1
|
De Meyer GRA, Morrison SG, Schepens T. Validity of volumetric capnography for the quantification of dead space during flow-controlled ventilation with active expiratory flow. Eur J Anaesthesiol 2024; 41:316-319. [PMID: 37982584 DOI: 10.1097/eja.0000000000001931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Affiliation(s)
- Gregory R A De Meyer
- From the Department of Anesthesia (GRADM, SGM), Department of Critical Care Medicine, Antwerp University Hospital, Edegem (GRADM), Laboratory of Experimental Medicine and Pediatrics, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp (GRADM), Department of Intensive Care Medicine, Ghent University Hospital (TS) and Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium (TS)
| | | | | |
Collapse
|
2
|
Abram J, Spraider P, Wagner J, Putzer G, Ranalter M, Rinner S, Lindner AK, Glodny B, Hell T, Barnes T, Enk D, Martini J. Individualised flow-controlled ventilation reduces applied mechanical power and improves ventilation efficiency in a porcine intra-abdominal hypertension model. Intensive Care Med Exp 2024; 12:27. [PMID: 38451347 PMCID: PMC10920549 DOI: 10.1186/s40635-024-00608-9] [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: 10/30/2023] [Accepted: 02/23/2024] [Indexed: 03/08/2024] Open
Abstract
BACKGROUND Aim of this study was to evaluate feasibility and effects of individualised flow-controlled ventilation (FCV), based on compliance guided pressure settings, compared to standard of pressure-controlled ventilation (PCV) in a porcine intra-abdominal hypertension (IAH) model. The primary aim of this study was to investigate oxygenation. Secondary aims were to assess respiratory and metabolic variables and lung tissue aeration. METHODS Pigs were randomly assigned to FCV (n = 9) and PCV (n = 9). IAH was induced by insufflation of air into the abdomen to induce IAH grades ranging from 0 to 3. At each IAH grade FCV was undertaken using compliance guided pressure settings, or PCV (n = 9) was undertaken with the positive end-expiratory pressure titrated for maximum compliance and the peak pressure set to achieve a tidal volume of 7 ml/kg. Gas exchange, ventilator settings and derived formulas were recorded at two timepoints for each grade of IAH. Lung aeration was assessed by a computed tomography scan at IAH grade 3. RESULTS All 18 pigs (median weight 54 kg [IQR 51-67]) completed the observation period of 4 h. Oxygenation was comparable at each IAH grade, but a significantly lower minute volume was required to secure normocapnia in FCV at all IAH grades (7.6 vs. 14.4, MD - 6.8 (95% CI - 8.5 to - 5.2) l/min; p < 0.001). There was also a significant reduction of applied mechanical power being most evident at IAH grade 3 (25.9 vs. 57.6, MD - 31.7 (95% CI - 39.7 to - 23.7) J/min; p < 0.001). Analysis of Hounsfield unit distribution of the computed tomography scans revealed a significant reduction in non- (5 vs. 8, MD - 3 (95% CI - 6 to 0) %; p = 0.032) and poorly-aerated lung tissue (7 vs. 15, MD - 6 (95% CI - 13 to - 3) %, p = 0.002) for FCV. Concomitantly, normally-aerated lung tissue was significantly increased (84 vs. 76, MD 8 (95% CI 2 to 15) %; p = 0.011). CONCLUSIONS Individualised FCV showed similar oxygenation but required a significantly lower minute volume for CO2-removal, which led to a remarkable reduction of applied mechanical power. Additionally, there was a shift from non- and poorly-aerated lung tissue to normally-aerated lung tissue in FCV compared to PCV.
Collapse
Affiliation(s)
- Julia Abram
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Patrick Spraider
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria.
| | - Julian Wagner
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Gabriel Putzer
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Manuela Ranalter
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Sarah Rinner
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | | | - Bernhard Glodny
- Department of Radiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Tobias Hell
- Department of Mathematics, Faculty of Mathematics, Computer Science and Physics, University of Innsbruck, Innsbruck, Austria
| | - Tom Barnes
- Professor Emeritus, University of Greenwich, London, UK
| | - Dietmar Enk
- Faculty of Medicine, University of Münster, Münster, Germany
| | - Judith Martini
- Department of Anesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| |
Collapse
|
3
|
Ponholzer F, Dumfarth J, Krapf C, Pircher A, Hautz T, Wolf D, Augustin F, Schneeberger S. The impact and relevance of techniques and fluids on lung injury in machine perfusion of lungs. Front Immunol 2024; 15:1358153. [PMID: 38510260 PMCID: PMC10950925 DOI: 10.3389/fimmu.2024.1358153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 02/26/2024] [Indexed: 03/22/2024] Open
Abstract
Primary graft dysfunction (PGD) is a common complication after lung transplantation. A plethora of contributing factors are known and assessment of donor lung function prior to organ retrieval is mandatory for determination of lung quality. Specialized centers increasingly perform ex vivo lung perfusion (EVLP) to further assess lung functionality and improve and extend lung preservation with the aim to increase lung utilization. EVLP can be performed following different protocols. The impact of the individual EVLP parameters on PGD development, organ function and postoperative outcome remains to be fully investigated. The variables relate to the engineering and function of the respective perfusion devices, such as the type of pump used, functional, like ventilation modes or physiological (e.g. perfusion solutions). This review reflects on the individual technical and fluid components relevant to EVLP and their respective impact on inflammatory response and outcome. We discuss key components of EVLP protocols and options for further improvement of EVLP in regard to PGD. This review offers an overview of available options for centers establishing an EVLP program and for researchers looking for ways to adapt existing protocols.
