Bronchodilator response in wheezing infants assessed by the raised volume rapid thoracic compression technique.
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.



To evaluate BDR by RVRTC technique in infants with recurrent wheezing and compare to control group.



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,FEF25-75were 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.



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.



34% WG showed BDR measured by the RVRTC. The best variables to detect BDR were FEF75, FEF25-75and FEV0.5. Patients with worse lung function showed better response to BD.
Discipline of Allergy, Clinical Immunology and Rheumatology, Department of Pediatrics, Federal University of Sao Paulo - UNIFESP, Sao Paulo, SP, Otonis St 725, 04025-002, Brazil. Electronic address: lanzafe@gmail.com.
Fernanda Cordoba
FC
Lanza
Discipline of Allergy, Clinical Immunology and Rheumatology, Department of Pediatrics, Federal University of Sao Paulo - UNIFESP, Sao Paulo, SP, Otonis St 725, 04025-002, Brazil. Electronic address: gfwandalsen@uol.com.br.
Gustavo Falbo
GF
Wandalsen
Neonatal Division of Medicine - Department of Pediatrics - Federal University of Sao Paulo - UNIFESP, Sao Paulo, SP, Marselhesa St 630, 04020-060, Brazil. Electronic address: ameliamiyashiro@yahoo.com.br.
Amelia Miyashiro
AM
Dos Santos
Discipline of Allergy, Clinical Immunology and Rheumatology, Department of Pediatrics, Federal University of Sao Paulo - UNIFESP, Sao Paulo, SP, Otonis St 725, 04025-002, Brazil. Electronic address: sole.dirceu@gmail.com.
Dirceu
D
Solé
D000420:Albuterol / Q000008:administration & dosage / Q000494:pharmacology*; D001938:Brazil; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*; D003430:Cross-Sectional Studies; D005260:Female; D005540:Forced Expiratory Flow Rates / Q000187:drug effects; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D007223:Infant; D008297:Male; D012129:Respiratory Function Tests / Q000379:methods; D012135:Respiratory Sounds / Q000187:drug effects / Q000503:physiopathology*; D014797:Vital Capacity / Q000187:drug effects
D001993:Bronchodilator Agents; D000420:Albuterol
Bronchodilator; Infants; Lung function; Wheezing