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Lung Volume Reduction in Emphysema Improves Chest Wall Asynchrony.

Zoumot Z, LoMauro A, Aliverti A, Nelson C, Ward S, Jordan S, Polkey MI, Shah PL, Hopkinson NS - Chest (2015)

Bottom Line: Participants had an FEV₁ of 34.6 ± 18% predicted and a residual volume of 217.8 ± 46.0% predicted with significant chest wall asynchrony during quiet breathing at baseline (θRC, 31.3° ± 38.4°; and θDIA, -38.7° ± 36.3°).Changes in θRC and θDIA were statistically significant on the treated but not the untreated sides.Successful LVR significantly reduces chest wall asynchrony in patients with emphysema.

View Article: PubMed Central - PubMed

ABSTRACT

Background: Lung volume reduction (LVR) techniques improve lung function in selected patients with emphysema, but the impact of LVR procedures on the asynchronous movement of different chest wall compartments, which is a feature of emphysema, is not known.

Methods: We used optoelectronic plethysmography to assess the effect of surgical and bronchoscopic LVR on chest wall asynchrony. Twenty-six patients were assessed before and 3 months after LVR (surgical [n = 9] or bronchoscopic [n = 7]) or a sham/unsuccessful bronchoscopic treatment (control subjects, n = 10). Chest wall volumes were divided into six compartments (left and right of each of pulmonary ribcage [Vrc,p], abdominal ribcage [Vrc,a], and abdomen [Vab]) and phase shift angles (θ) calculated for the asynchrony between Vrc,p and Vrc,a (θRC), and between Vrc,a and Vab (θDIA).

Results: Participants had an FEV₁ of 34.6 ± 18% predicted and a residual volume of 217.8 ± 46.0% predicted with significant chest wall asynchrony during quiet breathing at baseline (θRC, 31.3° ± 38.4°; and θDIA, -38.7° ± 36.3°). Between-group difference in the change in θRC and θDIA during quiet breathing following treatment was 44.3° (95% CI, -78 to -10.6; P = .003) and 34.5° (95% CI, 1.4 to 67.5; P = .007) toward 0° (representing perfect synchrony), respectively, favoring the LVR group. Changes in θRC and θDIA were statistically significant on the treated but not the untreated sides.

Conclusions: Successful LVR significantly reduces chest wall asynchrony in patients with emphysema.

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A, B, Time courses of Vrc,p, Vrc,a, Vab, and Vcw during a typical respiratory cycle during quiet breathing at rest in a representative patient before (A) and after (B) lung volume reduction surgery (LVRS). Black line represents the inspiratory portion of the respiratory cycle, and asynchronous movement of abdominal ribcage compartment (RC,a) before LVRS is clearly demonstrated, as is the improvement thereof after LVRS. Lissajou figures of the dynamic loops of ΔVrc,p vs ΔVrc,a (θRC) and ΔVrc,a vs ΔVab (θDIA) during quiet breathing are used to calculate θ. m = line parallel to the x axis at 50% of one compartment’s tidal volume; s = the second compartment’s tidal volume. Phase shift is calculated as θ = sin−1 (ms−1). θDIA = phase shift angle between Vrc,p and Vrc,a; θRC = phase shift angle between Vrc,p and Vrc,a. See Figure 1 legend for expansion of other abbreviations.
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fig02: A, B, Time courses of Vrc,p, Vrc,a, Vab, and Vcw during a typical respiratory cycle during quiet breathing at rest in a representative patient before (A) and after (B) lung volume reduction surgery (LVRS). Black line represents the inspiratory portion of the respiratory cycle, and asynchronous movement of abdominal ribcage compartment (RC,a) before LVRS is clearly demonstrated, as is the improvement thereof after LVRS. Lissajou figures of the dynamic loops of ΔVrc,p vs ΔVrc,a (θRC) and ΔVrc,a vs ΔVab (θDIA) during quiet breathing are used to calculate θ. m = line parallel to the x axis at 50% of one compartment’s tidal volume; s = the second compartment’s tidal volume. Phase shift is calculated as θ = sin−1 (ms−1). θDIA = phase shift angle between Vrc,p and Vrc,a; θRC = phase shift angle between Vrc,p and Vrc,a. See Figure 1 legend for expansion of other abbreviations.

Mentions: A run of at least eight stable tidal breaths were used to obtain an average typical respiratory cycle during quiet breathing. This and the technically best of five IC maneuvers were used to calculate changes in chest wall volumes. Changes in total chest wall volumes during quiet breathing and IC maneuvers were split into the nine volume subdivisions: RC,p (Vrc,p), RC,a (Vrc,a), Ab (Vab), and left and right of each of Vrc,p, Vrc,a and Vab (e-Fig 1). Phase shift angles (θ) were calculated and used to assess asynchrony between various combinations of chest wall compartments25 (further details and representations are available in in e-Appendix 2 and Fig 2). In this system, a θ of 0° represents perfectly synchronous movement of the two compartments compared and 180° absolute asynchrony. The primary phase shift angles measured were θRC (phase shift angle between RC,p and RC,a) and θDIA (phase shift angle between RCa and Ab), including separately for treated and nontreated sides. Also measured was θRC,p, θRC,a, and θAb, each assessing the phase shift between treated and nontreated sides of the denoted compartment.


