Abstract
Whether, and to what extent, β2-agonists protect against respiratory muscle overloading and breathlessness during bronchoconstriction remains to be defined in patients with asthma. In a double blind placebo-controlled study, 100 μg of fenoterol were administered to six stable asthmatics before a bronchial provocation test, performed by inhaling doubling concentrations of histamine from a Devilbiss 646 nebulizer. We recorded breathing pattern (tidal volume V(T), inspiratory time T(I), total time of the respiratory cycle T(TOT)), inspiratory capacity (IC), dynamic pleural pressure swing (P(plsw)), total lung resistance (R(L)) and FEV1. V(T) was expressed both in actual values and as % of IC. Changes in V(T) (%IC) during histamine inhalation reflected changes in dynamic end-inspiratory lung volume (EILV). P(plsw) was expressed as % of maximal (the most negative in sign) pleural pressure, obtained under control conditions during a sniff manoeuvre (P(plsn)). P(plsw)(%P(plsn)) is an index of inspiratory muscle effort. The test ended when the concentration of histamine which caused a decrease in FEV1 of ≥ 40% post-saline was reached. Dyspnoea rating was scored by a modified Borg scale. At the ultimate degree of bronchoconstriction (UDB) with histamine: (i) decrease in FEV1 was similar after placebo and fenoterol, while increase in R(L) was lower after fenoterol (P <0.005); (ii) V(T)(%IC) increased less after fenoterol (P <0.027); (iii) increases in P(plsw)(%P(plsw)) was lower after fenoterol (P <0.001); (iv) ΔBorg (from saline) was lower (P <0.01) after fenoterol; (v) differences in ΔBorg, from placebo to fenoterol, related to concurrent changes in V(T)(%IC) (r2 = 0.67). In conclusion, at UDB 100 μg of fenoterol produced a beneficial effect on the degree of inspiratory muscle loading and breathlessness, an effect greater than it would be expected from measuring FEV1 alone.
| Original language | English |
|---|---|
| Pages (from-to) | 299-304 |
| Number of pages | 6 |
| Journal | Pulmonary Pharmacology and Therapeutics |
| Volume | 10 |
| Issue number | 5-6 |
| DOIs | |
| Publication status | Published - Oct 1997 |
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Keywords
- Asthma
- Dyspnoea
- Fenoterol
- Respiratory muscles
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Pharmacology
Cite this
Respiratory muscle overloading and dyspnoea during bronchoconstriction in asthma : Protective effects of fenoterol. / Misuri, Gianni; Mancini, Marco; Iandelli, Iacopo; Duranti, Roberto; Stendardi, Loredana; Gigliotti, Francesco; Rosi, Elisabetta; Ronchi, Maria Cristina; Scano, Giorgio.
In: Pulmonary Pharmacology and Therapeutics, Vol. 10, No. 5-6, 10.1997, p. 299-304.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Respiratory muscle overloading and dyspnoea during bronchoconstriction in asthma
T2 - Protective effects of fenoterol
AU - Misuri, Gianni
AU - Mancini, Marco
AU - Iandelli, Iacopo
AU - Duranti, Roberto
AU - Stendardi, Loredana
AU - Gigliotti, Francesco
AU - Rosi, Elisabetta
AU - Ronchi, Maria Cristina
AU - Scano, Giorgio
PY - 1997/10
Y1 - 1997/10
N2 - Whether, and to what extent, β2-agonists protect against respiratory muscle overloading and breathlessness during bronchoconstriction remains to be defined in patients with asthma. In a double blind placebo-controlled study, 100 μg of fenoterol were administered to six stable asthmatics before a bronchial provocation test, performed by inhaling doubling concentrations of histamine from a Devilbiss 646 nebulizer. We recorded breathing pattern (tidal volume V(T), inspiratory time T(I), total time of the respiratory cycle T(TOT)), inspiratory capacity (IC), dynamic