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Large gains have been made in the management of respiratory diseases associated with cystic fibrosis (CF). Initial studies evaluating sleep issues in CF focused on respiratory problems of nocturnal hypoxia, alveolar hypoventilation and risk of airway obstruction from nasal polyps with treatment evaluations including long term oxygen therapy or noninvasive ventilation in case of nocturnal hypercapnia. More recent studies include patients whose lung function is better preserved, and have permitted more focus on sleep patterns and sleep quality. This literature identified that reduced sleep duration and poor sleep quality are common and may be explained by chronic pain and cough, frequent stools, gastro-oesophageal reflux, nasal obstruction or sinusitis, and drugs such as corticosteroids or beta-agonists. In the teenage years, poor sleep hygiene, sleep debt and poor sleep quality are associated with depression, poor academic performance, less physical activity, and a decrease in quality of life. Restless leg syndrome also seems to be common in adult patients with CF. These sleep problems seem more important in patients with a low lung function but may also be observed in patients with preserved lung function. The consequences of poor sleep may potentially exaggerate the multi-organ morbidity of CF, such as pain, inflammation, susceptibility to infection, and glucose intolerance, but these aspects are largely under-evaluated. Sleep should be evaluated on a routine basis in CF and prospective studies assessing the benefits of interventions aiming at improving sleep duration and sleep quality urgently needed., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Mycobacterium massiliense is closely related to Mycobacterium abscessus and is also a frequent cause of mycobacterial lung disease in patients with cystic fibrosis (CF). There has been no previous investigation of possible differences between M. massiliense and M. abscessus infections in the setting of CF., Methods: We studied a prospective cohort of 16 M. massiliense and 27 M. abscessus lung infection cases with CF, with a mean follow-up of 6 years., Results: M. massiliense cases were younger than M. abscessus cases (mean age: 12.8 vs 17.1 years; p=0.02) at the time of the first mycobacterial isolation and also had lower body mass index values (mean: 16.4 vs 19.3 kg/m(2), p=0.002). All M. massiliense cases, except one, had negative BMI Z-score values at the time of the first mycobacterial isolation (11/12 vs 16/23 M. abscessus cases, p=0.04). Clarithromycin-based combination therapies led to mycobacterial eradication in 100% of M. massiliense cases but only in 27% of M. abscessus cases (p=0.009)., Conclusion: Our data show a particular link between M. massiliense and malnutrition specifically in CF patients. Unlike M. abscessus, the bacteriological response of M. massiliense to combination antibiotic therapies containing clarithromycin was excellent. Distinguishing between M. massiliense and M. abscessus has major clinical implications for CF patients., (Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Objectives: The aim of the study was to evaluate sleep quality and nocturnal gas exchange in patients with cystic fibrosis (CF) and to assess if sleep quality and daytime lung function could predict nocturnal hypoxaemia or hypercapnia., Study Design: Daytime sleepiness and objective sleep quality were evaluated by the Pittsburgh Sleep Quality Index (PSQI) and actigraphy in 25 children and 55 young adults (mean age 24±10 years, forced expiratory volume in 1 s (FEV(1)) 41±11% predicted). Nocturnal gas exchange was assessed by pulse oximetry (SpO(2)) and transcutaneous carbon dioxide (PtcCO(2)) recordings. Eleven patients underwent simultaneous polysomnography (PSG)., Results: PSQI was 6.3±3.4 with 51% of the patients having a score >5 corresponding to significant sleep complaints. On actigraphy, sleep efficiency was impaired at 79±11% with a fragmentation index at 41±18. Mean nocturnal SpO(2) was 93±3% with 18% of the patients exhibiting >10% of night time spent with a value below 90%. Mean PtcCO(2) was 44±6 mm Hg with 47% of the patients exhibiting >10% of night time with a value >45 mm Hg. Daytime arterial blood gases correlated with nocturnal gas exchange. FEV(1) was the only lung function parameter that correlated with nocturnal SpO(2) (p<0.01). Compared with PSG, SpO(2) and PtcCO(2) accurately identified rapid eye movement sleep hypoventilation., Conclusions: Patients with CF exhibit poor sleep quality that does not predict nocturnal gas exchange. Nocturnal hypoxaemia and hypercapnia can be identified by simple tools.

Tracheomalacia has been observed in older patients with cystic fibrosis (CF). The acoustic reflection method (ARM) allows a noninvasive calculation of the longitudinal cross-sectional area of the trachea (MTAv) and the airway resistance (Raw). ARM measurements were performed in 20 CF children and 20 controls during spontaneous breathing (SB), forced inspiration (FI), and forced expiration (FE). The mean MTAv value was comparable in the CF patients and the control subjects during SB, FI, and FE. The Raw was also comparable during SB and FI. However, the Raw during FE was higher in the CF patients than in the control subjects (7.9±2.3 vs. 5.0±1.5 cm H2O l(-1) s(-1), respectively, p<0.001). In the patients with CF, only the Raw during FE correlated with the predicted forced expiratory volume in 1s (R2=0.37, p=0.04). The tracheal cross-sectional area measured by the ARM is normal in children with CF but the increase in Raw during FE suggests an increase in intrathoracic airway distensibility., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Cystic fibrosis (CF) lung disease is characterized by progressive airflow obstruction, due to mucus plugging and inflammation within the bronchial walls, and destruction of the lung parenchyma secondary to bronchiectasis. These alterations result in an increase of the work of breathing, leading to alveolar hypoventilation predominantly during sleep, exercise and acute respiratory exacerbations. Noninvasive positive pressure ventilation (NPPV) has been shown to unload the respiratory muscles in patients with CF, which increases alveolar ventilation and improves gas exchange. NPPV has been shown to reduce oxygen desaturation during sleep, exercise and chest physiotherapy and may facilitate the recovery of a severe hypercapnic respiratory exacerbation. Several ventilatory modes may be used in cystic fibrosis patients but the most physiological mode is pressure support. However, validated criteria to start NPPV as well as data on long term outcome, notably in terms of improved survival and quality of life, are lacking and should be assessed in the future.

