1
|
Alsaker M, Cárdenas DAC, Furuie SS, Mueller JL. Complementary use of priors for pulmonary imaging with electrical impedance and ultrasound computed tomography. JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS 2021; 395:113591. [PMID: 34092904 PMCID: PMC8177074 DOI: 10.1016/j.cam.2021.113591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
For medical professionals caring for patients undergoing mechanical ventilation due to respiratory failure, the ability to quickly and safely obtain images of pulmonary function at the patient's bedside would be highly desirable. Such images could be used to provide early warnings of developing pulmonary pathologies in real time, thereby reducing the incidence of complications and improving patient outcomes. Electrical impedance tomography (EIT) and low-frequency ultrasound computed tomography (USCT) are two imaging techniques with the potential to provide real-time non-ionizing pulmonary monitoring in the ICU setting, and each method has its own unique advantages as well as drawbacks. In this work, we describe a new algorithm for a system in which the strengths of the two modalities are combined in a complementary fashion. Specifically, preliminary reconstructions from each modality are used as priors to stabilize subsequent reconstructions, providing improved spatial resolution, sharper organ boundaries, and enhanced appearance of pathologies and other features. Results are validated using three numerically simulated thoracic phantoms representing pulmonary pathologies.
Collapse
Affiliation(s)
- Melody Alsaker
- Department of Mathematics; Gonzaga University, Spokane, WA 99258 USA
| | | | | | - Jennifer L. Mueller
- Department of Mathematics and School of Biomedical Engineering, Colorado State University, CO 80523 USA
| |
Collapse
|
2
|
Shi Y, Yang Z, Xie F, Ren S, Xu S. The Research Progress of Electrical Impedance Tomography for Lung Monitoring. Front Bioeng Biotechnol 2021; 9:726652. [PMID: 34660553 PMCID: PMC8517404 DOI: 10.3389/fbioe.2021.726652] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/09/2021] [Indexed: 01/16/2023] Open
Abstract
Medical imaging can intuitively show people the internal structure, morphological information, and organ functions of the organism, which is one of the most important inspection methods in clinical medical diagnosis. Currently used medical imaging methods can only be applied to some diagnostic occasions after qualitative lesions have been generated, and the general imaging technology is usually accompanied by radiation and other conditions. However, electrical impedance tomography has the advantages of being noninvasive and non-radiative. EIT (Electrical Impedance Tomography) is also widely used in the early diagnosis and treatment of some diseases because of these advantages. At present, EIT is relatively mature and more and more image reconstruction algorithms are used to improve imaging resolution. Hardware technology is also developing rapidly, and the accuracy of data collection and processing is continuously improving. In terms of clinical application, EIT has also been used for pathological treatment of lungs, the brain, and the bladder. In the future, EIT has a good application prospect in the medical field, which can meet the needs of real-time, long-term monitoring and early diagnosis. Aiming at the application of EIT in the treatment of lung pathology, this article reviews the research progress of EIT, image reconstruction algorithms, hardware system design, and clinical applications used in the treatment of lung diseases. Through the research and introduction of several core components of EIT technology, it clarifies the characteristics of EIT system complexity and its solutions, provides research ideas for subsequent research, and once again verifies the broad development prospects of EIT technology in the future.
