Induced sputum in children: Success determinants,safety,and cell profiles

Background: sputum induction is a noninvasive method for the assessment of airway inflammation. objectives: to evaluate the safety of the procedure and the clinical predictors of successful induction,and to analyze the relationship between sputum cell counts and clinical features in asthmatic and nonasthmatic children. methods: we reviewed sputum inductions performed in our department between 2006 and 2008 in individuals under 18 years; 34 asthmatic and 24 nonasthmatic children were included. sputum induction was performed with 4.5% saline for 5-minute periods with salbutamol pretreatment. the most viscid portions were selected for processing. inductions which were tolerated for less than 4 minutes or which produced a sample volume of less than 1 ml or a sample with a squamous cell percentage of over 80% were considered unsuccessful. results: sputum induction was successful in 43 (74%) of the 58 children studied. the total median induction time was 15 minutes (interquartile range,10-15 minutes). only 7 individuals (12%) experienced mild symptoms,which were easily reversed with salbutamol inhalation in all cases. the mean (sd) overall pef variation with induction was-2.5% (7%),with no signifi cant differences between asthmatics and nonasthmatics. asthmatics had signifi cantly higher total cell counts (p=.007),macrophages (p=.033),and relatively fewer neutrophils (p=.003) than nonasthmatics; metachromatic cells were rare and seen only in asthmatics (p=.026). we found a positive correlation between exhaled nitric oxide and sputum eosinophil count (r=0.363,p=.017). conclusions: sputum induction is a safe,noninvasive,and feasible procedure that allows the direct assessment of airway inflammation in most children. © 2011 esmon publicidad.