2023] Open
Abstract
Background Whether spontaneous breathing (SB) should be used in early acute respiratory distress syndrome (ARDS) is questioned because it may cause ventilator-induced lung injury (VILI) by tidal high strain/stress and recruitment/derecruitment (R/D). However, SB has shown beneficial effects when used appropriately. We hypothesized that high levels of positive end-expiratory pressure (PEEP), during assisted SB, would prevent tidal R/D, reducing ventilatory variation and respiratory rate while potentially increasing transpulmonary pressure (PTP). The aim was to test this hypothesis in experimental mild ARDS during continuous SB using neurally adjusted ventilator assist (NAVA) and uninterrupted computed tomography (CT) exposure. Methods Mild experimental ARDS (PaO2/FiO2-ratio of 250) was induced in anesthetized pigs (n = 5), ventilated using uninterrupted NAVA. PEEP was changed in steps of 3 cmH2O, from 0 to 15 and back to 0 cmH2O. Dynamic CT scans, ventilatory parameters, and esophageal pressure were acquired simultaneously. PTP and R/D were calculated and compared among PEEP levels. Results When increasing PEEP from 0 to 15 cmH2O, tidal R/D decreased from 4.3 ± 5.9 to 1.1 ± 0.7% (p < 0.01), breath-to-breath variability decreased, and PTP increased from 11.4 ± 3.7 to 29.7 ± 14.1 cmH2O (R2 = 0.96). Conclusion This study shows that injurious phenomena like R/D and high PTP are present in NAVA at the two extremes of the PEEP spectrum. Willing to titrate PEEP to limit these phenomena, the physician must choose the best compromise between restraining the R/D or PTP.
Collapse
Affiliation(s)
- Carl Hannes Widing
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.,NU-Hospital Organization, Trollhättan, Sweden
| | - Mariangela Pellegrini
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.,Department of Anaesthesia and Intensive Care Medicine, Uppsala University Hospital, Uppsala, Sweden
| | - Anders Larsson
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.,Department of Anaesthesia and Intensive Care Medicine, Uppsala University Hospital, Uppsala, Sweden
| | - Gaetano Perchiazzi
- Hedenstierna Laboratory, Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.,Department of Anaesthesia and Intensive Care Medicine, Uppsala University Hospital, Uppsala, Sweden
| |
Collapse
|
21
|
Arnal JM, Saoli M, Garnero A. Airway and transpulmonary driving pressures and mechanical powers selected by INTELLiVENT-ASV in passive, mechanically ventilated ICU patients. Heart Lung 2019; 49:427-434. [PMID: 31733881 DOI: 10.1016/j.hrtlng.2019.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 10/31/2019] [Accepted: 11/01/2019] [Indexed: 01/27/2023]
Abstract
BACKGROUND Driving pressure (ΔP) and mechanical power (MP) are predictors of the risk of ventilation- induced lung injuries (VILI) in mechanically ventilated patients. INTELLiVENT-ASV® is a closed-loop ventilation mode that automatically adjusts respiratory rate and tidal volume, according to the patient's respiratory mechanics. OBJECTIVES This prospective observational study investigated ΔP and MP (and also transpulmonary ΔP (ΔPL) and MP (MPL) for a subgroup of patients) delivered by INTELLiVENT-ASV. METHODS Adult patients admitted to the ICU were included if they were sedated and met the criteria for a single lung condition (normal lungs, COPD, or ARDS). INTELLiVENT-ASV was used with default target settings. If PEEP was above 16 cmH2O, the recruitment strategy used transpulmonary pressure as a reference, and ΔPL and MPL were computed. Measurements were made once for each patient. RESULTS Of the 255 patients included, 98 patients were classified as normal-lungs, 28 as COPD, and 129 as ARDS patients. The median ΔP was 8 (7 - 10), 10 (8 - 12), and 9 (8 - 11) cmH2O for normal-lungs, COPD, and ARDS patients, respectively. The median MP was 9.1 (4.9 - 13.5), 11.8 (8.6 - 16.5), and 8.8 (5.6 - 13.8) J/min for normal-lungs, COPD, and ARDS patients, respectively. For the 19 patients managed with transpulmonary pressure ΔPL was 6 (4 - 7) cmH2O and MPL was 3.6 (3.1 - 4.4) J/min. CONCLUSIONS In this short term observation study, INTELLiVENT-ASV selected ΔP and MP considered in safe ranges for lung protection. In a subgroup of ARDS patients, the combination of a recruitment strategy and INTELLiVENT-ASV resulted in an apparently safe ΔPL and MPL.
Collapse
Affiliation(s)
- Jean-Michel Arnal
- Service de Réanimation Polyvalente, Hôpital Sainte Musse, 54 Avenue Henri Sainte Claire Deville, 83056 Toulon, France; Department of Medical Research, Hamilton Medical AG, via Crusch 8, 7402 Bonaduz, Switzerland.
| | - Mathieu Saoli
- Service de Réanimation Polyvalente, Hôpital Sainte Musse, 54 Avenue Henri Sainte Claire Deville, 83056 Toulon, France
| | - Aude Garnero
- Service de Réanimation Polyvalente, Hôpital Sainte Musse, 54 Avenue Henri Sainte Claire Deville, 83056 Toulon, France
| |
Collapse
|
22
|
Braun F, Proença M, Wendler A, Solà J, Lemay M, Thiran JP, Weiler N, Frerichs I, Becher T. Noninvasive measurement of stroke volume changes in critically ill patients by means of electrical impedance tomography. J Clin Monit Comput 2019; 34:903-911. [PMID: 31624996 DOI: 10.1007/s10877-019-00402-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 10/10/2019] [Indexed: 10/25/2022]
Abstract
Previous animal experiments have suggested that electrical impedance tomography (EIT) has the ability to noninvasively track changes in cardiac stroke volume (SV). The present study intended to reproduce these findings in patients during a fluid challenge. In a prospective observational study including critically ill patients on mechanical ventilation, SV was estimated via ECG-gated EIT before and after a fluid challenge and compared to transpulmonary thermodilution reference measurements. Relative changes in EIT-derived cardiosynchronous impedance changes in the heart ([Formula: see text]) and lung region ([Formula: see text]) were compared to changes in reference SV by assessing the concordance rate (CR) and Pearson's correlation coefficient (R). We compared 39 measurements of 20 patients. [Formula: see text] did not show to be a reliable estimate for tracking changes of SV (CR = 52.6% and R = 0.13 with P = 0.44). In contrast, [Formula: see text] showed an acceptable trending performance (CR = 94.4% and R = 0.72 with P < 0.0001). Our results indicate that ECG-gated EIT measurements of [Formula: see text] are able to noninvasively monitor changes in SV during a fluid challenge in critically ill patients. However, this was not possible using [Formula: see text]. The present approach is limited by the influences induced by ventilation, posture or changes in electrode-skin contact and requires further validation.
