Dataset Information

Lung clearance index as an outcome measure for clinical trials in young children with cystic fibrosis. A pilot study using inhaled hypertonic saline.

ABSTRACT:

Rationale

Lung clearance index (LCI), measured by multiple breath washout (MBW), is a noninvasive measure of ventilation inhomogeneity that holds promise as an objective physiologic endpoint for clinical trials in infants and preschool children with cystic fibrosis (CF).

Objectives

To study the feasibility of using LCI to assess treatment effect outcomes in CF trials of infants and preschoolers.

Methods

The Infant Study of Inhaled Saline trial was a multicenter, randomized, controlled trial of hypertonic (7%) versus isotonic (0.9%) saline inhaled twice daily for 48 weeks in children with CF under 6 years of age. LCI measurements were performed in a single-center pilot substudy at baseline and 48 weeks using a respiratory mass spectrometer and sulfur hexafluoride as the tracer gas. LCI measurements were standardized using published normative data (zLCI) to account for height-related changes in LCI during early childhood. A generalized estimating equation model with an interaction between treatment group and test occasion was used to estimate a treatment effect.

Measurements and main results

A total of 27 participants were randomized; 25 participants, aged (median [range]) 2.6 (0.34-4.95) years, had acceptable baseline and follow-up LCI measures. On average, LCI decreased in the hypertonic saline group (n = 12) by 1.19 z-scores units (95% confidence interval [CI] = -2.46 to 0.06), and remained stable in the isotonic saline group (n = 13) at 0.81 (95% CI = -0.40 to 2.02). A significant treatment effect was observed for zLCI (2.01; 95% CI = 0.26 to 3.76; P = 0.025).

Conclusions

MBW testing is feasible in an interventional study in infants and preschool children with CF. These pilot findings support the development of MBW and LCI as an objective outcome measure in interventional trials in young children with CF, and provide estimates for sample size calculations for future studies.

SUBMITTER: Subbarao P

PROVIDER: S-EPMC3778738 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:Inhaled hypertonic saline (HS) is an attractive agent for chronic maintenance therapy in infants and toddlers with cystic fibrosis (CF) because it improves defective mucociliary clearance. Prior to undertaking a clinical trial of HS efficacy in young children with CF, tolerability, adherence, and safety must be established.Three-center, open label evaluation of the short-term tolerability, adherence, and safety of 7% HS administered twice daily for 14 days in children with CF 12-30 months of age. The primary objective was to evaluate the proportion of participants unable to tolerate single and repeated doses of 7% HS according to protocol-defined criteria. Participants inhaled a test dose of HS at the enrollment visit; test dose intolerance was defined as fulfillment of at least one of 4 criteria. Participants who tolerated the test dose inhaled 7% HS twice daily for 14±2 days.Twenty children were enrolled. One was withdrawn due to maternal concern over fussiness with application of the facemask for the test dose. Of the 19 participants administered the test dose, 1 was withdrawn due to test dose intolerance (5%, 95% confidence interval 0, 26%). Eighteen participants completed the study; 1 was intolerant (95% CI 0, 27%) at the final visit due to new wheezes on exam in association with an upper respiratory infection and otitis media. Home symptom diaries demonstrated cough as the main symptom in the hour following inhalation, which decreased in frequency over the study period. Adherence as assessed by daily home diary and returned study drug ampoules was high. Participants reported receiving both treatments on a median of 100% of days; a median of 25 ampoules were used during a median of 13 days.7% HS appears well tolerated for up to 14 days in infants and toddlers with CF, with high adherence. These results provide encouraging short-term tolerability and adherence data for future trials assessing the safety and efficacy of 7% HS in young children with CF.

Project description:ContextInhaled hypertonic saline is recommended as therapy for patients 6 years or older with cystic fibrosis (CF), but its efficacy has never been evaluated in patients younger than 6 years with CF.ObjectiveTo determine if hypertonic saline reduces the rate of protocol-defined pulmonary exacerbations in patients younger than 6 years with CF.Design, setting, and participantsThe Infant Study of Inhaled Saline in Cystic Fibrosis (ISIS), a multicenter, randomized, double-blind, placebo-controlled trial conducted from April 2009 to October 2011 at 30 CF care centers in the United States and Canada. Participants were aged 4 to 60 months and had an established diagnosis of CF. A total of 344 patients were assessed for eligibility; 321 participants were randomized; 29 (9%) withdrew prematurely.InterventionThe active treatment group (n = 158) received 7% hypertonic saline and the control group (n = 163) received 0.9% isotonic saline, nebulized twice daily for 48 weeks. Both groups received albuterol or levalbuterol prior to each study drug dose.Main outcome measuresRate during the 48-week treatment period of protocol-defined pulmonary exacerbations treated with oral, inhaled, or intravenous antibiotics.ResultsThe mean pulmonary exacerbation rate (events per person-year) was 2.3 (95% CI, 2.0-2.5) in the active treatment group and 2.3 (95% CI, 2.1-2.6) in the control group; the adjusted rate ratio was 0.98 (95% CI, 0.84-1.15). Among participants with pulmonary exacerbations, the mean number of total antibiotic treatment days for a pulmonary exacerbation was 60 (95% CI, 49-70) in the active treatment group and 52 (95% CI, 43-61) in the control group. There was no significant difference in secondary end points including height, weight, respiratory rate, oxygen saturation, cough, or respiratory symptom scores. Infant pulmonary function testing performed as an exploratory outcome in a subgroup (n = 73, with acceptable measurements at 2 visits in 45 participants) did not demonstrate significant differences between groups except for the mean change in forced expiratory volume in 0.5 seconds, which was 38 mL (95% CI, 1-76) greater in the active treatment group. Adherence determined by returned study drug ampoules was at least 75% in each group. Adverse event profiles were also similar, with the most common adverse event of moderate or severe severity in each group being cough (39% of active treatment group, 38% of control group).ConclusionAmong infants and children younger than 6 years with cystic fibrosis, the use of inhaled hypertonic saline compared with isotonic saline did not reduce the rate of pulmonary exacerbations over the course of 48 weeks of treatment.Trial registrationclinicaltrials.gov Identifier: NCT00709280.