A pilot study assessing the effect of bronchodilator on dynamic hyperinflation in LAM.
BACKGROUND
Positive responses to bronchodilators (BDs) on spirometry can be found in up to 30% of patients with lymphangioleiomyomatosis (LAM). However, no previous studies have investigated the impact of BDs on exercise outcomes, including dynamic hyperinflation (DH).


METHODS
A randomised, double-blind, placebo-controlled, crossover trial was conducted on 38 patients with LAM, comparing inhaled placebo versus salbutamol. Pulmonary function tests and a cycle endurance test at 75% of the maximal work capacity, with evaluation of DH by serial measurement of inspiratory capacity (IC), which was the primary endpoint, were performed after each intervention.


RESULTS
Although salbutamol produced a slight improvement in airway obstruction, compared with placebo, there was no significant variation in resting IC or air trapping. A total of 18% of the patients met the criteria for a positive response to BD. During submaximal exercise, BD did not reduce DH or dyspnoea nor did it improve exercise tolerance in the entire population. In addition, BD produced only slight improvement in FEV1 and air trapping in patients who had DH during incremental cardiopulmonary exercise testing, without the beneficial effects on exercise outcomes.


CONCLUSIONS
Although salbutamol produced a slight improvement in airway obstruction, it did not lead to a reduction in DH or increase in exercise tolerance in patients with LAM.


BACKGROUND
Brazilian Registry of Clinical Trials (ReBEC); www.ensaiosclinicos.gov.br; registration number: RBR-49sk2j.
Pulmonary Division, Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil. Electronic address: bruno.guedes2@terra.com.br.
Bruno Guedes
BG
Baldi
André Luis Pereira
AL
de Albuquerque
Suzana Pinheiro
SP
Pimenta
João Marcos
JM
Salge
Ronaldo Adib
RA
Kairalla
Carlos Roberto Ribeiro
CR
Carvalho
D058666:Adrenergic beta-2 Receptor Agonists / Q000627:therapeutic use; D000328:Adult; D000420:Albuterol / Q000627:therapeutic use*; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004417:Dyspnea / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D005080:Exercise Test / Q000379:methods; D017079:Exercise Tolerance / Q000187:drug effects / Q000502:physiology; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D018192:Lymphangioleiomyomatosis / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D008875:Middle Aged; D010865:Pilot Projects; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D012129:Respiratory Function Tests / Q000379:methods; D016896:Treatment Outcome; D014797:Vital Capacity / Q000187:drug effects
D058666:Adrenergic beta-2 Receptor Agonists; D001993:Bronchodilator Agents; D000420:Albuterol
Adrenergic beta-2 receptor agonists; Exercise test; Lymphangioleiomyomatosis; Pulmonary function tests