Collapse
Affiliation(s)
- Fabian Braun
- Centre Suisse d'Electronique et de Microtechnique (CSEM SA), Rue Jaquet-Droz 1, 2002, Neuchâtel, Switzerland. .,Signal Processing Laboratory LTS5, Swiss Federal Institute of Technology in Lausanne (EPFL), Lausanne, Switzerland.
| | - Martin Proença
- Centre Suisse d'Electronique et de Microtechnique (CSEM SA), Rue Jaquet-Droz 1, 2002, Neuchâtel, Switzerland.,Signal Processing Laboratory LTS5, Swiss Federal Institute of Technology in Lausanne (EPFL), Lausanne, Switzerland
| | - Anna Wendler
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Josep Solà
- Centre Suisse d'Electronique et de Microtechnique (CSEM SA), Rue Jaquet-Droz 1, 2002, Neuchâtel, Switzerland
| | - Mathieu Lemay
- Centre Suisse d'Electronique et de Microtechnique (CSEM SA), Rue Jaquet-Droz 1, 2002, Neuchâtel, Switzerland
| | - Jean-Phillipe Thiran
- Signal Processing Laboratory LTS5, Swiss Federal Institute of Technology in Lausanne (EPFL), Lausanne, Switzerland.,Department of Radiology, University Hospital Center and University of Lausanne, Lausanne, Switzerland
| | - Norbert Weiler
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Inéz Frerichs
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| | - Tobias Becher
- Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany
| |
Collapse
|
23
|
Ruiz Ferrón F, Serrano Simón J. La monitorización convencional no es suficiente para valorar el esfuerzo respiratorio durante la ventilación asistida. Med Intensiva 2019; 43:197-206. [DOI: 10.1016/j.medin.2018.02.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 01/25/2018] [Accepted: 02/14/2018] [Indexed: 12/28/2022]
|
24
|
Russotto V, Bellani G, Foti G. Respiratory mechanics in patients with acute respiratory distress syndrome. ANNALS OF TRANSLATIONAL MEDICINE 2018; 6:382. [PMID: 30460256 DOI: 10.21037/atm.2018.08.32] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Despite the recognition of its iatrogenic potential, mechanical ventilation remains the mainstay of respiratory support for patients with acute respiratory distress syndrome (ARDS). The low volume ventilation has been recognized as the only method to reduce mortality of ARDS patients and plateau pressure as the lighthouse for delivering safe ventilation. Recent investigations suggest that a ventilation based on lung mechanics (tidal ventilation tailored to the available lung volume able to receive it, i.e., driving pressure) is a successful approach to improve outcome. However, currently available bedside mechanical variables do not consider regional mechanical properties of ARDS affected lungs, which include the role of local stress risers at the boundaries of areas with different aeration. A unifying approach considers lung-related causes and ventilation-related causes of lung injury. These last may be incorporated in the mechanical power (i.e., amount of mechanical energy transferred per unit of time). Ventilation-induced lung injury (which includes the self-inflicted lung injury of a spontaneously breathing patient) can therefore be prevented by the adoption of measures promoting an increase of ventilable lung and its homogeneity and by delivering lower levels of mechanical power. Prone position promotes lung homogeneity without increasing the delivered mechanical power. This review describes the recent developments on respiratory mechanics in ARDS patients, providing both bedside and research insights from the most updated evidence.
Collapse
Affiliation(s)
- Vincenzo Russotto
- Department of Emergency and Intensive Care, University Hospital San Gerardo, Monza, Italy
| | - Giacomo Bellani
- Department of Emergency and Intensive Care, University Hospital San Gerardo, Monza, Italy.,University of Milano Bicocca, Milano, Italy
| | - Giuseppe Foti
- Department of Emergency and Intensive Care, University Hospital San Gerardo, Monza, Italy.,University of Milano Bicocca, Milano, Italy
| |
Collapse
|
25
|
Obi ON, Mazer M, Bangley C, Kassabo Z, Saadah K, Trainor W, Stephens K, Rice PL, Shaw R. Obesity and Weaning from Mechanical Ventilation-An Exploratory Study. CLINICAL MEDICINE INSIGHTS-CIRCULATORY RESPIRATORY AND PULMONARY MEDICINE 2018; 12:1179548418801004. [PMID: 30245572 PMCID: PMC6144576 DOI: 10.1177/1179548418801004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 08/22/2018] [Indexed: 12/25/2022]
Abstract
Introduction Obesity is associated with increased risk of hypercapnic respiratory failure, prolonged duration on mechanical ventilation, and extended weaning periods. Objective Pilot study to determine whether morbidly obese adult tracheotomized subjects (body mass index [BMI] ⩾ 40) can be more efficiently weaned from the ventilator by optimizing their positive end-expiratory pressure (PEEP) using either an esophageal balloon or the best achieved static effective compliance. Methods We randomly assigned 25 morbidly obese adult tracheotomized subjects (median [interquartile range] BMI 53.4 [26.4]; range 40.4-113.8) to 1 of 2 methods of setting PEEP; using either titration guided by esophageal balloon to overcome negative transpulmonary pressure (Ptp) (goal Ptp 0-5 cmH2O) (ESO group) or titration to maximize static effective lung compliance (Cstat group). Our outcomes of interest were number of subjects weaned by day 30 and time to wean. Results At day 30, there was no significant difference in percentage of subjects weaned. 8/13 subjects (62%) in the ESO Group were weaned vs. 9/12(75%) in the Cstat Group (P = 0.67). Among the 17 subjects who weaned, median time to ventilator liberation was significantly shorter in the ESO group: 3.5 days vs Cstat group 14 days (P = .01). Optimal PEEP in the ESO and Cstat groups was similar (ESO mean ± SD = 26.5 ± 5.7 cmH2O and Cstat 24.2 ± 7 cmH2O (P = .38). Conclusions Optimization of PEEP using esophageal balloon to achieve positive transpulmonary pressure did not change the proportion of patients weaned. Among patients who weaned, use of the esophageal balloon resulted in faster liberation from mechanical ventilation. There were no adverse consequences of the high PEEP (mean 25.4; range 13-37 cmH2O) used in our study. The study was approved by the Institutional Review Board at our institution (UMCIRB#10-0343) and registered with clinicaltrials.gov (NCT02323009).
