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Pan Y, Zhang H, Huang W, Liu W, You R, Chen C. Enhancing removal of air contaminants in existing aircraft cabins by optimizing supply air direction based on Re-field synergy and Bayesian optimization. Sci Total Environ 2024; 928:172363. [PMID: 38614342 DOI: 10.1016/j.scitotenv.2024.172363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 04/07/2024] [Accepted: 04/08/2024] [Indexed: 04/15/2024]
Abstract
There are a large number of airplanes currently being operated, in which the ventilation system needs to be improved to more effectively remove air contaminants. A potential approach is to adjust the supply air directions with the use of simple airflow deflectors. This study proposed a method for optimizing the supply air direction of ventilation in aircraft cabins based on the Re-field synergy index and Bayesian optimization. A validated numerical model was used to calculate the air distribution and air contaminant transport in a single-row single-aisle aircraft cabin to obtain the Re-field synergy values. The Bayesian optimization approach was used to identify the supply air direction which maximizes the Re-field synergy, namely, maximizes the mass transfer effectiveness. Finally, the air contaminant transport in a 7-row single-aisle aircraft cabin with the optimized supply air direction was evaluated to demonstrate the enhancement of ventilation performance. The results show that the proposed method based on the Re-field synergy index and Bayesian optimization can efficiently optimize the supply air direction in order to enhance the air contaminant removal in aircraft cabins. In the 7-row single-aisle aircraft cabin, the optimized supply air direction can reduce the average air contaminant concentration in the breathing zone of the passengers by up to 23 %.
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Affiliation(s)
- Yue Pan
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong
| | - Haiqiang Zhang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong
| | - Wenjie Huang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong
| | - Wei Liu
- Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China; Department of Civil and Architectural Engineering, KTH Royal Institute of Technology, Stockholm 100 44, Sweden
| | - Ruoyu You
- Department of Building Environment and Energy Engineering, The Hong Kong Polytechnic University, Kowloon 999077, Hong Kong
| | - Chun Chen
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong; Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, Shatin, N.T. 999077, Hong Kong.
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Zhang M, Guo X, Li J, Gao Z, Ji G, Zhang J, Buccolieri R. Urban-canopy airflow dynamics: A numerical investigation of drag forces and distribution for generic neighborhoods, and their relationships with breathability. Sci Total Environ 2024; 926:171836. [PMID: 38513853 DOI: 10.1016/j.scitotenv.2024.171836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/16/2024] [Accepted: 03/18/2024] [Indexed: 03/23/2024]
Abstract
Thorough investigations of urban-canopy drag primarily stemming from pressure drag on building surfaces are necessary given the turbulent flows within complex urban areas. Moreover, a gap persists regarding the relationships between canopy drag and breathability. Therefore, this work delves into the canopy-layer airflow dynamics for generic urban neighborhoods by performing three-dimensional Reynolds-Averaged Navier-Stokes simulations. A total of 32 subcases are examined, encompassing uniform- and varying-height and diverse plan area densities (λp, categorized into groups of sparse: 0.0625/0.067, medium: 0.23/0.25, and dense: 0.53/0.56). Results for the drag distribution highlight the windward-row shelter effect for the medium and the dense, local shelter by taller buildings, and distinct shapes of sectional drag forces (F⁎Z). Local velocity and mean age of air are found strongly positively and negatively correlated to F⁎Z, respectively, with distinct slopes in relation to λp. For the uniform-height, the normalized bulk drag (F⁎bulk, referred to as drag coefficient in literature) peaks for the medium with wake-interference regime; F⁎bulk demonstrates a maximum increase of over two times with height variation; moreover, F⁎bulk for varying-height groups exhibits a marked increase from the sparse to the medium, while remaining comparable values for the dense. The frontal area averaged drag (FAf,ave) exhibits a decreasing trend against λp across all cases. Further, FAf,ave exhibits strong correlations with λp and porosity, and with bulk ventilation indices such as spatially averaged velocity, air change rate, and normalized net escape velocity. Throughout the 'suburban-urban-suburban' canopy, medium neighborhoods exerting larger drag cause greater streamwise outdoor pressure drops and flow reductions compared to the sparse. However, dense neighborhoods with lower drag exhibit even larger pressure losses, which should be carefully scrutinized. The findings can inform urban planners in designing more aerodynamically efficient neighborhoods and guide strategies for improving air quality within urban environments.
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Affiliation(s)
- Mingjie Zhang
- School of Architecture and Urban Planning, Nanjing University, 22 Hankou Road, Nanjing 210093, Jiangsu Province, China; Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Laboratory of Micrometeorology, University of Salento, S.P. 6 Lecce-Monteroni, 73100 Lecce, Italy
| | - Xin Guo
- School of Architecture and Urban Planning, Nanjing University, 22 Hankou Road, Nanjing 210093, Jiangsu Province, China
| | - Jiaying Li
- School of Architecture and Urban Planning, Nanjing University, 22 Hankou Road, Nanjing 210093, Jiangsu Province, China
| | - Zhi Gao
- School of Architecture and Urban Planning, Nanjing University, 22 Hankou Road, Nanjing 210093, Jiangsu Province, China.
