Nocturnal hypoxemia in children and adolescents with cystic fibrosis

Breathing patterns during sleep and their relationship with FEV1 in pediatric patients with cystic fibrosis residing at high altitude

Introduction

Sleep-disordered breathing (SDB) and gas exchange disorders are common in patients with cystic fibrosis (CF). Currently, the impact of the disease on sleep patterns in patients living at high altitude and the relationship of these patterns to lung function are largely unknown. The aim of this study was to determine the frequency of SDB in children with CF aged 6-18 years and the relationship between SDB and lung function (FEV1).

Methods

This is an analytical cross-sectional study of children aged 6-18 years diagnosed with CF. Spirometry before and after bronchodilators and polysomnography with capnography were performed. Descriptive analysis of qualitative and continuous variables was performed. Spearman's correlation coefficient was used to determine the correlation between polysomnogram and lung function (FEV1).

Results

Twenty-four patients with CF were included. The mean age was 10.5 ± 3.1 years and 62.5% were male. Nine children had bronchiectasis on chest CT. The median absolute baseline FEV1 was 1,880 (1,355-2,325) ml and 98% (83%-110%) of predicted value. No significant difference in FEV1% was observed between subjects with obstructive sleep apnea (OSA) and those without OSA (P = 0.56). The prevalence of OSA was 66.7% in children younger than 13 years and 40% in children older than 13 years. The Spearman correlation coefficient between FEV1 and percentage of total sleep time with saturation less than 90% (T90) was rho -0.52 (p-value = 0.018), and between FEV1 and percentage of total sleep time with saturation less than 85% (T85) was statistically significant with rho -0.45 (p-value = 0.041). A positive correlation was observed between FEV1 and SpO2 during sleep with rho 0.53 and a statistically significant p-value (0.014).

Conclusions

A high prevalence of sleep apnea was found in children with CF living at high altitude, with a negative correlation between FEV1 and T90 and T85 oxygenation indices, and a positive correlation between FEV1 and SpO2 during sleep.

Sleep Respiratory Disorders in Children and Adolescents with Cystic Fibrosis and Primary Ciliary Dyskinesia

Cystic fibrosis (CF) and primary ciliary dyskinesia (PCD) are genetic respiratory diseases featured by chronic upper and lower airway inflammation and infection, mainly due to impaired mucociliary clearance due to genetic mutations. Sleep is crucial to healthy children's normal physical and psychological development and has an important value in chronic respiratory diseases. Impaired sleep quality, such as sleep deprivation or insufficient sleep during the night, and sleep respiratory disorders (SRDs) are common in 5% to 30% of the general population. Sleep disruption leads to attention deficits, daytime sleepiness, fatigue and mood disorders and correlates to a worsened quality of life. Furthermore, sleep respiratory disorders (SRSs) are under-recognized comorbidities in CF and PCD patients. SRSs include a spectrum of symptoms ranging from primary snoring through upper airway resistance to obstructive sleep apnea (OSA), nocturnal hypoventilation and hypoxemia occurring in people with moderate to severe lung disease and damaging the disease-related outcomes and quality of life. Effective screening during sleep with polysomnography is very important for the timely initiation of efficacious treatments and to prevent worsened respiratory, metabolic and cardiovascular outcomes. However, the impact of SRDs on health and quality of life is still underinvestigated.

Effects of Elexacaftor/Tezacaftor/Ivacaftor on Cardiorespiratory Polygraphy Parameters and Respiratory Muscle Strength in Cystic Fibrosis Patients with Severe Lung Disease

BACKGROUND

Cystic fibrosis transmembrane conductance regulator (CFTR) modulators represent targeted therapies directly acting on the CFTR channel. The triple therapy Elexacaftor/Tezacaftor/Ivacaftor (ELX/TEZ/IVA) has been demonstrated to improve lung function and quality of life in cystic fibrosis (CF) patients. However, the effects of ELX/TEZ/IVA on sleep-disordered breathing (SDB) and respiratory muscle strength are poorly studied. The aim of this study was to assess the effects of ELX/TEZ/IVA in patients with CF and severe lung disease on cardiorespiratory polygraphy parameters, maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) measures.