Collapse
Affiliation(s)
- Ogugua Ndili Obi
- Division of Pulmonary, Critical Care, and Sleep Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Mark Mazer
- Division of Pulmonary, Critical Care, and Sleep Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Charles Bangley
- Department of Respiratory Care, Vidant Medical Center, Greenville, NC, USA
| | - Zuheir Kassabo
- Division of Pulmonary, Critical Care, and Sleep Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Khalid Saadah
- Division of Pulmonary, Critical Care, and Sleep Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Wayne Trainor
- Department of Respiratory Care, Vidant Medical Center, Greenville, NC, USA
| | - Kenneth Stephens
- Department of Respiratory Care, Vidant Medical Center, Greenville, NC, USA
| | - Patricia L Rice
- Division of Pulmonary, Critical Care, and Sleep Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Robert Shaw
- Division of Pulmonary, Critical Care, and Sleep Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| |
Collapse
|
26
|
Becher T, Schädler D, Rostalski P, Zick G, Frerichs I, Weiler N. Determination of respiratory system compliance during pressure support ventilation by small variations of pressure support. J Clin Monit Comput 2017; 32:741-751. [DOI: 10.1007/s10877-017-0063-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 09/16/2017] [Indexed: 10/18/2022]
|
27
|
Vicario F, Buizza R, Truschel WA, Chbat NW. Noninvasive estimation of alveolar pressure. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2016:2721-2724. [PMID: 28268882 DOI: 10.1109/embc.2016.7591292] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This paper presents an algorithm for noninvasive estimation of alveolar pressure in mechanically ventilated patients who are spontaneously breathing. Continual monitoring of alveolar pressure is desirable to prevent ventilator-induced lung injury and to assess the intrinsic positive end-expiratory pressure (PEEPi), which is a parameter of clinical relevance in respiratory care and difficult to measure noninvasively. The algorithm is based on a physiological model of the respiratory system and, as such, it also provides insight into the respiratory mechanics of the patient under mechanical ventilation. In particular, the algorithm allows one to correctly estimate other clinical parameters of interest such as the patient's respiratory resistance and elastance, even in the presence of PEEPi.
Collapse
|
28
|
Perchiazzi G, Rylander C, Pellegrini M, Larsson A, Hedenstierna G. Robustness of two different methods of monitoring respiratory system compliance during mechanical ventilation. Med Biol Eng Comput 2017; 55:1819-1828. [PMID: 28243966 PMCID: PMC5603635 DOI: 10.1007/s11517-017-1631-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 02/18/2017] [Indexed: 11/24/2022]
Abstract
Robustness measures the performance of estimation methods when they work under non-ideal conditions. We compared the robustness of artificial neural networks (ANNs) and multilinear fitting (MLF) methods in estimating respiratory system compliance (CRS) during mechanical ventilation (MV). Twenty-four anaesthetized pigs underwent MV. Airway pressure, flow and volume were recorded at fixed intervals after the induction of acute lung injury. After consecutive mechanical breaths, an inspiratory pause (BIP) was applied in order to calculate CRS using the interrupter technique. From the breath preceding the BIP, ANN and MLF had to compute CRS in the presence of two types of perturbations: transient sensor disconnection (TD) and random noise (RN). Performance of the two methods was assessed according to Bland and Altman. The ANN presented a higher bias and scatter than MLF during the application of RN, except when RN was lower than 2% of peak airway pressure. During TD, MLF algorithm showed a higher bias and scatter than ANN. After the application of RN, ANN and MLF maintain a stable performance, although MLF shows better results. ANNs have a more stable performance and yield a more robust estimation of CRS than MLF in conditions of transient sensor disconnection.
Collapse
Affiliation(s)
- Gaetano Perchiazzi
- Department of Emergency and Organ Transplant, Bari University, Bari, Italy. .,Hedenstierna Laboratory, Surgical Sciences, Uppsala University, Akademiska Sjukhuset ing.40 tr.3, 75185, Uppsala, Sweden.