| | - Guohua Ji
- School of Architecture and Urban Planning, Nanjing University, 22 Hankou Road, Nanjing 210093, Jiangsu Province, China
| | - Jianshun Zhang
- School of Architecture and Urban Planning, Nanjing University, 22 Hankou Road, Nanjing 210093, Jiangsu Province, China; Department of Mechanical and Aerospace Engineering, Building Energy and Environmental Systems Laboratory, Syracuse University, Syracuse 13210, NY, USA
| | - Riccardo Buccolieri
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Laboratory of Micrometeorology, University of Salento, S.P. 6 Lecce-Monteroni, 73100 Lecce, Italy; Institute of Atmospheric Sciences and Climate (ISAC), National Research Council (CNR), S.P. Lecce-Monteroni km 1,2, 73100 Lecce, Italy
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Shi M, Qumu S, Wang S, Peng Y, Yang L, Huang K, He R, Dong F, Niu H, Yang T, Wang C. Abnormal heart rate responses to exercise in non-severe COPD: relationship with pulmonary vascular volume and ventilatory efficiency. BMC Pulm Med 2024; 24:183. [PMID: 38632576 PMCID: PMC11022473 DOI: 10.1186/s12890-024-03003-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 04/09/2024] [Indexed: 04/19/2024] Open
Abstract
BACKGROUND Despite being a prognostic predictor, cardiac autonomic dysfunction (AD) has not been well investigated in chronic obstructive pulmonary disease (COPD). We aimed to characterise computed tomography (CT), spirometry, and cardiopulmonary exercise test (CPET) features of COPD patients with cardiac AD and the association of AD with CT-derived vascular and CPET-derived ventilatory efficiency metrics. METHODS This observational cohort study included stable, non-severe COPD patients. They underwent clinical evaluation, spirometry, CPET, and CT. Cardiac AD was determined based on abnormal heart rate responses to exercise, including chronotropic incompetence (CI) or delayed heart rate recovery (HRR) during CPET. RESULTS We included 49 patients with FEV1 of 1.2-5.0 L (51.1-129.7%), 24 (49%) had CI, and 15 (31%) had delayed HRR. According to multivariate analyses, CI was independently related to reduced vascular volume (VV; VV ≤ median; OR [95% CI], 7.26 [1.56-33.91]) and low ventilatory efficiency (nadir VE/VCO2 ≥ median; OR [95% CI], 10.67 [2.23-51.05]). Similar results were observed for delayed HRR (VV ≤ median; OR [95% CI], 11.46 [2.03-64.89], nadir VE/VCO2 ≥ median; OR [95% CI], 6.36 [1.18-34.42]). CONCLUSIONS Cardiac AD is associated with impaired pulmonary vascular volume and ventilatory efficiency. This suggests that lung blood perfusion abnormalities may occur in these patients. Further confirmation is required in a large population-based cohort.
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Affiliation(s)
- Minghui Shi
- National Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- National Clinical Research Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Capital Medical University, 100069, Beijing, China
| | - Shiwei Qumu
- National Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- National Clinical Research Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
| | - Siyuan Wang
- Department of Rehabilitation Medicine, China-Japan Friendship Hospital, 100029, Beijing, China
| | - Yaodie Peng
- National Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- National Clinical Research Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Peking University Health Science Center, 100871, Beijing, China
| | - Lulu Yang
- Fangzhuang Community Health Service Center, Capital Medical University, 100078, Beijing, China
| | - Ke Huang
- National Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- National Clinical Research Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
| | - Ruoxi He
- National Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- National Clinical Research Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
| | - Feng Dong
- Department of Clinical Research and Data Management, Center of Respiratory Medicine, China-Japan Friendship Hospital, 100078, Beijing, China
| | - Hongtao Niu
- National Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- National Clinical Research Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
- Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China
| | - Ting Yang
- National Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China.
- Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China.
- National Clinical Research Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China.
- Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China.
| | - Chen Wang
- National Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China.
- Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China.
- National Clinical Research Center for Respiratory Diseases, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China.
- Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, China-Japan Friendship Hospital, No. 2 East Yinghua Road, Chaoyang District, 100029, Beijing, China.
- Capital Medical University, 100069, Beijing, China.
- Chinese Academy of Medical Sciences and Peking Union Medical College, No. 2 East Yinghua Road, Chaoyang District, 100730, Beijing, China.
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Ashikaga K, Itoh H, Maeda T, Itoh H, Tanaka S, Ichikawa Y, Nagayama M, Akashi YJ, Isobe M. Usefulness of the predicted percentage ventilatory efficiency for carbon dioxide output during exercise in patients with chronic heart failure. Heart Vessels 2023; 38:56-65. [PMID: 35895151 DOI: 10.1007/s00380-022-02132-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 06/29/2022] [Indexed: 01/06/2023]
Abstract
The ventilatory efficiency for carbon dioxide output ([Formula: see text]CO2) during exercise, as measured by the minute ventilation vs. [Formula: see text]CO2 slope ([Formula: see text]E vs. [Formula: see text]CO2 slope), is a powerful prognostic index in patients with chronic heart failure (CHF). This measurement is higher in women than in men, and it increases with age. This study aimed to investigate the usefulness of the predicted value of the percentage [Formula: see text]E vs. [Formula: see text]CO2 slope (%[Formula: see text]E vs. [Formula: see text]CO2 slope) as a prognostic index in patients with CHF. A total of 320 patients with CHF and a left ventricular ejection fraction (LVEF) < 45% (male, 85.6%; mean age, 64.6 years) who underwent symptom-limited cardiopulmonary exercise tests using a cycle ergometer were included in the study. The %[Formula: see text]E vs. [Formula: see text]CO2 was calculated using predictive formulae based on age and sex. Cardiovascular-related death was defined as the primary endpoint. The mean follow-up duration was 7.5 ± 3.3 years. Of 101 patients who died during the study period, 75 experienced cardiovascular-related deaths. The average [Formula: see text]E vs. [Formula: see text]CO2 slope was 32.8 ± 8.0, and the average %[Formula: see text]E vs. [Formula: see text]CO2 slope was 119.6 ± 28.2%. The cumulative incidence of cardiovascular-related death after 10 years of follow-up were 44.7% (95% CI 34.4-54.6%) in patients with %[Formula: see text]E vs. [Formula: see text]CO2 slope > 120 and 15.0% (95% CI 9.4-21.8%) in patients with %[Formula: see text]E vs. [Formula: see text]CO2 slope ≤ 120. The multivariate Cox regression analysis indicated that a %[Formula: see text]E vs. [Formula: see text]CO2 slope > 120 was an independent predictor of cardiovascular-related death (adjusted hazard ratio, 3.24; 95% confidence interval 1.65-6.67; p < 0.01). The %[Formula: see text]E vs. [Formula: see text]CO2 slope can be used for risk stratification in patients with CHF and an LVEF < 45%.