METHODS

patients with CF aged ≥ 12 who started treatment in a compassionate use program were retrospectively studied through the evaluation of nocturnal cardiorespiratory polygraphy parameters, MIP and MEP; and six-minute walk test (6MWT) at baseline and at months 3, 6, and 12 of treatment.

RESULTS

Nine patients (mean age 30.3 ± 6.5 years) with severe CF (mean baseline ppFEV1 34.6 ± 5.1%) were evaluated. A significant improvement in nocturnal oxygenation measured by mean SpO2 (92.4 vs. 96.4%, p < 0.05), time spent with SpO2 ≤ 90% (-12.6, -14.6, -15.2 min from baseline at months 3, 6, and 12, respectively, p < 0.05), and respiratory rate (RR) was shown, at month 12 and across the time points compared with baseline, as well as in respiratory muscle strength, although only the change in MEP was significant.

CONCLUSIONS

We provide further evidence on the efficacy of the CFTR modulators ELX/TEZ/IVA, adding information about their effect on the respiratory muscles' performance and cardiorespiratory polygraphy parameters in CF patients with severe lung disease.

Obstructive sleep apnea and nocturnal hypoxemia in adult patients with cystic fibrosis

Background

Obstructive sleep apnea (OSA), nocturnal hypoxemia and excessive daytime sleepiness (EDS) are common comorbidities in people with cystic fibrosis (pwCF). Most of the data showing this originates from children and adolescents. The aim of this study was to collect data on sleep parameters, EDS and pulmonary function from a large cohort of adult pwCF.

Methods

Full overnight polysomnography (PSG) was performed. EDS was determined using the Epworth Sleepiness Scale (ESS). Demographic and clinical data (body mass index [BMI], pulmonary function, capillary blood gases) were collected.

Results

A total of 52 adult pwCF were included (mean age 30.7 ± 8.0 years, mean percent predicted forced expiratory volume in 1 s [ppFEV1] of 52.1 ± 14.8). Overall AHI was in the normal range (4.5 ± 4.0/h); 21/52 pwCF (40%) had an apnea-hypopnea index > 5/h. Nocturnal hypoxemia was found in 25% of participants and this was associated with ppFEV1 (p = 0.014), awake oxygen saturation (SpO2; p = 0.021) and awake partial pressure of oxygen (pO2; p = 0.003); there were no significant differences in age, lung function and BMI were found for pwCF with versus without OSA (all p > 0.05). Eight pwCF (15%) had an ESS score > 10 (indicating EDS). OSA was best predicted by awake pO2 (area under the curve [AUC] 0.66, p = 0.048), while nocturnal hypoxemia was best predicted by ppFEV1 (AUC 0.74, p = 0.009), awake pO2 (AUC 0.76, p = 0.006) and awake SpO2 (AUC 0.71; p = 0.025).

Conclusion

OSA, nocturnal hypoxemia and EDS were common in adult pwCF, but no strong predictors were identified. Therefore, we suggest regular PSG and ESS scoring in adult pwCF, regardless of disease severity.

Sleep in children with cystic fibrosis: More under the covers

Cystic fibrosis (CF) is a chronic multisystem disease with manifestations from birth. It involves the entire respiratory system, with increased cough, and recurrent pulmonary infections, and it also leads to intestinal malabsorption, all of which can have an impact on sleep. In this review, we summarize the available literature on the various sleep disturbances in children with CF. Sleep quality and sleep efficiency are often impaired in children with CF. They may be accompanied by symptoms associated with sleep-disordered breathing (SDB), and objective findings, such as nocturnal hypoxemia. Importantly, a strong association has been shown between SDB and the severity of lung disease, and some studies have reported a similar association for sleep quality. Further research is needed to better characterize the association of sleep disturbances with respiratory outcomes and the impact of treatment of sleep disorders on pulmonary status in children with CF.