Collapse
Affiliation(s)
- Yan Shi
- The School of Automation Science and Electrical Engineering, Beihang University, Beijing, China
| | - ZhiGuo Yang
- The School of Automation Science and Electrical Engineering, Beihang University, Beijing, China
| | - Fei Xie
- Department of Pulmonary and Critical Care Medicine, Chinese PLA General Hospital, Beijing, China
| | - Shuai Ren
- The School of Automation Science and Electrical Engineering, Beihang University, Beijing, China
- State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, China
| | - ShaoFeng Xu
- The School of Automation Science and Electrical Engineering, Beihang University, Beijing, China
| |
Collapse
|
3
|
Martinsson A, Houltz E, Wallinder A, Lindgren S, Thorén A. Lung recruitment in the prone position after cardiac surgery: a randomised controlled study. Br J Anaesth 2021; 126:1067-1074. [PMID: 33602580 DOI: 10.1016/j.bja.2020.12.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Atelectasis after cardiac surgery is common and promotes ventilation/perfusion mismatch, infection, and delayed discharge from critical care. Recruitment manoeuvres are often performed to reduce atelectasis. In severe respiratory failure, recruitment manoeuvres in the prone position may increase oxygenation, survival, or both. We compared the effects of recruitment manoeuvres in the prone vs supine position on lung aeration and oxygenation in cardiac surgical patients. METHODS Subjects were randomised to recruitment manoeuvres (40 cm H2O peak inspiratory pressure and 20 cm H2O PEEP for 30 s) in either the prone or supine position after uncomplicated cardiac surgery. The co-primary endpoints were lung aeration (end-expiratory lung volume measured by electrical impedance tomography (arbitrary units [a.u.]) and lung oxygenation (ratio of arterial oxygen partial pressure to fractional inspired oxygen [Pao2/FiO2 ratio]). Secondary outcomes included postoperative oxygen requirement and adverse events. RESULTS Thirty subjects (27% female; age, 48-81 yr) were recruited. Dorsal lung tidal volume was higher after prone recruitment manoeuvres (363 a.u.; 95% confidence intervals [CI], 283-443; n=15) after extubation, compared with supine recruitment manoeuvres (212 a.u.; 95% CI, 170-254; n=15; P<0.001). Prone recruitment manoeuvres increased dorsal end-expiratory lung volume by 724 a.u. (95% CI, 456-992) after extubation, compared with 163 a.u. decrease (95% CI, 73-252) after supine recruitment manoeuvres (P<0.001). The Pao2/FiO2 ratio after extubation was higher after prone recruitment manoeuvres (46.6; 95% CI, 40.7-53.0) compared with supine recruitment manoeuvres (39.3; 95% CI, 34.8-43.8; P=0.04). Oxygen therapy after extubation was shorter after prone (33 h [13]) vs supine recruitment manoeuvres (52 h [22]; P=0.01). No adverse events occurred. CONCLUSIONS Recruitment manoeuvres in the prone position after cardiac surgery improve lung aeration and oxygenation. CLINICAL TRIAL REGISTRATION NCT03009331.
Collapse
Affiliation(s)
- Andreas Martinsson
- Department of Anaesthesiology and Intensive Care Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Erik Houltz
- Department of Anaesthesiology and Intensive Care Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Andreas Wallinder
- Department of Cardiothoracic Surgery, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Sophie Lindgren
- Department of Anaesthesiology and Intensive Care Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Anders Thorén
- Department of Anaesthesiology and Intensive Care Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden.
| |
Collapse
|
4
|
Mellenthin MM, Mueller JL, de Camargo EDLB, de Moura FS, Santos TBR, Lima RG, Hamilton SJ, Muller PA, Alsaker M. The ACE1 Electrical Impedance Tomography System for Thoracic Imaging. IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2019; 68:3137-3150. [PMID: 33223563 PMCID: PMC7678726 DOI: 10.1109/tim.2018.2874127] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The design and performance of the ACE1 (Active Complex Electrode) electrical impedance tomography system for single-ended phasic voltage measurements is presented. The design of the hardware and calibration procedures allow for reconstruction of conductivity and permittivity images. Phase measurement is achieved with the ACE1 active electrode circuit which measures the amplitude and phase of the voltage and the applied current at the location at which current is injected into the body. An evaluation of the system performance under typical operating conditions includes details of demodulation and calibration and an in-depth look at insightful metrics, such as signal-to-noise ratio variations during a single current pattern. Static and dynamic images of conductivity and permittivity are presented from ACE1 data collected on tank phantoms and human subjects to illustrate the system's utility.