Collapse
Affiliation(s)
- Florian Ponholzer
- Department of Visceral, Transplant and Thoracic Surgery, Center of Operative Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Julia Dumfarth
- Department of Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria
| | - Christoph Krapf
- Department of Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria
| | - Andreas Pircher
- Department of Haematology and Oncology, Internal Medicine V, Medical University of Innsbruck, Innsbruck, Austria
| | - Theresa Hautz
- Department of Visceral, Transplant and Thoracic Surgery, Center of Operative Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Dominik Wolf
- Department of Haematology and Oncology, Internal Medicine V, Medical University of Innsbruck, Innsbruck, Austria
| | - Florian Augustin
- Department of Visceral, Transplant and Thoracic Surgery, Center of Operative Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Stefan Schneeberger
- Department of Visceral, Transplant and Thoracic Surgery, Center of Operative Medicine, Medical University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
4
|
Mahieu L, Van Moll L, De Vooght L, Delputte P, Cos P. In vitro modelling of bacterial pneumonia: a comparative analysis of widely applied complex cell culture models. FEMS Microbiol Rev 2024; 48:fuae007. [PMID: 38409952 PMCID: PMC10913945 DOI: 10.1093/femsre/fuae007] [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: 10/02/2023] [Revised: 01/29/2024] [Accepted: 02/24/2024] [Indexed: 02/28/2024] Open
Abstract
Bacterial pneumonia greatly contributes to the disease burden and mortality of lower respiratory tract infections among all age groups and risk profiles. Therefore, laboratory modelling of bacterial pneumonia remains important for elucidating the complex host-pathogen interactions and to determine drug efficacy and toxicity. In vitro cell culture enables for the creation of high-throughput, specific disease models in a tightly controlled environment. Advanced human cell culture models specifically, can bridge the research gap between the classical two-dimensional cell models and animal models. This review provides an overview of the current status of the development of complex cellular in vitro models to study bacterial pneumonia infections, with a focus on air-liquid interface models, spheroid, organoid, and lung-on-a-chip models. For the wide scale, comparative literature search, we selected six clinically highly relevant bacteria (Pseudomonas aeruginosa, Mycoplasma pneumoniae, Haemophilus influenzae, Mycobacterium tuberculosis, Streptococcus pneumoniae, and Staphylococcus aureus). We reviewed the cell lines that are commonly used, as well as trends and discrepancies in the methodology, ranging from cell infection parameters to assay read-outs. We also highlighted the importance of model validation and data transparency in guiding the research field towards more complex infection models.
Collapse
Affiliation(s)
- Laure Mahieu
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Laurence Van Moll
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Linda De Vooght
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Peter Delputte
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Paul Cos
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| |
Collapse
|
5
|
Spraider P, Abram J, Martini J, Putzer G, Glodny B, Hell T, Barnes T, Enk D. Flow-controlled versus pressure-controlled ventilation in cardiac surgery with cardiopulmonary bypass - A single-center, prospective, randomized, controlled trial. J Clin Anesth 2023; 91:111279. [PMID: 37797394 DOI: 10.1016/j.jclinane.2023.111279] [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: 02/22/2023] [Revised: 09/16/2023] [Accepted: 09/27/2023] [Indexed: 10/07/2023]
Abstract
STUDY OBJECTIVE Multifactorial comparison of flow-controlled ventilation (FCV) to standard of pressure-controlled ventilation (PCV) in terms of oxygenation in cardiac surgery patients after chest closure. DESIGN Prospective, non-blinded, randomized, controlled trial. SETTING Operating theatre at an university hospital, Austria. PATIENTS Patients scheduled for elective, open, on-pump, cardiac surgery. INTERVENTIONS Participants were randomized to either individualized FCV (compliance guided end-expiratory and peak pressure setting) or control of PCV (compliance guided end-expiratory pressure setting and tidal volume of 6-8 ml/kg) for the duration of surgery. MEASUREMENTS The primary outcome measure was oxygenation (PaO2/FiO2) 15 min after intraoperative chest closure. Secondary endpoints included CO2-removal assessed as required minute volume to achieve normocapnia and lung tissue aeration assessed by Hounsfield unit distribution in postoperative computed tomography scans. MAIN RESULTS Between April 2020 and April 2021 56 patients were enrolled and 50 included in the primary analysis (mean age 70 years, 38 (76%) men). Oxygenation, assessed by PaO2/FiO2, was significantly higher in the FCV group (n = 24) compared to the control group (PCV, n = 26) (356 vs. 309, median difference (MD) 46 (95% CI 3 to 90) mmHg; p = 0.038). Additionally, the minute volume required to obtain normocapnia was significantly lower in the FCV group (4.0 vs. 6.1, MD -2.0 (95% CI -2.5 to -1.5) l/min; p < 0.001) and correlated with a significantly lower exposure to mechanical power (5.1 vs. 9.8, MD -5.1 (95% CI -6.2 to -4.0) J/min; p < 0.001). Evaluation of lung tissue aeration revealed a significantly reduced amount of non-aerated lung tissue in FCV compared to PCV (5 vs. 7, MD -3 (95% CI -4 to -1) %; p < 0.001). CONCLUSIONS In patients undergoing on-pump, cardiac surgery individualized FCV significantly improved oxygenation and lung tissue aeration compared to PCV. In addition, carbon dioxide removal was accomplished at a lower minute volume leading to reduced applied mechanical power.
Collapse
Affiliation(s)
- Patrick Spraider
- Department of Anaesthesiology and Intensive Care Medicine, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
| | - Julia Abram
- Department of Anaesthesiology and Intensive Care Medicine, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
| | - Judith Martini
- Department of Anaesthesiology and Intensive Care Medicine, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria.
| | - Gabriel Putzer
- Department of Anaesthesiology and Intensive Care Medicine, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
| | - Bernhard Glodny
- Department of Radiology, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria
| | - Tobias Hell
- Department of Mathematics, Faculty of Mathematics, Computer Science and Physics, University of Innsbruck, Technikerstrasse 15, 6020 Innsbruck, Austria
| | - Tom Barnes
- University of Greenwich, Old Royal Naval College, Park Row, SE109LS London, United Kingdom
| | - Dietmar Enk
- Faculty of Medicine, University of Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany
| |
Collapse
|
6
|
Altun D, Canbaz M, Altun D, Sen C, Çamcı E. Airway management during unusual tracheal stenosis: A clinical feasibility trial. Laryngoscope Investig Otolaryngol 2023; 8:1169-1177. [PMID: 37899870 PMCID: PMC10601558 DOI: 10.1002/lio2.1151] [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] [Received: 06/05/2023] [Revised: 08/12/2023] [Accepted: 08/18/2023] [Indexed: 10/31/2023] Open
Abstract
Objectives Prolonged intubation is a known risk factor of LTS. LTS related to COVID-19 may result in a different phenotype: pronation affects the location of stenosis and COVID-19 pneumonia can decline lung mechanics. Therefore, airway management in these patients may carry unique challenges for both anesthesiologists and surgeons.This prospective observational feasibility trial aims to evaluate the use of a novel thin, cuffed, endotracheal tube (Tritube) in combination with flow-controlled ventilation (FCV) in the management of patients with COVID-19-related LTS undergoing laryngeal surgery. Methods 20 patients suffering from COVID-19-related LTS, as diagnosed by CT, requiring endolaryngeal surgery, with or without CO2 laser, were included. Ultrathin endotracheal tube Tritube, together with FCV was used for airway management and ventilation. Feasibility, ventilation efficiency, and surgical exposure were evaluated. Results Median duration of mechanical ventilation during their ICU stay was 17 days, (range, 7-27), and all patients had been pronated. In 18/20 patients, endoscopic diagnosis confirmed the initial CT diagnosis: posterior subglottic stenosis. Surgeons' satisfaction on the view was rated 9 out of 10 (range 7-10), where 0 was the worst view and 10 was the best view. Hemodynamic and respiratory variables were within the normal clinical range during the surgical procedure. One patient that had a SpO2 of 90% before induction of anesthesia, a temporal drop to 89%, caused meeting the predefined requirement of "respiratory complication." Conclusion This study demonstrates the feasibility of using Tritube with FCV in patients with relatively unusual subglottic posterior location tracheal stenosis, undergoing laryngotracheal surgery. Tritube provides a good surgical field and FCV provides highly adequate ventilation especially in patients with compromised lung mechanics. Level of Evidence IV, non-comparitive prospective clinical trial with 20 patients.