A physiological rationale has been demonstrated for the use of noninvasive positive pressure ventilation (NPPV) in patients with cystic fibrosis. Indeed, as lung disease progresses, respiratory muscle load increases. As a result, patients develop a compensatory mechanism of a rapid shallow breathing pattern in an attempt to reduce this increase in load. Although this breathing strategy may maintain the level of minute ventilation, alveolar hypoventilation, characterized by hypercapnia and hypoxemia, may develop. Physiological studies during wakefulness and sleep have demonstrated that NPPV is associated with a reduction in respiratory muscle-load and work of breathing, an increase in minute ventilation and an improvement in gas exchange. NPPV has been shown to reduce oxygen desaturation during exercise and chest physiotherapy and may facilitate the recovery of a severe respiratory exacerbation. However, long-term data are lacking and are warranted to determine the optimal criteria to propose NPPV in these patients, and to assess the benefits in terms of improved survival and quality of life.

Background: Staphylococcus aureus infection in patients with cystic fibrosis (CF) is frequent and may be due to colonization by a few pathogenic lineages. Systematic genotyping of all isolates, methicillin-susceptible S. aureus (MSSA) as well as methicillin-resistant S. aureus (MRSA) is necessary to identify such lineages and follow their evolution in patients. Multiple-locus variable-number tandem repeat analysis (MLVA/VNTR) was used to survey S. aureus clinical isolates in a French paediatric CF centre., Results: During a 30 months period, 108 patients, aged 2 to 21 years, regularly followed up at the centre, provided sputum for culture. From 79 patients, a total of 278 isolates were genotyped by MLVA, resolving into 110 genotypes and 19 clonal complexes (CC) composed of similar or closely related isolates. 71% of the strains were distributed into four main CCs, in term of number of isolates and number of genotypes. Spa (Staphylococcus protein A) typing was performed on representative samples, showing an excellent concordance with MLVA. In 17 patients, strains from two to four different CCs were recovered over time. On six occasions, S. aureus isolates with the same genotype were shared by 2 different patients and they belonged to one of the four main clusters. Methicillin-resistance was observed in 60% of the isolates, 90% of which belonged to the main clonal complexes CC8, CC45 and CC5. In 5 patients, methicillin-resistance of S. aureus isolates was not associated with the mecA gene: for four patients, it was due to overproduction of beta-lactamase, leading to BOR-SA (borderline S. aureus) isolates, while a strain showing probably a new modified penicillin-binding capacity (MOD-SA) was observed from one patient., Conclusion: Systematic genotyping of S. aureus isolates recovered from sputum of CF children allows a thorough analysis of the strains responsible for sporadic as well as chronic colonization and the follow up of their evolution over time. We show here that more than 70% of these strains belong to 4 major CCs. MSSA as well as MRSA, BOR-SA and MOD-SA isolates can persist over several years, despite antibiotic treatments.

We performed a multicenter prevalence study of nontuberculous mycobacteria (NTM) involving 1,582 patients (mean age, 18.9 years; male/female ratio, 1.06) with cystic fibrosis in France. The overall NTM prevalence (percentage of patients with at least one positive culture) was 6.6% (104/1,582 patients), with prevalences ranging from 3.7% (in the east of France) to 9.6% (in the greater Paris area). Mycobacterium abscessus complex (MABSC; 50 patients) and Mycobacterium avium complex (MAC; 23 patients) species were the most common NTM, and the only ones associated with fulfillment of the American Thoracic Society bacteriological criteria for NTM lung disease. The "new" species, Mycobacterium bolletii and Mycobacterium massiliense, accounted for 40% of MABSC isolates. MABSC species were isolated at all ages, with a prevalence peak between 11 and 15 years of age (5.8%), while MAC species reached their highest prevalence value among patients over 25 years of age (2.2%).

A reduction of exhaled nitric oxide (NO) fraction and endothelial-mediated dysfunction have been reported in cystic fibrosis (CF). The aims of the present study were to search for relationships between flow-independent NO exchange parameters (bronchial NO flux (J'(aw,NO)) and alveolar NO concentration (C(A,NO))) and lung function tests characterising airflow limitation and pulmonary vascular bed (capillary blood volume and physiological dead space/tidal volume (V(D)/V(T)) ratio on exercise). In total, 34 patients (16 children, 18 adults) with CF, without resting pulmonary hypertension, underwent spirometry, exhaled NO measurement (multiple constant flow analytical method), gas transfer assessment (carbon monoxide and NO, allowing the calculation of capillary volume and membrane conductance) and a graded exercise test with oxygen uptake (V'(O(2))), carbon dioxide production (V'(CO(2))) and arterial blood gas evaluations. Both J'(aw,NO) and C(A,NO )correlated positively with airflow limitation. C(A,NO) correlated positively with capillary/alveolar volume. During exercise, criteria of mild pulmonary vascular disease were evidenced in some patients that participated in exercise limitation (negative correlation between physiological V(D)/V(T) and peak V'(O(2))). C(A,NO )at rest correlated positively with these parameters of wasted ventilation during exercise (physiological V(D)/V(T), minute ventilation (V'(E))/V'(CO(2)) at ventilatory threshold and V'(E)/V'(CO(2)) slope). Flow-independent exhaled NO parameters are linked to airway and early vascular diseases in patients with CF.

Sniff nasal inspiratory pressure is proposed as a noninvasive test of inspiratory muscle strength. During this manoeuvre, the nasal pressure is supposed to reflect oesophageal pressure. The aim of the present study was to compare the nasal pressure with the oesophageal pressure during a maximal sniff in children with neuromuscular disease (NM, n = 78), thoracic scoliosis (n = 12) and cystic fibrosis (CF, n = 23). A significant correlation was observed between the sniff nasal and oesophageal pressure. The ratio of the sniff nasal/oesophageal pressure was lower in patients with CF (0.72+/-0.13) than in NM patients (0.83+/-0.17) or patients with thoracic scoliosis (0.86+/-0.10). In patients with CF and NM disease, this ratio was not correlated to age or spirometric data. The difference between the sniff oesophageal and nasal pressure exceeded 15 cm H(2)O in 17, 33 and 87% of the NM, thoracic scoliosis and CF patients, respectively. Sniff nasal pressure often underestimates the strength of inspiratory muscles in cystic fibrosis. Such an underestimation occurs more rarely in neuromuscular disease disorders and thoracic scoliosis. A normal value excludes inspiratory muscle weakness but a low value requires the measurement of the oesophageal pressure.

