Outpatient Utilization of the RAM Cannula for Nasal Noninvasive Ventilation in Children.

Background: The RAM cannula® consists of nasal prongs that can be used to administer oxygen, continuous, and bilevel positive airway pressure therapies. Studies have reported the efficacy and utility of the RAM cannula in inpatients requiring noninvasive ventilation (NIV); however, there is limited literature on the use of the RAM cannula to provide NIV in the outpatient setting. Objectives: This study aimed to describe the clinical features and outcomes of children who used NIV via RAM cannula in the outpatient setting. Design: Retrospective review. Methods: We conducted a retrospective review of children treated with outpatient NIV via RAM cannula at our institution between January 2010 and March 2023. The analyzed data included age, diagnoses, indications for NIV, duration of RAM cannula use, complications, and outcomes at 6 months. Results: We identified 20 patients who used outpatient NIV via RAM cannula during the study period. The median age at initiation of NIV via RAM cannula was 5.8 months (IQR 2.4-9.9 months). Indications for NIV included sleep-related hypoventilation (15%), restrictive lung disease (25%), obstructive sleep apnea (45%), and chronic respiratory failure (50%), with 6 patients having ⩾2 indications for NIV. RAM cannula was utilized for inability to tolerate conventional NIV interfaces (80%), to alleviate dyspnea (60%), and to avoid tracheostomy (55%). Patients used NIV via RAM cannula for a median duration of 7.7 months (IQR 3.7-20.6 months). Patient outcomes included ongoing usage of RAM cannula (55%), changing to conventional NIV interfaces (15%) or oxygen (10%), weaning off respiratory support (5%), and death (15%). There were no complications related to using the RAM cannula. Conclusion: Our study demonstrates the utility of outpatient NIV via RAM cannula in children with a variety of diagnoses until clinical improvement or tolerance of conventional interfaces, and for avoidance of tracheostomy.

Images: Caffeine therapy for central sleep apnea, hypoxemia, and hypoventilation in a term neonate.

The evaluation of higher-risk infants with brief resolved unexplained events and term infants with central sleep apnea can be clinically challenging due to the multitude of potential etiologies. We report a 7-day-old term neonate hospitalized for evaluation of brief resolved unexplained events with oxygen desaturations during sleep. Polysomnography showed central sleep apnea, hypoxemia, hypoventilation, periodic breathing, and mild obstructive sleep apnea. Following initial evaluations and while awaiting genetic testing, primary central sleep apnea of infancy was suspected and caffeine was initiated. Three days after initiating caffeine, polysomnography showed resolution of hypoxemia, hypoventilation, obstructive sleep apnea, and periodic breathing and improved central sleep apnea. The central apnea-hypopnea index reduced from 58 to 6.8 events/h. Although caffeine is utilized in apnea of prematurity, there is limited literature regarding caffeine in term infants with apnea. Our case demonstrates that in term infants with primary central sleep apnea of infancy, immature regulation of respiration may persist and a trial of caffeine could be considered. CITATION: Shah AS, Leu RM, Shah SP, Martinez F, Kasi AS. Caffeine therapy for central sleep apnea, hypoxemia, and hypoventilation in a term neonate. J Clin Sleep Med. 2023;19(5):1005-1008.

A meta-analysis of diagnostic test performance of peripheral arterial tonometry studies.