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Affiliation(s)
- Kohei Ashikaga
- Department of Cardiology, Sakakibara Heart Institute, Fuchu, Tokyo, Japan. .,Division of Cardiology, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan. .,Department of Sports Medicine, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyakaeku, Kawasaki, Kanagawa, 216-8511, Japan.
| | - Haruki Itoh
- Department of Cardiology, Sakakibara Heart Institute, Fuchu, Tokyo, Japan
| | - Tomoko Maeda
- Department of Clinical Laboratory, Sakakibara Heart Institute Clinic, Tokyo, Japan
| | - Hidetaka Itoh
- Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shiori Tanaka
- Department of Clinical Laboratory, Sakakibara Heart Institute, Fuchu, Tokyo, Japan
| | - Yuri Ichikawa
- Department of Medical Technology, School of Health Science, Tokyo University of Technology, Hachioji, Tokyo, Japan
| | - Masatoshi Nagayama
- Department of Cardiology, Sakakibara Heart Institute, Fuchu, Tokyo, Japan
| | - Yoshihiro J Akashi
- Division of Cardiology, Department of Internal Medicine, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
| | - Mitsuaki Isobe
- Department of Cardiology, Sakakibara Heart Institute, Fuchu, Tokyo, Japan
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Zhang Y, Han O, Li A, Hou L, Olofsson T, Zhang L, Lei W. Adaptive Wall-Based Attachment Ventilation: A Comparative Study on Its Effectiveness in Airborne Infection Isolation Rooms with Negative Pressure. Engineering (Beijing) 2022; 8:130-137. [PMID: 33520328 PMCID: PMC7825860 DOI: 10.1016/j.eng.2020.10.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 08/24/2020] [Accepted: 09/14/2020] [Indexed: 05/07/2023]
Abstract
The transmission of coronavirus disease 2019 (COVID-19) has presented challenges for the control of the indoor environment of isolation wards. Scientific air distribution design and operation management are crucial to ensure the environmental safety of medical staff. This paper proposes the application of adaptive wall-based attachment ventilation and evaluates this air supply mode based on contaminants dispersion, removal efficiency, thermal comfort, and operating expense. Adaptive wall-based attachment ventilation provides a direct supply of fresh air to the occupied zone. In comparison with a ceiling air supply or upper sidewall air supply, adaptive wall-based attachment ventilation results in a 15%-47% lower average concentration of contaminants, for a continual release of contaminants at the same air changes per hour (ACH; 10 h-1). The contaminant removal efficiency of complete mixing ventilation cannot exceed 1. For adaptive wall-based attachment ventilation, the contaminant removal efficiency is an exponential function of the ACH. Compared with the ceiling air supply mode or upper sidewall air supply mode, adaptive wall-based attachment ventilation achieves a similar thermal comfort level (predicted mean vote (PMV) of -0.1-0.4; draught rate of 2.5%-6.7%) and a similar performance in removing contaminants, but has a lower ACH and uses less energy.
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Affiliation(s)
- Ying Zhang
- School of Building Services Science and Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
- Department of Applied Physics and Electronics, Umeå University, Umeå SE 90187, Sweden
| | - Ou Han
- School of Building Services Science and Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Angui Li
- School of Building Services Science and Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
- Department of Applied Physics and Electronics, Umeå University, Umeå SE 90187, Sweden
- School of Thermal Engineering, Shandong Jianzhu University, Jinan 250101, China
| | - Li'an Hou
- School of Building Services Science and Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Thomas Olofsson
- Department of Applied Physics and Electronics, Umeå University, Umeå SE 90187, Sweden
| | - Linhua Zhang
- School of Thermal Engineering, Shandong Jianzhu University, Jinan 250101, China
| | - Wenjun Lei
- School of Thermal Engineering, Shandong Jianzhu University, Jinan 250101, China
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González-Pacheco N, Sánchez-Luna M, Arribas-Sánchez C, Santos-González M, Orden-Quinto C, Tendillo-Cortijo F. DCO 2/PaCO 2 correlation on high-frequency oscillatory ventilation combined with volume guarantee using increasing frequencies in an animal model. Eur J Pediatr 2020; 179:499-506. [PMID: 31823075 DOI: 10.1007/s00431-019-03503-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 09/12/2019] [Accepted: 10/09/2019] [Indexed: 10/25/2022]
Abstract
To examine the correlation DCO2/PaCO2 on high-frequency oscillatory ventilation (HFOV) combined with volume guarantee (VG) throughout increasing frequencies in two different respiratory conditions, physiological and low compliance. Neonatal animal model was used, before and after a bronchoalveolar lavage (BAL). HFOV combined with VG was used. The frequency was increased from 10 to 20 Hz, and high-frequency tidal volume (VThf) was gradually decreased maintaining a constant DCO2. Arterial partial pressure of carbon dioxide (PaCO2) was evaluated after each frequency and VThf change. Six 2-day-old piglets were studied. A linear decrease in PaCO2 was observed throughout increasing frequencies in both respiratory conditions while maintaining a constant DCO2, showing a significant difference between the initial PaCO2 (at 10 Hz) and the PaCO2 obtained at 18 and 20 Hz. A new DCO2 equation (corrected DCO2) was calculated in order to better define the correlation between DCO2 and the observed PaCO2.Conclusion: The correlation DCO2/PaCO2 throughout increasing frequencies is not linear, showing a greater CO2 elimination efficiency at higher frequencies, in spite of maintaining a constant DCO2. So, using frequencies close to the resonant frequency of the respiratory system on HFOV combined with VG, optimizes the efficiency of gas exchange.What is Known: • The efficacy of CO2removal during high-frequency oscillatory ventilation (HFOV), described as the diffusion coefficient of CO2(DCO2) is related to the square of the high-frequency tidal volume (VThf) and the frequency (f), expressed as DCO2= VThf2× f.What is New: • The correlation between DCO2and PaCO2throughout increasing frequencies is not linear, showing a greater CO2elimination efficiency at higher frequencies. So, using very high frequencies on HFOV combined with volume guarantee optimizes the efficiency of gas exchange allowing to minimize lung injury.
