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Shikama M, Yamamoto M, Osawa I, Sato T, Hirayama I, Hayase N, Matsubara T, Doi K. Monitoring the Resolution of Acute Exacerbation of Airway Bronchoconstriction in an Asthma Attack Using Capnogram Waveforms. Crit Care Explor 2023; 5:e0899. [PMID: 37091476 PMCID: PMC10115549 DOI: 10.1097/cce.0000000000000899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Abstract
Patients with acute bronchospasm can show a distinct slope of the capnogram ("shark fin") as a result of asynchronous alveolar excretion. Although the slope of the upward alveolar plateau (phase III) in the capnogram waveforms of non-intubated patients is known to help monitor the therapeutic response to acute bronchospasm, little is known about the significance of its slope among intubated patients. Therefore, we quantified the phase III slope of an intubated patient with acute asthma to investigate whether capnogram waveforms could be useful for identifying the response to antibronchospasm treatment in real time. CASE SUMMARY The patient was a 53-year-old man who had a history of asthma. He presented to the emergency department with the primary complaint of respiratory distress. He was diagnosed with severe asthma attack and required invasive mechanical ventilation for 10 days, during which we quantified the phase III slope of the capnogram. The phase III slope decreased during treatment, with a significant reduction from the third to the fourth day; however, a significant decrease in end-tidal carbon dioxide (EtCO2) was observed from the fifth to the sixth day. We found that the slope values decreased earlier than EtCO2 reduction, although the absolute EtCO2 values eventually decreased in response to antibronchospasm treatment. CONCLUSION There were several reports that evaluated the phase III slope in non-intubated patients with asthma, but this is the first report measuring the phase III slope in an intubated patient over several days. Capnogram waveforms may serve as useful real-time indicators to monitor acute bronchospasm among mechanically ventilated patients.
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Affiliation(s)
- Mio Shikama
- All authors: Department of Emergency and Critical Care Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Miyuki Yamamoto
- All authors: Department of Emergency and Critical Care Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Itsuki Osawa
- All authors: Department of Emergency and Critical Care Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Takuya Sato
- All authors: Department of Emergency and Critical Care Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Ichiro Hirayama
- All authors: Department of Emergency and Critical Care Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Naoki Hayase
- All authors: Department of Emergency and Critical Care Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Takehiro Matsubara
- All authors: Department of Emergency and Critical Care Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Kent Doi
- All authors: Department of Emergency and Critical Care Medicine, The University of Tokyo Hospital, Tokyo, Japan
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Evaluation and Management of Asthma and Chronic Obstructive Pulmonary Disease Exacerbation in the Emergency Department. Emerg Med Clin North Am 2022; 40:539-563. [DOI: 10.1016/j.emc.2022.05.007] [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]
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Volumetric capnography pre- and post-surfactant during initial resuscitation of premature infants. Pediatr Res 2022; 91:1551-1556. [PMID: 34023855 PMCID: PMC9197760 DOI: 10.1038/s41390-021-01578-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/19/2021] [Accepted: 04/22/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND Volumetric capnography allows for continuous monitoring of expired tidal volume and carbon dioxide. The slope of the alveolar plateau of the capnogram (SIII) could provide information regarding ventilation homogeneity. We aimed to assess the feasibility of measuring SIII during newborn resuscitation and determine if SIII decreased after surfactant indicating ventilation inhomogeneity improvement. METHODS Respiratory function traces of preterm infants resuscitated at birth were analysed. Ten capnograms were constructed for each infant: five pre- and post-surfactant. If a plateau was present SIII was calculated by regression analysis. RESULTS Thirty-six infants were included, median gestational age of 28.7 weeks and birth weight of 1055 g. Average time between pre- and post-surfactant was 3.2 min. Three hundred and sixty capnograms (180 pre and post) were evaluated. There was adequate slope in 134 (74.4%) capnograms pre and in 100 (55.6%) capnograms post-surfactant (p = 0.004). Normalised for tidal volume SIII pre-surfactant was 18.89 mmHg and post-surfactant was 24.86 mmHg (p = 0.006). An increase in SIII produced an up-slanting appearance to the plateau indicating regional obstruction. CONCLUSION It was feasible to evaluate the alveolar plateau pre-surfactant in preterm infants. Ventilation inhomogeneity increased post-surfactant likely due to airway obstruction caused by liquid surfactant present in the airways. IMPACT Volumetric capnography can be used to assess homogeneity of ventilation by SIII analysis. Ventilation inhomogeneity increased immediately post-surfactant administration during the resuscitation of preterm infants, producing a characteristic up-slanting appearance to the alveolar plateau. The best determinant of alveolar plateau presence in preterm infants was the expired tidal volume.