The clinical course of cystic fibrosis (CF) varies considerably among patients carrying the same CF-causing gene mutation. Additional genetic modifiers may contribute to this variability. As airway inflammation is a key component of CF pathophysiology, we investigated whether major cytokine variants represent such modifiers in young CF patients. We tested 13 polymorphisms in 8 genes that play a key role in the inflammatory response: tumor necrosis factor, lymphotoxin alpha, interleukin (IL) 1B, IL1 receptor antagonist, IL6, IL8, IL10 and transforming growth factor beta 1 (TGFB1), for an association with lung disease progression and nutritional status in 329 CF patients. Variants in the TGFB1 gene at position +869T/C demonstrated a significant association with lung function decline. A less pronounced rate of decline in forced expiratory volume in 1 sec (FEV(1)) and forced vital capacity (FVC) were observed in patients heterozygous for TGFB1 +869 (+869CT), when compared to patients carrying either TGFB1 +869TT or +869CC genotypes. These findings support the concept that TGFB1 gene variants appear to be important genetic modifiers of lung disease progression in CF., ((c) 2008 Wiley-Liss, Inc.)

Background: No guidelines are available for noninvasive ventilation (NIV) for cystic fibrosis (CF)., Objective: To survey and evaluate the use of NIV for CF in France., Methods: We surveyed the coordinator physicians of every accredited CF center in France., Results: The respondents represented 36 centers (15 pediatric centers, 13 adult centers, and 8 centers that see both pediatric and adult patients), which had a total of 4,416 patients with CF at the time of the study, 168 (3.8%) of whom were using NIV. NIV was being used more often in the adults centers (7.6% of these patients) than in the pediatric centers (1.2% of these patients) or adult-and-pediatric centers (4.1% of these patients) (P= .01). All the respondent centers use NIV as first-line treatment for severe hypercapnic respiratory exacerbation and for stable diurnal hypercapnia, especially when associated with sleep disturbance. Bi-level pressure-targeted ventilation is the preferred ventilation mode. Settings are adjusted based on arterial blood gas values, noninvasive evaluation of patient-ventilator synchrony, patient comfort, and sometimes a sleep study. The surveyed centers reported a number of expected benefits from NIV, but few of those benefits have been proven. Problems with NIV are common and limit its use., Conclusions: We found a relative homogeneity in these French centers' stated indications for and use of NIV, which highlights their numerous expectations about the benefits of NIV, which contrasts with the few validated benefits. Studies of the benefits of NIV are needed.

Background: The benefits of long-termnoninvasive positive pressure ventilation (NPPV) have not yet been evaluated in patients with cystic fibrosis (CF)., Objectives: To evaluate the effect of 1 year of NPPV on lung function in patients with advanced CF., Methods: Data were obtained from the French CF Registry. Patients who started NPPV (ventilated group, n = 41) were compared to matched controls (control group, n = 41). Each ventilated patient was matched to a control 1 year before the start of NPPV (year -1) for gender, CFTR genotype, age +/- 5 years and forced expiratory volume in 1 s (FEV(1)) +/- 10%. The ventilated group was compared to the control group at year -1, during the year of NPPV initiation (year 0) and 1 year after NPPV (year +1)., Results: At year -1, the two groups were comparable with regard to forced vital capacity (FVC; 43.7 vs. 49.1% in the ventilated group and the control group, respectively) and FEV(1) (28.2 vs. 28.5%). At year 0, the ventilated group had significantly greater declines in FVC (-3.6 +/- 9.2 vs. +0.8 +/- 8.9%, p = 0.03) and in FEV(1) (-3.0 +/- 6.7 vs. +2.6 +/- 4.4, p < 0.0001). At year +1, the decreases in FVC (-2.1 +/- 10.0 vs. -2.2 +/- 9.9%) and in FEV(1) (-2.2 +/- 6.7 vs. -2.3 +/- 6.2%) were similar in both groups., Conclusions: These data show that NPPV is associated with stabilization of the decrease in lung function in patients with advanced CF., (Copyright 2007 S. Karger AG, Basel.)

Background: The variability in the inflammatory burden of the lung in cystic fibrosis (CF) patients together with the variable effect of glucocorticoid treatment led us to hypothesize that glucocorticoid receptor (GR) gene polymorphisms may affect glucocorticoid sensitivity in CF and, consequently, may contribute to variations in the inflammatory response., Methods: We evaluated the association between four GR gene polymorphisms, TthIII, ER22/23EK, N363S and BclI, and disease progression in a cohort of 255 young patients with CF. Genotypes were tested for association with changes in lung function tests, infection with Pseudomonas aeruginosa and nutritional status by multivariable analysis., Results: A significant non-corrected for multiple tests association was found between BclI genotypes and decline in lung function measured as the forced expiratory volume in one second (FEV1) and the forced vital capacity (FVC). Deterioration in FEV1 and FVC was more pronounced in patients with the BclI GG genotype compared to the group of patients with BclI CG and CC genotypes (p = 0.02 and p = 0.04 respectively for the entire cohort and p = 0.01 and p = 0.02 respectively for F508del homozygous patients)., Conclusion: The BclI polymorphism may modulate the inflammatory burden in the CF lung and in this way influence progression of lung function.