Collapse
Affiliation(s)
| | - Jennifer L Mueller
- Department of Mathematics and School of Biomedical Engineering and the Department of Electrical and Computer Engineering, Colorado State University, CO 80523 USA
| | | | - Fernando Silva de Moura
- Center for Engineering, Modeling and Applied Social Sciences, Federal University of ABC, São Paulo, Brazil
| | | | - Raul Gonzalez Lima
- Mechanical Engineering Department, University of São Paulo, São Paulo, Brazil
| | - Sarah J Hamilton
- Department of Mathematics, Statistics, and Computer Science; Marquette University, Milwaukee, WI, 53233 USA
| | - Peter A Muller
- Department of Mathematics, Colorado State University, CO 80523 USA
| | - Melody Alsaker
- Department of Mathematics, Colorado State University, Fort Collins, C0, 80523 USA
| |
Collapse
|
5
|
Acceleration sensors in abdominal wall position as a non-invasive approach to detect early breathing alterations induced by intolerance of increased airway resistance. J Cardiothorac Surg 2017; 12:96. [PMID: 29126451 PMCID: PMC5681836 DOI: 10.1186/s13019-017-0658-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 11/01/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Early detection of respiratory overload is crucial to mechanically ventilated patients, especially during phases of spontaneous breathing. Although a diversity of methods and indices has been established, there is no highly specific approach to predict respiratory failure. This study aimed to evaluate acceleration sensors in abdominal and thoracic wall positions to detect alterations in breathing excursions in a setting of gradual increasing airway resistance. METHODS Twenty-nine healthy volunteers were committed to a standardized protocol of a two-minutes step-down spontaneous breathing on a 5 mm, 4 mm and then 3 mm orally placed endotracheal tube. Accelerator sensors in thoracic and abdominal wall position monitored breathing excursions. 15 participants passed the breathing protocol ("completed" group), 14 individuals cancelled the protocol due to subjective intolerance to the increasing airway resistance ("abandoned" group). RESULTS Gradual increased respiratory workload led to a significant decrease of acceleration in abdominal wall position in the "abandoned" group compared to the "completed" group (p < 0.001), while these gradual accelerating changes were not observed in thoracic wall position (p = 0.484). Thoracic acceleration sensors did not detect any time- and group-specific changes (p = 0.746). CONCLUSIONS The abdominal wall position of the acceleration sensors may be a non-invasive, economical and practical approach to detect early breathing alterations prior to respiratory failure. TRIAL REGISTRATION EK 309-15; by the Ethics Committee of the Faculty of Medicine, RWTH Aachen, Aachen, Germany. Retrospectively registered 28th of December 2015.
Collapse
|
6
|
Electrical impedance tomography and trans-pulmonary pressure measurements in a patient with extreme respiratory drive. Respir Med Case Rep 2017; 20:141-144. [PMID: 28224077 PMCID: PMC5304242 DOI: 10.1016/j.rmcr.2017.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 01/13/2017] [Accepted: 01/13/2017] [Indexed: 11/13/2022] Open
Abstract
Preserving spontaneous breathing during mechanical ventilation prevents muscle atrophy of the diaphragm, but may lead to ventilator induced lung injury (VILI). We present a case in which monitoring of trans-pulmonary pressure and ventilation distribution using Electrical Impedance Tomography (EIT) provided essential information for preventing VILI.
