Elsevier

The Journal of Pediatrics

Volume 157, Issue 6, December 2010, Pages 1006-1011.e1
The Journal of Pediatrics

Original Article
Sputum Induction in Routine Clinical Care of Children with Cystic Fibrosis

https://doi.org/10.1016/j.jpeds.2010.06.001Get rights and content

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.

Study design

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.

Section snippets

Methods

This is a cross-sectional comparative study in children attending the outpatient CF clinic at the Hospital for Sick Children in Toronto. Inclusion criteria were diagnosis of CF (by sweat chloride ≥60 mmol/L and/or two confirmed disease-causing CFTR mutations), age between 6 and 18 years, ability to perform pulmonary function tests, and forced expiratory volume in 1 second (FEV1) ≥30% predicted.15 Exclusion criteria were acute respiratory distress or hypoxia (oxygen saturation <92% in room air),

Results

Of 120 patients approached for the study between December 2006 and May 2008, 95 (79%) agreed to participate (Table I). There was no significant difference in the baseline characteristics between the study population and the entire CF population meeting the inclusion criteria at the center (n = 200) (data not shown). The duration of the whole sputum induction procedure ranged from 30 to 85 minutes (median, 49 minutes). The median duration of each cycle of nebulization of HS was 7 minutes (range,

Discussion

We assessed the utility of sputum induction in patients with CF in routine clinical setting. This is also the first study to use a high-output electronic nebulizer (PARI eFlow) for the nebulization of hypertonic saline solutions for sputum induction. Sputum induction, with increasing concentrations of hypertonic saline was safe and tolerated by the majority of the patients in our study. There was a discrepancy in the culture results between IS and conventional airway samples in 27% of patients,

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  • Cited by (0)

    Supported by a grant from the Lynne and Arnold Irwin Foundation. The authors declare no conflicts of interest.

    Registered at ClinicalTrials.gov: NCT00721071

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