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Vijayam B, Supriyanto E, Malarvili MB. Digitization and Analysis of Capnography Using Image Processing Technique. Front Digit Health 2021; 3:723204. [PMID: 34778867 PMCID: PMC8585923 DOI: 10.3389/fdgth.2021.723204] [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: 06/10/2021] [Accepted: 09/29/2021] [Indexed: 11/13/2022] Open
Abstract
The study of carbon dioxide expiration is called capnometry. The graphical representation of capnometry is called capnography. There is a growing interest in the usage of capnography as the usage has expanded toward the study of metabolism, circulation, lung perfusion and diffusion, quality of spontaneous respiration, and patency of airways outside of its typical usage in the anesthetic and emergency medicine field. The parameters of the capnograph could be classified as carbon dioxide (CO2) concentration and time points and coordinates, slopes angle, volumetric studies, and functional transformation of wave data. Up to date, there is no gold standard device for the calculation of the capnographic parameters. Capnography digitization using the image processing technique could serve as an option. From the algorithm we developed, eight identical breath waves were tested by four investigators. The values of the parameters chosen showed no significant difference between investigators. Although there were no significant differences between any of the parameters tested, there were a few related parameters that were not calculable. Further testing after refinement of the algorithm could be done. As more capnographic parameters are being derived and rediscovered by clinicians and researchers alike for both lung and non-lung-related diseases, there is a dire need for data analysis and interpretation. Although the proposed algorithm still needs minor refinements and further large-scale testing, we proposed that the digitization of the capnograph via image processing technique could serve as an intellectual option as it is fast, convenient, easy to use, and efficient.
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Affiliation(s)
- Bhuwaneswaran Vijayam
- School of Biomedical Engineering and Health Sciences, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia
| | - Eko Supriyanto
- School of Biomedical Engineering and Health Sciences, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia.,Institut Jantung Negara - Universiti Teknologi Malaysia (IJN-UTM) Cardiovascular Engineering Center, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia
| | - M B Malarvili
- School of Biomedical Engineering and Health Sciences, Universiti Teknologi Malaysia (UTM), Skudai, Malaysia
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Malarvili MB, Alexie M, Dahari N, Kamarudin A. On Analyzing Capnogram as a Novel Method for Screening COVID-19: A Review on Assessment Methods for COVID-19. Life (Basel) 2021; 11:1101. [PMID: 34685472 PMCID: PMC8538964 DOI: 10.3390/life11101101] [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: 06/21/2021] [Revised: 08/12/2021] [Accepted: 10/12/2021] [Indexed: 12/15/2022] Open
Abstract
In November 2019, the novel coronavirus disease COVID-19 was reported in Wuhan city, China, and was reported in other countries around the globe. COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Strategies such as contact tracing and a vaccination program have been imposed to keep COVID-19 under control. Furthermore, a fast, noninvasive and reliable testing device is needed urgently to detect COVID-19, so that contact can be isolated and ringfenced before the virus spreads. Although the reverse transcription polymerase chain reaction (RT-PCR) test is considered the gold standard method for the diagnosis of SARS-CoV-2 infection, this test presents some limitations which cause delays in detecting the disease. The antigen rapid test (ART) test, on the other hand, is faster and cheaper than PCR, but is less sensitive, and may limit SARS-CoV-2 detection. While other tests are being developed, accurate, noninvasive and easy-to-use testing tools are in high demand for the rapid and extensive diagnosis of the disease. Therefore, this paper reviews current diagnostic methods for COVID-19. Following this, we propose the use of expired carbon dioxide (CO2) as an early screening tool for SARS-CoV-2 infection. This system has already been developed and has been tested on asthmatic patients. It has been proven that expired CO2, also known as capnogram, can help differentiate between respiratory conditions and, therefore, could be used to detect SARS-CoV-2 infection, as it causes respiratory tract-related diseases.
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Affiliation(s)
- M. B. Malarvili
- School of Biomedical and Health Science Engineering, Universiti Teknologi Malaysia, Skudai, Johor Bahru 81310, Malaysia; (M.A.); (N.D.)
| | - Mushikiwabeza Alexie
- School of Biomedical and Health Science Engineering, Universiti Teknologi Malaysia, Skudai, Johor Bahru 81310, Malaysia; (M.A.); (N.D.)
- College of Science and Technology (CST), Center or Excellence in Biomedical Engineering and E-Health (CEBE), University of Rwanda, KN 67 Street Nyarugenge, Kigali 3900, Rwanda
| | - Nadhira Dahari
- School of Biomedical and Health Science Engineering, Universiti Teknologi Malaysia, Skudai, Johor Bahru 81310, Malaysia; (M.A.); (N.D.)
| | - Anhar Kamarudin
- Faculty of Medicine, University Malaya Medical Centre (UMMC), Kuala Lumpur 59100, Malaysia;
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Williams E, Dassios T, Greenough A. Carbon dioxide monitoring in the newborn infant. Pediatr Pulmonol 2021; 56:3148-3156. [PMID: 34365738 DOI: 10.1002/ppul.25605] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 11/06/2022]
Abstract
Carbon dioxide (CO2 ) monitoring is vital during mechanical ventilation of newborn infants, as morbidity increases when CO2 levels are inappropriate. Our aim was to review the uses and limitations of such noninvasive monitoring methods. Colorimetry is primarily utilized during resuscitation to determine whether successful intubation has occurred. False negative and positive results can however lead to delays in detecting tracheal versus esophageal intubation. Transcutaneous carbon dioxide sensors have limited use during resuscitation, but can be utilized to provide continuous trend data during on-going ventilation. End-tidal capnography can provide clinicians with quantitative end-tidal CO2 (EtCO2 ) values and a continuous real-time capnogram waveform trace. These devices are becoming more widely accepted for use in the neonatal population as the new devices are lightweight with minimal additional dead space. Nevertheless, they have been reported to have variable accuracy when compared to arterial CO2 measurements, however, divergence of results may be related to disease severity rather than technological limitations. During resuscitation EtCO2 can be detected by capnography more rapidly than by colorimetry. Furthermore, capnography can be currently utilized in neonatal research settings to determine the physiological dead space and ventilation inhomogeneity, and thus has potential to be beneficial to clinical care. In conclusion, novel modes of noninvasive carbon dioxide monitoring can be safely and reliably utilized in newborn infants during mechanical ventilation. Future randomized trials should aim to address which device provides the most optimal form of monitoring in different clinical contexts.