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Affiliation(s)
- Noelia González-Pacheco
- Neonatology Division, Instituto de Investigación Sanitaria Gregorio Marañón, Universidad Complutense de Madrid, Hospital General Universitario "Gregorio Marañón", C/Dr. Esquerdo, 46, 28007, Madrid, Spain.
| | - Manuel Sánchez-Luna
- Neonatology Division, Instituto de Investigación Sanitaria Gregorio Marañón, Universidad Complutense de Madrid, Hospital General Universitario "Gregorio Marañón", C/Dr. Esquerdo, 46, 28007, Madrid, Spain
| | - Cristina Arribas-Sánchez
- Neonatology Division, Clínica Universidad de Navarra, C/Marquesado de Sta. Marta, 1, 28027, Madrid, Spain
| | - Martín Santos-González
- Medical and Surgical Research Unit, Instituto de Investigación Sanitaria Puerta de Hierro-Majadahonda, Hospital Universitario Puerta de Hierro-Majadahonda, C/Manuel de Falla, 1, 28222, Madrid, Spain
| | - Cristina Orden-Quinto
- Medical and Surgical Research Unit, Instituto de Investigación Sanitaria Puerta de Hierro-Majadahonda, Hospital Universitario Puerta de Hierro-Majadahonda, C/Manuel de Falla, 1, 28222, Madrid, Spain
| | - Francisco Tendillo-Cortijo
- Medical and Surgical Research Unit, Instituto de Investigación Sanitaria Puerta de Hierro-Majadahonda, Hospital Universitario Puerta de Hierro-Majadahonda, C/Manuel de Falla, 1, 28222, Madrid, Spain
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Salvioni E, Corrà U, Piepoli M, Rovai S, Correale M, Paolillo S, Pasquali M, Magrì D, Vitale G, Fusini L, Mapelli M, Vignati C, Lagioia R, Raimondo R, Sinagra G, Boggio F, Cangiano L, Gallo G, Magini A, Contini M, Palermo P, Apostolo A, Pezzuto B, Bonomi A, Scardovi AB, Filardi PP, Limongelli G, Metra M, Scrutinio D, Emdin M, Piccioli L, Lombardi C, Cattadori G, Parati G, Caravita S, Re F, Cicoira M, Frigerio M, Clemenza F, Bussotti M, Battaia E, Guazzi M, Bandera F, Badagliacca R, Di Lenarda A, Pacileo G, Passino C, Sciomer S, Ambrosio G, Agostoni P. Gender and age normalization and ventilation efficiency during exercise in heart failure with reduced ejection fraction. ESC Heart Fail 2020; 7:371-380. [PMID: 31893579 PMCID: PMC7083437 DOI: 10.1002/ehf2.12582] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/21/2019] [Accepted: 11/11/2019] [Indexed: 01/20/2023] Open
Abstract
Aims Ventilation vs. carbon dioxide production (VE/VCO2) is among the strongest cardiopulmonary exercise testing prognostic parameters in heart failure (HF). It is usually reported as an absolute value. The current definition of normal VE/VCO2 slope values is inadequate, since it was built from small groups of subjects with a particularly limited number of women and elderly. We aimed to define VE/VCO2 slope prediction formulas in a sizable population and to test whether the prognostic power of VE/VCO2 slope in HF was different if expressed as a percentage of the predicted value or as an absolute value. Methods and results We calculated the linear regressions between age and VE/VCO2 slope in 1136 healthy subjects (68% male, age 44.9 ± 14.5, range 13–83 years). We then applied age‐adjusted and sex‐adjusted formulas to predict VE/VCO2 slope to HF patients included in the metabolic exercise test data combined with cardiac and kidney indexes score database, which counts 6112 patients (82% male, age 61.4 ± 12.8, left ventricular ejection fraction 33.2 ± 10.5%, peakVO2 14.8 ± 4.9, mL/min/kg, VE/VCO2 slope 32.7 ± 7.7) from 24 HF centres. Finally, we evaluated whether the use of absolute values vs. percentages of predicted VE/VCO2 affected HF prognosis prediction (composite of cardiovascular mortality + urgent transplant or left ventricular assist device). We did so in the entire cardiac and kidney indexes score population and separately in HF patients with severe (peakVO2 < 14 mL/min/kg, n = 2919, 61.1 events/1000 pts/year) or moderate (peakVO2 ≥ 14 mL/min/kg, n = 3183, 19.9 events/1000 pts/year) HF. In the healthy population, we obtained the following equations: female, VE/VCO2 = 0.052 × Age + 23.808 (r = 0.192); male, VE/VCO2 = 0.095 × Age + 20.227 (r = 0.371) (P = 0.007). We applied these formulas to calculate the percentages of predicted VE/VCO2 values. The 2‐year survival prognostic power of VE/VCO2 slope was strong, and it was similar if expressed as absolute value or as a percentage of predicted value (AUCs 0.686 and 0.690, respectively). In contrast, in severe HF patients, AUCs significantly differed between absolute values (0.637) and percentages of predicted values (0.650, P = 0.0026). Moreover, VE/VCO2 slope expressed as a percentage of predicted value allowed to reclassify 6.6% of peakVO2 < 14 mL/min/kg patients (net reclassification improvement = 0.066, P = 0.0015). Conclusions The percentage of predicted VE/VCO2 slope value strengthens the prognostic power of VE/VCO2 in severe HF patients, and it should be preferred over the absolute value for HF prognostication. Furthermore, the widespread use of VE/VCO2 slope expressed as percentage of predicted value can improve our ability to identify HF patients at high risk, which is a goal of utmost clinical relevance.