pleural pressure swing (P(plsw)), total lung resistance (R(L)) and FEV1. V(T) was expressed both in actual values and as % of IC. Changes in V(T) (%IC) during histamine inhalation reflected changes in dynamic end-inspiratory lung volume (EILV). P(plsw) was expressed as % of maximal (the most negative in sign) pleural pressure, obtained under control conditions during a sniff manoeuvre (P(plsn)). P(plsw)(%P(plsn)) is an index of inspiratory muscle effort. The test ended when the concentration of histamine which caused a decrease in FEV1 of ≥ 40% post-saline was reached. Dyspnoea rating was scored by a modified Borg scale. At the ultimate degree of bronchoconstriction (UDB) with histamine: (i) decrease in FEV1 was similar after placebo and fenoterol, while increase in R(L) was lower after fenoterol (P <0.005); (ii) V(T)(%IC) increased less after fenoterol (P <0.027); (iii) increases in P(plsw)(%P(plsw)) was lower after fenoterol (P <0.001); (iv) ΔBorg (from saline) was lower (P <0.01) after fenoterol; (v) differences in ΔBorg, from placebo to fenoterol, related to concurrent changes in V(T)(%IC) (r2 = 0.67). In conclusion, at UDB 100 μg of fenoterol produced a beneficial effect on the degree of inspiratory muscle loading and breathlessness, an effect greater than it would be expected from measuring FEV1 alone.
AB - Whether, and to what extent, β2-agonists protect against respiratory muscle overloading and breathlessness during bronchoconstriction remains to be defined in patients with asthma. In a double blind placebo-controlled study, 100 μg of fenoterol were administered to six stable asthmatics before a bronchial provocation test, performed by inhaling doubling concentrations of histamine from a Devilbiss 646 nebulizer. We recorded breathing pattern (tidal volume V(T), inspiratory time T(I), total time of the respiratory cycle T(TOT)), inspiratory capacity (IC), dynamic pleural pressure swing (P(plsw)), total lung resistance (R(L)) and FEV1. V(T) was expressed both in actual values and as % of IC. Changes in V(T) (%IC) during histamine inhalation reflected changes in dynamic end-inspiratory lung volume (EILV). P(plsw) was expressed as % of maximal (the most negative in sign) pleural pressure, obtained under control conditions during a sniff manoeuvre (P(plsn)). P(plsw)(%P(plsn)) is an index of inspiratory muscle effort. The test ended when the concentration of histamine which caused a decrease in FEV1 of ≥ 40% post-saline was reached. Dyspnoea rating was scored by a modified Borg scale. At the ultimate degree of bronchoconstriction (UDB) with histamine: (i) decrease in FEV1 was similar after placebo and fenoterol, while increase in R(L) was lower after fenoterol (P <0.005); (ii) V(T)(%IC) increased less after fenoterol (P <0.027); (iii) increases in P(plsw)(%P(plsw)) was lower after fenoterol (P <0.001); (iv) ΔBorg (from saline) was lower (P <0.01) after fenoterol; (v) differences in ΔBorg, from placebo to fenoterol, related to concurrent changes in V(T)(%IC) (r2 = 0.67). In conclusion, at UDB 100 μg of fenoterol produced a beneficial effect on the degree of inspiratory muscle loading and breathlessness, an effect greater than it would be expected from measuring FEV1 alone.
KW - Asthma
KW - Dyspnoea
KW - Fenoterol
KW - Respiratory muscles
UR - http://www.scopus.com/inward/record.url?scp=0031260623&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031260623&partnerID=8YFLogxK
U2 - 10.1006/pupt.1998.0108
DO - 10.1006/pupt.1998.0108
M3 - Article
C2 - 9778494
AN - SCOPUS:0031260623
VL - 10
SP - 299
EP - 304
JO - Pulmonary Pharmacology and Therapeutics
JF - Pulmonary Pharmacology and Therapeutics
SN - 1094-5539
IS - 5-6
ER -