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Affiliation(s)
- Emma Williams
- Department of Woman and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Theodore Dassios
- Department of Woman and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,Neonatal Intensive Care Centre, King's College Hospital NHS Foundation Trust, London, UK
| | - Anne Greenough
- Department of Woman and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.,Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, London, UK.,National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK
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Gurlu R, Tolu Kendir O, Baspinar O, Erkek N. Can Non-Invasive Capnography and Integrated Pulmonary Index Contribute to Patient Monitoring in the Pediatric Emergency Department? KLINISCHE PADIATRIE 2021; 234:26-32. [PMID: 34359093 DOI: 10.1055/a-1546-1473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVES Noninvasive capnography (NICG) devices can measure oxygen saturation, end-tidal carbon dioxide (EtCO2), respiratory rate, heart rate values and integrated pulmonary index (IPI). This study aimed to evaluate patients who were monitored using NICG for various indications in a pediatric emergency department and to determine its contribution to patient management in the pediatric emergency department (PED). METHODS In this study, children aged <18 years who had been monitored with a NICG at the PED in our university between August 2018-May 2019 were evaluated. Of them 48 patients' file records and monitored capnography parameters such as heart rate, respiratory rate, blood pressure, capillary refill time, Glasgow Coma Score, SpO2, EtCO2, IPI recorded in the forms were reviewed. RESULTS Patients most often presented to the emergency room due to seizures (35.4%), change in consciousness (22.9%), other neurological reasons (18.8%) with %50 were female. Seizure treatment(16.7%), circulatory-respiratory support(16.7%), and antiedema treatments(6.3%) were required for 39.5% patients as life-saving interventions, and 72.9% patients were hospitalized. Patients with low IPI(<8) values at the beginning and decreasing IPI (<8) measurements within monitoring period needed more life-saving treatments(p=0.005 and p=0.001, respectively). Low IPI values of the patients during monitoring showed a significant difference in the decision to be hospitalized(p=0.048). CONCLUSIONS The results of the present study indicate that monitoring with NICG in the pediatric emergency room can be an important early indicator in establishing clinical prediction. The study particularly points out that the IPI value can be a guide in decisions regarding life-saving treatment and hospitalization. Among the capnographic data of these patients who had a change in consciousness IPI values those measured at the beginning and within the monitorizarion period showed a significant correlation with low GCS (<8) (r=0.478, p=0.001 and r=0.456, p=0.02, respectively). Prospective comprehensive large scale studies are needed to examine the use of NICG and IPI in routine PED practice for various indications.
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Affiliation(s)
- Ramazan Gurlu
- Pediatrics, Emergency Care Unit, Akdeniz University, Antalya, Turkey
| | - Ozlem Tolu Kendir
- Pediatrics, Emergency Care Unit, Akdeniz University, Antalya, Turkey
| | - Omer Baspinar
- Pediatrics, Emergency Care Unit, Akdeniz University, Antalya, Turkey
| | - Nilgun Erkek
- Pediatrics, Emergency Care Unit, Akdeniz University, Antalya, Turkey
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El-Badawy IM, Singh OP, Omar Z. Automatic classification of regular and irregular capnogram segments using time- and frequency-domain features: A machine learning-based approach. Technol Health Care 2020; 29:59-72. [PMID: 32716337 DOI: 10.3233/thc-202198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The quantitative features of a capnogram signal are important clinical metrics in assessing pulmonary function. However, these features should be quantified from the regular (artefact-free) segments of the capnogram waveform. OBJECTIVE This paper presents a machine learning-based approach for the automatic classification of regular and irregular capnogram segments. METHODS Herein, we proposed four time- and two frequency-domain features experimented with the support vector machine classifier through ten-fold cross-validation. MATLAB simulation was conducted on 100 regular and 100 irregular 15 s capnogram segments. Analysis of variance was performed to investigate the significance of the proposed features. Pearson's correlation was utilized to select the relatively most substantial ones, namely variance and the area under normalized magnitude spectrum. Classification performance, using these features, was evaluated against two feature sets in which either time- or frequency-domain features only were employed. RESULTS Results showed a classification accuracy of 86.5%, which outperformed the other cases by an average of 5.5%. The achieved specificity, sensitivity, and precision were 84%, 89% and 86.51%, respectively. The average execution time for feature extraction and classification per segment is only 36 ms. CONCLUSION The proposed approach can be integrated with capnography devices for real-time capnogram-based respiratory assessment. However, further research is recommended to enhance the classification performance.