STUDY OBJECTIVES: The objective of this meta-analysis was to analyze agreement in apnea-hypopnea index (AHI) determination between peripheral arterial tonometry (PAT) and polysomnography (PSG) studies. METHODS: Mean AHI bias and standard deviation extracted from Bland-Altman plots reported in studies were pooled in a meta-analysis, which was then used to calculate percentage errors of limit agreement in AHI determination by PAT using PSG AHI as the reference. Individual participant data (where reported in studies) were used to compute Cohen's kappa to assess agreement between PSG and PAT on sleep apnea severity and for computing the sensitivity and specificity of PAT at different AHI thresholds using PSG AHI as the reference. RESULTS: From 17 studies and 1,318 participants (all underwent simultaneous PSG and use of the WatchPAT device), a pooled mean AHI bias of 0.30 (standard error [SE], 0.74) and a WatchPAT AHI percentage error of 230% was calculated. The meta-analysis of Cohen's kappa for agreement between PSG and WatchPAT studies for classifying patients with no sleep apnea, mild, moderate, or severe sleep apnea severity was 0.45 (SE, 0.06), 0.29 (SE, 0.05), 0.25 (SE, 0.07), and 0.64 (SE, 0.05), respectively. At AHI thresholds of 5, 15 and 30 events/h, WatchPAT studies showed pooled sensitivities and specificities of 94.11% and 43.47%, 92.21% and 72.39%, and 74.11% and 87.10%, respectively. Likelihood ratios were not significant at any AHI threshold. CONCLUSIONS: The results of this meta-analysis suggest clinically significant discordance between WatchPAT and PSG measurements of AHI, significant sleep apnea severity misclassification by PAT studies, and poor diagnostic test performance. CITATION: Iftikhar IH, Finch CE, Shah AS, Augunstein CA, Ioachimescu OC. A meta-analysis of diagnostic test performance of peripheral arterial tonometry studies. J Clin Sleep Med. 2022;18(4):1093-1102.

Annual Respiratory Evaluations in Congenital Central Hypoventilation Syndrome and Changes in Ventilatory Management.

Background: Annual in-hospital respiratory evaluations (AREs) during wakefulness and sleep are recommended to assess ventilatory requirements in patients with congenital central hypoventilation syndrome (CCHS) aged ≥2-3 years based on expert consensus. This study aimed to determine if AREs in patients with CCHS led to changes in ventilatory management. Methods: Retrospective review of patients with CCHS who underwent AREs with or without polysomnography between 2017 and 2019 was conducted. Clinical symptoms, results of AREs, and subsequent changes in ventilatory management were analyzed. Results: We identified 10 patients with CCHS aged 4-20 years. All patients required assisted ventilation (AV) only during sleep delivered by positive pressure ventilation via tracheostomy (n = 7) or diaphragm pacing (n = 3). In total, 7 (70%) patients had abnormal oxygenation and/or ventilation requiring changes in ventilator settings or duration of AV. Six patients required an increase in settings and/or duration of AV, and only 1 patient required a decrease in ventilator settings. Two patients had awake hypercapnia during a routine outpatient visit that improved following increase in ventilator settings and a period of continuous AV. One patient who was previously ventilator-dependent only during sleep was identified to require 16 h per day of AV. All patients (n = 3) who reported symptoms such as headache or oxygen desaturations during sleep required an increase in ventilator settings. Conclusion: We report a high prevalence of changes in AV management following an ARE. Our results demonstrate the importance of regular AREs in patients with CCHS to assess their ventilatory requirements and optimize AV.

Heterogeneous Pulmonary Phenotypes in Filamin A Mutation-Related Lung Disease.

Background: Interstitial lung disease (ILD) has been recently reported in a few patients with pathogenic variants in the Filamin A (FLNA) gene with variable presentation and prognosis. This study evaluated the respiratory manifestations and clinical features in children with FLNA disease. Methods: We conducted a retrospective review of pediatric patients with variants in FLNA in a tertiary children's hospital. The clinical features, genotype, management, and outcomes were analyzed. Results: We identified 9 patients with variants in FLNA aged 15 months to 24 years, 4 females and 5 males. Six patients had abnormal chest imaging ranging from mild interstitial prominence to atelectasis, interstitial densities, and hyperinflation. Three patients with ILD presented during the neonatal period or early infancy with respiratory distress or respiratory failure requiring supplemental oxygen or assisted ventilation via tracheostomy. We report male twins with the same FLNA variant and lung disease, but different ages and clinical features at presentation eventually culminating in respiratory failure requiring assisted ventilation. All patients had FLNA variants identified by FLNA sequencing, had abnormal echocardiograms, and none of the patients underwent lung biopsy or lung transplantation. The outcomes were variable and could be as severe as chronic respiratory failure. Conclusion: The wide spectrum of respiratory manifestations and abnormal chest imaging in our study highlights the importance of evaluation for lung disease in patients with variants in FLNA. FLNA sequencing in suspected cases with ILD may obviate the need for a lung biopsy, prompt surveillance for progressive lung disease, and evaluation for associated clinical features.