Effect of Triple Combination CFTR Modulator Therapy on Sleep in Adult Patients with Cystic Fibrosis

<b><i>Background:</i></b> Sleep-disordered breathing (SDB) and disturbed sleep are common, often underrecognized, comorbidities in people with cystic fibrosis (pwCF). <b><i>Objectives:</i></b> We studied the effect of CFTR triple combination therapy elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) on sleep in pwCF. <b><i>Method:</i></b> This was a prospective, observational sleep study in clinically stable adult pwCF. All participants underwent overnight polysomnography (PSG), before (T0) and after (T1) initiation of CFTR modulator therapy with ELX/TEZ/IVA. In addition, pulmonary function tests, calculation of BMI, and sweat chloride testing were performed. <b><i>Results:</i></b> Twenty-nine pwCF (mean age 32 ± 8 years; 15 female) participated in the study. Mean time between T0 and T1 was 194 ± 21 days. Total sleep time (TST) was 298 ± 40 min, with decreased sleep efficiency (SE) (76 ± 109) and increased sleep latency (SL) (73 ± 38 min). Sleep stages for NREM (N1–3) and REM sleep were within the normal range. Nocturnal respiratory events mainly occur during REM sleep (T0: AHI REM 8.3 ± 9.0/h; ODI REM 9.4 ± 10.6/h), whereas the overall AHI was normal (3.6 ± 3.7/h). After initiation of ELX/TEZ/IVA, we saw significant improvements in ppFEV1 (<i>p</i> &#x3c; 0.001) and BMI (<i>p</i> &#x3c; 0.001) and a reduction in sweat chloride levels (<i>p</i> &#x3c; 0.001). In parallel, there was a reduction in AHI (<i>p</i> = 0.003), ODI (<i>p</i> = 0.001), and nocturnal respiratory rate (<i>p</i> &#x3c; 0.001), both in total, REM and NREM sleep. Neither TST, SL, SE, nor sleep architecture was influenced (all <i>p</i> &#x3e; 0.05). <b><i>Conclusions:</i></b> Initiation of ELX/TEZ/IVA resulted in significant improvements in SDB in adult pwCF.

Association of sleep disorders with heart rate variability in children and adolescents with cystic fibrosis

Objective:

To assess the association of sleep disorders with the findings of heart rate variability (HRV) in children and adolescents with cystic fibrosis (CF).

Methods:

Cross-sectional study including children and adolescents aged six to 18 years with a clinical diagnosis of CF. Sociodemographic and clinical data were collected. Sleep disorders were evaluated using baseline nocturnal polysomnography. The autonomic nervous system (ANS) was evaluated through resting HRV.

Results:

A total of 30 individuals (11.2 years) with a mean forced expiratory volume in the first second (FEV₁) of 62.7% were included. The respiratory disturbance index presented a median of 2.6 and obstructive sleep apnea syndrome (OSAS) was identified in 30%. In the HRV analysis, a mean standard deviation of all inter-beat (RR) intervals (SDNN) of 60.8±45.9ms was found. There was a significant correlation between the HRV low-frequency/high-frequency (LF/HF) global modulation index and the minimum SpO₂ during sleep in patients with FEV₁<60% (r=0.71; p=0.02). The prevalence of sleep disorders and HRV abnormalities was higher in individuals with lesser pulmonary function (FEV₁<60%).

Conclusions:

The results indicate a weak correlation of sleep disorders (minimum SpO₂) with HRV parameters (LH/HF) in children and adolescents with CF. When pulmonary function was reduced, a stronger correlation was found, highlighting the influence of disease severity. A high prevalence of ANS disorders, nocturnal hypoxemia, and presence of OSAS was also found.

Association between habitual physical activity (HPA) and sleep quality in patients with cystic fibrosis

PURPOSE

Sleep disturbances and poor sleep quality are known to be present in patients with CF. Regular physical activity plays an important role in the treatment of CF patients due to its positive influence on progression of disease and quality of life. The aim of this work is to create a home-based sleep and activity profile and to investigate the influence of habitual physical activity (HPA) on sleep quality in children, adolescents, and adults with CF.