| | - Christian Rylander
- Department of Anaesthesia and Intensive Care Medicine, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Mariangela Pellegrini
- Department of Emergency and Organ Transplant, Bari University, Bari, Italy.,Hedenstierna Laboratory, Surgical Sciences, Uppsala University, Akademiska Sjukhuset ing.40 tr.3, 75185, Uppsala, Sweden
| | - Anders Larsson
- Hedenstierna Laboratory, Surgical Sciences, Uppsala University, Akademiska Sjukhuset ing.40 tr.3, 75185, Uppsala, Sweden
| | - Göran Hedenstierna
- Hedenstierna Laboratory, Medical Sciences, Uppsala University, Uppsala, Sweden
| |
Collapse
|
29
|
Gil Cano A, Gracia Romero M, Monge García MI, Guijo González P, Ruiz Campos J. Preemptive hemodynamic intervention restricting the administration of fluids attenuates lung edema progression in oleic acid-induced lung injury. Med Intensiva 2016; 41:135-142. [PMID: 27986329 DOI: 10.1016/j.medin.2016.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 07/04/2016] [Accepted: 08/03/2016] [Indexed: 11/28/2022]
Abstract
OBJECTIVE A study is made of the influence of preemptive hemodynamic intervention restricting fluid administration upon the development of oleic acid-induced lung injury. DESIGN A randomized in vivo study in rabbits was carried out. SETTING University research laboratory. SUBJECTS Sixteen anesthetized, mechanically ventilated rabbits. VARIABLES Hemodynamic measurements obtained by transesophageal Doppler signal. Respiratory mechanics computed by a least square fitting method. Lung edema assessed by the ratio of wet weight to dry weight of the right lung. Histological examination of the left lung. INTERVENTIONS Animals were randomly assigned to either the early protective lung strategy (EPLS) (n=8) or the early protective hemodynamic strategy (EPHS) (n=8). In both groups, lung injury was induced by the intravenous infusion of oleic acid (OA) (0.133mlkg-1h-1 for 2h). At the same time, the EPLS group received 15mlkg-1h-1 of Ringer lactate solution, while the EPHS group received 30mlkg-1h-1. Measurements were obtained at baseline and 1 and 2h after starting OA infusion. RESULTS After 2h, the cardiac index decreased in the EPLS group (p<0.05), whereas in the EPHS group it remained unchanged. Lung compliance decreased significantly only in the EPHS group (p<0.05). Lung edema was greater in the EPHS group (p<0.05). Histological damage proved similar in both groups (p=0.4). CONCLUSIONS In this experimental model of early lung injury, lung edema progression was attenuated by preemptively restricting the administration of fluids.
Collapse
Affiliation(s)
- A Gil Cano
- Laboratorio de Investigación Experimental, Unidad de Gestión Clínica de Medicina Intensiva, Hospital del SAS de Jerez, Jerez de la Frontera, Cádiz, Spain.
| | - M Gracia Romero
- Laboratorio de Investigación Experimental, Unidad de Gestión Clínica de Medicina Intensiva, Hospital del SAS de Jerez, Jerez de la Frontera, Cádiz, Spain
| | - M I Monge García
- Laboratorio de Investigación Experimental, Unidad de Gestión Clínica de Medicina Intensiva, Hospital del SAS de Jerez, Jerez de la Frontera, Cádiz, Spain
| | - P Guijo González
- Laboratorio de Investigación Experimental, Unidad de Gestión Clínica de Medicina Intensiva, Hospital del SAS de Jerez, Jerez de la Frontera, Cádiz, Spain
| | - J Ruiz Campos
- Servicio de Anatomía Patológica, Hospital del SAS de Jerez, Jerez de la Frontera, Cádiz, Spain
| |
Collapse
|
30
|
Spaeth J, Ott M, Karzai W, Grimm A, Wirth S, Schumann S, Loop T. Double-lumen tubes and auto-PEEP during one-lung ventilation. Br J Anaesth 2016; 116:122-30. [DOI: 10.1093/bja/aev398] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
31
|
Spadaro S, Grasso S, Cricca V, Dalla Corte F, Di Mussi R, Biondi G, Valpiani G, Zardi S, Romanello A, Marangoni E, Volta CA. Comparing two different modes of mechanical ventilation by the least square fitting method: nava versus PSV. Intensive Care Med Exp 2015. [PMCID: PMC4797029 DOI: 10.1186/2197-425x-3-s1-a319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
32
|
Chiew YS, Pretty C, Docherty PD, Lambermont B, Shaw GM, Desaive T, Chase JG. Time-varying respiratory system elastance: a physiological model for patients who are spontaneously breathing. PLoS One 2015; 10:e0114847. [PMID: 25611069 PMCID: PMC4303416 DOI: 10.1371/journal.pone.0114847] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 11/14/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Respiratory mechanics models can aid in optimising patient-specific mechanical ventilation (MV), but the applications are limited to fully sedated MV patients who have little or no spontaneously breathing efforts. This research presents a time-varying elastance (E(drs)) model that can be used in spontaneously breathing patients to determine their respiratory mechanics. METHODS A time-varying respiratory elastance model is developed with a negative elastic component (E(demand)), to describe the driving pressure generated during a patient initiated breathing cycle. Data from 22 patients who are partially mechanically ventilated using Pressure Support (PS) and Neurally Adjusted Ventilatory Assist (NAVA) are used to investigate the physiology relevance of the time-varying elastance model and its clinical potential. E(drs) of every breathing cycle for each patient at different ventilation modes are presented for comparison. RESULTS At the start of every breathing cycle initiated by patient, E(drs) is < 0. This negativity is attributed from the E(demand) due to a positive lung volume intake at through negative pressure in the lung compartment. The mapping of E(drs) trajectories was able to give unique information to patients' breathing variability under different ventilation modes. The area under the curve of E(drs) (AUCE(drs)) for most patients is > 25 cmH2Os/l and thus can be used as an acute respiratory distress syndrome (ARDS) severity indicator. CONCLUSION The E(drs) model captures unique dynamic respiratory mechanics for spontaneously breathing patients with respiratory failure. The model is fully general and is applicable to both fully controlled and partially assisted MV modes.