Collapse
Affiliation(s)
- Demet Altun
- Istanbul Faculty of Medicine, Department of AnesthesiologyIstanbul UniversityIstanbulTurkey
| | - Mert Canbaz
- Istanbul Faculty of Medicine, Department of AnesthesiologyIstanbul UniversityIstanbulTurkey
| | - Dilek Altun
- Department of Anesthesiology and ReanimationBakırköy Acıbadem HospitalIstanbulTurkey
| | - Cömert Sen
- Istanbul Faculty of Medicine, Department of Otolaryngology&Head and Neck SurgeryIstanbul UniversityIstanbulTurkey
| | - Emre Çamcı
- Istanbul Faculty of Medicine, Department of AnesthesiologyIstanbul UniversityIstanbulTurkey
| |
Collapse
|
7
|
Abram J, Martini J, Spraider P, Putzer G, Ranalter M, Wagner J, Glodny B, Hell T, Barnes T, Enk D. Individualised flow-controlled versus pressure-controlled ventilation in a porcine oleic acid-induced acute respiratory distress syndrome model. Eur J Anaesthesiol 2023; 40:511-520. [PMID: 36749046 PMCID: PMC10256303 DOI: 10.1097/eja.0000000000001807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND A continuous gas flow provided by flow-controlled ventilation (FCV) facilitates accurate dynamic compliance measurement and allows the clinician to individually optimise positive end-expiratory and peak pressure settings accordingly. OBJECTIVE The aim of this study was to compare the efficiency of gas exchange and impact on haemodynamics between individualised FCV and pressure-controlled ventilation (PCV) in a porcine model of oleic acid-induced acute respiratory distress syndrome (ARDS). DESIGN Randomised controlled interventional trial conducted on 16 pigs. SETTING Animal operating facility at the Medical University Innsbruck. INTERVENTIONS ARDS was induced in lung healthy pigs by intravenous infusion of oleic acid until moderate-to-severe ARDS at a stable Horowitz quotient (PaO 2 FiO 2-1 ) of 80 to 120 over a period of 30 min was obtained. Ventilation was then either performed with individualised FCV ( n = 8) established by compliance-guided pressure titration or PCV ( n = 8) with compliance-guided titration of the positive end-expiratory pressure and peak pressure set to achieve a tidal volume of 6 ml kg -1 over a period of 2 h. MAIN OUTCOME MEASURES Gas exchange parameters were assessed by the PaO 2 FiO 2-1 quotient and CO 2 removal by the PaCO 2 value in relation to required respiratory minute volume. Required catecholamine support for haemodynamic stabilisation was measured. RESULTS The FCV group showed significantly improved oxygenation [149.2 vs. 110.4, median difference (MD) 38.7 (8.0 to 69.5) PaO 2 FiO 2-1 ; P = 0.027] and CO 2 removal [PaCO 2 7.25 vs. 9.05, MD -1.8 (-2.87 to -0.72) kPa; P = 0.006] at a significantly lower respiratory minute volume [8.4 vs. 11.9, MD -3.6 (-5.6 to -1.5) l min -1 ; P = 0.005] compared with PCV. In addition, in FCV-pigs, haemodynamic stabilisation occurred with a significant reduction of required catecholamine support [norepinephrine 0.26 vs. 0.86, MD -0.61 (-1.12 to -0.09) μg kg -1 min -1 ; P = 0.037] during 2 ventilation hours. CONCLUSION In this oleic acid-induced porcine ARDS model, individualised FCV significantly improved gas exchange and haemodynamic stability compared with PCV. TRIAL REGISTRATION Protocol no.: BMBWF-66.011/0105-V/3b/2019).
Collapse
Affiliation(s)
- Julia Abram
- From the Department of Anaesthesia and Intensive Care Medicine (JA, JM, PS, GP, MR, JW), Department of Radiology, Medical University of Innsbruck (BG), Department of Mathematics, Faculty of Mathematics, Computer Science and Physics, University of Innsbruck, Innsbruck, Austria (TH), University of Greenwich, London, UK (TB), Faculty of Medicine, University of Münster, Münster, Germany (DE)
| | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Ding B, Xu F, Wang J, Pan C, Pang J, Chen Y, Li K. Design and evaluation of portable emergency ventilator prototype with novel titration methods. Biomed Signal Process Control 2023. [DOI: 10.1016/j.bspc.2023.104619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
|
9
|
Grassetto A, Pettenuzzo T, Badii F, Carlon R, Sella N, Navalesi P. Flow-controlled ventilation may reduce mechanical power and increase ventilatory efficiency in severe coronavirus disease-19 acute respiratory distress syndrome. Pulmonology 2023; 29:154-156. [PMID: 35864057 PMCID: PMC9186429 DOI: 10.1016/j.pulmoe.2022.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/15/2022] [Accepted: 05/20/2022] [Indexed: 11/24/2022] Open
Affiliation(s)
- A Grassetto
- Anesthesia and Intensive Care, Vittorio Veneto Hospital, Via C. Forlanini 71, 31029 Vittorio Veneto, Italy.