Collapse
|
7
|
Physiological Effects of the Open Lung Approach in Patients with Early, Mild, Diffuse Acute Respiratory Distress Syndrome: An Electrical Impedance Tomography Study. Anesthesiology 2016; 123:1113-21. [PMID: 26397017 DOI: 10.1097/aln.0000000000000862] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND To test the hypothesis that in early, mild, acute respiratory distress syndrome (ARDS) patients with diffuse loss of aeration, the application of the open lung approach (OLA) would improve homogeneity in lung aeration and lung mechanics, without affecting hemodynamics. METHODS Patients were ventilated according to the ARDS Network protocol at baseline (pre-OLA). OLA consisted in a recruitment maneuver followed by a decremental positive end-expiratory pressure trial. Respiratory mechanics, gas exchange, electrical impedance tomography (EIT), cardiac index, and stroke volume variation were measured at baseline and 20 min after OLA implementation (post-OLA). Esophageal pressure was used for lung and chest wall elastance partitioning. The tomographic lung image obtained at the fifth intercostal space by EIT was divided in two ventral and two dorsal regions of interest (ROIventral and ROIDorsal). RESULTS Fifteen consecutive patients were studied. The OLA increased arterial oxygen partial pressure/inspired oxygen fraction from 216 ± 13 to 311 ± 19 mmHg (P < 0.001) and decreased elastance of the respiratory system from 29.4 ± 3 cm H2O/l to 23.6 ± 1.7 cm H2O/l (P < 0.01). The driving pressure (airway opening plateau pressure - total positive end-expiratory pressure) decreased from 17.9 ± 1.5 cm H2O pre-OLA to 15.4 ± 2.1 post-OLA (P < 0.05). The tidal volume fraction reaching the dorsal ROIs increased, and consequently the ROIVentral/Dorsal impedance tidal variation decreased from 2.01 ± 0.36 to 1.19 ± 0.1 (P < 0.01). CONCLUSIONS The OLA decreases the driving pressure and improves the oxygenation and lung mechanics in patients with early, mild, diffuse ARDS. EIT is useful to assess the impact of OLA on regional tidal volume distribution.
Collapse
|
8
|
Karsten J, Stueber T, Voigt N, Teschner E, Heinze H. Influence of different electrode belt positions on electrical impedance tomography imaging of regional ventilation: a prospective observational study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2016; 20:3. [PMID: 26743570 PMCID: PMC4705633 DOI: 10.1186/s13054-015-1161-9] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 12/04/2015] [Indexed: 12/03/2022]
Abstract
Background Electrical impedance tomography (EIT) is a non-invasive bedside tool which allows an individualized ventilator strategy by monitoring tidal ventilation and lung aeration. EIT can be performed at different cranio-caudal thoracic levels, but data are missing about the optimal belt position. The main goal of this prospective observational study was to evaluate the impact of different electrode layers on tidal impedance variation in relation to global volume changes in order to propose a proper belt position for EIT measurements. Methods EIT measurements were performed in 15 mechanically ventilated intensive care patients with the electrode belt at different thoracic layers (L1-L7). All respiratory and hemodynamic parameters were recorded. Blood gas analyses were obtained once at the beginning of EIT examination. Off-line tidal impedance variation/tidal volume (TV/VT) ratio was calculated, and specific patterns of impedance distribution due to automatic and user-defined adjustment of the colour scale for EIT images were identified. Results TV/VT ratio is the highest at L1. It decreases in caudal direction. At L5, the decrease of TV/VT ratio is significant. We could identify patterns of diaphragmatic interference with ventilation-related impedance changes, which owing to the automatically adjusted colour scales are not obvious in the regularly displayed EIT images. Conclusions The clinical usability and plausibility of EIT measurements depend on proper belt position, proper impedance visualisation, correct analysis and data interpretation. When EIT is used to estimate global parameters like VT or changes in end-expiratory lung volume, the best electrode plane is between the 4th and 5th intercostal space. The specific colour coding occasionally suppresses user-relevant information, and manual rescaling of images is necessary to visualise this information.
Collapse
Affiliation(s)
- Jan Karsten
- Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - Thomas Stueber
- Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - Nicolas Voigt
- Department of Anaesthesiology and Intensive Care Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - Eckhard Teschner
- Draeger Medical GmbH, Moislinger Allee 53, 23558, Lübeck, Germany.
| | - Hermann Heinze
- Department of Anaesthesiology and Intensive Care Medicine, University of Lübeck, Ratzeburger Allee 160, 23538, Lübeck, Germany.
