Sputum induction in routine clinical care of children with cystic fibrosis.
OBJECTIVE
To determine the microbiological yield of induced sputum (IS) samples compared with conventional airway samples, spontaneously expectorated sputum and throat swabs, in children with cystic fibrosis (CF) attending an outpatient clinic.


METHODS
Ninety-five children with CF (75 able to spontaneously expectorate sputum) were included in this prospective cross-sectional comparative study. After obtaining expectorated sputum or throat swabs samples, IS was obtained by performing the sputum induction procedure using an eFlow device (PARI, Starnberg, Germany). CF bacterial culture results were compared between the two procedures.


RESULTS
Differences in culture results between samples were observed in 25 of 94 (27%) patients. IS had a significantly higher yield for CF pathogens, with 80% of the differences being due to detection of additional organisms in IS samples. Overall, SI was well tolerated, but 12 of 95 cases had a >20% postinduction decline in forced expiratory volume in 1 second. The whole SI procedure took 30 to 85 minutes of clinic time, and its estimated additional cost was $150 (US)/patient.


CONCLUSIONS
Induced sputum has a higher microbiological yield compared with the conventional samples in children with CF, even in patients capable of expectorating sputum spontaneously. Although sputum induction is safe and tolerable, it is time-consuming and expensive in routine clinical settings.
Al-Saleh
Suhail
S
Division of Respiratory Medicine, Toronto, Ontario, Canada; Research Institute, The Hospital for Sick Children, and the University of Toronto, Toronto, Ontario, Canada.
Dell
Sharon D
SD
Grasemann
Hartmut
H
Yau
Yvonne C W
YC
Waters
Valerie
V
Martin
Sean
S
Ratjen
Felix
F
D000293:Adolescent; D002648:Child; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D013183:Sputum / Q000382:microbiology*