METHODS

A total of 109 CF patients (64 male, mean age 22.7 ± 12.0 years; mean ppFEV1 63.0 ± 26.7) were equipped with an actigraph for a home-based collection of data on sleep and activity over 4 weeks.

RESULTS

Age, FEV1, and BMI affect sleep and activity in CF patients. Especially younger age and higher FEV1 show a great influence on certain aspects of sleep (SE, TST, TIB, WASO, # of awakenings) and activity and its different intensities. General HPA does not affect sleep, but there is a strong correlation between times spent in vigorous to very vigorous intensities and better sleep quality.

CONCLUSION

Besides younger age and higher FEV1, daily activity in higher intensities influences sleeping behavior of CF patients in a positive way. Patients with poor sleep quality and sleep disturbances possibly benefit from an intensification of physical activity in the home environment. TRAIL REGISTRATION: number: 14-6117-BO (University Duisburg-Essen) and NCT03518697 (clinical trials).

Sleep-disordered breathing and markers of morbidity in children and adolescents with cystic fibrosis

BACKGROUND

Studies have shown that sleep disorders occur in cystic fibrosis (CF) patients and may be present before daytime clinical manifestations.

OBJECTIVES

To evaluate the presence of sleep disorders among children and adolescents with CF, attempting to identify associations with pulmonary function, nutritional status, days in hospital, and days taking antibiotics.

METHODS

Individuals with a diagnosis of CF aged between 6 and 18 years were included. Information on sociodemographic, clinical profile, history of hospitalizations, and use of antibiotics in the last year were collected. Spirometry, bioimpedance, and polysomnography were performed. The presence of nocturnal hypoxemia and obstructive sleep apnea syndrome (OSAS) were evaluated and participants divided according to their presence.

RESULTS

Thirty-one patients were included. The prevalence of OSAS was 32.3% and nocturnal hypoxemia was 29.0%. Average nocturnal peripheral oxyhemoglobin saturation (SpO₂ ) correlated (P < .001) with forced vital capacity (r = .55) and forced expiratory volume in the first second (r = .62). The higher the percentage of total sleep time (TST) with SpO₂ less than 90%, the lower the pulmonary function. Individuals with OSAS and nocturnal hypoxemia had lower spirometric values compared to patients without these disorders, but the nocturnal hypoxemia group also had lower Shwachman-Kulczycki score, longer hospitalization time and antibiotic use. TST with SpO₂ less than 90% was associated with length of hospitalization (r²  = .53).

CONCLUSION

Children and adolescents with CF have sleep disorders, including OSAS (32.3%) and nocturnal hypoxemia (29%). Individuals with nocturnal hypoxemia presented lower lung function, worse clinical score, and higher morbidity. TST with SpO₂ less than 90% was associated with length of hospitalization.

Sleep-disordered breathing in cystic fibrosis

INTRODUCTION

Cystic fibrosis (CF) is a life-shortening, genetic disease that affects approximately 30,000 Americans. Although patients frequently report snoring, mouth breathing, and insomnia, the extent to which sleep-disordered breathing (SDB) may underlie these complaints remains unknown.

METHODS

Single-center retrospective review of polysomnography results from referred patients with and without CF individually-matched (1:2) for age, gender, race, and body mass index (BMI).

RESULTS

Mean ages were 8.0 ± 5.2 (sd) and 35.9 ± 12.9 years, among 29 children and 23 adults with CF respectively. The CF and non-CF groups were well-matched in age and BMI. Subjects with vs. without CF had three times greater odds of moderate-severe SDB (apnea-hypopnea index (AHI) ≥ 5 in children, ≥ 15 in adults) (p = 0.01). Nocturnal oxygen saturation nadir (Minimum SpO₂) was lower among CF vs. non-CF groups (p = 0.002). For every 1-unit increase in AHI, the decline in Minimum SpO₂ was larger for subjects with vs. without CF (p = 0.05). In subjects with CF, forced expiratory volume in 1 s percent predicted (FEV1 PPD) was associated with Minimum SpO₂ (Pearson r = 0.68, p < 0.0001) but not AHI (r = -0.19, p = 0.27). For every 1-unit increase in AHI, magnitude of decline in Minimum SpO₂ was larger for those with low vs. normal FEV1 PPD (p = 0.01).