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Affiliation(s)
| | - Ugo Corrà
- Cardiology Department, Istituti Clinici Scientifici Maugeri, IRCCS, Veruno Institute, Veruno, Italy
| | | | - Sara Rovai
- Centro Cardiologico Monzino, IRCCS, Via Parea 4, Milan, 20138, Italy.,Università degli Studi di Padova, Padova, Italy
| | | | - Stefania Paolillo
- Department of Advanced Biomedical Sciences, Federico II University of Naples, Naples, Italy
| | - Mario Pasquali
- Dipartimento di medicina e scienze dell'invecchiamento, Università G. D'Annunzio, Chieti, Italy
| | - Damiano Magrì
- Department of Clinical and Molecular Medicine, Azienda Ospedaliera Sant'Andrea, "Sapienza" Università degli Studi di Roma, Roma, Italy
| | - Giuseppe Vitale
- Cardiovascular Rehabilitation Unit, Buccheri La Ferla Fatebenefratelli Hospital, Palermo, Italy
| | - Laura Fusini
- Centro Cardiologico Monzino, IRCCS, Via Parea 4, Milan, 20138, Italy
| | - Massimo Mapelli
- Centro Cardiologico Monzino, IRCCS, Via Parea 4, Milan, 20138, Italy
| | - Carlo Vignati
- Centro Cardiologico Monzino, IRCCS, Via Parea 4, Milan, 20138, Italy.,Department of Clinical Sciences and Community Health, Cardiovascular Section, University of Milano, Milano, Italy
| | - Rocco Lagioia
- Division of Cardiology, "S. Maugeri" Foundation, IRCCS, Institute of Cassano Murge, Bari, Italy
| | - Rosa Raimondo
- Fondazione Salvatore Maugeri, IRCCS, Istituto Scientifico di Tradate, Tradate, Italy
| | - Gianfranco Sinagra
- Cardiovascular Department, Ospedali Riuniti and University of Trieste, Trieste, Italy
| | - Federico Boggio
- Centro Cardiologico Monzino, IRCCS, Via Parea 4, Milan, 20138, Italy
| | - Lorenzo Cangiano
- Centro Cardiologico Monzino, IRCCS, Via Parea 4, Milan, 20138, Italy
| | - Giovanna Gallo
- Department of Clinical and Molecular Medicine, Azienda Ospedaliera Sant'Andrea, "Sapienza" Università degli Studi di Roma, Roma, Italy
| | - Alessandra Magini
- Centro Cardiologico Monzino, IRCCS, Via Parea 4, Milan, 20138, Italy
| | - Mauro Contini
- Centro Cardiologico Monzino, IRCCS, Via Parea 4, Milan, 20138, Italy
| | - Pietro Palermo
- Centro Cardiologico Monzino, IRCCS, Via Parea 4, Milan, 20138, Italy
| | - Anna Apostolo
- Centro Cardiologico Monzino, IRCCS, Via Parea 4, Milan, 20138, Italy
| | - Beatrice Pezzuto
- Centro Cardiologico Monzino, IRCCS, Via Parea 4, Milan, 20138, Italy
| | - Alice Bonomi
- Centro Cardiologico Monzino, IRCCS, Via Parea 4, Milan, 20138, Italy
| | | | | | - Giuseppe Limongelli
- Cardiologia SUN, Ospedale Monaldi (Azienda dei Colli), Seconda Università di Napoli, Napoli, Italy
| | - Marco Metra
- Cardiology, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy
| | - Domenico Scrutinio
- Division of Cardiology, "S. Maugeri" Foundation, IRCCS, Institute of Cassano Murge, Bari, Italy
| | - Michele Emdin
- Fondazione Gabriele Monasterio, CNR-Regione Toscana, Pisa, Italy.,Life Science Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Lucrezia Piccioli
- Department of Advanced Biomedical Sciences, Federico II University of Naples, Naples, Italy
| | - Carlo Lombardi
- Cardiology, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy
| | - Gaia Cattadori
- Unità Operativa Cardiologia Riabilitativa, Multimedica IRCCS, Milano, Italy
| | - Gianfranco Parati
- Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy.,Department of Cardiovascular, Neural and Metabolic Sciences, San Luca Hospital, Istituto Auxologico Italiano, Milan, Italy
| | - Sergio Caravita
- Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
| | - Federica Re
- Cardiology Division, Cardiac Arrhythmia Center and Cardiomyopathies Unit, San Camillo-Forlanini Hospital, Roma, Italy
| | | | - Maria Frigerio
- Dipartimento Cardiologico "A. De Gasperis", Ospedale Cà Granda-A.O. Niguarda, Milano, Italy
| | - Francesco Clemenza
- Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, IRCCS-ISMETT, Palermo, Italy
| | - Maurizio Bussotti
- Cardiac Rehabilitation Unit, Fondazione Salvatore Maugeri, IRCCS, Scientific Institute of Milan, Milan, Italy
| | - Elisa Battaia
- Department of Cardiology, S. Chiara Hospital, Trento, Italy
| | - Marco Guazzi
- Cardiology University Department, Heart Failure Unit and Cardiopulmonary Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Francesco Bandera
- Cardiology University Department, Heart Failure Unit and Cardiopulmonary Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, Italy
| | - Roberto Badagliacca
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Nefrologiche, Anestesiologiche e Geriatriche, "Sapienza", Rome University, Rome, Italy
| | - Andrea Di Lenarda
- Cardiovascular Center, Health Authority no. 1, University of Trieste, Trieste, Italy
| | - Giuseppe Pacileo
