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Bronchodilator response in wheezing infants assessed by the raised volume rapid thoracic compression technique
Fernanda Cordoba Lanza1, Gustavo Falbo Wandalsen1, Amelia Miyashiro Dos Santos2
1Discipline of Allergy, Clinical Immunology and Rheumatology, Department of Pediatrics, Federal University of Sao Paulo - UNIFESP, Sao Paulo, SP, Otonis St 725, 04025-002, Brazil.
Insights
Bronchodilator response in wheezing infants was evaluated using the raised volume rapid thoracic compression (RVRTC) technique. Thirty-four percent of infants with recurrent wheezing showed a significant response to bronchodilators, with worse lung function indicating a better response.
Area of Science:
- Pediatric Pulmonology
- Respiratory Physiology
- Infant Health
Background:
- Bronchodilator response (BDR) in infants with recurrent wheezing is not well characterized.
- Bronchodilators (BD) are a standard treatment for this population.
- The raised volume rapid thoracic compression (RVRTC) technique offers a method to assess BDR.
Purpose of the Study:
- To evaluate BDR using the RVRTC technique in infants experiencing recurrent wheezing.
- To compare BDR in infants with recurrent wheezing to a control group.
- To identify lung function parameters indicative of BDR in infants.
Main Methods:
- A cross-sectional study involving 45 infants (38-67 weeks old) divided into a wheezing group (WG) and a control group (CG).
- Lung function parameters including FVC, FEV0.5, FEF50, FEF75, FEF85, and FEF25-75 were measured using RVRTC before and after salbutamol administration.
- BDR was defined as an increase exceeding two standard deviations from the mean change observed in the CG.
Main Results:
- Infants in the WG exhibited poorer lung function compared to the CG (p < 0.05).
- A significant bronchodilator response (BDR) was observed in 34% of the WG (11 out of 32 infants).
- Responders in the WG had significantly worse baseline lung function and demonstrated a greater improvement in lung function post-BD compared to non-responders (p < 0.05).
Conclusions:
- The RVRTC technique can effectively assess BDR in infants with recurrent wheezing.
- FEF75, FEF25-75, and FEV0.5 were identified as key indicators for detecting BDR.
- Infants with more severe lung function impairment showed a more pronounced response to bronchodilator therapy.
Background:
Bronchodilator response (BDR) analyzed by the raised volume rapid thoracic compression (RVRTC) in wheezing infants is not yet well described, although bronchodilators (BD) are routine in the treatment of this population.
Objective:
To evaluate BDR by RVRTC technique in infants with recurrent wheezing and compare to control group.
Method:
Cross sectional study, 45 infants, age 56 weeks (38-67 weeks). Two groups: wheezing group (WG: history of recurrent wheezing) and control group (CG). RVRTC was evaluated, FVC, FEV0.5, FEF50, FEF75, FEF85, FEF25-75 were measured. Salbutamol was delivered to infants and RVRTC evaluated again. BDR was determined by the increase greater than two standard deviation from the mean change in the CG.
Results:
In WG (n = 32) lung function was worse than in CG (n = 13): FEV0.5: 0.0(-0.9-0.9z score) vs 0.8(0.2-1.4z score); FEF50: 0.2(-0.3-1.1z score) vs 0.9(0.5-1.4z score); and FEF25-75: 0.2(-0.5-1.1z score) vs 1.1(0.6-1.6z score), respectively, p < 0.05. Both groups had similar increase after BD. In WG 11 patients (34%) were responder and these had worse lung function compared to nonresponder (n = 21) (p < 0.05). The increase in lung function after BD in responder was higher than in nonresponder: FEV0.5: 6.5(2.1-7.1%) vs -0.5(-2.5-0.7%), FEF50: 5.1(2.7-11.7%) vs 0.4(-1.1-2.8%), FEF75: 20.7(4.7-23.6%) vs -1.3(-6.4-3.9%), FEF25-75: 9.9(3.8-16.4%) vs 0.0(-1.5-1.0%), respectively, p < 0.05.
Conclusion:
34% WG showed BDR measured by the RVRTC. The best variables to detect BDR were FEF75, FEF25-75 and FEV0.5. Patients with worse lung function showed better response to BD.
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