| |
Collapse
|
9
|
Karsten J, Grusnick C, Paarmann H, Heringlake M, Heinze H. Positive end-expiratory pressure titration at bedside using electrical impedance tomography in post-operative cardiac surgery patients. Acta Anaesthesiol Scand 2015; 59:723-32. [PMID: 25867049 DOI: 10.1111/aas.12518] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 12/29/2014] [Accepted: 02/16/2015] [Indexed: 11/26/2022]
Abstract
BACKGROUND Post-operative positive end-expiratory pressure (PEEP) setting to minimize the risk of ventilator-associated lung injury is still controversial. Assessment of regional ventilation distribution by electrical impedance tomography (EIT) might be superior as compared with global parameters. The aim of this prospective observational study was to compare global dynamic compliance (CRS ) with different EIT indices during a short clinical applicable descending PEEP trial. METHODS Twenty mechanically ventilated patients after elective cardiac surgery received a standard recruitment manoeuvre (RM) following descending PEEP trial in steps of 2 cmH2 O from PEEP 14 cmH2 O to 6 cmH2 O. During baseline and all PEEP steps, CRS was assessed and regional ventilation distribution was measured by means of EIT. The individual 'best' PEEP values for the derived EIT indices and CRS were calculated and compared. RESULTS The descending PEEP trial lasted less than 10 min. CRS increased after the RM and showed a maximum value at PEEP 8 cmH2 O. Ventilation distribution shifted more to dependent lung regions after RM and back to more non-dependent regions during the PEEP trial. Individual 'best' PEEP by CRS showed significantly lower values than 'best' PEEP by ventilation distribution measured with EIT indices. CONCLUSION During a short descending PEEP trial at bedside, EIT is capable of following the status of regional ventilation distribution in ventilated patients. The 'best' PEEP value identified by individual maximum CRS was lower than optimal PEEP levels as determined by means of EIT indices. EIT could help setting PEEP in post-operative ventilated patients.
Collapse
Affiliation(s)
- J. Karsten
- Department of Anaesthesiology and Intensive Care; Hannover Medical School; Hannover Germany
| | - C. Grusnick
- Department of Anaesthesiology and Intensive Care; University of Lübeck; Lübeck Germany
| | - H. Paarmann
- Department of Anaesthesiology and Intensive Care; University of Lübeck; Lübeck Germany
| | - M. Heringlake
- Department of Anaesthesiology and Intensive Care; University of Lübeck; Lübeck Germany
| | - H. Heinze
- Department of Anaesthesiology and Intensive Care; University of Lübeck; Lübeck Germany
| |
Collapse
|
10
|
Galvagno SM, Brayanov J, Corneille MG, Voscopoulos CJ, Sordo S, Ladd D, Freeman J. Non-invasive respiratory volume monitoring in patients with traumatic thoracic injuries. TRAUMA-ENGLAND 2015. [DOI: 10.1177/1460408614551977] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background Respiratory decompensation is common after traumatic thoracic injuries such as multiple rib fractures and pulmonary contusions. A continuous, non-invasive, impedance-based respiratory volume monitor generates right and left tidal volume measurements, reflecting air exchange in the lungs and derives an instantaneous respiratory rate. The feasibility of using unilateral respiratory volume monitor–based tidal impedance measurements to monitor respiratory status in trauma patients is evaluated. Methods Three intensive care unit patients with three or more rib fractures following blunt trauma had continuous respiratory volume monitor measurements with a novel non-invasive impedance-based device (ExSpiron, Respiratory Motion Inc., Waltham, MA) and corresponding clinical data to permit analysis. Tidal impedance measurements were collected from both the injured and non-injured sides and converted into bilateral respiratory volume monitor measurements using advanced algorithms. Results In Patient 1, following evacuation of a pneumothorax, the respiratory volume monitor showed a significant increase in tidal measurements coupled with a compensatory decrease in tidal measurements on the uninjured side and a decrease in respiratory rate. In Patient 2, tidal measurements were only slightly decreased on both the injured side and uninjured side; respiratory rate remained unchanged. This patient remained stable and required no intervention. Patient 3 demonstrated a sustained decrease in tidal measurements on the injured side that corresponded with radiograph findings and clinical deterioration leading to the need for endotracheal intubation. Conclusions The results from these cases demonstrate that respiratory volume monitor can generate unilateral respiratory tidal measurements and respiratory rate in patients with traumatic thoracic injuries. Continuous respiratory volume monitor in patients with thoracic trauma has strong potential for application in the military, aeromedical, and other austere environments where respiratory monitoring is problematic. Future studies to investigate the utility of this technology are warranted.