In order to identify the source of infection by Pseudomonas aeruginosa in patients with cystic fibrosis (CF), systematic genotyping of isolates is necessary. Multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) was used to survey the sources of P. aeruginosa infections in a French (Paris, France) pediatric CF center. Between January 2004 and December 2006, 108 patients ages 2 to 21 years who were regularly monitored at the center provided sputum for culture. P. aeruginosa was detected in 46 children, 17 of whom had primary colonization. A total of 163 isolates were recovered. MLVA was improved from a previously published method by the addition of new, informative, and easily typeable markers. Upon genotyping with 15 VNTRs, a total of 39 lineages composed of indistinguishable or closely related isolates, were observed. One of them corresponds to "clone C," which is widely distributed in Europe, and another corresponds to reference strain PA14. Six patients were colonized with two different strains, and the remaining 40 patients were colonized with a single strain. Strains from seven lineages were shared by at least two and up to four patients among a total of 20 patients. The study demonstrates that MLVA is an efficient, easy, and rapid molecular method for epidemiological surveillance for P. aeruginosa infection. The resulting data and strain genetic profiles can be queried on http://bacterial-genotyping.igmors.u-psud.fr.

The aim of the study was to determine whether a decrease in the ventilatory response to carbon dioxide (CO2) in children with cystic fibrosis (CF) is related to a mechanical limitation of the respiratory muscle capacity. The ventilatory response during CO2 rebreathing was performed in 15 patients (mean forced expiratory volume in 1 s (FEV1): 37 +/- 21% predicted, mean arterial CO2: 41+/- 5 mmHg). The slope of the minute ventilation normalised for weight per mmHg CO2 increment correlated negatively with respiratory muscle output, assessed by the oesophageal (p = 0.002), the diaphragmatic pressure time product (p = 0.01), and the tension time index (p = 0.005). In addition, this slope was correlated with dynamic lung compliance (p < 0.0001) and FEV1 (p = 0.03) but not with airway resistance and maximal transdiaphragmatic pressure. Therefore, an excessive load imposed on the respiratory muscles explains the blunting of the ventilatory response to CO2 in young patients with CF.

Background: Macrolides display immunomodulatory effects that may be beneficial in chronic inflammatory pulmonary diseases. The aim of the study was to document whether long term use of azithromycin may be associated with respiratory benefits in young patients with cystic fibrosis., Methods: A multicentre, randomised, double blind, placebo controlled trial was conducted from October 2001 to June 2003. The criteria for enrollment were age older than 6 years and forced expiratory volume in 1 second (FEV1) of 40% or more. The active group received either 250 mg or 500 mg (body weight < or > or =40 kg) of oral azithromycin three times a week for 12 months. The primary end point was change in FEV1., Results: Eighty two patients of mean (SD) age 11.0 (3.3) years and mean (SD) FEV1 85 (22)% predicted were randomised: 40 in the azithromycin group and 42 in the placebo group. Nineteen patients were infected with Pseudomonas aeruginosa. The relative change in FEV1 at month 12 did not differ significantly between the two groups. The number of pulmonary exacerbations (count ratio 0.50 (95% CI 0.32 to 0.79), p < 0.005), the time elapsed before the first pulmonary exacerbation (hazard ratio 0.37 (95% CI 0.22 to 0.63), p < 0.0001), and the number of additional courses of oral antibiotics were significantly reduced in the azithromycin group regardless of the infectious status (count ratio 0.55 (95% CI 0.36 to 0.85), p < 0.01). No severe adverse events were reported., Conclusion: Long term use of low dose azithromycin in young patients with cystic fibrosis has a beneficial effect on lung disease expression, even before infection with Pseudomonas aeruginosa.

The chlorhexidine method was compared to the N-acetyl-l-cysteine-NaOH-oxalic acid decontamination method currently recommended for the recovery of nontuberculous mycobacteria (NTM) from patients with cystic fibrosis. Sputum samples (n = 827) treated with chlorhexidine yielded twice as many NTM-positive cultures as those treated by the reference method (54 [6.50%] versus 27 [3.25%]; P < 0.0001) despite a higher contamination rate (20% versus 14.2%; P = 0.0017).

We studied the prevalence and species distribution of nontuberculous mycobacteria (NTM) in relation to age in 385 patients with cystic fibrosis (CF) (mean age +/- standard deviation [range], 12.0 +/- 6.1 [1 to 24] years; sex ratio, 0.53) attending three Parisian centers. The overall prevalence of NTM in sputum was 8.1% (31 out of 385). The following NTM were isolated (n = 33): Mycobacterium abscessus (n = 13, 39.4%), Mycobacterium avium complex (MAC) (n = 7, 21.2%), Mycobacterium gordonae (n = 6, 18.2%), and other (n = 7, 21.2%). Sixteen patients met the American Thoracic Society microbiological criteria for NTM infection, including 11 patients positive for M. abscessus, 4 for MAC, and 1 for MAC and Mycobacterium kansasii. The overall prevalence of NTM was significantly lower in patients under 15 years old than for patients equal to or more than 15 years old (4.8 versus 14.9%, respectively; P = 0.001). M. abscessus was isolated at all ages, while MAC was not recovered before 15 years (prevalence of 0.0 and 5.2% in patients aged 1 to 14 and 15 to 24, respectively; P = 0.001).

Recent evidence suggests that genetic polymorphisms that affect the production of interleukin (IL)-10 may play a role in the response to pathogens in cystic fibrosis (CF). The present study was designed to investigate a possible association between alleles carried at position -1082 in the promoter region of the IL-10 gene and clinical data on 378 patients with CF. After adjustment for potential confounding variables, a significant relationship was found between the -1082GG genotype and both colonization with Aspergillus fumigatus and allergic bronchopulmonary aspergillosis. In addition, higher serum levels of IL-10 were observed in patients colonized with A. fumigatus. These results suggest that polymorphisms in the promoter region of the IL-10 gene may influence the host response to A. fumigatus in the context of CF.

