Comparison of nocturnal pulse oximetry with polysomnography in children with sleep disordered breathing.

PURPOSE: Polysomnography (PSG) is the gold standard in the diagnosis of obstructive sleep apnea (OSA). However, due to high cost and limited availability, this is difficult to access and often delayed. To evaluate the reliability of overnight oximetry as a screening tool for OSA diagnosis. METHOD: All children suspected of OSA who underwent an overnight oximetry and subsequent PSG between January 2014 and April 2016 were studied retrospectively. The "McGill oximetry scoring" was compared with OSA diagnosis as per the American Association of Sleep Medicine. RESULTS: A total of 110 patients had both oximetry and PSG. Sixty-one children (56%) had normal oximetry, whereas 30 (27%) had McGill grade 2 and 19 (17%) had McGill 3 and 4. Sixty-four percent (64%) of children with normal oximetry had a normal PSG. Seventy percent (70%) of children with McGill 2 had either a normal or mild OSA on PSG. All the children with McGill 3 and 4 had moderate/severe OSA by PSG. The overall sensitivity and specificity of oximetry in identifying OSA were 63% and 78%, respectively, and the positive and negative predictive values (PPV and NPV) were 78% and 64%, respectively. The sensitivity and specificity of McGill 3 and 4 in diagnosing moderate/severe OSA on PSG were 59% and 100%, respectively, and the PPV and NPV were 100% and 78%, respectively. CONCLUSION: Overnight oximetry provides satisfactory diagnostic performance in detecting moderate and severe OSA; however, a normal or McGill 2 score does not rule out OSA and a PSG is required for diagnosis.

Delivery of average assured pressure support (AVAPS) through tracheostomy in paediatric patients.

Average volume-assured pressure support (AVAPS) mode has been available since 2009 and allows the ventilator to deliver a constant pre-set tidal volume by automatically adjusting the inspiratory pressures within a set range. Data in AVAPS mode use is limited in both paediatric populations, and in patients who are ventilated through a tracheostomy. This case series reports on the successful use of AVAPS mode in four paediatric patients with tracheostomy ventilation.

Pediatric Average Volume Assured Pressure Support.

Average volume assured pressure support (AVAPS) is a modality of non-invasive ventilation that enables the machine to deliver a pre-set tidal volume by adjusting the inspiratory pressure support within a set range. Data on its use in the pediatric population are limited to case reports and single centre case series. This article reviews paediatric data on use of AVAPS and highlights the need for validation to help develop specific guidelines on use of AVAPS in children.

Daytime predictors of nocturnal hypercapnic hypoventilation in children with neuromuscular disorders.

OBJECTIVES: To examine objective daytime predictors of nocturnal hypercapnic hypoventilation (NHH) and identify a forced vital capacity (FVC) z-score cut off that predicts NHH using the 2012 Global Lung Function Initiative (GLI) reference equations in pediatric neuromuscular patients. DESIGN: Single-centre retrospective medical record review. SETTING: Tertiary pediatric hospital in Australia. PATIENTS: Children (<18 years old) with a neuromuscular disorder (NMD) who had a diagnostic sleep study over a 5-year period. RESULTS: Fifty children were included, median age 11.9 years (interquartile range [IQR]: 4.5-14.3). The majority of children had a diagnosis of Duchenne Muscular Dystrophy (32%). NHH was diagnosed in 18 children (36%). Multivariate logistic regression analysis performed for the entire cohort confirmed a statistically significant association between NHH and scoliosis (odds ratio [OR]: 3.3, p = 0.03), but not age (OR: 1.01, p = 0.26), body mass index z-score (OR: 0.86, p = 0.26) or use of a wheelchair for mobility (OR: 1.25, p = 0.72). For the subset of 29 children who had spirometry testing (median age 12.9 years [IQR: 10.2-14.3]), FVC z-score was the only statistically significant predictor of NHH (OR: 0.45, p = 0.02). NHH was predicted by an FVC z-score <-3.24 (sensitivity 78%, specificity 73%), or FVC <60% predicted (sensitivity 78%, specificity 73%). There was a strong positive correlation between FVC and forced expiratory volume in 1 s z-scores (rp = 0.98, p = 0.00) and FVC and peak expiratory flow  z-scores (rp = 0.72, p = 0.00). CONCLUSION: Children with a NMD and scoliosis or a lower FVC z-score have increased odds of having NHH.

Three generations of a family diagnosed with congenital central hypoventilation syndrome: A case series.

Congenital central hypoventilation syndrome (CCHS) is an autosomal dominant disorder characterized by alveolar hypoventilation and autonomic dysregulation secondary to mutations of the PHOX2B genes. We present five cases from three generations within the same family with varying degrees of phenotypic expression of the PHOX2B gene mutation. The cases were diagnosed following identification of CCHS in index case at birth. This case series underscores the importance of screening first-degree relatives of individuals with confirmed CCHS and alerts the clinicians to maintain a high degree of suspicion in asymptomatic family members given the high degree of phenotypic variability of CCHS.

Average volume-assured pressure support vs conventional bilevel pressure support in pediatric nocturnal hypoventilation: a case series.