Collapse
Affiliation(s)
- Yeong Shiong Chiew
- Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand
- * E-mail:
| | - Christopher Pretty
- Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand
| | - Paul D. Docherty
- Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand
| | | | - Geoffrey M. Shaw
- Department of Intensive Care, Christchurch Hospital, Christchurch, New Zealand
| | - Thomas Desaive
- GIGA Cardiovascular Science, University of Liege, Liege, Belgium
| | - J. Geoffrey Chase
- Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand
| |
Collapse
|
33
|
Vicario F, Albanese A, Karamolegkos N, Wang D, Seiver A, Chbat N. Noninvasive Estimation of Respiratory Mechanics in Spontaneously Breathing Ventilated Patients: A Constrained Optimization Approach. IEEE Trans Biomed Eng 2015; 63:775-87. [DOI: 10.1109/tbme.2015.2470641] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
34
|
Dalla Corte F, Spadaro S, Grasso S, Cricca V, Biondi G, Fogagnolo A, Valpiani G, Di Mussi R, Bertacchini S, Colamussi MV, Marangoni E, Volta CA. VALIDATION OF THE LEAST SQUARES FITTING METHOD (LSF) DURING NAVA AND PSV VENTILATION. Intensive Care Med Exp 2015. [PMCID: PMC4796464 DOI: 10.1186/2197-425x-3-s1-a1005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
35
|
Assessment of respiratory system compliance with electrical impedance tomography using a positive end-expiratory pressure wave maneuver during pressure support ventilation: a pilot clinical study. Crit Care 2014; 18:679. [PMID: 25492307 PMCID: PMC4301036 DOI: 10.1186/s13054-014-0679-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 11/19/2014] [Indexed: 11/10/2022] Open
Abstract
Introduction Assessment of respiratory system compliance (Crs) can be used for individual optimization of positive end-expiratory pressure (PEEP). However, in patients with spontaneous breathing activity, the conventional methods for Crs measurement are inaccurate because of the variable muscular pressure of the patient. We hypothesized that a PEEP wave maneuver, analyzed with electrical impedance tomography (EIT), might be suitable for global and regional assessment of Crs during assisted spontaneous breathing. Methods After approval of the local ethics committee, we performed a pilot clinical study in 18 mechanically ventilated patients (61 ± 16 years (mean ± standard deviation)) who were suitable for weaning with pressure support ventilation (PSV). For the PEEP wave, PEEP was elevated by 1 cmH2O after every fifth breath during PSV. This was repeated five times, until a total PEEP increase of 5 cmH2O was reached. Subsequently, PEEP was reduced in steps of 1 cmH2O in the same manner until the original PEEP level was reached. Crs was calculated using EIT from the global, ventral and dorsal lung regions of interest. For reference measurements, all patients were also examined during controlled mechanical ventilation (CMV) with a low-flow pressure-volume maneuver. Global and regional Crs(low-flow) was calculated as the slope of the pressure-volume loop between the pressure that corresponded to the selected PEEP and PEEP +5 cmH2O. For additional reference, Crs during CMV (Crs(CMV)) was calculated as expired tidal volume divided by the difference between airway plateau pressure and PEEP. Results Respiratory system compliance calculated from the PEEP wave (Crs(PEEP wave)) correlated closely with both reference measurements (r = 0.79 for Crs(low-flow) and r = 0.71 for Crs(CMV)). No significant difference was observed between the mean Crs(PEEP wave) and the mean Crs(low-flow). However, a significant bias of +17.1 ml/cmH2O was observed between Crs(PEEP wave) and Crs(CMV). Conclusion Analyzing a PEEP wave maneuver with EIT allows calculation of global and regional Crs during assisted spontaneous breathing. In mechanically ventilated patients with spontaneous breathing activity, this method might be used for assessment of the global and regional mechanical properties of the respiratory system. Electronic supplementary material The online version of this article (doi:10.1186/s13054-014-0679-6) contains supplementary material, which is available to authorized users.
Collapse
|
36
|
Bradbrook CA, Clark L, Dugdale AHA, Burford J, Mosing M. Reply to the letter to the editor regarding Bradbrook et al. (2013). Vet Anaesth Analg 2014; 41:333-4. [PMID: 24673967 DOI: 10.1111/vaa.12153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
37
|
Bradbrook CA, Clark L, Dugdale AHA, Burford J, Mosing M. Measurement of respiratory system compliance and respiratory system resistance in healthy dogs undergoing general anaesthesia for elective orthopaedic procedures. Vet Anaesth Analg 2013; 40:382-9. [DOI: 10.1111/j.1467-2995.2012.00778.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
38
|
Zhao Z, Eger M, Handzsuj T, Ranieri VM, Appendini L, Micelli C, Moller K. Noninvasive method for measuring respiratory system compliance during pressure support ventilation. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2012; 2011:3808-11. [PMID: 22255169 DOI: 10.1109/iembs.2011.6090772] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
PURPOSE To date, few methods have been accepted for assessing the respiratory system compliance (C(rs)) in patients under assisted ventilation at the bedside. The aim of this study was to evaluate our adaptive time slice method (ATSM) to continuously calculate the C(rs). METHODS One breath is divided into several time periods (slices). For each slice, a compliance value C(i) is calculated. The slice width is adapted according to the confidence interval of C(i). After all C(i) values are obtained and the outliers are eliminated, the C(rs) of this breath is calculated as the mean value of the remainder of C(i)'s. Seven patients with Chronic Obstructive Pulmonary Disease were evaluated during pressure support ventilation. The results are compared with the values calculated with the transdiaphragmatic pressure (P(di)). RESULTS 95 ± 4% of the recorded data could be analyzed with ATSM. In 6 patients out of 7, the results delivered with ATSM and with P(di) had similar variation (standard deviation) and accuracy (difference<20%). They were strongly correlated (weighted correlation coefficient = 0.86, p<10(-5)) with a mean difference of 3.22 ml/mbar. CONCLUSIONS The ATSM is a robust method and able to provide accurate C(rs) in spontaneously breathing patients during pressure support ventilation noninvasively without extra instrumentation or complicated maneuvers.