- Cardiologia SUN, Ospedale Monaldi (Azienda dei Colli), Seconda Università di Napoli, Napoli, Italy
| | - Claudio Passino
- Fondazione Gabriele Monasterio, CNR-Regione Toscana, Pisa, Italy.,Life Science Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Susanna Sciomer
- Dipartimento di Scienze Cardiovascolari, Respiratorie, Nefrologiche, Anestesiologiche e Geriatriche, "Sapienza", Rome University, Rome, Italy
| | - Giuseppe Ambrosio
- Division of Cardiology, University of Perugia School of Medicine, Perugia, Italy
| | - Piergiuseppe Agostoni
- Centro Cardiologico Monzino, IRCCS, Via Parea 4, Milan, 20138, Italy.,Department of Clinical Sciences and Community Health, Cardiovascular Section, University of Milano, Milano, Italy
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Yumoto T, Fujita T, Asaba S, Kanazawa S, Nishimatsu A, Yamanouchi H, Nakagawa S, Nagano O. Comparison of the ventilation characteristics in two adult oscillators: a lung model study. Intensive Care Med Exp 2019; 7:15. [PMID: 30868327 PMCID: PMC6419651 DOI: 10.1186/s40635-019-0229-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Accepted: 02/28/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Two recent large randomized controlled trials did not show the superiority of high-frequency oscillatory ventilation (HFOV) in adults with ARDS. These two trials had differing results, and possible causes could be the different oscillators used and their different settings, including inspiratory time % (IT%). The aims of this study were to obtain basic data about the ventilation characteristics in two adult oscillators and to elucidate the effect of the oscillator and IT% on ventilation efficiency. METHODS The Metran R100 or SensorMedics 3100B was connected to an original lung model internally equipped with a simulated bronchial tree. The actual stroke volume (aSV) was measured with a flow sensor placed at the Y-piece. Carbon dioxide (CO2) was continuously insufflated into the lung model ([Formula: see text]CO2), and the partial pressure of CO2 (PCO2) in the lung model was monitored. Alveolar ventilation ([Formula: see text]A; L/min) was estimated as [Formula: see text]CO2 divided by the stabilized value of PCO2. [Formula: see text]A was evaluated with several stroke volume settings in the R100 (IT = 50%) or several airway pressure amplitude settings in the 3100B (IT = 33%, 50%) at a frequency of 6 and 8 Hz, a mean airway pressure of 25 cmH2O, and a bias flow of 30 L/min. Assuming that [Formula: see text]A = frequencya × aSVb, values of a and b were determined. Ventilation efficiency was calculated as [Formula: see text]A divided by actual minute ventilation. RESULTS The relationship between aSV and [Formula: see text]A or ventilation efficiency were different depending on the oscillator and IT%. The values of a and b were 0 < a < 1 and 1 < b < 2 and were different for three conditions at both frequencies. [Formula: see text]A and ventilation efficiency were highest with R100 (IT = 50%) and lowest with 3100B (IT = 33%) for high aSV ranges at both frequencies. CONCLUSIONS In this lung model study, ventilation characteristics were different depending on the oscillator and IT%. Ventilation efficiency was highest with R100 (IT = 50%) and lowest with 3100B (IT = 33%) for high aSV ranges.
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Affiliation(s)
- Tetsuya Yumoto
- Advanced Emergency and Critical Care Medical Center, Okayama University Hospital, 2-5-1, Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Takahisa Fujita
- Center for Innovative and Translational Medicine, Kochi University Medical School, 185-1, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan
| | - Sunao Asaba
- Center for Innovative and Translational Medicine, Kochi University Medical School, 185-1, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan
| | - Shunsuke Kanazawa
- Center for Innovative and Translational Medicine, Kochi University Medical School, 185-1, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan
| | - Atsunori Nishimatsu
- Center for Innovative and Translational Medicine, Kochi University Medical School, 185-1, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan
| | - Hideo Yamanouchi
- Department of Disaster and Emergency Medicine, Kochi University Medical School, 185-1, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan
| | - Satoshi Nakagawa
- Department of Critical Care and Anesthesia, National Center for Child Health and Development, 2-10-1, Okura, Setagaya-ku, Tokyo, 157-8535, Japan
| | - Osamu Nagano
- Department of Disaster and Emergency Medicine, Kochi University Medical School, 185-1, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan.