| | - T Pettenuzzo
- Institute of Anesthesiology and Intensive Care, Padua University Hospital, Padua, Via V. Gallucci 13, 35121 Padua, Italy
| | - F Badii
- Anesthesia and Intensive Care, Vittorio Veneto Hospital, Via C. Forlanini 71, 31029 Vittorio Veneto, Italy
| | - R Carlon
- Anesthesia and Intensive Care, Vittorio Veneto Hospital, Via C. Forlanini 71, 31029 Vittorio Veneto, Italy
| | - N Sella
- Institute of Anesthesiology and Intensive Care, Padua University Hospital, Padua, Via V. Gallucci 13, 35121 Padua, Italy
| | - P Navalesi
- Institute of Anesthesiology and Intensive Care, Padua University Hospital, Padua, Via V. Gallucci 13, 35121 Padua, Italy; Department of Medicine, University of Padua, Via Giustiniani 2, 35128 Padua, Italy
| |
Collapse
|
10
|
Schranc Á, Diaper J, Südy R, Fodor GH, Habre W, Albu G. Benefit of Flow-Controlled Over Pressure-Regulated Volume Control Mode During One-Lung Ventilation: A Randomized Experimental Crossover Study. Anesth Analg 2023; 136:605-612. [PMID: 36729097 DOI: 10.1213/ane.0000000000006322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Application of a ventilation modality that ensures adequate gas exchange during one-lung ventilation (OLV) without inducing lung injury is of paramount importance. Due to its beneficial effects on respiratory mechanics and gas exchange, flow-controlled ventilation (FCV) may be considered as a protective alternative mode of traditional pressure- or volume-controlled ventilation during OLV. We investigated whether this new modality provides benefits compared with conventional ventilation modality for OLV. METHODS Ten pigs were anaesthetized and randomly assigned in a crossover design to be ventilated with FCV or pressure-regulated volume control (PRVC) ventilation. Arterial partial pressure of oxygen (Pa o2 ), carbon dioxide (Pa co2 ), ventilation and hemodynamical parameters, and lung aeration measured by electrical impedance tomography were assessed at baseline and 1 hour after the application of each modality during OLV using an endobronchial blocker. RESULTS Compared to PRVC, FCV resulted in increased Pa o2 (153.7 ± 12.7 vs 169.9 ± 15.0 mm Hg; P = .002) and decreased Pa co2 (53.0 ± 11.0 vs 43.2 ± 6.0 mm Hg; P < .001) during OLV, with lower respiratory elastance (103.7 ± 9.5 vs 77.2 ± 10.5 cm H 2 O/L; P < .001) and peak inspiratory pressure values (27.4 ± 1.9 vs 22.0 ± 2.3 cm H 2 O; P < .001). No differences in lung aeration or hemodynamics could be detected between the 2 ventilation modalities. CONCLUSIONS The application of FCV in OLV led to improvement in gas exchange and respiratory elastance with lower ventilatory pressures. Our findings suggest that FCV may offer an optimal, protective ventilation modality for OLV.
Collapse
Affiliation(s)
- Álmos Schranc
- From the Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
| | - John Diaper
- From the Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
| | - Roberta Südy
- From the Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
| | - Gergely H Fodor
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Walid Habre
- From the Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
- Pediatric Anesthesia Unit, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University Hospitals of Geneva, Geneva, Switzerland
| | - Gergely Albu
- From the Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
- Division of Anesthesiology, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University Hospitals of Geneva, Geneva, Switzerland
| |
Collapse
|
11
|
Accuracy of calculating mechanical power of ventilation by one commonly used equation. J Clin Monit Comput 2022; 36:1753-1759. [PMID: 35426575 PMCID: PMC9637605 DOI: 10.1007/s10877-022-00823-3] [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] [Received: 10/04/2021] [Accepted: 01/29/2022] [Indexed: 11/21/2022]
Abstract
Gattinoni's equation, [Formula: see text], now commonly used to calculate the mechanical power (MP) of ventilation. However, it calculates only inspiratory MP. In addition, the inclusion of PEEP in Gattinoni's equation raises debate because PEEP does not produce net displacement or contribute to MP. Measuring the area within the pressure-volume loop accurately reflects the MP received in a whole ventilation cycle and the MP thus obtained is not influenced by PEEP. The MP of 25 invasively ventilated patients were calculated by Gattinoni's equation and measured by integration of the areas within the pressure-volume loops of the ventilation cycles. The MP obtained from both methods were compared. The effects of PEEPs on MP were also evaluated. We found that the MP obtained from both methods were correlated by R2 = 0.75 and 0.66 at PEEP 5 and 10 cmH2O, respectively. The biases of the two methods were 3.13 (2.03 to 4.23) J/min (P < 0.0001) and - 1.23 (- 2.22 to - 0.24) J/min (P = 0.02) at PEEP 5 and 10 cmH2O, respectively. These P values suggested that both methods were significantly incongruent. When the tidal volume used was 6 ml/Kg, the MP by Gattinoni's equation at PEEP 5 and 10 cmH2O were significantly different (4.51 vs 7.21 J/min, P < 0.001), but the MP by PV loop area was not influenced by PEEPs (6.46 vs 6.47 J/min, P = 0.331). Similar results were observed across all tidal volumes. We conclude that the Gattinoni's equation is not accurate in calculating the MP of a whole ventilatory cycle and is significantly influenced by PEEP, which theoretically does not contribute to MP.