CONCLUSION

Severity of SDB may be worse among referred patients with vs. without CF. The SDB may modify the relationship between CF lung disease and nocturnal hypoxemia. Markers of lung disease severity including lung function do not predict SDB severity, suggesting the need for routine polysomnography to screen for this sleep disorder.

Sleep disorders in cystic fibrosis: A systematic review and meta-analysis

Cystic fibrosis (CF) is a genetic disorder that leads to airway mucus accumulation, chronic inflammation, and recurrent respiratory infections - all likely impacting sleep. However, controlled studies of sleep in CF patients are limited, and have shown mixed results. We reviewed all publications on CF and sleep indexed in PubMed, CINAHL, and Scopus through April 2019. In the meta-analysis, we calculated pooled weighted mean differences for sleep quality, sleepiness, oximetry, and polysomnographic (PSG) parameters, using fixed or random-effects models as appropriate. A total of 87 manuscripts were reviewed. Compared to controls, children with CF had lower nighttime oxygen saturation nadirs, decreased sleep efficiency and a higher respiratory event index, with no differences in the percentage of REM sleep. Adults with CF had lower oxygen saturation nadirs, with a trend towards reduced sleep efficiency and no differences in REM sleep. In addition, patients with CF cough more during sleep and experience painful events that interfere with sleep. Actigraphy and questionnaires suggest disturbed sleep and daytime sleepiness. Noninvasive ventilation appears to improve gas exchange and symptoms. We conclude that when sleep is evaluated objectively or subjectively in patients with CF, perturbations are common, emphasizing the importance of their identification and treatment and inclusion as part of routine care. Additional research, with larger sample sizes and standardized outcomes, are necessary.

Nocturnal oximetry in children with obstructive lung disease or sleep-disordered breathing

OBJECTIVES

Although progress has been made in the standardized interpretation of nocturnal oximetry in children with obstructive sleep-disordered breathing (SDB), no evidence exists on oximetry abnormalities in other respiratory disorders. We aimed to compare obstructive lung disease (OLD) and SDB regarding nocturnal oximetry parameters.

METHODS

We analyzed oximetry recordings from children with (i) OLD (obliterative bronchiolitis; cystic fibrosis); (ii) snoring and adenotonsillar hypertrophy (SDB); and (iii) no respiratory disorder (controls). The three groups were compared regarding: (i) oxygen desaturation of hemoglobin index (SpO₂ drops ≥3%/h-ODI3) and (ii) basal SpO₂ (average SpO₂ between SpO₂ drops). The associations of oximetry parameters (natural logarithm) with study group were tested using linear regression including age as covariate.

RESULTS

Data of 16 subjects with OLD (median age: 7.3 years; Q25, Q75: 5.4, 12), 22 children with SDB (6.3 years; 4, 9) and 22 controls (6.8 years; 5.6, 10.3) were analyzed. Children with OLD or SDB had significantly lower basal SpO₂ than controls (91.9% [90.8, 93.4] vs 96.3% [96, 97.4] vs 97.6% [97.1, 97.9]; P < 0.01). No subjects in the SDB or control groups had basal SpO₂  < 95%. Children with SDB had significantly higher ODI3 than children with OLD or controls [8.4 episodes/h (6.2, 16.6) vs 4.4 episodes/h (3.6, 6.6) vs 2 episodes/h (1.3, 2.7); P < 0.01]. OLD had the greatest negative effect on basal SpO₂ (R²  = 0.62; P < 0.001) and SDB the greatest positive effect on ODI3 (R²  = 0.34; P < 0.001).