The aim of the study was to evaluate the impact of Burkholderia cepacia on cardiovascular status and mortality in cystic fibrosis. Seven patients infected with B. cepacia were matched with 31 patients not infected with this organism for gender, age, height, weight, genotype, and percent predicted forced expiratory volume in one second, partial arterial oxygen pressure, and pancreatic sufficiency status. The pulmonary artery systolic pressure, as assessed by transthoracic echocardiography, was significantly higher in patients infected with B. cepacia (61.3 +/- 17.2 mm Hg) than in controls (37.3 +/- 13.9 mm Hg; P = 0.02), and the mean acceleration time was significantly lower (77 +/- 33 ms versus 108 +/- 25 ms; P = 0.02). The 6-month mortality was significantly higher in patients infected with B. cepacia (57% versus 16%; P = 0.02). Six of the seven patients infected with B. cepacia harbored the same ribotype (genomovar II, B. multivorans). Pulmonary hypertension was significantly more frequent in patients infected by B. cepacia and could contribute to the increased mortality rate.

Background: The effect of nutritional status and lung disease progression on diaphragm strength in young patients with cystic fibrosis remains unclear., Objective: The aim of this study was to investigate the effect of nutritional status and airway obstruction on diaphragm strength., Design: Twitch transdiaphragmatic pressure (Tw Pdi) obtained by bilateral anterior magnetic phrenic nerve stimulation, body mass index (BMI) z score, fat mass, fat-free mass (FFM), arm muscle circumference (AMC), forced expiratory volume in 1 s (FEV(1)), and functional residual capacity (FRC) were measured in 20 patients aged 15.1 +/- 2.8 y (x +/- SD). Values were expressed as a percentage of predicted values., Results: Mean (+/-SD) Tw Pdi was 24.3 +/- 5.5 cm H(2)O. Univariate regression analysis showed positive correlations between Tw Pdi and nutrition scores (BMI z score: r = 0.63, P = 0.003; FFM: r = 0.47, P = 0.04; AMC: r = 0.45, P = 0.04), airway obstruction (FEV(1): r = 0.68, P = 0.001), and arterial oxygen partial pressure (r = 0.68, P = 0.001). Negative correlations were observed between Tw Pdi and dynamic hyperinflation (FRC: r = -0.65, P = 0.005) and arterial carbon dioxide pressure (r = -0.50, P = 0.03). Furthermore, stepwise regression analysis showed that Tw Pdi correlated with BMI z score (r = 0.75, P = 0.0002) and FEV(1) (r = 0.69, P = 0.001)., Conclusions: Diaphragm strength is relatively well preserved in young patients with cystic fibrosis. However, the strength of the diaphragm decreases with the progression of malnutrition and airway obstruction.

The aim of the current study was to compare a clinical noninvasive method of setting up noninvasive pressure support ventilation (PS-NI) in young patients with cystic fibrosis (CF), based on parameters such as breathing frequency, arterial oxygen saturation and comfort rating, with a more invasive method (PS-I) targeted at optimising unloading of the inspiratory muscles and enhancing patient-ventilator synchronisation. PS-NI and PS-I were compared in random order in 10 children with CF. PS-NI differed from PS-I with regard to the level of inspiratory pressure (n=5), rate of inspiratory pressurisation (n=1), inspiratory trigger sensitivity (n=2) and expiratory trigger sensitivity (n=5). Although both methods modified breathing pattern, improved oxygen saturation and reduced diaphragmatic pressure time product (450+/-91 cmH2O.s(-1).min(-1) during spontaneous breathing, and 129+/-125 and 104+/-75 cmH2O.s(-1).min(-1) during PS-NI and PS-I, respectively), patient-ventilator synchrony and patient comfort were enhanced more during PS-I. In young patients with cystic fibrosis, setting up pressure support using a clinical noninvasive approach based on easily measurable parameters, such as respiratory rate and comfort rating, is as effective as a more invasive technique based on unloading of the inspiratory muscles and optimising patient-ventilator synchronisation. However, whilst the standard clinical method is satisfactory in the majority of patients, more invasive measurements should be considered in patients who have difficulty synchronising with the ventilator to enhance patient tolerance and compliance.

Background: The assessment of lung ventilation by radionuclide imaging has proved useful for the optimization of aerosol therapy in children with cystic fibrosis. Further analysis of lung perfusion may provide additional information., Methods: Quantitative analysis of regional lung aerosol distribution (Tc phytates) and perfusion (Tc macroaggregates) homogeneity was performed in 18 children with cystic fibrosis, using the third and fourth spatial moments (skew and Kurtosis) of count distribution. Patients were chosen from a prospective study whose goal was to compare the efficacy of two nebulization methods of a radiolabelled aerosol: one session involved a nebulizer activated by patient inspiratory flow (control session), whereas the other involved a nebulizer powered by a pressure support device (PS session)., Results: Quantitative regional distribution of perfusion was similar to aerosol distribution, although skew and Kurtosis were lower, indicating better homogeneity. Perfusion skew was inversely correlated with pulmonary volumes and Shwachman score, even more significantly than ventilation skew. Using receiver operating characteristic curve analysis, a perfusion skew threshold of 0.67 was predictive of disease severity (FEV1 > or =60% or FEV1 <60%) with 86% sensitivity and 91% specificity. Furthermore, same skew threshold allowed the identification of patients who were 'PS responders' (greater amount of radioactivity deposited after the PS session) or 'PS non-responders' with 80% sensitivity and 77% specificity., Conclusion: Quantification of regional lung perfusion is easy to perform and heterogeneity of the distribution is closely correlated to disease severity. Moreover, perfusion skew can identify patients who are likely to benefit from pressure support (to optimize aerosol therapy) and may be helpful for orienting potential non-responders towards alternative therapies.