Collapse
Affiliation(s)
- Zhanqi Zhao
- Department of Biomedical Engineering, Furtwangen University, D-78054 VS-Schwenningen, Germany.
| | | | | | | | | | | | | |
Collapse
|
39
|
Arnal JM, Wysocki M, Novotni D, Demory D, Lopez R, Donati S, Granier I, Corno G, Durand-Gasselin J. Safety and efficacy of a fully closed-loop control ventilation (IntelliVent-ASV®) in sedated ICU patients with acute respiratory failure: a prospective randomized crossover study. Intensive Care Med 2012; 38:781-7. [PMID: 22460854 DOI: 10.1007/s00134-012-2548-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 02/28/2012] [Indexed: 01/11/2023]
Abstract
PURPOSE IntelliVent-ASV(®) is a development of adaptive support ventilation (ASV) that automatically adjusts ventilation and oxygenation parameters. This study assessed the safety and efficacy of IntelliVent-ASV(®) in sedated intensive care unit (ICU) patients with acute respiratory failure. METHODS This prospective randomized crossover comparative study was conducted in a 12-bed ICU in a general hospital. Two periods of 2 h of ventilation in randomly applied ASV or IntelliVent-ASV(®) were compared in 50 sedated, passively ventilated patients. Tidal volume (V(T)), respiratory rate (RR), inspiratory pressure (P(INSP)), SpO(2) and E(T)CO(2) were continuously monitored and recorded breath by breath. Mean values over the 2-h period were calculated. Respiratory mechanics, plateau pressure (P(PLAT)) and blood gas exchanges were measured at the end of each period. RESULTS There was no safety issue requiring premature interruption of IntelliVent-ASV(®). Minute ventilation (MV) and V(T) decreased from 7.6 (6.5-9.5) to 6.8 (6.0-8.0) L/min (p < 0.001) and from 8.3 (7.8-9.0) to 8.1 (7.7-8.6) mL/kg PBW (p = 0.003) during IntelliVent-ASV(®) as compared to ASV. P(PLAT) and FiO(2) decreased from 24 (20-29) to 20 (19-25) cmH(2)O (p = 0.005) and from 40 (30-50) to 30 (30-39) % (p < 0.001) during IntelliVent-ASV(®) as compared to ASV. RR, P(INSP), and PEEP decreased as well during IntelliVent-ASV(®) as compared to ASV. Respiratory mechanics, pH, PaO(2) and PaO(2)/FiO(2) ratio were not different but PaCO(2) was slightly higher during IntelliVent-ASV(®) as compared to ASV. CONCLUSIONS In passive patients with acute respiratory failure, IntelliVent-ASV(®) was safe and able to ventilate patients with less pressure, volume and FiO(2) while producing the same results in terms of oxygenation.
Collapse
Affiliation(s)
- Jean-Michel Arnal
- Intensive Care Unit, Hôpital Font Pré, 1208 avenue du colonel Picot, 83100, Toulon, France.
| | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Nassar BS, Collett ND, Schmidt GA. The flow-time waveform predicts respiratory system resistance and compliance. J Crit Care 2012; 27:418.e7-14. [PMID: 22226421 DOI: 10.1016/j.jcrc.2011.10.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 09/28/2011] [Accepted: 10/31/2011] [Indexed: 02/09/2023]
Abstract
PURPOSE Knowledge of patients' lung compliance and resistance aids clinical management. We investigated whether these values, readily measured during volume assist-control ventilation (VACV), could also be estimated during pressure assist-control ventilation (PACV). METHODS Data were collected in 12 mechanically ventilated human subjects. During VACV, peak pressure, plateau pressure, end-expiratory pressure, tidal volume, and inspiratory flow rate were measured. During PACV, inspiratory pressure, end-expiratory pressure, and tidal volume were recorded. The linear component of the pressure-time waveform was extrapolated to time and flow axes. Using the equation of motion for the respiratory system, assuming a nonlinear resistance, we calculated inspiratory resistance and compliance. During VACV, compliance and inspiratory resistance were calculated in the conventional manner. RESULTS In ventilated subjects, mean compliance during PACV was 37.06 ± 15.65 mL/cm H(2)O, and during VACV, 36.93 ± 12.18 mL/cm H(2)O. Mean inspiratory resistance during PACV was 15.17 ± 5.14 cm H(2)O/L per second, whereas during VACV, it was 12.50 ± 2.99 cm H(2)O/L per second. A strong correlation is evident between compliance and inspiratory resistance calculated during PACV vs VACV (r(2) of 0.73 and 0.51, respectively). CONCLUSIONS During PACV, the inspiratory flow waveform is linear, and its slope contains information regarding inspiratory resistance and compliance. Calculated values correlate with those during VACV.
Collapse
Affiliation(s)
- Boulos S Nassar
- Division of Pulmonary, Critical Care, and Occupational Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA.
| | | | | |
Collapse
|
41
|
Zhao Z, Guttmann J, Möller K. Adaptive SLICE method: an enhanced method to determine nonlinear dynamic respiratory system mechanics. Physiol Meas 2011; 33:51-64. [PMID: 22155927 DOI: 10.1088/0967-3334/33/1/51] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The objective of this paper is to introduce and evaluate the adaptive SLICE method (ASM) for continuous determination of intratidal nonlinear dynamic compliance and resistance. The tidal volume is subdivided into a series of volume intervals called slices. For each slice, one compliance and one resistance are calculated by applying a least-squares-fit method. The volume window (width) covered by each slice is determined based on the confidence interval of the parameter estimation. The method was compared to the original SLICE method and evaluated using simulation and animal data. The ASM was also challenged with separate analysis of dynamic compliance during inspiration. If the signal-to-noise ratio (SNR) in the respiratory data decreased from +∞ to 10 dB, the relative errors of compliance increased from 0.1% to 22% for the ASM and from 0.2% to 227% for the SLICE method. Fewer differences were found in resistance. When the SNR was larger than 40 dB, the ASM delivered over 40 parameter estimates (42.2 ± 1.3). When analyzing the compliance during inspiration separately, the estimates calculated with the ASM were more stable. The adaptive determination of slice bounds results in consistent and reliable parameter values. Online analysis of nonlinear respiratory mechanics will profit from such an adaptive selection of interval size.