Collapse
|
12
|
Spraider P, Martini J, Abram J, Putzer G, Ranalter M, Mathis S, Hell T, Barnes T, Enk D. Individualised flow-controlled ventilation versus pressure-controlled ventilation in a porcine model of thoracic surgery requiring one-lung ventilation: A laboratory study. Eur J Anaesthesiol 2022; 39:885-894. [PMID: 36125005 DOI: 10.1097/eja.0000000000001745] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Flow-controlled ventilation (FCV) enables precise determination of dynamic compliance due to a continuous flow coupled with direct tracheal pressure measurement. Thus, pressure settings can be adjusted accordingly in an individualised approach. OBJECTIVE The aim of this study was to compare gas exchange of individualised FCV to pressure-controlled ventilation (PCV) in a porcine model of simulated thoracic surgery requiring one-lung ventilation (OLV). DESIGN Controlled interventional trial conducted on 16 domestic pigs. SETTING Animal operating facility at the Medical University of Innsbruck. INTERVENTIONS Thoracic surgery was simulated with left-sided thoracotomy and subsequent collapse of the lung over a period of three hours. When using FCV, ventilation was performed with compliance-guided pressure settings. When using PCV, end-expiratory pressure was adapted to achieve best compliance with peak pressure adjusted to achieve a tidal volume of 6 ml kg -1 during OLV. MAIN OUTCOME MEASURES Gas exchange was assessed by the Horowitz index (= P aO 2 /FIO 2 ) and CO 2 removal by the P aCO 2 value in relation to required respiratory minute volume. RESULTS In the FCV group ( n = 8) normocapnia could be maintained throughout the OLV trial despite a significantly lower respiratory minute volume compared to the PCV group ( n = 8) (8.0 vs. 11.6, 95% confidence interval, CI -4.5 to -2.7 l min -1 ; P < 0.001), whereas permissive hypercapnia had to be accepted in PCV ( P aCO 2 5.68 vs. 6.89, 95% CI -1.7 to -0.7 kPa; P < 0.001). The Horowitz index was comparable in both groups but calculated mechanical power was significantly lower in FCV (7.5 vs. 22.0, 95% CI -17.2 to -11.8 J min -1 ; P < 0.001). CONCLUSIONS In this porcine study FCV maintained normocapnia during OLV, whereas permissive hypercapnia had to be accepted in PCV despite a substantially higher minute volume. Reducing exposure of the lungs to mechanical power applied by the ventilator in FCV offers a possible advantage for this mode of ventilation in terms of lung protection.
Collapse
Affiliation(s)
- Patrick Spraider
- From the Department of Anaesthesia and Intensive Care Medicine, Medical University Innsbruck, Austria (PS, JM, JA, GP, MR, SM), Department of Mathematics, Faculty of Mathematics, Computer Science and Physics, University of Innsbruck, Austria (TH), University of Greenwich, UK (TB), Faculty of Medicine, University of Münster, Germany (DE)
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Chen S, Qiu X, Tan X, Fang Z, Jin Y. A model-based hybrid soft actor-critic deep reinforcement learning algorithm for optimal ventilator settings. Inf Sci (N Y) 2022. [DOI: 10.1016/j.ins.2022.08.028] [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]
|
14
|
Grassetto A, Pettenuzzo T, Badii F, Barzaghi F, Carlon R, Dellarole S, Pipitone M, Versaci A, Sella N, Lionello M, Bertolin A. A new perspective during laryngo-tracheal surgery: the use of an ultra-thin endotracheal tube (Tritube®) and flow-controlled ventilation—a retrospective case series and a review of the literature. JOURNAL OF ANESTHESIA, ANALGESIA AND CRITICAL CARE 2022. [PMCID: PMC9411832 DOI: 10.1186/s44158-022-00066-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Abstract
Background
Upper airway surgery often poses a challenge to both anesthesiologists and surgeons, as airway access, mechanical ventilation, and surgical difficulties may occur in a tricky combination. To fulfill the need for a tubeless surgery, techniques such as apneic oxygenation or jet ventilation may be used, which carry the risk of several complications. The ultrathin cuffed endotracheal tube Tritube can be used with flow-controlled ventilation (FCV) to provide adequate surgical field and ventilation. To assess the feasibility, safety, and effectiveness of this technique, we describe a series of 21 patients, with various lung conditions, undergoing laryngo-tracheal surgery with FCV delivered via Tritube. Moreover, we perform a narrative systematic review to summarize clinical data on the use of Tritube during upper airway surgery.
Results
All patients were successfully intubated in one attempt with Tritube. The median (interquartile range [IQR]) tidal volume was 6.7 (6.2–7.1) mL/kg of ideal body weight, the median end-expiratory pressure was 5.3 (5.0–6.4) cmH2O, and the median peak tracheal pressure was 16 (15–18) cmH2O. The median minute volume was 5.3 (5.0–6.4) L/min. Median global alveolar driving pressure was 8 (7–9) cmH2O. The median maximum level of end-tidal CO2 was 39 (35–41) mmHg. During procedures involving laser, the maximum fraction of inspired oxygen was 0.3, with the median lowest peripheral oxygen saturation of 96% (94–96%). No complications associated with intubation or extubation occurred. In one patient, the ventilator needed to be rebooted for a software issue. In two (10%) patients, Tritube needed to be flushed with saline to remove secretions. In all patients, optimal visualization and accessibility of the surgical site were obtained, according to the surgeon in charge. Thirteen studies (seven case reports, two case series, three prospective observational studies, and one randomized controlled trial) were included in the narrative systematic review and described.
Conclusions
Tritube in combination with FCV provided adequate surgical exposure and ventilation in patients undergoing laryngo-tracheal surgery. While training and experience with this new method is needed, FCV delivered with Tritube may represent an ideal approach that benefits surgeons, anesthesiologists, and patients with difficult airways and compromised lung mechanics.
Collapse
|
15
|
Van Dessel ED, De Meyer GR, Morrison SG, Jorens PG, Schepens T. Flow-controlled ventilation in moderate acute respiratory distress syndrome due to COVID-19: an open-label repeated-measures controlled trial. Intensive Care Med Exp 2022; 10:19. [PMID: 35608696 PMCID: PMC9127816 DOI: 10.1186/s40635-022-00449-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 05/09/2022] [Indexed: 01/07/2023] Open
Abstract
Background Flow-controlled ventilation (FCV), a novel mode of mechanical ventilation characterised by constant flow during active expiration, may result in more efficient alveolar gas exchange, better lung recruitment and might be useful in limiting ventilator-induced lung injury. However, data regarding FCV in mechanically ventilated patients with acute lung injury or acute respiratory distress syndrome (ARDS) are scarce. Objectives We hypothesised that the use of FCV is feasible and would improve oxygenation in moderate COVID-19 ARDS compared to conventional ventilation. Design Open-label repeated-measures controlled trial. Setting From February to April 2021, patients with moderate COVID-19 ARDS were recruited in a tertiary referral intensive care unit. Patients Patients with moderate ARDS (PaO2/FIO2 ratio 100–200 mmHg, SpO2 88–94% and PaO2 60–80 mmHg) were considered eligible. Exclusion criteria were: extremes of age (< 18 years, > 80 years), obesity (body mass index > 40 kg/m2), prone positioning at the time of intervention, mechanical ventilation for more than 10 days and extracorporeal membrane oxygenation. Eleven patients were recruited. Intervention Participants were ventilated in FCV mode for 30 min, and subsequently in volume-control mode (VCV) for 30 min. Main outcome measures Feasibility of FCV to maintain oxygenation was assessed by the PaO2/FiO2 ratio (mmHg) as a primary outcome parameter. Secondary outcomes included ventilator parameters, PaCO2 and haemodynamic data. All adverse events were recorded. Results FCV was feasible in all patients and no adverse events were observed. There was no difference in the PaO2/FIO2 ratio after 30 min of ventilation in FCV mode (169 mmHg) compared to 30 min of ventilation in VCV mode subsequently (168 mmHg, 95% CI of pseudo-medians (− 10.5, 3.6), p = 0.56). The tidal volumes (p < 0.01) and minute ventilation were lower during FCV (p = 0.01) while PaCO2 was similar at the end of the 30-min ventilation periods (p = 0.31). Mean arterial pressure during FCV was comparable to baseline. Conclusions Thirty minutes of FCV in patients with moderate COVID-19 ARDS receiving neuromuscular blocking agents resulted in similar oxygenation, compared to VCV. FCV was feasible and did not result in adverse events. Trial registration: Clinicaltrials.gov identifier: NCT04894214.