Objective: The aim of the study was to evaluate the effect of the back-up rate on respiratory effort during non-invasive mechanical ventilation., Design: An in vitro study evaluated the inspiratory trigger in seven domiciliary ventilators. Then, a prospective, randomized, crossover trial compared the effect on respiratory effort of three different back-up rates during pressure support (PS) and assist-control/volume-targeted (AC/VT) ventilation., Setting: A research unit and a tertiary referral pediatric center., Patients: Ten patients with cystic fibrosis (CF)., Interventions: During the in vivo study, the back-up rate was progressively increased to the maximum that patients could tolerate (Fmax) and respiratory effort, as judged by pressure/time product of the diaphragm (PTPdi/min), was compared between the two ventilatory modes., Results: Differences were observed between trigger pressure, trigger time delay, trigger pressure/time product and the slope between flow and pressure in the seven ventilators. PS and AC/VT ventilation were associated with a decrease in respiratory effort (PTPdi/min was 518+/-172, 271+/-119 and 291+/-138 cmH(2)O. s(-1). min(-1), for spontaneous breathing, PS and AC/VT ventilation, respectively, p=0.05). During the two modes, increasing the back-up rate to Fmax resulted in a greater reduction in PTPdi/min (p=0.001), which was more pronounced during AC/VT ventilation, due to the automatic adjustment of the inspiratory/expiratory time ratio., Conclusions: Increasing the back-up rate during PS and AC/VT ventilation decreases respiratory effort in young patients with CF, but this effect was more marked with AC/VT ventilation.

In the past few years since the cloning of the gene defective in cystic fibrosis, much has been learned on the function of the protein cystic fibrosis transmembrane conductance regulator (CFTR) and on the mechanisms regulating its expression. Based on the current understanding of the processes involved in lung disease progression, a number of approaches have been developed using not only gene therapy, but also pharmacological agents. Several of these agents have been reported to restore function to CFTR with specific mutations.

Chronic respiratory insufficiency in cystic fibrosis (CF) is characterised by an increase in respiratory load, which leads to alveolar hypoventilation with the preservation of respiratory muscle strength. Non-invasive mechanical ventilation (NIMV) is able to improve alveolar ventilation and thus gas exchange and allow the the respiratory muscles to rest in patients with cystic fibrosis with variable severity of lung disease. These effects state the superiority of NIMV compared to oxygen therapy in CF. Invasive, highly specialized monitoring is recommended for the evaluation of ventilatory modes and the performances of new ventilators. After a successful evaluation, the monitoring of patients starting NIMV can be performed with simple, non invasive parameters such as gas exchange, tidal volume, respiratory rate, minute ventilation and comfort. In the long term however, studies are warranted to assess the benefit of NIMV in terms of lung function, quality of sleep and most importantly, quality of life.

As forced expiratory volume in 1 second (FEV(1)) is a major predictor of outcome in patients with cystic fibrosis (CF), we investigated the effect of FEV(1) on pulmonary mechanics in children and young adults with CF. We measured respiratory rate; tidal volume; minute ventilation; arterial blood gases; sniff esophageal pressure; dynamic lung compliance; total pulmonary resistance; intrinsic positive end expiratory pressure; and total, elastic, and resistive work of breathing in 32 patients (FEV(1) range: 12-49% predicted). We observed correlations between FEV(1) and Pa(O(2)) (r = 0.76, p < 0.0001) and Pa(CO(2)) (r = -0.70, p < 0.0001), FEV(1) and respiratory rate/tidal volume (r = -0.41, p = 0.02), FEV(1) and dynamic lung compliance (r = 0.64, p < 0.0001), and FEV(1) and total work of breathing (r = -0.52, p = 0.002) and elastic work of breathing (r = -0.60. p = 0.0003). No correlations were observed between FEV(1) and sniff esophageal pressure (p = 0.5), minute ventilation (p = 0.9), total pulmonary resistance (p = 0.3), intrinsic positive end expiratory pressure (p = 0.3), or resistive work of breathing (p = 0.1). As FEV(1) declines in children and young adults with CF, there is an increase in the elastic load and work of breathing, resulting in a rapid shallow breathing pattern, that is associated with further impairment of gas exchange.

Severe respiratory syncytial virus (RSV) disease is associated with unacceptable morbidity and mortality in children, especially in young children. Underlying conditions including prematurity with or without bronchopulmonary dysplasia, congenital heart disease, immunosuppression or another underlying respiratory condition, such as cystic fibrosis, increase the risk of contracting and developing severe RSV disease. Environmental factors such as crowding, day-care attendance, and exposure to passive smoke can increase the risk of severe RSV disease. Children with severe RSV disease often require intensified medical care, including hospitalization, which places a burden on the child, the family, and the health care system. There are currently no effective curative treatments for severe RSV disease. Preventive measures, such as infection control and prophylaxis, appear to be the best options in the management of RSV disease in these high-risk patients.

Objective: Home noninvasive mechanical ventilation (NIMV) is used with increasing frequency for the treatment of patients with respiratory failure caused by cystic fibrosis, yet the optimal mode of ventilation in such children is unknown. We compared the physiologic short-term effects of two ventilators with different modes (one pressure support and the other assist control/volume-targeted [AC/VT]) commonly used for domiciliary ventilation., Design: Prospective, randomized, crossover comparison of two ventilators with different modes., Setting: Tertiary pediatric university hospital., Patients: Eight children with cystic fibrosis (age, 11-17 yrs) and chronic respiratory failure (pH 7.4 +/- 0.0; PaO2, 57.5 +/- 7.5 torr; PaCO2, 46.1 +/- 2.5 torr), naive to NIMV., Interventions: Two 20-min runs of pressure support and AC/VT ventilation were performed in random order, each run being preceded and followed by 20 mins of spontaneous breathing., Measurements: Flow and airway pressure and esophageal and gastric pressures were measured to calculate esophageal (PTPes) and diaphragmatic pressure-time product (PTPdi) and the work of breathing., Results: The two NIMV sessions significantly improved blood gas variables and increased tidal volume with no change in respiratory rate. Indexes of respiratory effort decreased significantly during the two modes of NIMV compared with spontaneous breathing, with PTPdi/min decreasing from 497.8 +/- 115.4 cm H2O x sec x min(-1) during spontaneous breathing to 127.8 +/- 98.3 cm H2O x sec x min(-1) and 184.3 +/- 79.8 cm H2O x sec x min(-1), during AC/VT and pressure support, respectively (p <.0001), and the work of breathing decreasing from 1.83 +/- 0.12 J.L-1 during spontaneous breathing to 0.48 +/- 0.32 J.L-1 and 0.75 +/- 0.30 J.L-1, during AC/VT and pressure support, respectively (p <.0001). In addition, the effect of AC/VT ventilation was significantly superior to pressure support judged by PTPes and the work of breathing, but this result was explained by three patients who adapted extremely well to the AC/VT ventilation, with the disappearance of ventilator triggering, in effect adopting a controlled mode. There was a correlation between the improvement in PTPdi/min or the work of breathing and patient's subjective impression of comfort during the AC/VT ventilation., Conclusions: In awake, stable children with cystic fibrosis, both AC/VT and pressure support unloaded the respiratory muscles. The disappearance of ventilator triggering occurred in a subgroup of patients during AC/VT ventilation, and this explained the good tolerance and the superiority of this mode in the present study.