Collapse
Affiliation(s)
- Zhanqi Zhao
- Department of Biomedical Engineering, Furtwangen University, Jakob-Kienzle Straße 17, D-78054, Villingen-Schwenningen, Germany.
| | | | | |
Collapse
|
42
|
Henderson WR, Sheel AW. Pulmonary mechanics during mechanical ventilation. Respir Physiol Neurobiol 2011; 180:162-72. [PMID: 22154694 DOI: 10.1016/j.resp.2011.11.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 11/16/2011] [Accepted: 11/23/2011] [Indexed: 10/14/2022]
Abstract
The use of mechanical ventilation has become widespread in the management of hypoxic respiratory failure. Investigations of pulmonary mechanics in this clinical scenario have demonstrated that there are significant differences in compliance, resistance and gas flow when compared with normal subjects. This paper will review the mechanisms by which pulmonary mechanics are assessed in mechanically ventilated patients and will review how the data can be used for investigative research purposes as well as to inform rational ventilator management.
Collapse
Affiliation(s)
- William R Henderson
- Program of Critical Care Medicine, University of British Columbia, Vancouver, BC, Canada.
| | | |
Collapse
|
43
|
Arnal JM, Paquet J, Wysocki M, Demory D, Donati S, Granier I, Corno G, Durand-Gasselin J. Optimal duration of a sustained inflation recruitment maneuver in ARDS patients. Intensive Care Med 2011; 37:1588-94. [PMID: 21858522 DOI: 10.1007/s00134-011-2323-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2010] [Accepted: 04/28/2011] [Indexed: 12/28/2022]
Abstract
PURPOSE To measure the dynamics of recruitment and the hemodynamic status during a sustained inflation recruitment maneuver (RM) in order to determine the optimal duration of RM in acute respiratory distress syndrome (ARDS) patients. METHODS This prospective study was conducted in a 12-bed intensive care unit (ICU) in a general hospital. A 40 cmH(2)O sustained inflation RM maintained for 30 s was performed in 50 sedated ventilated patients within the first 24 h of meeting ARDS criteria. Invasive arterial pressures, heart rate, and SpO(2) were measured at 10-s intervals during the RM. The volume increase during the RM was measured by integration of the flow required to maintain the pressure at 40 cmH(2)O, which provides an estimation of the volume recruited during the RM. Raw data were corrected for gas consumption and fitted with an exponential curve in order to determine an individual time constant for the volume increase. RESULTS The average volume increase and time constant were 210 ± 198 mL and 2.3 ± 1.3 s, respectively. Heart rate, diastolic arterial pressure, and SpO(2) did not change during or after the RM. Systolic and mean arterial pressures were maintained at 10 s, decreased significantly at 20 and 30 s during the RM, and recovered to the pre-RM value 30 s after the end of the RM (ANOVA, p < 0.01). CONCLUSIONS In early-onset ARDS patients, most of the recruitment occurs during the first 10 s of a sustained inflation RM. However, hemodynamic impairment is significant after the tenth second of RM.
Collapse
Affiliation(s)
- Jean-Michel Arnal
- Service de Réanimation Polyvalente, Hôpital Font Pré, 1208 Avenue du Colonel Picot, 83100 Toulon, France.
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Scholz AW, Weiler N, David M, Markstaller K. Respiratory mechanics measured by forced oscillations during mechanical ventilation through a tracheal tube. Physiol Meas 2011; 32:571-83. [PMID: 21454925 DOI: 10.1088/0967-3334/32/5/006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The forced oscillation technique (FOT) allows the measurement of respiratory mechanics in the intensive care setting. The aim of this study was to compare the FOT with a reference method during mechanical ventilation through a tracheal tube. The respiratory impedance spectra were measured by FOT in nine anaesthetized pigs, and resistance and compliance were estimated on the basis of a linear resistance-compliance inertance model. In comparison, resistance and compliance were quantified by the multiple linear regression analysis (LSF) of conventional ventilator waveforms to the equation of motion. The resistance of the sample was found to range from 6 to 21 cmH(2)O s l(-1) and the compliance from 12 to 32 ml cmH(2)O(-1). A Bland-Altman analysis of the resistance resulted in a sufficient agreement (bias -0.4 cmH(2)O s l(-1); standard deviation of differences 1.4 cmH(2)O s l(-1); correlation coefficient 0.93) and test-retest reliability (coefficient of variation of repeated measurements: FOT 2.1%; LSF 1.9%). The compliance, however, was poor in agreement (bias -8 ml cmH(2)O(-1), standard deviation of differences 7 ml cmH(2)O(-1), correlation coefficient 0.74) and repeatability (coefficient of variation: FOT 23%; LSF 1.7%). In conclusion, FOT provides an alternative for monitoring resistance, but not compliance, in tracheally intubated and ventilated subjects.
Collapse
Affiliation(s)
- Alexander-Wigbert Scholz
- Department of Anaesthesiology, University Medical Centre of the Johannes Gutenberg-University, 55131 Mainz, Germany.