Collapse
Affiliation(s)
- Eleni D Van Dessel
- Department of Critical Care Medicine, Antwerp University Hospital/University of Antwerp, Drie Eikenstraat 655, 2650, Edegem, Belgium
| | - Gregory R De Meyer
- Department of Critical Care Medicine, Antwerp University Hospital/University of Antwerp, Drie Eikenstraat 655, 2650, Edegem, Belgium.,Department of Anesthesiology, Antwerp University Hospital/University of Antwerp, Edegem, Belgium
| | - Stuart G Morrison
- Department of Anesthesiology, Antwerp University Hospital/University of Antwerp, Edegem, Belgium
| | - Philippe G Jorens
- Department of Critical Care Medicine, Antwerp University Hospital/University of Antwerp, Drie Eikenstraat 655, 2650, Edegem, Belgium
| | - Tom Schepens
- Department of Critical Care Medicine, Antwerp University Hospital/University of Antwerp, Drie Eikenstraat 655, 2650, Edegem, Belgium.
| |
Collapse
|
16
|
Gonzales Carazas MM, Gavidia CM, Davila Fernandez R, Vargas Zuñiga JA, Crespo Paiva A, Bocanegra W, Calderon J, Sanchez E, Perales R, Zeña B, Calcina Isique JF, Reategui J, Castañeda B, Casado FL. Biological evaluation of a mechanical ventilator that operates by controlling an automated manual resuscitator. A descriptive study in swine. PLoS One 2022; 17:e0264774. [PMID: 35239740 PMCID: PMC8893637 DOI: 10.1371/journal.pone.0264774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 02/17/2022] [Indexed: 11/26/2022] Open
Abstract
The Covid-19 outbreak challenged health systems around the world to design and implement cost-effective devices produced locally to meet the increased demand of mechanical ventilators worldwide. This study evaluates the physiological responses of healthy swine maintained under volume- or pressure-controlled mechanical ventilation by a mechanical ventilator implemented to bring life-support by automating a resuscitation bag and closely controlling ventilatory parameters. Physiological parameters were monitored in eight sedated animals (t0) prior to inducing deep anaesthesia, and during the next six hours of mechanical ventilation (t1-7). Hemodynamic conditions were monitored periodically using a portable gas analyser machine (i.e. BEecf, carbonate, SaO2, lactate, pH, PaO2, PaCO2) and a capnometer (i.e. ETCO2). Electrocardiogram, echocardiography and lung ultrasonography were performed to detect in vivo alterations in these vital organs and pathological findings from necropsy were reported. The mechanical ventilator properly controlled physiological levels of blood biochemistry such as oxygenation parameters (PaO2, PaCO2, SaO2, ETCO2), acid-base equilibrium (pH, carbonate, BEecf), and perfusion of tissues (lactate levels). In addition, histopathological analysis showed no evidence of acute tissue damage in lung, heart, liver, kidney, or brain. All animals were able to breathe spontaneously after undergoing mechanical ventilation. These preclinical data, supports the biological safety of the medical device to move forward to further evaluation in clinical studies.
Collapse
Affiliation(s)
| | - Cesar Miguel Gavidia
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | | | | | | | - William Bocanegra
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Joan Calderon
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Evelyn Sanchez
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Rosa Perales
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Brandon Zeña
- Instituto Veterinario de Oftalmologia (IVO), Lima, Peru
| | | | | | - Benjamin Castañeda
- Institute of Omics and Applied Biotechnology, Pontificia Universidad Catolica del Peru, Lima, Peru
- Department of Engineering, Pontificia Universidad Catolica del Peru, Lima, Peru
| | - Fanny L. Casado
- Institute of Omics and Applied Biotechnology, Pontificia Universidad Catolica del Peru, Lima, Peru
- Department of Engineering, Pontificia Universidad Catolica del Peru, Lima, Peru
- * E-mail:
| |
Collapse
|
17
|
Schranc Á, Balogh ÁL, Diaper J, Südy R, Peták F, Habre W, Albu G. Flow-controlled ventilation maintains gas exchange and lung aeration in a pediatric model of healthy and injured lungs: A randomized cross-over experimental study. Front Pediatr 2022; 10:1005135. [PMID: 36160799 PMCID: PMC9500311 DOI: 10.3389/fped.2022.1005135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 08/24/2022] [Indexed: 11/30/2022] Open
Abstract
Flow-controlled ventilation (FCV) is characterized by a constant flow to generate active inspiration and expiration. While the benefit of FCV on gas exchange has been demonstrated in preclinical and clinical studies with adults, the value of this modality for a pediatric population remains unknown. Thus, we aimed at observing the effects of FCV as compared to pressure-regulated volume control (PRVC) ventilation on lung mechanics, gas exchange and lung aeration before and after surfactant depletion in a pediatric model. Ten anesthetized piglets (10.4 ± 0.2 kg) were randomly assigned to start 1-h ventilation with FCV or PRVC before switching the ventilation modes for another hour. This sequence was repeated after inducing lung injury by bronchoalveolar lavage and injurious ventilation. The primary outcome was respiratory tissue elastance. Secondary outcomes included oxygenation index (PaO2/FiO2), PaCO2, intrapulmonary shunt (Qs/Qt), airway resistance, respiratory tissue damping, end-expiratory lung volume, lung clearance index and lung aeration by chest electrical impedance tomography. Measurements were performed at the end of each protocol stage. Ventilation modality had no effect on any respiratory mechanical parameter. Adequate gas exchange was provided by FCV, similar to PRVC, with sufficient CO2 elimination both in healthy and surfactant-depleted lungs (39.46 ± 7.2 mmHg and 46.2 ± 11.4 mmHg for FCV; 36.0 ± 4.1 and 39.5 ± 4.9 mmHg, for PRVC, respectively). Somewhat lower PaO2/FiO2 and higher Qs/Qt were observed in healthy and surfactant depleted lungs during FCV compared to PRVC (p < 0.05, for all). Compared to PRVC, lung aeration was significantly elevated, particularly in the ventral dependent zones during FCV (p < 0.05), but this difference was not evidenced in injured lungs. Somewhat lower oxygenation and higher shunt ratio was observed during FCV, nevertheless lung aeration improved and adequate gas exchange was ensured. Therefore, in the absence of major differences in respiratory mechanics and lung volumes, FCV may be considered as an alternative in ventilation therapy of pediatric patients with healthy and injured lungs.