Collapse
Affiliation(s)
- Samuel M Galvagno
- Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD, USA
- Program in Trauma, Shock Trauma Center Divisions of Trauma Anesthesiology and Critical Care Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
- United States Air Force Reserve, Davis Monthan Air Force Base, AZ, USA
| | | | - Michael G Corneille
- Department of Surgery, University of Texas Health Science Center, San Antonio, TX, USA
| | - Christopher J Voscopoulos
- Department of Anesthesiology, Pain and Perioperative Medicine, Brigham and Woman’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Salvador Sordo
- Department of Surgery, University of Texas Health Science Center, San Antonio, TX, USA
| | - Diane Ladd
- Respiratory Motion, Inc., Waltham, MA, USA
- West Virginia University, Morgantown, WV, USA
| | | |
Collapse
|
11
|
Dostal P, Truhlar A, Polak J, Sedlak V, Turek Z. Assessment of regional ventilation with the electrical impedance tomography in a patient after asphyxial cardiac arrest. Resuscitation 2014; 85:e115-7. [PMID: 24830867 DOI: 10.1016/j.resuscitation.2014.04.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 04/29/2014] [Indexed: 10/25/2022]
Affiliation(s)
- Pavel Dostal
- Department of Anaesthesiology and Intensive Care Medicine, Charles University Prague, Faculty of Medicine Hradec Kralove, University Hospital Hradec Kralove, Czech Republic
| | - Anatolij Truhlar
- Department of Anaesthesiology and Intensive Care Medicine, Charles University Prague, Faculty of Medicine Hradec Kralove, University Hospital Hradec Kralove, Czech Republic; Emergency Medical Services of the Hradec Kralove Region, Hradec Kralove, Czech Republic.
| | - Josef Polak
- Department of Anaesthesiology and Intensive Care Medicine, Charles University Prague, Faculty of Medicine Hradec Kralove, University Hospital Hradec Kralove, Czech Republic
| | - Vratislav Sedlak
- Department of Pulmonary Medicine, Charles University Prague, Faculty of Medicine Hradec Kralove, University Hospital Hradec Kralove, Czech Republic
| | - Zdenek Turek
- Department of Anaesthesiology and Intensive Care Medicine, Charles University Prague, Faculty of Medicine Hradec Kralove, University Hospital Hradec Kralove, Czech Republic
| |
Collapse
|
12
|
Schaefer MS, Wania V, Bastin B, Schmalz U, Kienbaum P, Beiderlinden M, Treschan TA. Electrical impedance tomography during major open upper abdominal surgery: a pilot-study. BMC Anesthesiol 2014; 14:51. [PMID: 25018668 PMCID: PMC4094413 DOI: 10.1186/1471-2253-14-51] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 07/02/2014] [Indexed: 11/16/2022] Open
Abstract
Background Electrical impedance tomography (EIT) of the lungs facilitates visualization of ventilation distribution during mechanical ventilation. Its intraoperative use could provide the basis for individual optimization of ventilator settings, especially in patients at risk for ventilation-perfusion mismatch and impaired gas exchange, such as patients undergoing major open upper abdominal surgery. EIT throughout major open upper abdominal surgery could encounter difficulties in belt positioning and signal quality. Thus, we conducted a pilot-study and tested whether EIT is feasible in patients undergoing major open upper abdominal surgery. Methods Following institutional review board’s approval and written informed consent, we included patients scheduled for major open upper abdominal surgery of at least 3 hours duration. EIT measurements were conducted prior to intubation, at the time of skin incision, then hourly during surgery until shortly prior to extubation and after extubation. Number of successful intraoperative EIT measurements and reasons for failures were documented. From the valid measurements, a functional EIT image of changes in tidal impedance was generated for every time point. Regions of interest were defined as horizontal halves of the picture. Monitoring of ventilation distribution was assessed using the center of ventilation index, and also using the total and dorsal ventilated lung area. All parameter values prior to and post intubation as well as extubation were compared. A p < 0.05 was considered statistically significant. Results A total of 120 intraoperative EIT measurements during major abdominal surgery lasting 4-13 hours were planned in 14 patients. The electrode belt was attached between the 2nd and 4th intercostal space. Consecutive valid measurements could be acquired in 13 patients (93%). 111 intraoperative measurements could be retrieved as planned (93%). Main obstacle was the contact of skin electrodes. Despite the high belt position, distribution of tidal volume showed a significant shift of ventilation towards ventral lung regions after intubation. This was reversed after weaning from mechanical ventilation. Conclusions Despite a high belt position, monitoring of ventilation distribution is feasible in patients undergoing major open upper abdominal surgery lasting from 4 to 13 hours. Therefore, further interventional trials in order to optimize ventilatory management should be initiated.
