Lung Clearance Index In Infants Research Articles

Repeatability of lung clearance index in infants with cystic fibrosis and recurrent wheeze.

To describe the short- and medium-term repeatability of lung clearance index at 2.5%(LCI2.5 ) in infants and calculate the number of patients needed to enroll in a study (N) using LCI2.5 as a primary outcome. An 8-month follow-up observational study was employed for assessing short-term [coefficient of repeatability (CR) and intraclass correlation (ICC)]and medium-term repeatability (Bland-Altman method) of LCI2.5 in infants with cystic fibrosis (CF) or recurrent wheeze (RW) measured by the nitrogen multiple-breath washout test (N2 -MBW). Using these variability data, the N to reach 90% test power at the level of statistical significance (0.05) was calculated. Forty infants with CF and 21 with RW were enrolled. Initial N2 -MBW testing was successful in 33 and 17 patients, respectively. Follow-up data were available for 23 and 11 infants, respectively. Short-term repeatability of LCI2.5 was high (CR = 1.10 and 1.04 in CF and RW patients, respectively; ICC = 0.88 and 0.83 in CF and RW patients, respectively). The between-subject standard deviation was <13% of the actual LCI2.5 value. In clinically stable patients, LCI2.5 did not significantly change during the 8-month follow-up. Mean LCI2.5 change was -0.08 (1% of baseline) in CF and -0.05 (0.6%) in RW, with 95% limits of agreement being (-1.70; 1.53) in CF and (-1.51; 1.40) in RW patients. N = 23 infants if both intragroup differences of LCI2.5 and minimal difference to be detected would be 2.0. N2 -MBW may be a reproducible tool with reasonable test power to detect differences in infant studies.

WS06.3 Lung Clearance Index in infants with cystic fibrosis may predict lung function in preschoolers

WS06.3 Lung Clearance Index in infants with cystic fibrosis may predict lung function in preschoolers

2019 Year in Review: Aerosol Therapy.

Relevant publications related to medicinal and toxic aerosols are discussed in this review. Treatment of COPD includes a combination of long-acting bronchodilators and long-acting muscarinic antagonists. A combination of aclidinium bromide and formoterol fumarate was approved in the United States. The combination was superior to its components alone, as well as tiotropium and a salmeterol-fluticasone combination. Increased risk of an asthma exacerbation was reported in children exposed to electronic nicotine delivery systems. A smart inhaler capable of recording inspiratory flow was approved in the United States. The use of as-needed budesonide-formoterol was reported to be superior to scheduled budesonide and as-needed terbutaline for the treatment of adults with mild-to-moderate asthma. A survey among teens with asthma and their caregivers revealed a disagreement in the number of inhaled controller medications the teen was taking. Treatment with inhaled hypertonic saline resulted in a decreased lung clearance index in infants and preschool children with cystic fibrosis. Surgical masks were well tolerated and significantly decreased the burden of aerosolized bacteria generated by coughing in adults with cystic fibrosis. Inhaled liposomal amikacin in addition to guideline-based therapy was reported to be superior to guideline-based therapy alone in achieving negative sputum cultures in adult subjects with Mycobacterium avium complex pulmonary disease. During 2019, lung injury associated to e-cigarette or vaping was reported, including 60 casualties.

Elevated lung clearance index in infants with cystic fibrosis shortly after birth.

It is not known at what age lung function impairment may arise in children with cystic fibrosis (CF). We assessed lung function shortly after birth in infants with CF diagnosed by newborn screening.We performed infant lung function measurements in a prospective cohort of infants with CF and healthy controls. We assessed lung clearance index (LCI), functional residual capacity (FRC) and tidal breathing parameters. The primary outcome was prevalence and severity of abnormal lung function (±1.64 z-scores) in CF.We enrolled 53 infants with CF (mean age 7.8 weeks) and 57 controls (mean age 5.2 weeks). Compared to controls, LCI and FRC were elevated (mean difference 0.30, 95% CI 0.02-0.60; p=0.034 and 14.5 mL, 95% CI 7.7-21.3 mL; p<0.001, respectively), while ratio of time to peak tidal expiratory flow to expiratory time was decreased in infants with CF. In 22 (41.5%) infants with CF, either LCI or FRC exceeded 1.64 z-scores; three infants had both elevated LCI and FRC.Shortly after birth, abnormal lung function is prevalent in CF infants. Ventilation inhomogeneity or hyperinflation may serve as noninvasive markers to monitor CF lung disease and specific treatment effects, and could thus be used as outcome parameters for future intervention studies in this age group.