Chronic respiratory insufficiency in childhood can be caused by a heterogeneous group of diseases whose management and prognosis differ. Bronchopulmonary dysplasia in infants, and cystic fibrosis and neuromuscular diseases in older children, represent the most common causes of chronic respiratory insufficiency. The improvements in medical treatments, with the development of long term oxygen therapy and non invasive mechanical ventilation, have contributed to the increased survival and the better quality of life of these children. An objective evaluation of treatments, such as long term oxygen therapy and non invasive mechanical ventilation, are warranted to improve the indications and benefits of these therapies.

Nebulized aerosols are commonly used to deliver drugs into the lungs of patients with cystic fibrosis (CF). The aim of this study was to assess the effectiveness of pressure-support (PS) ventilation in increasing aerosol deposition within the lungs of children with CF. An in vitro study demonstrated the feasibility of coupling a breath-actuated nebulizer to a PS device. An in vivo study was done with 18 children (ages 6 to 21 yr) with clinically stable CF, each of whom underwent both a standard and a PS-driven ventilation scan (control session and PS session, respectively). In addition, a perfusion scan was used to determine lung outlines and to construct a geometric model for quantifying aerosol deposition by radioactivity counting in MBq. Homogeneity of nebulization was evaluated from the four first-order moments of aerosol distribution in the peripheral and central lung regions. The time-activity nebulization curve was linear in all patients, with higher slopes during the PS than during the control session (0.43 +/- 0.07 [mean +/- SD] MBq/min and 0.32 +/- 0.23 MBq/min, respectively; p < 0.018). Quantitatively, aerosol deposition was about 30% greater after the PS session (4.4 +/- 2.7 MBq) than after the control session (3.4 +/- 2.1 MBq; p < 0.05). Similarly, deposition efficacy (as a percentage of nebulizer output) was significantly better during the PS session than during the control session (15.3 +/- 8.3% versus 11.5 +/- 5.7%, p < 0.05). No differences in the regional deposition pattern or in homogeneity of uptake were observed. In conclusion, our data show that driving the delivery of a nebulized aerosol by noninvasive PS ventilation enhances total lung aerosol deposition without increasing particle impaction in the proximal airways.

Study Objectives: Cystic fibrosis (CF) is one of the most common inherited diseases among whites. Since the cloning of the CF transmembrane conductance regulator (CFTR) gene, a number of studies have focused on associations between the genotype and phenotype in CF. This had led to the progressive identification of new groups of patients, including those who have mild lung disease and those who have normal sweat chloride values (< 60 mEq/L). The aim of the present work was to provide information on the genotype and the phenotypic characteristics of children with intermediate-range sweat chloride test results., Patients and Results: We focused on children referred to the pulmonary department for various types of pulmonary disease and who had several sweat chloride test results with median values in the range of 40 to 60 mEq/L. Twenty-four patients over a 10-year period were enrolled (mean age, 4.8 years). Respiratory manifestations at initial evaluation included recurrent bronchitis, wheezing, chronic cough, and pneumonia. The duration of the follow-up ranged from 0.5 to 10.5 years. Sputum cultures revealed the presence of Haemophilus influenzae (10 children), Staphylococcus aureus (4 children), and Pseudomonas aeruginosa (3 children). Pancreatic insufficiency was found in two patients. Analysis of the entire coding sequence allowed identification of 16 known mutations in CFTR gene. Fifteen chromosomes (31.2%) carried a mutation in CFTR gene and one allele carried two mutations. Three patients were homozygous or double heterozygous (DeltaF508/DeltaF508, DeltaF508/3849 + 10 kb C-->T, S1235R/G551D). The 5-thymidine allele was identified in four children., Conclusion: These results indicate an higher frequency of CFTR gene mutations in patients with borderline sweat chloride test results, compared to data reported in the general population. They lead to the recommendations for complete pulmonary and GI investigations in this group of patients, as well as assiduous care and medical follow-up.

Cystic fibrosis is a genetic disease occurring more frequently in Caucasians. The cystic fibrosis gene, cloned in 1999, codes for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. Dysfunction of this protein leads to the clinical manifestations of cystic fibrosis, mainly lung disease and exocrine pancreas disorders. The pathophysiology of the respiratory component is quite complex, basically related to major and excessive inflammatory processes and to early microbial colonization. Respiratory physical therapy is a key element to management of the respiratory disorder. Antibiotic treatments should be adapted to the bacterial ecology, mainly using antistaphylococcal and antihaemophilus drugs initially, then directed against Pseudomonas aeruginosa. Other drugs including inhaled antiinflammatory drugs are currently in the evaluation stage. In addition, nutritional care and correction of pancreas insufficiency are necessary. The diagnosis of this disease must be made early although systematic neonatal screening is not proposed. Early diagnosis is necessary for improved care and prognosis. Currently, median survival is 29 years. This survival time should probably improve with better understanding of the pathophysiological mechanisms and new therapeutic perspectives.