Collapse
Affiliation(s)
- Maximilian S Schaefer
- Department of Anaesthesiology, Duesseldorf University Hospital, Heinrich-Heine University Duesseldorf, Moorenstraße 5, Duesseldorf 40225, Germany
| | - Viktoria Wania
- Department of Anaesthesiology, Duesseldorf University Hospital, Heinrich-Heine University Duesseldorf, Moorenstraße 5, Duesseldorf 40225, Germany
| | - Bea Bastin
- Department of Anaesthesiology, Duesseldorf University Hospital, Heinrich-Heine University Duesseldorf, Moorenstraße 5, Duesseldorf 40225, Germany
| | - Ursula Schmalz
- Department of Anaesthesiology, Duesseldorf University Hospital, Heinrich-Heine University Duesseldorf, Moorenstraße 5, Duesseldorf 40225, Germany
| | - Peter Kienbaum
- Department of Anaesthesiology, Duesseldorf University Hospital, Heinrich-Heine University Duesseldorf, Moorenstraße 5, Duesseldorf 40225, Germany
| | - Martin Beiderlinden
- Department of Anaesthesiology, Duesseldorf University Hospital, Heinrich-Heine University Duesseldorf, Moorenstraße 5, Duesseldorf 40225, Germany ; Department of Anaesthesiology, Marienhospital Osnabrück, Bischofsstraße 1, Osnabrück 49074, Germany
| | - Tanja A Treschan
- Department of Anaesthesiology, Duesseldorf University Hospital, Heinrich-Heine University Duesseldorf, Moorenstraße 5, Duesseldorf 40225, Germany
| |
Collapse
|
13
|
Petrović MD, Petrovic J, Daničić A, Vukčević M, Bojović B, Hadžievski L, Allsop T, Lloyd G, Webb DJ. Non-invasive respiratory monitoring using long-period fiber grating sensors. BIOMEDICAL OPTICS EXPRESS 2014; 5:1136-44. [PMID: 24761295 PMCID: PMC3986006 DOI: 10.1364/boe.5.001136] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 01/18/2014] [Accepted: 02/19/2014] [Indexed: 05/06/2023]
Abstract
In non-invasive ventilation, continuous monitoring of respiratory volumes is essential. Here, we present a method for the measurement of respiratory volumes by a single fiber-grating sensor of bending and provide the proof-of-principle by applying a calibration-test measurement procedure on a set of 18 healthy volunteers. Results establish a linear correlation between a change in lung volume and the corresponding change in a local thorax curvature. They also show good sensor accuracy in measurements of tidal and minute respiratory volumes for different types of breathing. The proposed technique does not rely on the air flow through an oronasal mask or the observation of chest movement by a clinician, which distinguishes it from the current clinical practice.