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Affiliation(s)
- Ismail M El-Badawy
- Electronics and Communications Engineering Department, Arab Academy for Science and Technology, Cairo, Egypt.,School of Electrical Engineering, Universiti Teknologi Malaysia, Johor, Malaysia
| | - Om Prakash Singh
- School of Biomedical Engineering and Health Sciences, Universiti Teknologi Malaysia, Johor, Malaysia
| | - Zaid Omar
- School of Electrical Engineering, Universiti Teknologi Malaysia, Johor, Malaysia
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End tidal carbon dioxide monitoring in acute asthma: a prospective pilot study in emergency department patients. Eur J Emerg Med 2020; 26:412-416. [PMID: 30362973 DOI: 10.1097/mej.0000000000000581] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The peak expiratory flow rate (PEFR) is the gold standard for monitoring asthmatic patients. However, its measurement requires understanding and active participation. End tidal carbon dioxide (EtCO2) may be considered an accurate surrogate for PaCO2, a severity marker in acute asthma. We studied the use of EtCO2 as a monitoring tool in acute asthma. PATIENTS AND METHODS This was a prospective study that included consecutive patients admitted to our emergency department for acute asthma exacerbation. Data were collected at first medical contact (T0) and after 1 h of treatment (T60). The primary endpoint was the change in EtCO2; the secondary endpoints included changes in the EtCO2 Q angle value, plateau T time, and change in EtCO2 values for the patients with a PEFR ratio less than 50% after treatment. RESULTS Fifty-five patients were included and 36 waveforms were analysed. The mean age was 37 years and 26 (47%) were women. The median initial PEFR was 200 [interquartile range (IQR): 150-240]; the median EtCO2 at T0 and T60 was 35 (IQR: 30-38) and 34 (IQR: 29-37). There was no significant change in EtCO2 after treatment. There was no significant change in the Q angle and the T time after treatment. At T60, 20 (36%) patients had a PEFR ratio less than 50%. Change in EtCO2 from T60 to T0 was associated with a PEFR ratio less than 50%. CONCLUSION After 1 h of treatment, there was no significant change in EtCO2. A decrease in EtCO2 seems to be associated with a higher risk of PEFR ratio less than 50% after treatment.
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Long B, Lentz S, Koyfman A, Gottlieb M. Evaluation and management of the critically ill adult asthmatic in the emergency department setting. Am J Emerg Med 2020; 44:441-451. [PMID: 32222313 DOI: 10.1016/j.ajem.2020.03.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/08/2020] [Accepted: 03/16/2020] [Indexed: 01/09/2023] Open
Abstract
INTRODUCTION Asthma is a common reason for presentation to the Emergency Department and is associated with significant morbidity and mortality. While patients may have a relatively benign course, there is a subset of patients who present in a critical state and require emergent management. OBJECTIVE This narrative review provides evidence-based recommendations for the assessment and management of patients with severe asthma. DISCUSSION It is important to consider a broad differential diagnosis for the cause and potential mimics of asthma exacerbation. Once the diagnosis is determined, the majority of the assessment is based upon the clinical examination. First line therapies for severe exacerbations include inhaled short-acting beta agonists, inhaled anticholinergics, intravenous steroids, and magnesium. Additional therapies for refractory cases include parenteral epinephrine or terbutaline, helium‑oxygen mixture, and consideration of ketamine. Intravenous fluids should be administered, as many of these patients are dehydrated and at risk for hypotension if they receive positive pressure ventilatory support. Noninvasive positive pressure ventilation may prevent the need for endotracheal intubation. If mechanical ventilation is required, it is important to avoid breath stacking by setting a low respiratory rate and allowing permissive hypercapnia. Patients with severe asthma exacerbations will require intensive care unit admission. CONCLUSIONS This review provides evidence-based recommendations for the assessment and management of severe asthma with a focus on the emergency clinician.
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Affiliation(s)
- Brit Long
- Brooke Army Medical Center, Department of Emergency Medicine, 3841 Roger Brooke Dr, Fort Sam Houston, TX 78234, United States.