Objective: Chest physiotherapy (CPT) is an integral part of the treatment of patients with cystic fibrosis (CF). CPT imposes additional respiratory work that may carry a risk of respiratory muscle fatigue. Inspiratory pressure support ventilation (PSV) is a new mode of ventilatory assistance designed to maintain a constant preset positive airway pressure during spontaneous inspiration with the goal of decreasing the patient's inspiratory work. The aim of our study was 1) to evaluate respiratory muscle fatigue and oxygen desaturation during CPT and 2) to determine whether noninvasive PSV can relieve these potential adverse effects of CPT., Methods: Sixteen CF patients in stable condition with a mean age of 13 +/- 4 years participated to the study. For CPT, we used the forced expiratory technique (FET), which consisted of one or more slow active expirations starting near the total lung capacity (TLC) and ending near the residual volume. After each expiration, the child was asked to perform a slow, nonmaximal, diaphragmatic inspiration. After one to four forced breathing cycles, the child was asked to cough and to expectorate. A typical 20-minute CPT session consisted of 10 to 15 FET maneuvers separated by rest periods of 10 to 20 breathing cycles each. During the study, each patient received two CPT sessions in random order on two different days, at the same time of day, with the same physiotherapist. During one of these two sessions, PSV was provided throughout the session (PSV session) via a nasal mask using the pressure support generator ARM25 designed for acute patients (TAEMA, Antony, France). The control session was performed with no nasal mask or PSV. Both CPT sessions were performed without supplemental oxygen. Lung function and maximal inspiratory pressures (PImax) and expiratory pressures (PEmax) were recorded before and after each CPT session., Results: Mean lung function parameters were comparable before the PSV and the control sessions. Baseline pulse oximetry (SpO2) was significantly correlated with the baseline vital capacity (% predicted) and forced expiratory volume in 1 second (FEV1) (% predicted). PSV was associated with an increase in tidal volume (Vt) from 0.42 +/- 0.01 liters to 1.0 +/- 0.02 liters. Respiratory rate was significantly lower during PSV. SpO2 between the FET maneuvers was significantly higher during PSV as compared with the control session. SpO2 decreases after FET were significantly larger during the control session (nadir: 91.8 +/- 0. 7%) than during the PSV session (93.8 +/- 0.6%). Maximal pressures decreased during the control session (from 71.9 +/- 6.1 to 60.9 +/- 5.3 cmH2O, and from 85.3 +/- 7.9 to 77.5 +/- 4.8 cmH2O, for PImax and PEmax, respectively) and increased during the PSV session (from 71.6 +/- 8.6 to 83.9 +/- 8.7 cmH2O, and from 80.4 +/- 7.8 to 88.0 +/- 7.4 cmH2O, for PImax and PEmax, respectively). The decrease in PEmax was significantly correlated with the severity of bronchial obstruction as evaluated based on baseline FEV1 (% predicted). Forced expiratory flows did not change after either CPT session. The amount of sputum expectorated was similar for the two CPT sessions (5.3 +/- 5.3 g vs 4.6 +/- 4.8 g after the control and PSV session, respectively; NS). Fifteen patients felt less tired after the PSV session. Ten patients reported that expectoration was easier with PSV, whereas 4 did not note any difference; 2 patients did not expectorate. Nine patients expressed a marked and 5 a small preference for PSV, and 2 patients had no preference. The physiotherapists found it easier to perform CPT with PSV in 14 patients and did not perceive any difference in 2 patients., Discussion: Our study in CF children shows that respiratory muscle performance, as evaluated based on various parameters, decreased after CPT and that significant falls in oxygen saturation occurred after the FET maneuvers despite the quiet breathing periods between each FET cycle. These unwanted effects of CPT were

Since the cloning of the defective gene in cystic fibrosis, much has been learned on the function of CFTR and on the mechanisms regulating its expression. Based on the current understanding of the processes involved in lung disease progression, a number of approaches have been developed using gene therapy and pharmacological agents. Several of these agents have been reported to restitute a function to CFTR with specific mutations. Other molecules act on channels other than CFTR, and may be effective by bypassing CFTR itself. In the present review the various therapeutical strategies currently investigated are discussed.

Background: Patients with cystic fibrosis (CF) may be predisposed to airway infections with unusual organisms, such as mycobacteria. The aim of the study was to determine the incidence and clinical picture of mycobacterial infection in CF children., Methods: At least 2 acid-fast bacillus (AFB) smears and mycobacterial cultures were performed on a prospective basis on 682 sputum specimens from 106 patients during a 1-year period., Results: Thirty-three percent of the cultures were contaminated with other bacteria. Seven children had at least one sputum culture positive for one mycobacterium. Five children had only one positive AFB culture. Their clinical status and lung function remained stable during follow-up. Two teenagers with severe lung disease had several positive AFB smears and cultures for Mycobacterium chelonae and Mycobacterium abscessus. The isolation of M. chelonae and M. abscessus was associated with a clinical and functional decline. Clarithromycin treatment resulted in temporary improvement with the disappearance of the mycobacteria after 6 months of treatment. This prospective study shows an incidence of 2.3% for positive cultures. The prevalence was 6.6% for mycobacterial colonization but only 1.9% for mycobacterial lung disease in our pediatric population., Conclusions: We recommend performing AFB smears and cultures in CF children with severe lung disease and/or during a lung exacerbation. In these patients persistence of M. chelonae or M. abscessus in sputum should lead to consideration of treatment with clarithromycin.

Background: Chronic respiratory failure (CRF) with hypoxia and hypercapnia is the last ineluctable phase in cystic fibrosis (CF). Nasal positive pressure ventilation (NPPV), a non-invasive method, may be given to CF children with CRF, especially to patients accepted for transplantation (T). This method improves ventilatory function by resting the chronically exhausted respiratory muscles, facilitates bronchial drainage by physiotherapy, prevents the exacerbations of the illness and prepares patients for T., Methods and Patients: NPPV was used in 6 CF patients (mean age 13 years 6 months). One of them was transplanted 15 days later, two of them were accepted for T. All had hypoxia. Five of them had hypercapnia., Results: NPPV was given to four patients for 3 to 14 months. The preliminary results were positive. One patient gained weight, two had more fluid sputum. One patient showed an increase in functional respiratory tests (FRT: PaO2, vital capacity, FEV-1) while these tests were stabilized in the others., Conclusions: NPPV in an effective non-invasive method for use with CF children. It is indicated for CF patients accepted for T and also earlier, for CF patients with CRF in order to prevent acute exacerbations and functional respiratory deterioration.