Collapse
Affiliation(s)
- M. D. Petrović
- Vinča Institute of Nuclear Sciences,University of Belgrade, Mike Petrovića Alasa 12-14, 11000 Belgrade, Serbia
| | - J. Petrovic
- Vinča Institute of Nuclear Sciences,University of Belgrade, Mike Petrovića Alasa 12-14, 11000 Belgrade, Serbia
| | - A. Daničić
- Vinča Institute of Nuclear Sciences,University of Belgrade, Mike Petrovića Alasa 12-14, 11000 Belgrade, Serbia
| | - M. Vukčević
- School of Medicine, University of Belgrade, Dr Subotića 8, 11000 Belgrade, Serbia
| | - B. Bojović
- Vinča Institute of Nuclear Sciences,University of Belgrade, Mike Petrovića Alasa 12-14, 11000 Belgrade, Serbia
| | - Lj. Hadžievski
- Vinča Institute of Nuclear Sciences,University of Belgrade, Mike Petrovića Alasa 12-14, 11000 Belgrade, Serbia
| | - T. Allsop
- Aston Institute of Photonic Technologies, Aston Triangle, B4 7ET Birmingham, UK
| | - G. Lloyd
- Moog Insensys LTD, Ocean House, Whittle Avenue, Segensworth West, Fareham, P015 5SX, UK
| | - D. J. Webb
- Aston Institute of Photonic Technologies, Aston Triangle, B4 7ET Birmingham, UK
| |
Collapse
|
14
|
Ventilation parameters used to guide cardiopulmonary function during mechanical ventilation. Curr Opin Crit Care 2014; 19:215-20. [PMID: 23563923 DOI: 10.1097/mcc.0b013e3283609288] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
PURPOSE OF REVIEW To describe the newly introduced ventilation parameters that are used at the bedside to estimate cardiopulmonary function during positive pressure ventilation (PPV). RECENT FINDINGS PPV induces right atrial pressure changes over the ventilator cycle. Positive end-expiratory pressure-induced central venous pressure changes and pulse pressure variation have been introduced as parameters that predict fluid responsiveness. Pulse pressure variation seems to be valid even at low tidal volume ventilation. A capnometer can be used to measure low perfusion lung area and to monitor the continuous breath-by-breath cardiac output of ventilated patients. Ultrasound evaluation of the lung parenchyma and diaphragm status is likely to become more popular. To evaluate ventilator settings, functional residual capacity (FRC) measurement and visual lung recruitment estimation via electric impedance tomography (EIT) have been introduced. SUMMARY The utility of lung ultrasound is expanding. Although the clinical implications of FRC measurement and lung monitoring with imaging tools such as EIT are starting to be realized, their efficacy in severe hypoxic respiratory failure should be evaluated further in well designed clinical trials. To improve the preemptive management of impending respiratory failure, an alarm index that integrates noninvasive cardiopulmonary function parameters should be developed.
Collapse
|
15
|
Garnero A, Abbona H, Gordo-Vidal F, Hermosa-Gelbard C. Modos controlados por presión versus volumen en la ventilación mecánica invasiva. Med Intensiva 2013; 37:292-8. [DOI: 10.1016/j.medin.2012.10.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 10/01/2012] [Accepted: 10/05/2012] [Indexed: 01/03/2023]
|
16
|
Abstract
The ability to compensate for life-threatening failure of respiratory function is perhaps the signature technology of intensive care medicine. Unchanging needs for providing effective life-support with minimized risk and optimized comfort have been, are now, and will be the principal objectives of providing mechanical ventilation. Important lessons acquired over nearly half-a-century of ICU care have brought us closer to meeting them, as technological advances in instrumentation now effectively put this hard-won knowledge into action. Rising demand in the face of economic constraints is likely to drive future innovations focused on reducing the need for user input, automating multi-element protocols, and carefully monitoring the patient for progress and complications.
Collapse
Affiliation(s)
- John J Marini
- University of Minnesota, Regions Hospital MS11203B, 640 Jackson Street, St Paul, MN 55101, USA.
| |
Collapse
|