| | - Skyler Lentz
- Division of Emergency Medicine, Department of Surgery, Larner College of Medicine, University of Vermont, Burlington, VT, United States
| | - Alex Koyfman
- The University of Texas Southwestern Medical Center, Department of Emergency Medicine, 5323 Harry Hines Boulevard, Dallas, TX 75390, United States
| | - Michael Gottlieb
- Department of Emergency Medicine, Rush University Medical Center, United States
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Tolnai J, Fodor GH, Babik B, Dos Santos Rocha A, Bayat S, Peták F, Habre W. Volumetric but Not Time Capnography Detects Ventilation/Perfusion Mismatch in Injured Rabbit Lung. Front Physiol 2018; 9:1805. [PMID: 30618817 PMCID: PMC6299046 DOI: 10.3389/fphys.2018.01805] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/29/2018] [Indexed: 12/31/2022] Open
Abstract
Whereas time capnography (Tcap) is routinely displayed during mechanical ventilation, the volumetric representation (Vcap) is seldom used. We compared the diagnostic value of indices derived from Tcap and Vcap following ventilation to perfusion ratio ( ) mismatch subsequent to experimentally induced acute respiratory distress syndrome (ARDS), and alveolar recruitment by elevating the positive end-expiratory pressure (PEEP). Lung injury was induced by iv lipopolysaccharide, whole lung lavage and injurious ventilation in anesthetized, mechanically ventilated rabbits (n = 26). Mainstream Tcap and Vcap were performed to assess normalized phase 2 (Sn2T, Sn2V) and phase 3 slopes (Sn3T, Sn3V) in the time and volumetric domains. Vcap was also used to estimate Enghoff’s physiological dead space (VDE). Lung oxygenation index (PaO2/FiO2) and intrapulmonary shunt (Qs/Qt) were derived from arterial and central venous blood gas samples. All measurements were made under baseline conditions, and, following lung injury, under moderate (6 cmH2O) and high PEEP levels (9 cmH2O). Lung injury deteriorated the PaO2/FiO2 (baseline vs. injured 466 ± 10.2 [95% confidence interval] vs. 77.3 ± 17.1 mmHg, p < 0.05) and compromised all mechanical parameters significantly, whereas Tcap parameters exhibited contradictory or inconsistent changes. Conversely, Vcap indices exhibited consistent changes and provided excellent diagnostic value in detecting lung-function deterioration subsequent to lung injury [area under the receiver operating characteristic (ROC) curve of 1.0 ± 0.0, 0.87 ± 0.22 and 0.86 ± 0.22 for VDE, Sn3V and Sn3V/Sn2V, respectively]. Elevated PEEP increased PaO2/FiO2 and decreased Qs/Qt, which was reflected only in the Vcap slope ratio (Sn3V/Sn2V, p < 0.05). Our findings demonstrate the limited value of Tcap to detect ventilation to perfusion ratio ( ) mismatch, following severe lung injury. Conversely, indices derived from Vcap proved to be sensitive for detecting lung volume loss and alveolar recruitment. Therefore, promotion of Vcap is of paramount importance as a real-time, non-invasive, bedside monitoring modality to detect the development of and to follow-up the progression of lung injury in a model of ARDS.
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Affiliation(s)
- József Tolnai
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Gergely H Fodor
- Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology and Intensive Care, University of Geneva, Geneva, Switzerland
| | - Barna Babik
- Department of Anesthesiology and Intensive Therapy, University of Szeged, Szeged, Hungary
| | - André Dos Santos Rocha
- Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology and Intensive Care, University of Geneva, Geneva, Switzerland
| | - Sam Bayat
- EA-7442 RSRM Laboratory, Department of Clinical Physiology, Sleep and Exercise, Grenoble University Hospital, University of Grenoble, Grenoble, France
| | - Ferenc Peták
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Walid Habre
- Unit for Anesthesiological Investigations, Department of Anesthesiology, Pharmacology and Intensive Care, University of Geneva, Geneva, Switzerland
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Modrin A, Gilbert ML. De l’entrée à la sortie du service de réanimation adulte : une mise au point sur l’utilisation courante du monitoring du CO 2 expiré. MEDECINE INTENSIVE REANIMATION 2018. [DOI: 10.3166/rea-2018-0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
L’objectif de cette mise au point est d’effectuer une revue des indications de l’utilisation du monitorage du CO2 expiré en réanimation adulte. De par sa physiologie, sa mesure est un reflet de l’état hémodynamique, respiratoire et métabolique du patient. La spectrométrie infrarouge est la méthode de mesure la plus courante. La capnographie commune (CO2 expiré en fonction du temps) est divisée en plusieurs phases dont l’analyse visuelle peut faire évoquer de nombreuses anomalies ventilatoires. La capnographie volumétrique fournit une mesure de l’espace mort. La capnométrie est recommandée en réanimation pour contrôler l’intubation trachéale ou bien au cours d’un arrêt cardiorespiratoire comme facteur pronostique. Tout patient traité par ventilation mécanique invasive, surtout lors d’un transport, doit être équipé d’un capnomètre afin d’anticiper toute complication respiratoire (extubation, bronchospasme, hypoventilation). La pression de fin d’expiration en CO2 (PetCO2) est une évaluation de la pression artérielle en CO2 (PaCO2) utile pour limiter le nombre de prélèvements biologiques, par exemple en neuroréanimation, mais de nombreux facteurs font varier le gradient entre ces deux valeurs. Les études n’apportent pas de preuve pour l’utilisation de la capnographie volumétrique dans le diagnostic d’embolie pulmonaire en réanimation. Chez les patients souffrant de syndrome de détresse respiratoire aiguë, la littérature médicale n’apporte pas de preuve suffisante pour un intérêt en pratique clinique courante de la capnométrie volumétrique qui semble limitée dans ce cas à la recherche.
