Pediatric OSAS: Oximetry can provide answers when polysomnography is not available

Accuracy of clinical scoring tools for the diagnosis of pediatric obstructive sleep apnea

OBJECTIVES

To assess the diagnostic test accuracy of questionnaire and clinical examination-based scoring tools in the diagnosis of pediatric obstructive sleep apnea (OSA).

METHODS

A comprehensive literature search was performed to identify studies published from 1960 to 2018 that evaluated the accuracy of clinical scoring tools in the diagnosis of pediatric OSA. Studies that did not include attended polysomnography as a reference standard were excluded. The study populations were children under 18 years old without craniofacial abnormalities, congenital syndromes, or other complex medical conditions. Outcomes measures were diagnostic test accuracy (DTA) statistics including sensitivity, specificity, and area under the curve (AUC) from receiver operating characteristic curve analysis.

RESULTS

Fifteen different scoring tools were identified. Authors chose different polysomnographic criteria to diagnose OSA. Four of the tools had undergone multiple DTA studies by different authors (OSA Score, Sleep-Related Breathing Disorder [SRBD] scale, Severity Score, and OSA-18). The Pediatric Sleep Questionnaire SRBD scale, which is widely used, has a sensitivity of 71% to 84% in included studies, but specificity as low as 13% and a low AUC of 0.57-0.69, indicating poor diagnostic accuracy. None of the 15 scoring tools performed well enough to be considered accurate diagnostic tests for pediatric OSA.

CONCLUSIONS

A well-designed questionnaire can provide crucial information on the impact of sleep-disordered breathing on a child's physical and psychological health, which may not be adequately reflected in objective polysomnography outcomes measures. However, DTA results indicate that published clinical scoring tools do not accurately predict a diagnosis of pediatric OSA as defined by polysomnography outcome measures. Laryngoscope, 130:1034-1043, 2020.

A System for Monitoring Breathing Activity Using an Ultrasonic Radar Detection with Low Power Consumption

Continuous monitoring of breathing activity plays a major role in detecting and classifying a breathing abnormality. This work aims to facilitate detection of abnormal breathing syndromes, including tachypnea, bradypnea, central apnea, and irregular breathing by tracking of thorax movement resulting from respiratory rhythms based on ultrasonic radar detection. This paper proposes a non-contact, non-invasive, low cost, low power consumption, portable, and precise system for simultaneous monitoring of normal and abnormal breathing activity in real-time using an ultrasonic PING sensor and microcontroller PIC18F452. Moreover, the obtained abnormal breathing syndrome is reported to the concerned physician’s mobile telephone through a global system for mobile communication (GSM) modem to handle the case depending on the patient’s emergency condition. In addition, the power consumption of the proposed monitoring system is reduced via a duty cycle using an energy-efficient sleep/wake scheme. Experiments were conducted on 12 participants without any physical contact at different distances of 0.5, 1, 2, and 3 m and the breathing rates measured with the proposed system were then compared with those measured by a piezo respiratory belt transducer. The experimental results illustrate the feasibility of the proposed system to extract breathing rate and detect the related abnormal breathing syndromes with a high degree of agreement, strong correlation coefficient, and low error ratio. The results also showed that the total current consumption of the proposed monitoring system based on the sleep/wake scheme was 6.936 mA compared to 321.75 mA when the traditional operation was used instead. Consequently, this led to a 97.8% of power savings and extended the battery life time from 8 h to approximately 370 h. The proposed monitoring system could be used in both clinical and home settings.

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.

Pediatric Tracheostomy Decannulation: 11-Year Experience

OBJECTIVE

To determine the successful decannulation rate with a published pediatric tracheostomy decannulation protocol.

STUDY DESIGN

Case series with chart review.

SETTING

A single tertiary care institution.

SUBJECTS AND METHODS

A chart review was performed for patients aged ≤5 years who underwent tracheostomy. Extracted data included demographic data, indication for tracheostomy, age at tracheostomy and decannulation, comorbidities, and surgical complications. Records were searched for documentation of early decannulation failure (within 1 month of decannulation) or late failure (within 1 year).

RESULTS

Forty patients with a tracheostomy aged ≤5 years underwent attempted decannulation during the 11-year study period. Seventeen patients were excluded from the study for documentation of nonprotocol decannulation. The final study population of 23 patients underwent a total of 27 decannulations, 26 of which were performed by protocol. Of the 26 protocol decannulations, 22 were successful, for a failure rate of 15%.

CONCLUSION

Twenty-six protocol decannulations were attempted among 23 patients, 4 of which were unsuccessful for an overall failure rate of 15%. This result is consistent with rates reported in other published decannulation protocols. We believe that our protocol minimizes resource utilization in its use of pulse oximetry over polysomnography, while maximizing patient safety and success through the use of capping trials for very young and very small pediatric patients.

Quantitative assessment of nocturnal neural respiratory drive in children with and without obstructive sleep apnoea using surface EMG

NEW FINDINGS

What is the central question of this study? Recent studies have suggested potential utility of non-normalized respiratory muscle EMG as an index of neural respiratory drive (NRD). Whether NRD measured using non-normalized surface EMG of the lateral chest wall overlying the diaphragm (sEMGcw) recorded during nocturnal clinical polysomnography can differentiate children with and without obstructive sleep apnoea (OSA) is not known. What is the main finding and its importance? Non-normalized sEMGcw was increased in children with OSA and an additional group of snoring children without OSA but subjectively increased respiratory effort compared with primary snorers. The sEMGcw has potential clinical utility in evaluation of children with sleep-disordered breathing as an objective, non-invasive, non-volitional marker of NRD.