Lung Volume Reduction in Emphysema Improves Chest Wall Asynchrony.

Zoumot Z, LoMauro A, Aliverti A, Nelson C, Ward S, Jordan S, Polkey MI, Shah PL, Hopkinson NS - Chest (2015)

A, B, Time courses of Vrc,p, Vrc,a, Vab, and Vcw during a typical respiratory cycle during quiet breathing at rest in a representative patient before (A) and after (B) lung volume reduction surgery (LVRS). Black line represents the inspiratory portion of the respiratory cycle, and asynchronous movement of abdominal ribcage compartment (RC,a) before LVRS is clearly demonstrated, as is the improvement thereof after LVRS. Lissajou figures of the dynamic loops of ΔVrc,p vs ΔVrc,a (θRC) and ΔVrc,a vs ΔVab (θDIA) during quiet breathing are used to calculate θ. m = line parallel to the x axis at 50% of one compartment’s tidal volume; s = the second compartment’s tidal volume. Phase shift is calculated as θ = sin−1 (ms−1). θDIA = phase shift angle between Vrc,p and Vrc,a; θRC = phase shift angle between Vrc,p and Vrc,a. See Figure 1 legend for expansion of other abbreviations.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493874&req=5

fig02: A, B, Time courses of Vrc,p, Vrc,a, Vab, and Vcw during a typical respiratory cycle during quiet breathing at rest in a representative patient before (A) and after (B) lung volume reduction surgery (LVRS). Black line represents the inspiratory portion of the respiratory cycle, and asynchronous movement of abdominal ribcage compartment (RC,a) before LVRS is clearly demonstrated, as is the improvement thereof after LVRS. Lissajou figures of the dynamic loops of ΔVrc,p vs ΔVrc,a (θRC) and ΔVrc,a vs ΔVab (θDIA) during quiet breathing are used to calculate θ. m = line parallel to the x axis at 50% of one compartment’s tidal volume; s = the second compartment’s tidal volume. Phase shift is calculated as θ = sin−1 (ms−1). θDIA = phase shift angle between Vrc,p and Vrc,a; θRC = phase shift angle between Vrc,p and Vrc,a. See Figure 1 legend for expansion of other abbreviations.
Mentions: A run of at least eight stable tidal breaths were used to obtain an average typical respiratory cycle during quiet breathing. This and the technically best of five IC maneuvers were used to calculate changes in chest wall volumes. Changes in total chest wall volumes during quiet breathing and IC maneuvers were split into the nine volume subdivisions: RC,p (Vrc,p), RC,a (Vrc,a), Ab (Vab), and left and right of each of Vrc,p, Vrc,a and Vab (e-Fig 1). Phase shift angles (θ) were calculated and used to assess asynchrony between various combinations of chest wall compartments25 (further details and representations are available in in e-Appendix 2 and Fig 2). In this system, a θ of 0° represents perfectly synchronous movement of the two compartments compared and 180° absolute asynchrony. The primary phase shift angles measured were θRC (phase shift angle between RC,p and RC,a) and θDIA (phase shift angle between RCa and Ab), including separately for treated and nontreated sides. Also measured was θRC,p, θRC,a, and θAb, each assessing the phase shift between treated and nontreated sides of the denoted compartment.

Bottom Line: Participants had an FEV₁ of 34.6 ± 18% predicted and a residual volume of 217.8 ± 46.0% predicted with significant chest wall asynchrony during quiet breathing at baseline (θRC, 31.3° ± 38.4°; and θDIA, -38.7° ± 36.3°).Changes in θRC and θDIA were statistically significant on the treated but not the untreated sides.Successful LVR significantly reduces chest wall asynchrony in patients with emphysema.

View Article: PubMed Central - PubMed

ABSTRACT

Background: Lung volume reduction (LVR) techniques improve lung function in selected patients with emphysema, but the impact of LVR procedures on the asynchronous movement of different chest wall compartments, which is a feature of emphysema, is not known.

Methods: We used optoelectronic plethysmography to assess the effect of surgical and bronchoscopic LVR on chest wall asynchrony. Twenty-six patients were assessed before and 3 months after LVR (surgical [n = 9] or bronchoscopic [n = 7]) or a sham/unsuccessful bronchoscopic treatment (control subjects, n = 10). Chest wall volumes were divided into six compartments (left and right of each of pulmonary ribcage [Vrc,p], abdominal ribcage [Vrc,a], and abdomen [Vab]) and phase shift angles (θ) calculated for the asynchrony between Vrc,p and Vrc,a (θRC), and between Vrc,a and Vab (θDIA).

Results: Participants had an FEV₁ of 34.6 ± 18% predicted and a residual volume of 217.8 ± 46.0% predicted with significant chest wall asynchrony during quiet breathing at baseline (θRC, 31.3° ± 38.4°; and θDIA, -38.7° ± 36.3°). Between-group difference in the change in θRC and θDIA during quiet breathing following treatment was 44.3° (95% CI, -78 to -10.6; P = .003) and 34.5° (95% CI, 1.4 to 67.5; P = .007) toward 0° (representing perfect synchrony), respectively, favoring the LVR group. Changes in θRC and θDIA were statistically significant on the treated but not the untreated sides.

Conclusions: Successful LVR significantly reduces chest wall asynchrony in patients with emphysema.

Show MeSH
Related in: MedlinePlus