CONCLUSION

OLD is associated mostly with reduced basal SpO₂ , whereas SDB is characterized by elevated ODI3.

Predictors of sleep hypoxemia in children with cystic fibrosis

OBJECTIVES

To identify the determinants of nocturnal hypoxemia in children with CF using clinical parameters, polysomnography (PSG), and lung function.

HYPOTHESIS

Sleep hypoxemia in children with CF is predicted by both apnea hypopnea index (AHI) and percent predicted forced expiratory volume in one second (pFEV1).

DESIGN

Retrospective case series.

METHODS

Children aged 5-18 years were included based on (i) a diagnosis of CF; and (ii) availability of concurrent PSG and pFEV1 data. The impact of (i) demographic and clinical parameters; and (ii) PSG and pFEV1, on the total sleep time spent with arterial oxygen saturation below 90% (TSpO₂  < 90) was measured using regression analysis. P-value <0.05 was considered significant.

RESULTS

The mean age was 11.6 years (95% confidence interval: 9.5, 13.1). Twenty of 35 (57%) were boys and the mean body mass index percentile was 42.1 (31.5, 52.6). The most common ethnicity was white (66%). OSA was diagnosed in 50%. Neither demographic predictors nor clinical variables predicted the severity of hypoxemia (R²  = 0.23, P = 0.09). While pFEV1 and PSG variables accounted for significant proportion of the overall variance in TSpO₂  < 90 (R²  = 0.53, P < 0.001), pFEV1 was identified as the single best predictor of sleep hypoxemia. A pFEV1 cut-off of 53% indicated a sensitivity of 0.80 and a specificity of 0.87 in predicting sleep hypoxemia.

CONCLUSIONS

pFEV1 is the best predictor of sleep hypoxemia in children with CF and referred for PSG. No demographic or clinical predictors of hypoxemia were identified in this population.

Sleep-disordered breathing in cystic fibrosis pediatric subjects

Objectives

To describe the frequency of sleep-disordered breathing (SDB) in pediatric cystic fibrosis (CF) and to study associations between polysomnographic respiratory parameters and available clinical information.

Methods

This was a retrospective, cross-sectional study. The sample data were obtained from information recorded on patient charts in 2015 and 2016. The study included all individuals with CF aged from 2 to 20 years for whom records were available for polysomnography performed within the previous two years.

Results

Sixteen individuals with CF (mean age 11 ± 5.6 years old) were included. Polysomnographic respiratory parameter abnormalities were defined as an apnea-hypopnea index (AHI) exceeding one event per hour of sleep or an oxyhemoglobin saturation (SpO₂) nadir below 90%; observed in 10 subjects (62.5%). Forced expiratory volume in first second (FEV₁) was correlated (r=0.602, p=0.023) with mean sleep SpO₂. FEV₁ was also negatively correlated with sleep peak end-tidal carbon dioxide (EtpCO₂) (r=-0.645, p=0.024). Additionally, chronic airway colonization by Pseudomonas aeruginosa was associated with mean EtpCO₂ in non-REM sleep (p=0.024).

Discussion

SDB was frequently observed in this sample of children with CF. There was an association between CF respiratory disease progression markers and sleep breathing parameters in children. Sleep studies appear to be an important tool for assessment of the respiratory status of these individuals with CF, although further studies are needed, especially with carbon dioxide sleep analysis.

Sleep disturbances and their impact in pediatric cystic fibrosis

Cystic fibrosis is a chronic, life-shortening illness that affects multiple systems and results in frequent respiratory infections, chronic cough, fat malabsorption and malnutrition. Poor sleep is often reported by patients with cystic fibrosis. Although objective data to explain these complaints have been limited, they do show poor sleep efficiency and frequent arousals. Abnormalities in gas exchange are also observed during sleep in patients with cystic fibrosis. The potential impact of these abnormalities in sleep on health and quality of life remains largely unstudied. This review summarizes what is known about sleep in children with cystic fibrosis, and implications for clinical practice. This report also highlights new evidence on the impact of sleep problems on disease-specific outcomes such as lung function, and identifies areas that need further exploration.