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9
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Nagano O, Yumoto T, Nishimatsu A, Kanazawa S, Fujita T, Asaba S, Yamanouchi H. Bias flow rate and ventilation efficiency during adult high-frequency oscillatory ventilation: a lung model study. Intensive Care Med Exp 2018; 6:11. [PMID: 29675732 PMCID: PMC5908780 DOI: 10.1186/s40635-018-0176-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Accepted: 04/05/2018] [Indexed: 11/26/2022] Open
Abstract
Background Bias flow (BF) is essential to maintain mean airway pressure (MAP) and to washout carbon dioxide (CO2) from the oscillator circuit during high-frequency oscillatory ventilation (HFOV). If the BF rate is inadequate, substantial CO2 rebreathing could occur and ventilation efficiency could worsen. With lower ventilation efficiency, the required stroke volume (SV) would increase in order to obtain the same alveolar ventilation with constant frequency. The aim of this study was to assess the effect of BF rate on ventilation efficiency during adult HFOV. Methods The R100 oscillator (Metran, Japan) was connected to an original lung model internally equipped with a simulated bronchial tree. The actual SV was measured with a flow sensor placed at the Y-piece. Carbon dioxide (CO2) was continuously insufflated into the lung model (\documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}} $$\end{document}V˙CO2), and the partial pressure of CO2 (PCO2) in the lung model was monitored. Alveolar ventilation (\documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}} $$\end{document}V˙A) was estimated as \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}} $$\end{document}V˙CO2 divided by the stabilized value of PCO2. \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}} $$\end{document}V˙A was evaluated by setting SV from 80 to 180 mL (10 mL increments, n = 5) at a frequency of 8 Hz, a MAP of 25 cmH2O, and a BF of 10, 20, 30, and 40 L/min (study 1). Ventilation efficiency was calculated as \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}} $$\end{document}V˙A divided by the actual minute volume. The experiment was also performed with an actual SV of 80, 100, and 120 mL and a BF from 10 to 60 L/min (10 L/min increments: study 2). Results Study 1: With the same setting SV, the \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}} $$\end{document}V˙A with a BF of 20 L/min or more was significantly higher than that with a BF of 10 L/min. Study 2: With the same actual SV, the \documentclass[12pt]{minimal}
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\begin{document}$$ \dot{\mathrm{V}} $$\end{document}V˙A and the ventilation efficiency with a BF of 30 L/min or more were significantly higher than those with a BF of 10 or 20 L/min. Conclusions Increasing BF up to 30 L/min or more improved ventilation efficiency in the R100 oscillator. Electronic supplementary material The online version of this article (10.1186/s40635-018-0176-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Osamu Nagano
- Department of Disaster and Emergency Medicine, Kochi University Medical School, 185-1, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan.
| | - Tetsuya Yumoto
- Advanced Emergency and Critical Care Medical Center, Okayama University Hospital, 2-5-1, Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Atsunori Nishimatsu
- Center for Innovative and Translational Medicine, Kochi University Medical School, 185-1, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan
| | - Shunsuke Kanazawa
- Center for Innovative and Translational Medicine, Kochi University Medical School, 185-1, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan
| | - Takahisa Fujita
- Center for Innovative and Translational Medicine, Kochi University Medical School, 185-1, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan
| | - Sunao Asaba
- Center for Innovative and Translational Medicine, Kochi University Medical School, 185-1, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan
| | - Hideo Yamanouchi
- Department of Disaster and Emergency Medicine, Kochi University Medical School, 185-1, Kohasu, Oko-cho, Nankoku, Kochi, 783-8505, Japan
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10
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Li F, Liu J, Ren J, Cao X, Zhu Y. Numerical investigation of airborne contaminant transport under different vortex structures in the aircraft cabin. Int J Heat Mass Transf 2016; 96:287-295. [PMID: 32226103 PMCID: PMC7094279 DOI: 10.1016/j.ijheatmasstransfer.2016.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 01/01/2016] [Accepted: 01/01/2016] [Indexed: 05/04/2023]
Abstract
Airborne contaminants such as pathogens, odors and CO2 released from an individual passenger could spread via air flow in an aircraft cabin and make other passengers unhealthy and uncomfortable. In this study, we introduced the airflow vortex structure to analyze how airflow patterns affected contaminant transport in an aircraft cabin. Experimental data regarding airflow patterns were used to validate a computational fluid dynamics (CFD) model. Using the validated CFD model, we investigated the effects of the airflow vortex structure on contaminant transmission based on quantitative analysis. It was found that the contaminant source located in a vorticity-dominated region was more likely to be "locked" in the vortex, resulting in higher 62% higher average concentration and 14% longer residual time than that when the source was on a deformation dominated location. The contaminant concentrations also differed between the front and rear parts of the cabin because of different airflow structures. Contaminant released close to the heated manikin face was likely to be transported backward according to its distribution mean position. Based on these results, the air flow patterns inside aircraft cabins can potentially be improved to better control the spread of airborne contaminant.
