Diagnostic yield and safety of sputum induction with nebulized racemic salbutamol versus hypertonic saline in smear-negative pulmonary tuberculosis.

Abstract

The aim of the study was to compare the diagnostic yield and safety profile of sputum induction (SI) with nebulized racemic salbutamol solution versus hypertonic saline in smear-negative pulmonary tuberculosis (TB). The prospective study was conducted at Songklanagarind Hospital, Thailand. Suspected smear-negative pulmonary TB cases were recruited and randomized to receive SI with either nebulized racemic salbutamol solution or 3% sodium chloride (NaCl) solution. Induced sputum was examined with the acid-fast bacilli (AFB) smear test and cultured for Mycobacterium tuberculosis. The efficacy and adverse events of SI were analyzed. A total of 59 patients received SI with nebulized racemic salbutamol solution and 53 received 3% NaCl solution. There was no significant difference between the two groups in the average quantity of induced sputum (1.3 ± 0.1 versus 1.2 ± 0.2 ml, p = 0.5). The percentages of positive AFB smear and TB cultures in the salbutamol group were 15% and 22%, and 13% and 17% in the 3% NaCl group (p = 0.5), respectively. Racemic salbutamol solution could increase the TB diagnostic yield similarly to 3% NaCl, but incurred less chest tightness (5% versus 15%) and bronchospasm (0% versus 11.3%, p = 0.02) compared with 3% NaCl. SI by nebulized racemic salbutamol solution offers equal benefits to 3% NaCl solution in increasing both sputum quantity and diagnostic yield in smear-negative patients suspected of having pulmonary TB. Nebulized racemic salbutamol does not produce bronchospasm and chest tightness occurs less frequently than with 3% NaCl. Therefore, SI with nebulized racemic salbutamol solution should be considered as a good alternative noninvasive diagnostic tool for the diagnosis of pulmonary TB when hypertonic saline is unavailable or contraindicated.