Obstructive sleep-disordered breathing (SDB) has significant impacts on health, and therefore, a timely and accurate diagnosis is crucial for effective management and intervention. This narrative review provides an overview of the current approaches utilised in the diagnosis of SDB in children. Diagnostic methods for SDB in children involve a combination of clinical assessment, medical history evaluation, questionnaires, and objective measurements. Polysomnography (PSG) is the diagnostic gold standard. It records activity of brain and tibial and submental muscles, heart rhythm, eye movements, oximetry, oronasal airflow, abdominal and chest movements, body position. Despite its accuracy, it is a time-consuming and expensive tool. Respiratory polygraphy instead monitors cardiorespiratory function without simultaneously assessing sleep and wakefulness; it is more affordable than PSG, but few paediatric studies compare these techniques and there is optional recommendation in children. Nocturnal oximetry is a simple and accessible exam that has high predictive value only for children at high risk. The daytime nap PSG, despite the advantage of shorter duration and lower costs, is not accurate for predicting SDB. Few paediatric data support the use of home testing during sleep. Finally, laboratory biomarkers and radiological findings are potentially useful hallmarks of SDB, but further investigations are needed to standardise their use in clinical practice.

Background: The sweat chloride test (ST) is the gold standard for cystic fibrosis (CF) diagnosis in symptomatic patients, within the newborn screening and in the follow-up of CF patients during molecular therapies. However, false positives have been reported in patients with different diseases. We describe and discuss 4 cases due to different clinical conditions in which we recorded false positive ST, and the test remained altered for a period of varying length.Cases presentation: Case 1: Eight months old female child suffering from constipation, recurrent vomiting and failure to thrive, family history of recurrent pancreatitis without mutations in thePRSS1andSPINK1genes. Both ST and fecal elastase were altered although noCFTRgene mutations were found. Due to rapid clinical deterioration, celiac disease was suspected and diagnosed by laboratory tests and intestinal biopsy. After 2 weeks of gluten-free diet ST and fecal elastase normalized.Case 2: 14 months old male suffering from bilateral renal dysplasia, episodes of metabolic alkalosis, recurrent respiratory infections and recurrent vomiting. The child had more ST positives, but noCFTRmutations were found. During follow-up, he developed sensorineural hearing loss and an atrial septic defect was found. Finally, a diagnosis of Klinefelter was made, but the ST normalized several years later.Case 3 and 4: Two boys with stubborn constipation and fecal occlusion treated with Poly Ethylene Glycol (PEG) with salts showed pathological ST. The test returned normal a few days after stopping treatment.Conclusions: We hypotesized the possible causes of ST alteration in these conditions: in celiac disease it could be due to a transient dysregulation of the aquaporins, rapidly reversed by the diet; in Klinefelter, it may be due to stable pubertal hypoandrogenism; while, the PEG formulation itself contains salts that can temporarily alter ST.

Background: Currently, no consensus guidelines recommend routine bronchoscopy procedure in cystic fibrosis (CF), as no evidence is available concerning its use as either a diagnostic or therapeutic tool. Its efficacy is controversial, and no randomized controlled prospective trials are available to check its effectiveness. The aims of the present study were to evaluate the effectiveness of bronchoscopy as a diagnostic/therapeutic tool in CF children and adolescents; and to verify the effect of serial bronchoscopy on lung disease progression in subjects with CF not responding to a single procedure. Methods: Data of patients who received bronchoscopy at 2 Italian CF centers were collected. Bronchoalveolar lavage was performed during the procedure including airway clearance with mucolytics, inhaled antibiotics, and/or surfactant instillation. Results: A total of 16 patients in center 1 and 17 in center 2 underwent, respectively, 28 and 23 bronchoscopic procedure in the study period. Five patients in each center underwent >1 procedure. All procedures were generally well tolerated. No patient required admission to the pediatric intensive therapy unit. In 19.6% of bronchoalveolar lavages, growth of Aspergillus fumigatus was evident, although not detected by sputum analyses. After the procedure, an increase in mean percent predicted forced expiratory volume in the 1 second >10% was observed, and a significant decrease in pulmonary exacerbations yearly was evident. Conclusion: Based on the results, we suggest bronchoscopy is not to be considered an obsolete tool, and it remains useful in CF management, although in selected cases. We encourage to support longitudinal observational studies to standardize the procedure, focusing on the choice of drugs to be instilled, modalities and timing of serial bronchoscopy and subsequent follow-up in selected severe clinical conditions.

Background: An increase in hemoglobin (Hb) has been reported in subjects with CF treated with the CFTR modulator Ivacaftor and with the combination Lumacaftor/Ivacaftor (LI), while the literature about the impact of Elexacaftor/Tezacaftor/Ivacaftor (ETI) on Hb levels in the pediatric population is lacking. Materials and Methods: We retrospectively evaluated Hb levels in 35 subjects with CF (18 males, median age: 8 years; interquartile range (IQR): 6–13 years) treated with LI and 60 (24 males, median age: 10 years; IQR: 6–14 years) treated with ETI. For each subject we considered the values of Hb, serum potassium, total bilirubin (TB), and conjugated bilirubin (CB) at baseline, after 3 days, and 1, 3, 6, 9, and 12 months from the start of treatment. Results: In subjects with CF treated with LI, we observed a significant increase in Hb values 3 days after the introduction of the drug, which remained constant throughout the year of treatment. In subjects treated with ETI, a significant decrease in Hb was observed 3 days after the first dose up to 1 month. At 6 months, Hb returned to pre-treatment values remaining stable for up to 12 months. At 3 days of treatment, we also observed a significant increase in serum potassium, which returned to normal at one month, while both TB and CB values significantly increased at 3 days of treatment and remained significantly higher for the whole one-year period of ETI therapy. Conclusions: We confirmed an increase in Hb values over time in subjects treated with LI. While the Hb response in those treated with ETI showed a transient reduction that lasted for one month, this may have depended on hemolysis, and returned to pre-treatment levels. Further studies will clarify the mechanisms that govern changes in Hb in subjects with CF treated with ETI.