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Detection of changes in respiratory mechanics due to increasing degrees of airway obstruction in asthma by the forced oscillation technique.
Respir Med. 2006 Dec; 100(12):2207-19.RM

Abstract

Forced expiratory airflows and volumes are often used to assess the airway obstruction in asthmatics. However, forced maneuvers may change bronchial tone and modify airway patency. The aim of this study was to determine whether the Forced Oscillation Technique (FOT), which does not require forced manoeuvres, may be useful to describe the changes in respiratory mechanics in progressive asthma. This study involved 25 healthy and 84 asthmatics, including patients with normal spirometric exam (NE), mild moderate and severe obstruction. Resistive data were interpreted using the respiratory system resistance extrapolated at 0 Hz (R0), the mean respiratory resistance (Rm), and the resistance/frequency slope (S). Reactance data were interpreted by its mean values (Xm), the dynamic compliance (Crs,dyn), and resonant frequency (fr). Receiver operating characteristics curves were used to determine the sensitivity (Se) and specificity (Sp) of FOT parameters in identifying asthma. There were not statistically significant differences between the control and NE groups. Comparing the control and mild groups, significant increases of R0 (P<0.0007), Rm (P<0.003), and S (P<0.003) were observed. In reactive parameters, a significant reduction in Crs,dyn (P<0.04) was observed, while Xm and fr presented significant increases (P<0.0007 and P<0.006, respectively). Comparison between mild and moderate groups showed non-significant modifications in all of the parameters, except for Xm (P<0.02). In the late stages (moderate to severe obstruction), all of the resistive parameters, as well as the reactive ones Xm (P<0.007) and Crs,dyn (P<0.03), presented statistically significant modifications. Among the studied parameters, the effects of airway obstruction in asthma seem to be well described by R0, Rm, S and Xm, which were in close agreement with physiological fundamentals. The best parameters for detecting asthma were R0 (Se=81%, Sp=76%), S (Se=78%, Sp=72%) and Xm (Se=81%, Sp=80%). In conclusion, the results of this study suggest that the FOT can be proposed as an alternative method for the assessment of the respiratory mechanics in asthmatic patients, representing a promising solution to the problem of effort dependence.

Authors+Show Affiliations

Biomedical Instrumentation Laboratory, Institute of Biology and Faculty of Engineering, Brazil.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16713226

Citation

Cavalcanti, Juliana V., et al. "Detection of Changes in Respiratory Mechanics Due to Increasing Degrees of Airway Obstruction in Asthma By the Forced Oscillation Technique." Respiratory Medicine, vol. 100, no. 12, 2006, pp. 2207-19.
Cavalcanti JV, Lopes AJ, Jansen JM, et al. Detection of changes in respiratory mechanics due to increasing degrees of airway obstruction in asthma by the forced oscillation technique. Respir Med. 2006;100(12):2207-19.
Cavalcanti, J. V., Lopes, A. J., Jansen, J. M., & Melo, P. L. (2006). Detection of changes in respiratory mechanics due to increasing degrees of airway obstruction in asthma by the forced oscillation technique. Respiratory Medicine, 100(12), 2207-19.
Cavalcanti JV, et al. Detection of Changes in Respiratory Mechanics Due to Increasing Degrees of Airway Obstruction in Asthma By the Forced Oscillation Technique. Respir Med. 2006;100(12):2207-19. PubMed PMID: 16713226.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Detection of changes in respiratory mechanics due to increasing degrees of airway obstruction in asthma by the forced oscillation technique. AU - Cavalcanti,Juliana V, AU - Lopes,Agnaldo J, AU - Jansen,José M, AU - Melo,Pedro L, Y1 - 2006/05/18/ PY - 2005/10/05/received PY - 2006/01/25/revised PY - 2006/03/09/accepted PY - 2006/5/23/pubmed PY - 2007/3/23/medline PY - 2006/5/23/entrez SP - 2207 EP - 19 JF - Respiratory medicine JO - Respir Med VL - 100 IS - 12 N2 - Forced expiratory airflows and volumes are often used to assess the airway obstruction in asthmatics. However, forced maneuvers may change bronchial tone and modify airway patency. The aim of this study was to determine whether the Forced Oscillation Technique (FOT), which does not require forced manoeuvres, may be useful to describe the changes in respiratory mechanics in progressive asthma. This study involved 25 healthy and 84 asthmatics, including patients with normal spirometric exam (NE), mild moderate and severe obstruction. Resistive data were interpreted using the respiratory system resistance extrapolated at 0 Hz (R0), the mean respiratory resistance (Rm), and the resistance/frequency slope (S). Reactance data were interpreted by its mean values (Xm), the dynamic compliance (Crs,dyn), and resonant frequency (fr). Receiver operating characteristics curves were used to determine the sensitivity (Se) and specificity (Sp) of FOT parameters in identifying asthma. There were not statistically significant differences between the control and NE groups. Comparing the control and mild groups, significant increases of R0 (P<0.0007), Rm (P<0.003), and S (P<0.003) were observed. In reactive parameters, a significant reduction in Crs,dyn (P<0.04) was observed, while Xm and fr presented significant increases (P<0.0007 and P<0.006, respectively). Comparison between mild and moderate groups showed non-significant modifications in all of the parameters, except for Xm (P<0.02). In the late stages (moderate to severe obstruction), all of the resistive parameters, as well as the reactive ones Xm (P<0.007) and Crs,dyn (P<0.03), presented statistically significant modifications. Among the studied parameters, the effects of airway obstruction in asthma seem to be well described by R0, Rm, S and Xm, which were in close agreement with physiological fundamentals. The best parameters for detecting asthma were R0 (Se=81%, Sp=76%), S (Se=78%, Sp=72%) and Xm (Se=81%, Sp=80%). In conclusion, the results of this study suggest that the FOT can be proposed as an alternative method for the assessment of the respiratory mechanics in asthmatic patients, representing a promising solution to the problem of effort dependence. SN - 0954-6111 UR - https://www.unboundmedicine.com/medline/citation/16713226/Detection_of_changes_in_respiratory_mechanics_due_to_increasing_degrees_of_airway_obstruction_in_asthma_by_the_forced_oscillation_technique_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0954-6111(06)00124-7 DB - PRIME DP - Unbound Medicine ER -