Respiratory sleep disturbance in children and adolescents with cystic fibrosis

Sleep disturbance has been described in cystic fibrosis (CF) patients as relevant to clinical and lung function predictive factors helping to improve the diagnosis and early intervention. Related paediatric studies are scarce.

OBJECTIVE

To describe respiratory sleep disturbance (RSD) and its association with spirometric indices in a population of CF children. A second aim was to determine if spirometric indices and wake-time SpO2 are predictors of sleep disturbance.

METHODS

A cross-sectional study involving 33CF paediatric patients. All participants underwent in-lab polysomnography (PSG), pulse oximetry and spirometry. A standardized sleep questionnaire was completed for each patient. Two subgroups were considered: I - Normal (FEV1>-1.64 z-score); II - Obstructed (FEV1≤-1.64 z-score).

RESULTS

Participant's median age was 12 (6-18) years, 16 (48.5%) were male. Twenty-nine patients (87.9%) presented sleep complaints. Sleep efficiency was reduced; sleep latency and waking after sleep onset (WASO) increased. N1 increased, N2, N3, REM and awakenings were normal. The apnoea-hypopnoea index was 0.6/h (sd 0.9); respiratory disturbance index (RDI) was 6.6/h (sd 5.2). Mean awaking (97% (sd 1.1)) and sleep SpO2 (95% (sd 2.7)) were normal; mean nocturnal oximetry desaturation index was 2.36/h; minimal nocturnal SpO2 was 89% (sd 4.1). We found associations between mean nocturnal SPO2 and mean values of FEV1 (r=0.528; p=0.002) and FEF25-75 (r=0.426; p=0.013). There were significant differences in nocturnal SpO2 between normal and obstructed patients (p<0.000). PSG data correlated with the questionnaire answers for night awakenings and WASO (p=0.985) and difficult breathing during sleep and RDI (p=0.722). This study points to most CF children having sleep complaints, and highlights the correlation between subjective assessment of sleep and PSG and spirometric results. Awake-time SpO2 and spirometric values are possible risk predictors for nocturnal desaturation.

Sleep disordered breathing and sleep quality in children with bronchiolitis obliterans

The incidence of sleep-disordered breathing (SDB) increases in chronic lung diseases. Our aim was to evaluate SDB and sleep quality in children with postinfectious bronchiolitis obliterans (BO) and assess associated risk factors. We hypothesized that children with BO are at increased risk for SDB and have impaired sleep quality. We also hypothesized that severity of SDB and impairment of sleep quality is related to the severity of lung disease. Sleep Related Breathing Disorder (SRBD) subscale of the Pediatric Sleep Questionnaire (PSQ) and Pittsburgh Sleep Quality Index (PSQI) questionnaires; spirometry, impulse oscillometry (IOS), and overnight polysomnography (PSG) were performed. Twenty-one patients (14 male, median age: 8.3 years) were enrolled. Five patients (25%) had a PSQ score of >0.33, predictive of a SDB. Ten patients (48%) had poor sleep quality. Four patients (19%) had an OAHI of >1/hr. Nineteen patients (90%) had a high desaturation index. Four patients (19%) had a mean oxygen saturation of <93%. Median central apnea time was 7.5 (IQR: 6.9-9.1) seconds. Central apnea index of the patients correlated positively with R5, R10, R15, R20, Z5, and negatively with X10 and X15 at IOS. There was a positive correlation between the lowest oxygen saturation and FVC, FEV1 , X5, X10, X15, X20 while there was a negative correlation between lowest saturation and the central apnea index at PSG, R5, R10, and Z5 at IOS. Mean oxygen saturation during PSG correlated positively with FVC, FEV1, FEF(25-75), X5, X10, X15, X20 results. The risk of nocturnal hypoxia is increased in patients with BO and correlated to the severity of lung disease determined by pulmonary function tests. Although BO patients have a shorter duration of central apneas, they are more prone to desaturate.