Three-center feasibility of lung clearance index in infants and preschool children with cystic fibrosis and other lung diseases

BackgroundLung clearance index (LCI) detects early ventilation inhomogeneity and has been suggested as sensitive endpoint in multicenter intervention trials in infants and preschoolers with cystic fibrosis (CF). However, the feasibility of multicenter LCI in this age group has not been determined. We, therefore, investigated the feasibility of LCI in infants and preschoolers with and without CF in a three-center setting. MethodsFollowing central training, standardized SF6-MBW measurements were performed in 73 sedated children (10 controls, 49 with CF and 14 with other lung diseases), mean age 2.3±1.2years across three centers, and data were analyzed centrally. ResultsOverall success rate of LCI measurements was 91.8% ranging from 78.9% to 100% across study sites. LCI was increased in patients with CF (P<0.05) and with other lung diseases (P<0.05) compared to controls. ConclusionOur results support feasibility of LCI as multicenter endpoint in clinical trials in infants and preschoolers with CF.

Functional residual capacity and lung clearance index in infants treated for esophageal atresia and tracheoesophageal fistula

BackgroundNewborn babies with esophageal atresia/tracheoesophageal fistula (EA/TEF) are prone to respiratory tract disorders. Functional residual capacity (FRC) and lung clearance index (LCI) are commonly considered useful and sensitive tools to investigate lung function and early detecting airways diseases. The aim of the present study is to report the first series of EA/TEF infants prospectively evaluated for FRC and LCI. MethodsProspective observational cohort study of all patients treated for EA/TEF. Lung volume and ventilation inhomogeneity were measured by helium gas dilution technique using an ultrasonic flow meter. Babies were studied both in assisted controlled ventilation (sedated) and in spontaneous breathing (quiet sleep). Three consecutive FRC and LCI measurements were collected for each test at three different time points: before surgery (T0), 24hours after surgery (T1) and after extubation (T2). Results16 EA newborns were eligible for the study between December 2011 and July 2013. Three were excluded because of technical problems. At T0 FRC values were in the normal range regardless the presence of TEF but worsened afterwards at T1, with a subsequent recovering after extubation; a significant improvement after surgery was observed concerning LCI while no differences were found in tidal volume. ConclusionHelium gas dilution technique is a suitable method to measure the effect of surgery on lung physiology, even in ventilated infants with EA. The changes observed could be related to the ventilatory management and lung compression during surgical procedure.

False normal Lung Clearance Index in infants with cystic fibrosis due to software algorithms.

Lung clearance index (LCI), a marker of ventilation inhomogeneity, is elevated early in children with cystic fibrosis (CF). However, in infants with CF, LCI values are found to be normal, although structural lung abnormalities are often detectable. We hypothesized that this discrepancy is due to inadequate algorithms of the available software package. Our aim was to challenge the validity of these software algorithms. We compared multiple breath washout (MBW) results of current software algorithms (automatic modus) to refined algorithms (manual modus) in 17 asymptomatic infants with CF, and 24 matched healthy term-born infants. The main difference between these two analysis methods lies in the calculation of the molar mass differences that the system uses to define the completion of the measurement. In infants with CF the refined manual modus revealed clearly elevated LCI above 9 in 8 out of 35 measurements (23%), all showing LCI values below 8.3 using the automatic modus (paired t-test comparing the means, P < 0.001). Healthy infants showed normal LCI values using both analysis methods (n = 47, paired t-test, P = 0.79). The most relevant reason for false normal LCI values in infants with CF using the automatic modus was the incorrect recognition of the end-of-test too early during the washout. We recommend the use of the manual modus for the analysis of MBW outcomes in infants in order to obtain more accurate results. This will allow appropriate use of infant lung function results for clinical and scientific purposes.

EPS04.2 Infant lung function: First report of a novel infant multiple breath washout apparatus

Objectives The value of lung clearance index (LCI) is well recognised in children and adults and has also been shown to be elevated in infants with CF. At present, there are considerable technical challenges in measuring LCI in infants. There is no simple method of assessing lung function in this population. The Innocor photoacoustic gas analyser measures very low concentrations of the inert tracer gas SF6. This has been developed into a novel mixed open–closed circuit system: expired gas is collected during washout to measure Functional Residual Capacity (FRC) and cumulative expired volume. This permits a low deadspace and ability to perform at rapid ventilation rates. Methods A prototype system was assessed using a lung model based on a mechanically driven 100 ml syringe and ventilation tank. The model delivered FRC's of 100–250 ml, with corresponding tidal volumes of 30–90 ml and respiratory rates of 20–40 min −1 . Improvements to hardware and washin protocol were made following initial testing. Results Following modification, overall mean error of FRC measurement was 0.04%. Actual mean FRC (ml) are shown in Table 1. Of 21 repeats, only 1 measurement was outside ±5% error range for FRC. Table 1Model FRC a (ml)Measured FRC (95% CI) (ml)Mean (SD) % error10299.2 (97.0–101.5)−1.76 (1.8)202203.3 (199.4–207.3)1.17 (2.34)252250.6 (247.4–253.8)−0.18 (1.63)aIncludes deadspace. Conclusion This system is capable of highly accurate measurement of FRC at volumes down to 100 ml in a realistic infant lung simulation. Accuracy is superior to previously described systems at higher FRC, and within the targets set by guidelines. In vivo testing is due to commence in 2015.