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Singh OP, Howe TA, Malarvili MB. Real-time human respiration carbon dioxide measurement device for cardiorespiratory assessment. J Breath Res 2018; 12:026003. [PMID: 28928295 DOI: 10.1088/1752-7163/aa8dbd] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The development of a human respiration carbon dioxide (CO2) measurement device to evaluate cardiorespiratory status inside and outside a hospital setting has proven to be a challenging area of research over the few last decades. Hence, we report a real-time, user operable CO2 measurement device using an infrared CO2 sensor (Arduino Mega2560) and a thin film transistor (TFT, 3.5″), incorporated with low pass (cut-off frequency, 10 Hz) and moving average (span, 8) filters. The proposed device measures features such as partial end-tidal carbon dioxide (EtCO2), respiratory rate (RR), inspired carbon dioxide (ICO2), and a newly proposed feature-Hjorth activity-that annotates data with the date and time from a real-time clock, and is stored onto a secure digital (SD) card. Further, it was tested on 22 healthy subjects and the performance (reliability, validity and relationship) of each feature was established using (1) an intraclass correlation coefficient (ICC), (2) standard error measurement (SEM), (3) smallest detectable difference (SDD), (4) Bland-Altman plot, and (5) Pearson's correlation (r). The SEM, SDD, and ICC values for inter- and intra-rater reliability were less than 5% and more than 0.8, respectively. Further, the Bland-Altman plot demonstrates that mean differences ± standard deviations for a set limit were 0.30 ± 0.77 mmHg, -0.34 ± 1.41 mmHg and 0.21 ± 0.64 breath per minute (bpm) for CO2, EtCO2 and RR. The findings revealed that the developed device is highly reliable, providing valid measurements for CO2, EtCO2, ICO2 and RR, and can be used in clinical settings for cardiorespiratory assessment. This research also demonstrates that EtCO2 and RR (r, -0.696) are negatively correlated while EtCO2 and activity (r, 0.846) are positively correlated. Thus, simultaneous measurement of these features may possibly assist physicians in understanding the subject's cardiopulmonary status. In future, the proposed device will be tested with asthmatic patients for use as an early screening tool outside a hospital setting.
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Affiliation(s)
- Om Prakash Singh
- Bio-signal Processing Research Group (BSPRG), Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor Bahru, Johor, Malaysia
| | - Teo Aik Howe
- Emergency Department, Hospital Pulau Pinang, Pinang, Malaysia
| | - M B Malarvili
- Bio-signal Processing Research Group (BSPRG), Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia (UTM), 81310 Skudai, Johor Bahru, Johor, Malaysia
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Guerrero Zúñiga S, Sánchez Hernández J, Mateos Toledo H, Mejía Ávila M, Gochicoa-Rangel L, Miguel Reyes JL, Selman M, Torre-Bouscoulet L. Small airway dysfunction in chronic hypersensitivity pneumonitis. Respirology 2017; 22:1637-1642. [PMID: 28748646 DOI: 10.1111/resp.13124] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 04/22/2017] [Accepted: 05/02/2017] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVE Lung biopsies from patients with hypersensitivity pneumonitis (HP) have demonstrated small airway (SA) involvement, but there is no information concerning SA function in HP, and it is unknown whether pharmacological treatment could modify its function. SA function in patients with chronic HP using ultrasonic pneumography (UPG) and impulse oscillometry (IOS) was explored. We also compared initial results with those obtained after 4 weeks of standardized treatment with azathioprine and prednisone. METHODS The study group consisted of adults with recent diagnoses of HP. All patients completed UPG, IOS, spirometry, body plethysmography, single-breath carbon monoxide diffusing capacity (DLCO ) and the 6-min walk test (6MWT). The fraction of exhaled nitric oxide (FENO ) was obtained to assess eosinophilic airway inflammation. Measurements were taken at diagnosis and after 4 weeks of treatment. RESULTS A total of 20 consecutive patients (16 women) with chronic HP participated in the study. Median age was 50 years (interquartile range (IQR): 42-54). At diagnosis, the UPG phase 3 slope was abnormally high, consistent with maldistribution of ventilation. For IOS, all patients had low reactance at 5 Hz (X5) and elevated reactance area (AX) reflecting low compliance, and only eight (40%) patients had elevated R5 (resistance at 5 Hz (total)) and R5-20 (resistance at 5 Hz-resistance at 20 Hz (peripheral)) attributed to SA resistance. In contrast, FENO parameters were within normal limits. After treatment, forced vital capacity (FVC), the 6-min walk distance and the distribution of ventilation showed significant improvement, although DLCO did not. CONCLUSION Patients with chronic HP have SA abnormalities that are partially revealed by the UPG and IOS tests. Lung volumes, but not gas exchange, improved after treatment with azathioprine and prednisone.
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Affiliation(s)
- Selene Guerrero Zúñiga
- Department of Respiratory Physiology, National Institute of Respiratory Diseases, Mexico City, Mexico
| | - Julia Sánchez Hernández
- Department of Respiratory Physiology, National Institute of Respiratory Diseases, Mexico City, Mexico
| | - Heidegger Mateos Toledo
- Interstitial Lung Diseases Clinic, National Institute of Respiratory Diseases, Mexico City, Mexico
| | - Mayra Mejía Ávila
- Interstitial Lung Diseases Clinic, National Institute of Respiratory Diseases, Mexico City, Mexico
| | - Laura Gochicoa-Rangel
- Department of Respiratory Physiology, National Institute of Respiratory Diseases, Mexico City, Mexico
| | | | - Moisés Selman
- Research Unit, National Institute of Respiratory Diseases, Mexico City, Mexico
| | - Luis Torre-Bouscoulet
- Department of Respiratory Physiology, National Institute of Respiratory Diseases, Mexico City, Mexico.,Research Unit, National Institute of Respiratory Diseases, Mexico City, Mexico
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Csorba Z, Petak F, Nevery K, Tolnai J, Balogh AL, Rarosi F, Fodor GH, Babik B. Capnographic Parameters in Ventilated Patients. Anesth Analg 2016; 122:1412-20. [DOI: 10.1213/ane.0000000000001185] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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16
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Nassar BS, Schmidt GA. Capnography During Critical Illness. Chest 2016; 149:576-585. [DOI: 10.1378/chest.15-1369] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 09/15/2015] [Accepted: 09/16/2015] [Indexed: 11/01/2022] Open
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Rasera CC, Gewehr PM, Domingues AMT. PETCO2measurement and feature extraction of capnogram signals for extubation outcomes from mechanical ventilation. Physiol Meas 2015; 36:231-42. [DOI: 10.1088/0967-3334/36/2/231] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Betancourt JP, Tangel ML, Yan F, Diaz MO, Otaño AEP, Dong F, Hirota K. Segmented Wavelet Decomposition for Capnogram Feature Extraction in Asthma Classification. JOURNAL OF ADVANCED COMPUTATIONAL INTELLIGENCE AND INTELLIGENT INFORMATICS 2014. [DOI: 10.20965/jaciii.2014.p0480] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A feature extraction method from capnograms used for classifying asthma is proposed based on wavelet decomposition. Its computational cost is low and its performance is adequate for classifying asthma in real time. Experiments performed using 23 capnograms from an asthma camp in Cuba showed 97.39% best classification accuracy. The time required for a physiological multiparameter monitor to determine the suitable features of capnograms averaged 8 seconds. The proposal is to be used as part of a decision support system for asthma classification being developed by TITECH and TMDU research groups.