Collapse
Affiliation(s)
- Álmos Schranc
- Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
| | - Ádám L Balogh
- Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
| | - John Diaper
- Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
| | - Roberta Südy
- Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland
| | - Ferenc Peták
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Walid Habre
- Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland.,Pediatric Anesthesia Unit, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University Hospitals of Geneva, Geneva, Switzerland
| | - Gergely Albu
- Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University of Geneva, Geneva, Switzerland.,Division of Anesthesiology, Department of Anesthesiology, Pharmacology, Intensive Care and Emergency Medicine, University Hospitals of Geneva, Geneva, Switzerland
| |
Collapse
|
18
|
Spraider P, Putzer G, Breitkopf R, Abram J, Mathis S, Glodny B, Martini J. A case report of individualized ventilation in a COVID-19 patient - new possibilities and caveats to consider with flow-controlled ventilation. BMC Anesthesiol 2021; 21:145. [PMID: 33980178 PMCID: PMC8113787 DOI: 10.1186/s12871-021-01365-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/05/2021] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Flow-controlled ventilation (FCV) is a novel ventilation method increasingly being used clinically, particularly during the current COVID-19 pandemic. However, the continuous flow pattern in FCV during inspiration and expiration has a significant impact on respiratory parameters and ventilatory settings compared to conventional ventilation modes. In addition, the constant flow combined with direct intratracheal pressure measurement allows determination of dynamic compliance and ventilation settings can be adjusted accordingly, reflecting a personalized ventilation approach. CASE PRESENTATION A 50-year old women with confirmed SARS-CoV-2 infection suffering from acute respiratory distress syndrome (ARDS) was admitted to a tertiary medical center. Initial ventilation occurred with best standard of care pressure-controlled ventilation (PCV) and was then switched to FCV, by adopting PCV ventilator settings. This led to an increase in oxygenation by 30 %. Subsequently, to reduce invasiveness of mechanical ventilation, FCV was individualized by dynamic compliance guided adjustment of both, positive end-expiratory pressure and peak pressure; this intervention reduced driving pressure from 18 to 12 cm H2O. However, after several hours, compliance further deteriorated which resulted in a tidal volume of only 4.7 ml/kg. CONCLUSIONS An individualized FCV approach increased oxygenation parameters in a patient suffering from severe COVID-19 related ARDS. Direct intratracheal pressure measurements allow for determination of dynamic compliance and thus optimization of ventilator settings, thereby reducing applied and dissipated energy. However, although desirable, this personalized ventilation strategy may reach its limits when lung function is so severely impaired that patient's oxygenation has to be ensured at the expense of lung protective ventilation concepts.
Collapse
Affiliation(s)
- Patrick Spraider
- Department of Anaesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria.
| | - Gabriel Putzer
- Department of Anaesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Robert Breitkopf
- Department of Anaesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Julia Abram
- Department of Anaesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Simon Mathis
- Department of Anaesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Bernhard Glodny
- Department of Radiology, Medical University Innsbruck, Innsbruck, Austria
| | - Judith Martini
- Department of Anaesthesiology and Intensive Care Medicine, Medical University Innsbruck, Innsbruck, Austria
| |
Collapse
|
19
|
Flow-controlled ventilation with the Evone ventilator and Tritube versus volume-controlled ventilation: A clinical cross-over pilot study describing oxygenation, ventilation and haemodynamic variables. Eur J Anaesthesiol 2021; 38:209-211. [PMID: 33394805 DOI: 10.1097/eja.0000000000001326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
20
|
Tsuboi N, Tsuboi K, Nosaka N, Nishimura N, Nakagawa S. The Ventilatory Strategy to Minimize Expiratory Flow Rate in Ventilated Patients with Chronic Obstructive Pulmonary Disease. Int J Chron Obstruct Pulmon Dis 2021; 16:301-304. [PMID: 33603356 PMCID: PMC7886110 DOI: 10.2147/copd.s296343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 01/25/2021] [Indexed: 01/15/2023] Open
Abstract
Although the pathophysiology of chronic obstructive pulmonary disease (COPD) is multifactorial, central airway collapse is reported to have a great impact on symptom severity. In COPD patients, positive pressure formed by hyperinflated lungs compressing the tracheal wall and negative changes in intratracheal static pressure due to rapid expiratory flow velocity at the beginning of expiration collapse the trachea. This phenomenon can be explained by fluid dynamics theory. Our hypothesis is that ventilatory strategy focusing on minimization of expiratory flow rate may be advantageous for patients receiving mechanical ventilation for COPD. If appropriate counter pressure could be applied on exhalation, patients may be able to exhale slowly with reduced expiratory flow rates which may prevent negative changes of the intratracheal static pressure. We devised a new conceptual ventilation mode “minimized expiratory flow rate ventilation (MExV)” which applies regulated counter pressure on exhalation. The conceptual waveforms of “minimized expiratory flow rate ventilation” including flow rate, volume, and airway pressure are shown, compared with typical waveforms of the conventional ventilation modes.