STUDY OBJECTIVES: Average volume-assured pressure support (AVAPS) is a modality of noninvasive ventilation that provides a targeted tidal volume by automatically adjusting the inspiratory pressure support within a set range. Pediatric studies evaluating the efficacy of AVAPS in treating nocturnal hypoventilation are confined to case reports. The aim of this study was to compare AVAPS to conventional bilevel positive airway pressure (BPAP) support in improving hypercarbia in a cohort of pediatric patients with nocturnal hypoventilation. METHODS: Retrospective review of patient records at an established tertiary pediatric sleep laboratory over a 6-year period. Ventilatory and sleep study parameters from AVAPS and conventional BPAP titration studies were compared. AVAPS was used only if hypoventilation was not controlled using conventional BPAP. Inspiratory pressures, tidal volumes, and adherence were downloaded on final titrated ventilatory settings. Comparisons were made using paired t test. RESULTS: A total of 19 patients (11 boys, 8 girls; median age 10.5 years, range 1 to 20 years) were identified. Diagnoses included neuromuscular disease (n = 9), obstructive hypoventilation (n = 5), parenchymal lung disease (n = 4), and congenital central hypoventilation syndrome (n = 2). AVAPS demonstrated significant improvement in peak (P = .009) and mean (P = .001). Transcutaneous CO2 parameters compared to conventional bilevel. Oxygenation on AVAPS showed positive trend but did not reach statistical significance. AVAPS delivered higher tidal volumes (P = .04) using similar pressures. There was no statistically significant difference in obstructive apnea-hypopnea index, respiratory arousal index, sleep efficiency, and adherence between AVAPS and conventional BPAP. CONCLUSIONS: AVAPS was an effective alternative to conventional BPAP in improving hypercarbia in our selective cohort of pediatric patients. Prospective, longitudinal studies are needed to evaluate the benefits of AVAPS feature in the pediatric population.

Non-invasive home ventilation using the average volume assured pressure support feature in an infant with severe bronchopulmonary dysplasia and chronic respiratory failure.

INTRODUCTION: While majority of infants with bronchopulmonary dysplasia (BPD) can be discharged home without low flow oxygen or on supplemental low flow oxygen, some require long term home mechanical ventilation. CASE PRESENTATION: We present a case of an extremely premature infant with severe bronchopulmonary dysplasia who was successfully managed at home on a new feature of non-invasive ventilation called average volume assured pressure support (AVAPS) without the need for tracheostomy. The AVAPS feature enables the machine to deliver a consistent tidal volume by automatically adjusting the inspiratory pressure within a set range. CONCLUSION: The use of AVAPS feature in our case improved ventilation as indicated by a more stable gas exchange profile, making home non-invasive ventilation a more practicable method of managing severe BPD in this infant.

Nasal mask average volume-assured pressure support in an infant with congenital central hypoventilation syndrome.

Congenital central hypoventilation syndrome (CCHS) is a rare disorder characterized by alveolar hypoventilation and autonomic dysregulation secondary to mutations of the PHOX 2B genes. Treatment consists of assisted ventilation using positive pressure ventilators via tracheostomy, bi-level positive airway pressure (BPAP), negative pressure ventilators, or diaphragm pacing. Previous case reports have highlighted early use of nasal non-invasive BPAP use in infants with CCHS. We present a case of a 10-month-old infant who was successfully managed on a new feature of non-invasive ventilation called average volume assured pressure support (AVAPS) without the need for tracheostomy. The AVAPS feature enables the machine to automatically adjust the inspiratory pressures to deliver a constant targeted tidal volume. This feature enabled a better control of ventilation as indicated by a more stable transcutaneous carbon dioxide profile compared to conventional nasal non-invasive BPAP, making non-invasive ventilation a more accessible method of managing sleep hypoventilation in CCHS.

The role of polysomnography in tracheostomy decannulation of the paediatric patient.

INTRODUCTION: Tracheostomy decannulation in the paediatric patient is usually considered when there is resolution or significant improvement in the original indication for the tracheostomy. The child's cardiorespiratory function needs to be optimized and assessment of the readiness for decannulation is generally by endoscopic evaluation to confirm airway patency and vocal cord mobility. Functional airway assessment procedures include downsizing the tracheostomy, adding fenestration, speaking valves and capping the tracheostomy tube. Few objective measures have been demonstrated to accurately predict the likelihood of successful decannulation. This study aims to evaluate the usefulness of polysomnography (PSG) with a capped tracheostomy tube, as an adjunct to airway endoscopy and traditional decannulation procedures, to predict decannulation outcome. METHODS: A retrospective review was conducted for patients who underwent "capped" PSG prior to a trial of tracheostomy decannulation at the Sydney Children's Hospitals Network. The charts were reviewed for clinical data and PSG results. RESULTS: 30 children with a total of 40 PSG reports were included in this study. There was a statistically significant difference in mean oxygen saturation, minimum oxygen saturation, total apnoea/hypopnoea index, desaturations >3%, and desaturations >3% index between those that had successful decannulation compared to failed decannulation. The measures with the greatest significance, and therefore, the best predictors of decannulation outcome were total apnoea/hypopnoea index (3.35events/h vs. 18.5events/h, p=0.004) and desaturation events (20.33 events vs. 192 events, p=0.001). CONCLUSIONS: PSG with a capped tracheostomy tube is a useful, objective tool to complement endoscopy and functional airway assessment in the consideration of decannulation in the paediatric population.

Nocturnal respiratory failure in a child with congenital myopathy - management using average volume-assured pressure support (AVAPS).

This is a case report of the effective use of bi-level positive airway pressure support (BPAP) using the volume-assured pressure support feature in a pediatric patient with a congenital myopathy and significant nocturnal hypoventilation. Our patient was started on nocturnal nasal mask BPAP but required high pressures to improve her oxygen saturations and CO2 baseline. She was then trialed on a BPAP machine with the volume-assured pressure support feature on. The ability of this machine to adjust inspiratory pressures to give a targeted tidal volume allowed the patient to be on lower pressure settings for periods of the night, with the higher pressures only when required. She tolerated the ventilation well and her saturations, CO2 profiles, and clinical condition improved. This case report highlights the benefits of the volume-assured pressure support feature on a BPAP machine in a child with a neuromuscular disorder.