| | | | | | | |
Collapse
|
45
|
Lee KS, Chung WY, Jung YJ, Park JH, Sheen SS, Hwang SC, Park KJ. Evaluation of Respiratory Parameters in Patients with Acute Lung Injury Receiving Adaptive Support Ventilation. Tuberc Respir Dis (Seoul) 2011. [DOI: 10.4046/trd.2011.70.1.36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Keu Sung Lee
- Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea
| | - Wou Young Chung
- Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea
| | - Yun Jung Jung
- Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea
| | - Joo Hun Park
- Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea
| | - Seung Soo Sheen
- Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea
| | - Sung Chul Hwang
- Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea
| | - Kwang Joo Park
- Department of Pulmonary and Critical Care Medicine, Ajou University School of Medicine, Suwon, Korea
| |
Collapse
|
46
|
Zhao Z, Steinmann D, Frerichs I, Guttmann J, Möller K. PEEP titration guided by ventilation homogeneity: a feasibility study using electrical impedance tomography. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:R8. [PMID: 20113520 PMCID: PMC2875520 DOI: 10.1186/cc8860] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 12/10/2009] [Accepted: 01/30/2010] [Indexed: 12/16/2022]
Abstract
Introduction Lung protective ventilation requires low tidal volume and suitable positive end-expiratory pressure (PEEP). To date, few methods have been accepted for clinical use to set the appropriate PEEP. The aim of this study was to test the feasibility of PEEP titration guided by ventilation homogeneity using the global inhomogeneity (GI) index based on electrical impedance tomography (EIT) images. Methods In a retrospective study, 10 anesthetized patients with healthy lungs mechanically ventilated under volume-controlled mode were investigated. Ventilation distribution was monitored by EIT. A standardized incremental PEEP trial (PEEP from 0 to 28 mbar, 2 mbar per step) was conducted. During the PEEP trial, "optimal" PEEP level for each patient was determined when the air was most homogeneously distributed in the lung, indicated by the lowest GI index value. Two published methods for setting PEEP were included for comparison based on the maximum global dynamic compliance and the intra-tidal compliance-volume curve. Results No significant differences in the results were observed between the GI index method (12.2 ± 4.6 mbar) and the dynamic compliance method (11.4 ± 2.3 mbar, P > 0.6), or between the GI index and the compliance-volume curve method (12.2 ± 4.9 mbar, P > 0.6). Conclusions According to the results, it is feasible and reasonable to use the GI index to select the PEEP level with respect to ventilation homogeneity. The GI index may provide new insights into the relationship between lung mechanics and tidal volume distribution and may be used to guide ventilator settings.
Collapse
Affiliation(s)
- Zhanqi Zhao
- Department of Biomedical Engineering, Furtwangen University, Jakob-Kienzle-Strasse 17, D-78054 Villingen-Schwenningen, Germany.
| | | | | | | | | |
Collapse
|
47
|
Mulqueeny Q, Tassaux D, Vignaux L, Jolliet P, Schindhelm K, Redmond S, Lovell NH. Online estimation of respiratory mechanics in non-invasive pressure support ventilation: a bench model study. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2010; 2010:2489-2492. [PMID: 21096167 DOI: 10.1109/iembs.2010.5626534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
An online algorithm for determining respiratory mechanics in patients using non-invasive ventilation (NIV) in pressure support mode was developed and embedded in a ventilator system. Based on multiple linear regression (MLR) of respiratory data, the algorithm was tested on a patient bench model under conditions with and without leak and simulating a variety of mechanics. Bland-Altman analysis indicates reliable measures of compliance across the clinical range of interest (± 11-18% limits of agreement). Resistance measures showed large quantitative errors (30-50%), however, it was still possible to qualitatively distinguish between normal and obstructive resistances. This outcome provides clinically significant information for ventilator titration and patient management.
Collapse
Affiliation(s)
- Qestra Mulqueeny
- ResMed Pty Ltd, and the Graduate School of Biomedical Engineering, University of New South Wales, Sydney 2052, Australia
| | | | | | | | | | | | | |
Collapse
|
48
|
Adaptive support ventilation for gynaecological laparoscopic surgery in Trendelenburg position: bringing ICU modes of mechanical ventilation to the operating room. Eur J Anaesthesiol 2009; 26:135-9. [PMID: 19142087 DOI: 10.1097/eja.0b013e32831aed42] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND OBJECTIVE The aim of the present study was to test the efficacy of adaptive support ventilation (ASV) to automatically adapt the ventilatory settings to the changes in the respiratory mechanics that occur during pneumoperitoneum and Trendelenburg position in gynaecological surgeries. METHODS We prospectively studied 22 ASA I women scheduled for gynaecological laparoscopic surgery in the Trendelenburg position. After intravenous induction of general anaesthesia, patients were ventilated with ASV, a closed-loop mode of mechanical ventilation based on the Otis formula, designed to automatically adapt the ventilatory settings to changes in the patient's respiratory system mechanics, while maintaining preset minute ventilation. Respiratory mechanics variables, ventilatory setting parameters and analysis of blood gases were recorded at three time points: 5 min after induction (baseline), 15 min after pneumoperitoneum and Trendelenburg positioning (Pneumo-Trend) and 15 min after pneumoperitoneum withdrawal (final). RESULTS A reduction of 44.4% in respiratory compliance and an increase of 29.1% in airway resistance were observed during the Pneumo-Trend period. Despite these changes in respiratory mechanics, minute ventilation was kept constant. ASV adapted the ventilatory settings by automatically increasing inspiratory pressure by 3.2 +/- 0.9 cmH(2)O (+19%), P < 0.01, respiratory rate by 1.3 +/- 0.5 breaths per minute (+9%) and the inspiratory to total time ratio (T(i)/T(tot)) by 43.3%. At final time, these parameters returned towards their baseline values. Adequate gas exchange was maintained throughout all periods. PaCO(2) increased moderately (+13%) from 4.4 +/- 0.6 (baseline) to 5.0 +/- 0.9 kPa (Pneumo-Trend), P < 0.01; and decreased slightly at final time (4.7 +/- 0.8 kPa), P < 0.05. Clinician's intervention was needed in only one patient who showed a moderate hypercapnia (PaCO(2) 6.9 kPa) during pneumoperitoneum. CONCLUSION In healthy women undergoing gynaecologic laparoscopy, ASV automatically adapted the ventilatory settings to the changes in the respiratory mechanics, keeping constant the preset minute ventilation, providing an adequate exchange of respiratory gases and obviating clinician's interventions.
Collapse
|
49
|
Zhao Z, Möller K, Steinmann D, Guttmann J. Global and local inhomogeneity indices of lung ventilation based on electrical impedance tomography. IFMBE PROCEEDINGS 2009. [DOI: 10.1007/978-3-540-89208-3_63] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|
50
|
Letter to the Editor. J Clin Monit Comput 2008; 22:385-6; author reply 387-9. [DOI: 10.1007/s10877-008-9138-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Accepted: 08/11/2008] [Indexed: 10/21/2022]
|