Collapse
Affiliation(s)
- Norihiko Tsuboi
- Critical Care Medicine, National Center for Child Health and Development, Tokyo, Japan
| | - Kaoru Tsuboi
- Critical Care Medicine, National Center for Child Health and Development, Tokyo, Japan
| | - Nobuyuki Nosaka
- Critical Care Medicine, National Center for Child Health and Development, Tokyo, Japan.,Department of Intensive Care Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Nao Nishimura
- Critical Care Medicine, National Center for Child Health and Development, Tokyo, Japan
| | - Satoshi Nakagawa
- Critical Care Medicine, National Center for Child Health and Development, Tokyo, Japan
| |
Collapse
|
21
|
Spraider P, Martini J, Abram J, Putzer G, Glodny B, Hell T, Barnes T, Enk D. Individualized flow-controlled ventilation compared to best clinical practice pressure-controlled ventilation: a prospective randomized porcine study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2020; 24:662. [PMID: 33239039 PMCID: PMC7686826 DOI: 10.1186/s13054-020-03325-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 10/04/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND Flow-controlled ventilation is a novel ventilation method which allows to individualize ventilation according to dynamic lung mechanic limits based on direct tracheal pressure measurement at a stable constant gas flow during inspiration and expiration. The aim of this porcine study was to compare individualized flow-controlled ventilation (FCV) and current guideline-conform pressure-controlled ventilation (PCV) in long-term ventilation. METHODS Anesthetized pigs were ventilated with either FCV or PCV over a period of 10 h with a fixed FiO2 of 0.3. FCV settings were individualized by compliance-guided positive end-expiratory pressure (PEEP) and peak pressure (Ppeak) titration. Flow was adjusted to maintain normocapnia and the inspiration to expiration ratio (I:E ratio) was set at 1:1. PCV was performed with a PEEP of 5 cm H2O and Ppeak was set to achieve a tidal volume (VT) of 7 ml/kg. The respiratory rate was adjusted to maintain normocapnia and the I:E ratio was set at 1:1.5. Repeated measurements during observation period were assessed by linear mixed-effects model. RESULTS In FCV (n = 6), respiratory minute volume was significantly reduced (6.0 vs 12.7, MD - 6.8 (- 8.2 to - 5.4) l/min; p < 0.001) as compared to PCV (n = 6). Oxygenation was improved in the FCV group (paO2 119.8 vs 96.6, MD 23.2 (9.0 to 37.5) Torr; 15.97 vs 12.87, MD 3.10 (1.19 to 5.00) kPa; p = 0.010) and CO2 removal was more efficient (paCO2 40.1 vs 44.9, MD - 4.7 (- 7.4 to - 2.0) Torr; 5.35 vs 5.98, MD - 0.63 (- 0.99 to - 0.27) kPa; p = 0.006). Ppeak and driving pressure were comparable in both groups, whereas PEEP was significantly lower in FCV (p = 0.002). Computed tomography revealed a significant reduction in non-aerated lung tissue in individualized FCV (p = 0.026) and no significant difference in overdistended lung tissue, although a significantly higher VT was applied (8.2 vs 7.6, MD 0.7 (0.2 to 1.2) ml/kg; p = 0.025). CONCLUSION Our long-term ventilation study demonstrates the applicability of a compliance-guided individualization of FCV settings, which resulted in significantly improved gas exchange and lung tissue aeration without signs of overinflation as compared to best clinical practice PCV.
Collapse
Affiliation(s)
- Patrick Spraider
- Department of Anaesthesia and Intensive Care Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Judith Martini
- Department of Anaesthesia and Intensive Care Medicine, Medical University of Innsbruck, Innsbruck, Austria.
| | - Julia Abram
- Department of Anaesthesia and Intensive Care Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Gabriel Putzer
- Department of Anaesthesia and Intensive Care Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Bernhard Glodny
- Department of Radiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Tobias Hell
- Department of Mathematics, Faculty of Mathematics, Computer Science and Physics, University of Innsbruck, Innsbruck, Austria
| | | | - Dietmar Enk
- Faculty of Medicine, University of Münster, Münster, Germany
| |
Collapse
|
22
|
Weber J, Straka L, Borgmann S, Schmidt J, Wirth S, Schumann S. Flow-controlled ventilation (FCV) improves regional ventilation in obese patients - a randomized controlled crossover trial. BMC Anesthesiol 2020; 20:24. [PMID: 31992213 PMCID: PMC6986135 DOI: 10.1186/s12871-020-0944-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 01/16/2020] [Indexed: 12/13/2022] Open
Abstract
Background In obese patients, high closing capacity and low functional residual capacity increase the risk for expiratory alveolar collapse. Constant expiratory flow, as provided by the new flow-controlled ventilation (FCV) mode, was shown to improve lung recruitment. We hypothesized that lung aeration and respiratory mechanics improve in obese patients during FCV. Methods We compared FCV and volume-controlled (VCV) ventilation in 23 obese patients in a randomized crossover setting. Starting with baseline measurements, ventilation settings were kept identical except for the ventilation mode related differences (VCV: inspiration to expiration ratio 1:2 with passive expiration, FCV: inspiration to expiration ratio 1:1 with active, linearized expiration). Primary endpoint of the study was the change of end-expiratory lung volume compared to baseline ventilation. Secondary endpoints were the change of mean lung volume, respiratory mechanics and hemodynamic variables. Results The loss of end-expiratory lung volume and mean lung volume compared to baseline was lower during FCV compared to VCV (end-expiratory lung volume: FCV, − 126 ± 207 ml; VCV, − 316 ± 254 ml; p < 0.001, mean lung volume: FCV, − 108.2 ± 198.6 ml; VCV, − 315.8 ± 252.1 ml; p < 0.001) and at comparable plateau pressure (baseline, 19.6 ± 3.7; VCV, 20.2 ± 3.4; FCV, 20.2 ± 3.8 cmH2O; p = 0.441), mean tracheal pressure was higher (baseline, 13.1 ± 1.1; VCV, 12.9 ± 1.2; FCV, 14.8 ± 2.2 cmH2O; p < 0.001). All other respiratory and hemodynamic variables were comparable between the ventilation modes. Conclusions This study demonstrates that, compared to VCV, FCV improves regional ventilation distribution of the lung at comparable PEEP, tidal volume, PPlat and ventilation frequency. The increase in end-expiratory lung volume during FCV was probably caused by the increased mean tracheal pressure which can be attributed to the linearized expiratory pressure decline. Trial registration German Clinical Trials Register: DRKS00014925. Registered 12 July 2018.
Collapse
Affiliation(s)
- Jonas Weber
- Department of Anesthesiology and Critical Care, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - Leonie Straka
- Department of Anesthesiology and Critical Care, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Silke Borgmann
- Department of Anesthesiology and Critical Care, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Johannes Schmidt
- Department of Anesthesiology and Critical Care, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Steffen Wirth
- Department of Anesthesiology and Critical Care, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Stefan Schumann
- Department of Anesthesiology and Critical Care, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| |
Collapse
|