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Affiliation(s)
- Fei Li
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Junjie Liu
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Jianlin Ren
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Xiaodong Cao
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, China
| | - Yifang Zhu
- Department of Environmental Health Sciences, Jonathan and Karin Fielding School of Public Health, University of California, Los Angeles, CA 90095-1772, USA
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11
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Contini M, Apostolo A, Cattadori G, Paolillo S, Iorio A, Bertella E, Salvioni E, Alimento M, Farina S, Palermo P, Loguercio M, Mantegazza V, Karsten M, Sciomer S, Magrì D, Fiorentini C, Agostoni P. Multiparametric comparison of CARvedilol, vs. NEbivolol, vs. BIsoprolol in moderate heart failure: the CARNEBI trial. Int J Cardiol 2013; 168:2134-40. [PMID: 23506636 DOI: 10.1016/j.ijcard.2013.01.277] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 01/18/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Several β-blockers, with different pharmacological characteristics, are available for heart failure (HF) treatment. We compared Carvedilol (β1-β2-α-blocker), Bisoprolol (β1-blocker), and Nebivolol (β1-blocker, NO-releasing activity). METHODS Sixty-one moderate HF patients completed a cross-over randomized trial, receiving, for 2 months each, Carvedilol, Nebivolol, Bisoprolol (25.6 ± 12.6, 5.0 ± 2.4 and 5.0 ± 2.4 mg daily, respectively). At the end of each period, patients underwent: clinical evaluation, laboratory testing, echocardiography, spirometry (including total DLCO and membrane diffusion), O2/CO2 chemoreceptor sensitivity, constant workload, in normoxia and hypoxia (FiO2=16%), and maximal cardiopulmonary exercise test. RESULTS No significant differences were observed for clinical evaluation (NYHA classification, Minnesota questionnaire), laboratory findings (including kidney function and BNP), echocardiography, and lung mechanics. DLCO was lower on Carvedilol (18.3 ± 4.8*mL/min/mmHg) compared to Nebivolol (19.9 ± 5.1) and Bisoprolol (20.0 ± 5.0) due to membrane diffusion 20% reduction (*=p<0.0001). Constant workload exercise showed in hypoxia a faster VO2 kinetic and a lower ventilation with Carvedilol. Peripheral and central sensitivity to CO2 was lower in Carvedilol while response to hypoxia was higher in Bisoprolol. Ventilation efficiency (VE/VCO2 slope) was 26.9 ± 4.1* (Carvedilol), 28.8 ± 4.0 (Nebivolol), and 29.0 ± 4.4 (Bisoprolol). Peak VO2 was 15.8 ± 3.6*mL/kg/min (Carvedilol), 16.9 ± 4.1 (Nebivolol), and 16.9 ± 3.6 (Bisoprolol). CONCLUSIONS β-Blockers differently affect several cardiopulmonary functions. Lung diffusion and exercise performance, the former likely due to lower interference with β2-mediated alveolar fluid clearance, were higher in Nebivolol and Bisoprolol. On the other hand, Carvedilol allowed a better ventilation efficiency during exercise, likely via a different chemoreceptor modulation. Results from this study represent the basis for identifying the best match between a specific β-blocker and a specific HF patient.
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12
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Sung M, Kato S. Estimating the germicidal effect of upper-room UVGI system on exhaled air of patients based on ventilation efficiency. Build Environ 2011; 46:2326-2332. [PMID: 32288012 PMCID: PMC7127715 DOI: 10.1016/j.buildenv.2011.05.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 04/28/2011] [Accepted: 05/16/2011] [Indexed: 05/23/2023]
Abstract
Upper room (UR)-ultraviolet germicidal (UVGI) systems, one of several disinfection applications of UV, target airborne infectious diseases in rooms of buildings such as healthcare facilities. Previous studies have introduced many experiments showing the germicidal effect of UR-UVGI systems. In this study, a novel numerical method of estimating the germicidal effect of UR-UVGI systems for air exhaled by ward patients was introduced. The method adopts and modifies the concept of ventilation efficiency because the germicidal effect depends upon how the air containing airborne infectious particles flows and stays within UV-radiated area. A case study based on a four-patient ward showed that UV doses were correlated with the age of the air exhaled by a source patient, as expected. Moreover, the UV doses were considerably affected by the position of the UR-UVGI system. Inactivation rates of the influenza virus estimated using the UV doses, were in the range of 48-74%, and those of Mycobacterium tuberculosis were 68-90% in the breathing area of a neighboring patient. The results indicate not directly the decreased concentration of airborne infectious particles, but the possibility of inactivation caused by the UR-UVGI system, which is useful for system optimization.
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Affiliation(s)
- Minki Sung
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
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13
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Zhu S, Demokritou P, Spengler J. Experimental and numerical investigation of micro-environmental conditions in public transportation buses. Build Environ 2010; 45:2077-2088. [PMID: 32288006 PMCID: PMC7125921 DOI: 10.1016/j.buildenv.2010.03.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 03/09/2010] [Accepted: 03/10/2010] [Indexed: 05/03/2023]
Abstract
This study examines both numerically and experimentally the micro-environmental conditions in public transportation buses. A Computational Fluid Dynamics (CFD) model was developed and experimentally validated. The developed CFD model was used to calculate the spatial distributions of the mean age and mean residual lifetime of air in the bus environment and evaluate the efficiency of the bus ventilation system. Additionally, the passengers' exposures to a variety of environmental conditions were experimentally monitored in "real world" field campaigns using the Harvard University shuttle bus system. Real time continuous monitoring systems were used to assess indoor environmental quality in the buses. It was found that CO levels were very low, while the levels of particulate matter varied and were influenced by the ambient air penetrated into the bus through the operation of the doors and the ventilation system. The CO2 level was found elevated and greatly affected by occupancy conditions. The elevated CO2 level indicates that the current bus ventilation is insufficient to dilute air pollutants in the bus especially under heavy occupancy conditions. This lack of sufficient ventilation indicates an elevated risk for airborne transmitted diseases in such a popular public transportation system.
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Affiliation(s)
- Shengwei Zhu
- Department of Environment Health, School of Public Health, Harvard University, Boston, MA, USA
- Harvard University Center for the Environment, Cambridge, MA, USA
| | - Philip Demokritou
- Department of Environment Health, School of Public Health, Harvard University, Boston, MA, USA
| | - John Spengler
- Department of Environment Health, School of Public Health, Harvard University, Boston, MA, USA
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