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Langhan ML, Kurtz JC, Schaeffer P, Asnes AG, Riera A. Experiences with capnography in acute care settings: a mixed-methods analysis of clinical staff. J Crit Care 2014; 29:1035-40. [PMID: 25129575 DOI: 10.1016/j.jcrc.2014.06.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 06/19/2014] [Accepted: 06/21/2014] [Indexed: 10/25/2022]
Abstract
PURPOSE Although capnography is being incorporated into clinical guidelines, it is not used to its full potential. We investigated reasons for limited implementation of capnography in acute care areas and explored facilitators and barriers to its implementation. METHODS A purposeful sample of physicians and nurses in emergency departments and intensive care units participated in semistructured interviews. Grounded theory, iterative data analysis, and the constant comparative method were used to analyze the data to inductively generate ideas and build theories. RESULTS Nineteen providers were interviewed from 5 hospitals. Six themes were identified: variability in use of capnography among acute care units, availability and accessibility of capnography equipment, the evidence behind capnography use, the impact of capnography on patient care, personal experiences impacting use of capnography, and variable knowledge about capnography. Barriers and facilitators to use were found within each theme. CONCLUSIONS We observed varied responsiveness to capnography and identified factors that work to foster or discourage its use. These data can guide future implementation strategies. A deliberate strategy to foster utilization, mitigate barriers, and broadly accelerate implementation has the potential to profoundly impact use of capnography in acute care areas with the goal of improving patient care.
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Affiliation(s)
| | | | - Paula Schaeffer
- Department of Pediatrics, Yale University School of Medicine
| | - Andrea G Asnes
- Department of Pediatrics, Yale University School of Medicine
| | - Antonio Riera
- Section of Emergency Medicine, Yale University School of Medicine
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Fodor GH, Peták F, Erces D, Balogh AL, Babik B. Lung mechanical changes following bronchoaspiration in a porcine model: differentiation of direct and indirect mechanisms. Respir Physiol Neurobiol 2014; 199:41-9. [PMID: 24814560 DOI: 10.1016/j.resp.2014.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 04/01/2014] [Accepted: 05/02/2014] [Indexed: 01/13/2023]
Abstract
Bronchoaspiration results in local deterioration of lung function through direct damage and/or indirect systemic effects related to neurohumoral pathways. We distinguished these effects by selectively intubating the two main bronchi in pigs while a PEEP of 4 or 10cm H2O was maintained. Gastric juice was instilled only into the right lung. Lung mechanical and ventilation defects were assessed by measuring unilateral pulmonary input impedance (ZL,s) and the third phase slope of the capnogram (SIII) for each lung side separately before the aspiration and for 120min thereafter. Marked transient elevations in ZL,s parameters and SIII were observed in the affected lung after aspiration. Elevating PEEP did not affect these responses in the ZL,s parameters, whereas it prevented the SIII increases. None of these indices changed in the intact left lung. These findings furnish evidence of the predominance of the local direct damage over the indirect systemic effects in the development of the deterioration of lung function, and demonstrate the benefit of an initially elevated PEEP following aspiration.
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Affiliation(s)
- Gergely H Fodor
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Ferenc Peták
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary.
| | - Dániel Erces
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Adám L Balogh
- Department of Anaesthesiology and Intensive Therapy, University of Szeged, Szeged, Hungary
| | - Barna Babik
- Department of Anaesthesiology and Intensive Therapy, University of Szeged, Szeged, Hungary
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Betancourt JP, Fatichah C, Tangel ML, Yan F, Sanchez JAG, Dong FY, Hirota K. Similarity-Based Fuzzy Classification of ECG and Capnogram Signals. JOURNAL OF ADVANCED COMPUTATIONAL INTELLIGENCE AND INTELLIGENT INFORMATICS 2013. [DOI: 10.20965/jaciii.2013.p0302] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A method for ECG and capnogram signals classification is proposed based on fuzzy similarity evaluation, where shape exchange algorithm and fuzzy inference are combined. It aims to be applied to quasi-periodic biomedical signals and has low computational cost. On the experiments for atrial fibrillation (AF) classification using two databases: MIT-BIH AF and MITBIH Normal Sinus Rhythm, values of 100%, 94.4%, and 97.6% for sensitivity, specificity, and accuracy respectively, and execution time of 0.6 s are obtained. The proposal is capable of been extended to classify different diseases, from ECG and capnogram signals, such as: Brugada syndrome, AV block, hypoventilation, and asthma among others to be implemented in low computational resources devices.
