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http://dx.doi.org/10.3904/kjim.2011.26.4.421

Sound Analysis in an In Vitro Endotracheal Tube Model  

Park, Young-Sik (Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute)
Kee, Young-Wook (Department of Biomedical Engineering, Seoul National University College of Medicine)
Park, Kwang-Suk (Department of Biomedical Engineering, Seoul National University College of Medicine)
Lee, Jin-Woo (Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute)
Lee, Sang-Min (Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute)
Yim, Jae-Joon (Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute)
Yoo, Chul-Gyu (Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute)
Kim, Young-Whan (Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute)
Han, Sung-Koo (Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute)
Yang, Seok-Chul (Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute)
Publication Information
The Korean journal of internal medicine / v.26, no.4, 2011 , pp. 421-426 More about this Journal
Abstract
Background/Aims: Complete endotracheal tube obstruction is a medical emergency, and partial occlusion causes increased breathing rates and failure to wean off mechanical ventilation. Partial occlusion may be underestimated due to the lack of proper detection methods. We tested whether the sound of an endotracheal tube could be used to detect an endotracheal tube obstruction using an in vitro model. Methods: An endotracheal tube was connected to a ventilator on one end and a test lung on the other. Sounds were recorded with a microphone located inside the endotracheal tube via a connector. During mechanical ventilation, we changed the endotracheal tube internal diameter from 5.0 to 8.0 mm and different grades of obstruction at different sites were used along the tube. Sound energy was compared among the different conditions. Results: The energy of endotracheal tube sounds was positively correlated with the internal diameter and negatively correlated with the degree of obstruction. The rate of decline in energy differed with obstruction location. When the obstruction was more distal, the rate of decline in endotracheal sound energy was more rapid. Conclusions: Changes in the sound of an endotracheal tube can be used to detect an obstruction. Further studies are needed for clinical application.
Keywords
Intubation, intratracheal; Sound; Airway obstruction;
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1 Kawati R, Vimlati L, Guttmann J, et al. Change in expiratory flow detects partial endotracheal tube obstruction in pressurecontrolled ventilation. Anesth Analg 2006;103:650-657.   DOI   ScienceOn
2 Jarreau PH, Louis B, Desfrere L, et al. Detection of positional airway obstruction in neonates by acoustic reflection. Am J Respir Crit Care Med 2000;161:1754-1756.   DOI   ScienceOn
3 Schumann S, Lichtwarck-Aschoff M, Haberthur C, Stahl CA, Möller K, Guttmann J. Detection of partial endotracheal tube obstruction by forced pressure oscillations. Respir Physiol Neurobiol 2007;155:227-233.   DOI   ScienceOn
4 Visaria RK, Westenskow DR. Model-based detection of partially obstructed endotracheal tube. Crit Care Med 2005;33:149-154.   DOI   ScienceOn
5 Sovijarvi AR, Vanderschoot J, Earis JE. Standardization of computerized respiratory sound analysis. Eur Respir Rev 2000;10:585.
6 Oppenheim AV, Willsky AS, Nawab SH. Singals and Systems. 2nd ed. Englewood Cliffs, NJ: Prentice-Hall, 1997.
7 Oppenheim AV, Schafer RW, Buck JR. Discrete-Time Signal Processing. Englewood Cliffs, NJ: Prentice-Hall, 1989.
8 Elad D, Soffer G, Zaretsky U, Wolf M, Shiner RJ. Time-frequency analysis of breathing signals: in vitro airway model. Technol Health Care 2001;9:269-280.
9 Raphael DT. Acoustic reflectometry profiles of endotracheal and esophageal intubation. Anesthesiology 2000;92:1293-1299.   DOI   ScienceOn
10 Raphael DT, Benbassat M, Arnaudov D, Bohorquez A, Nasseri B. Validation study of two-microphone acoustic reflectometry for determination of breathing tube placement in 200 adult patients. Anesthesiology 2002;97:1371-1377.   DOI   ScienceOn
11 Boque MC, Gualis B, Sandiumenge A, Rello J. Endotracheal tube intraluminal diameter narrowing after mechanical ventilation: use of acoustic reflectometry. Intensive Care Med 2004;30:2204-2209.   DOI   ScienceOn
12 Shah C, Kollef MH. Endotracheal tube intraluminal volume loss among mechanically ventilated patients. Crit Care Med 2004;32:120-125.   DOI   ScienceOn
13 Ramirez P, Ferrer M, Torres A. Prevention measures for ventilator- associated pneumonia: a new focus on the endotracheal tube. Curr Opin Infect Dis 2007;20:190-197.   DOI   ScienceOn
14 Adair CG, Gorman SP, Feron BM, et al. Implications of endotracheal tube biofilm for ventilator-associated pneumonia. Intensive Care Med 1999;25:1072-1076.   DOI   ScienceOn
15 Feldman C, Kassel M, Cantrell J, et al. The presence and sequence of endotracheal tube colonization in patients undergoing mechanical ventilation. Eur Respir J 1999;13:546-551.   DOI   ScienceOn
16 Tung A, Morgan SE. Modeling the effect of progressive endotracheal tube occlusion on tidal volume in pressure-control mode. Anesth Analg 2002;95:192-197.   DOI   ScienceOn
17 Kawati R, Lattuada M, Sjostrand U, et al. Peak airway pressure increase is a late warning sign of partial endotracheal tube obstruction whereas change in expiratory flow is an early warning sign. Anesth Analg 2005;100:889-893.   DOI   ScienceOn