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Brown RH, Brooker A, Wise RA, Reynolds C, Loccioni C, Russo A, Risby TH. Forced expiratory capnography and chronic obstructive pulmonary disease (COPD). J Breath Res 2013; 7:017108. [PMID: 23445906 PMCID: PMC3805024 DOI: 10.1088/1752-7155/7/1/017108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This report proposes a potentially sensitive and simple physiological method to detect early changes and to follow disease progression in obstructive pulmonary disease (COPD) based upon the usual pulmonary function test. Pulmonary function testing is a simple, although relatively insensitive, method to detect and follow COPD. As a proof-of-concept, we have examined the slope of the plateau for carbon dioxide during forced expiratory capnography in healthy (n = 10) and COPD subjects (n = 10). We compared the change in the rate of exhalation of carbon dioxide over time as a marker of heterogeneous ventilation of the lung. All subjects underwent pulmonary function testing, body-plethysmography, and forced exhalation capnography. The subjects with COPD also underwent high-resolution computed tomography of the chest. Regression lines were fitted to the slopes of the forced exhalation capnogram curves. There was no difference in the mean levels of exhaled carbon dioxide between the COPD and the healthy groups (p > 0.48). We found a significant difference in the mean slope of the forced exhalation capnogram for the COPD subjects compared to the healthy subjects (p = 0.01). Most important, for the COPD subjects, there was a significant positive correlation between the slope of the forced exhaled capnogram and a defined radiodensity measurement of the lung by high-resolution computed tomography (r(2) = 0.49, p = 0.02). The slope of the forced exhalation capnogram may be a simple way to determine physiological changes in the lungs in patients with COPD that are not obtainable with standard pulmonary function tests. Forced exhalation capnography would be of great clinical benefit if it can identify early disease changes and at-risk individuals.
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Affiliation(s)
- Robert H Brown
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21205, USA.
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Babik B, Csorba Z, Czövek D, Mayr PN, Bogáts G, Peták F. Effects of respiratory mechanics on the capnogram phases: importance of dynamic compliance of the respiratory system. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2012; 16:R177. [PMID: 23031408 PMCID: PMC3682277 DOI: 10.1186/cc11659] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 10/02/2012] [Indexed: 11/10/2022]
Abstract
INTRODUCTION The slope of phase III of the capnogram (SIII) relates to progressive emptying of the alveoli, a ventilation/perfusion mismatch, and ventilation inhomogeneity. S(III) depends not only on the airway geometry, but also on the dynamic respiratory compliance (Crs); this latter effect has not been evaluated. Accordingly, we established the value of SIII for monitoring airway resistance during mechanical ventilation. METHODS Sidestream capnography was performed during mechanical ventilation in patients undergoing elective cardiac surgery (n = 144). The airway resistance (Raw), total respiratory resistance and Crs displayed by the ventilator, the partial pressure of arterial oxygen (PaO2) and S(III) were measured in time domain (S(T-III)) and in a smaller cohort (n = 68) by volumetry (S(V-III)) with and without normalization to the average CO2 phase III concentration. Measurements were performed at positive end-expiratory pressure (PEEP) levels of 3, 6 and 9 cmH2O in patients with healthy lungs (Group HL), and in patients with respiratory symptoms involving low (Group LC), medium (Group MC) or high Crs (Group HC). RESULTS S(T-III) and S(V-III) exhibited similar PEEP dependencies and distribution between the protocol groups formed on the basis of Crs. A wide interindividual scatter was observed in the overall Raw-S(T-III) relationship, which was primarily affected by Crs. Decreases in Raw with increasing PEEP were reflected in sharp falls in S(III) in Group HC, and in moderate decreases in S(III) in Group MC, whereas S(T-III) was insensitive to changes in airway caliber in Groups LC and HL. CONCLUSIONS SIII assessed in the time domain and by volumetry provide meaningful information about alterations in airway caliber, but only within an individual patient. Although S(T-III) may be of value for bedside monitoring of the airway properties, its sensitivity depends on Crs. Thus, assessment of the capnogram shape should always be coupled with Crs when the airway resistance or oxygenation are evaluated.
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Abstract
PURPOSE Asthma is a chronic disorder of the airways involving inflammation and airway hyper-reactivity. Clinical diagnosis and monitoring of asthma must incorporate the immunological, biochemical, and histological changes of a chronic disorder, while recognizing acute phenotypic changes in order to optimally tailor therapeutics to each individual. RECENT FINDINGS Articles published within the previous 18 months are summarized in this article in order to present an up to date review of the latest findings regarding the monitoring of asthma. The articles encompass a wide array of specialties from basic research and histology to clinical medicine as well as community medicine and nursing. SUMMARY Exciting new advancements in the monitoring of asthma continue to unfold. Potentially new diagnostic and monitoring tools are highlighted in this study. Continued investigations may enable a select few methodologies to reach clinical utility in the ongoing monitoring and treatment of patients with asthma.
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