ABSTRACT

Our aim was to investigate whether neural respiratory drive measured by non-normalized surface EMG recorded from the chest wall overlying the diaphragm (sEMGcw) differentiates children with and without obstructive sleep apnoea (OSA). Polysomnography data of children aged 0-18 years were divided into the following three groups: (i) primary snorers (PS); (ii) snoring children without OSA but with increased work of breathing (incWOB; subjective physician report of increased respiratory effort during sleep); and (iii) children with OSA [obstructive apnoea-hypopnoea index (OAHI) >1 h^-1 ]. Excerpts of sEMGcw obtained during tidal unobstructed breathing from light, deep and rapid eye movement sleep were exported for quantitative analysis. Overnight polysomnography data from 45 PS [median age 4.4 years (interquartile range 3.0-7.7 years), OAHI 0 h^-1 (0.0-0.2 h^-1 )], 19 children with incWOB [age 2.8 years (2.4-5.7 years), OAHI 0.1 h^-1 (0.0-0.4 h^-1 )] and 27 children with OSA [age 3.6 years (2.6-6.2 years), OAHI 3.7 h^-1 (2.3-6.9 h^-1 )] were analysed. The sEMGcw was higher in those with OSA [8.47 μV (5.98-13.07 μV); P < 0.0001] and incWOB [8.97 μV (5.94-13.43 μV); P < 0.001] compared with PS [4.633 μV (2.98-6.76 μV)]. There was no significant difference in the sEMGcw between children with incWOB and OSA (P = 0.78). Log sEMGcw remained greater in children with OSA and incWOB compared with PS after age, body mass index centiles, sleep stages and sleep positions were included in the mixed linear models (P < 0.0001). The correlation between sEMGcw and OAHI in children without OSA was small (r_s  = 0.254, P = 0.04). The sEMGcw is increased in children with OSA and incWOB compared with PS.

[Sleep-Disordered Breathing in Childhood]

Sleep-Disordered Breathing in Childhood Abstract. One out of ten healthy children is a habitual snorer, and one fourth of snoring children suffer from obstructive sleep apnea syndrome (OSAS). While OSAS is widely recognized as a relevant social and health problem due to its negative impact on behavior and neurocognitive development, the medical significance of habitual snoring remains debated. Sleep-disordered breathing remains underestimated and underdiagnosed in childhood, in part due to the variability of clinical manifestations. This is particularly true for children with an underlying syndromal morbidity such as Down syndrome or Prader-Willi syndrome. This review summarizes the essential key points of Sleep-Disordered Breathing (SDB) in childhood.

Wavelet analysis of oximetry recordings to assist in the automated detection of moderate-to-severe pediatric sleep apnea-hypopnea syndrome

BACKGROUND

The gold standard for pediatric sleep apnea hypopnea syndrome (SAHS) is overnight polysomnography, which has several limitations. Thus, simplified diagnosis techniques become necessary.

OBJECTIVE

The aim of this study is twofold: (i) to analyze the blood oxygen saturation (SpO2) signal from nocturnal oximetry by means of features from the wavelet transform in order to characterize pediatric SAHS; (ii) to evaluate the usefulness of the extracted features to assist in the detection of pediatric SAHS.

METHODS

981 SpO2 signals from children ranging 2-13 years of age were used. Discrete wavelet transform (DWT) was employed due to its suitability to deal with non-stationary signals as well as the ability to analyze the SAHS-related low frequency components of the SpO2 signal with high resolution. In addition, 3% oxygen desaturation index (ODI3), statistical moments and power spectral density (PSD) features were computed. Fast correlation-based filter was applied to select a feature subset. This subset fed three classifiers (logistic regression, support vector machines (SVM), and multilayer perceptron) trained to determine the presence of moderate-to-severe pediatric SAHS (apnea-hypopnea index cutoff ≥ 5 events per hour).

RESULTS

The wavelet entropy and features computed in the D9 detail level of the DWT reached significant differences associated with the presence of SAHS. All the proposed classifiers fed with a selected feature subset composed of ODI3, statistical moments, PSD, and DWT features outperformed every single feature. SVM reached the highest performance. It achieved 84.0% accuracy (71.9% sensitivity, 91.1% specificity), outperforming state-of-the-art studies in the detection of moderate-to-severe SAHS using the SpO2 signal alone.

CONCLUSION

Wavelet analysis could be a reliable tool to analyze the oximetry signal in order to assist in the automated detection of moderate-to-severe pediatric SAHS. Hence, pediatric subjects suffering from moderate-to-severe SAHS could benefit from an accurate simplified screening test only using the SpO2 signal.

Cloud algorithm-driven oximetry-based diagnosis of obstructive sleep apnoea in symptomatic habitually snoring children

The ability of a cloud-driven Bluetooth oximetry-based algorithm to diagnose obstructive sleep apnoea syndrome (OSAS) was examined in habitually snoring children concurrently undergoing overnight polysomnography.

Children clinically referred for overnight in-laboratory polysomnographic evaluation for suspected OSAS were simultaneously hooked to a Bluetooth oximeter linked to a smartphone. Polysomnography findings were scored and the apnoea/hypopnoea index (AHIPSG) was tabulated, while oximetry data yielded an estimated AHIOXI using a validated algorithm.

The accuracy of the oximeter in identifying correctly patients with OSAS in general, or with mild (AHI 1–5 events·h−1), moderate (5–10 events·h−1) or severe (>10 events·h−1) OSAS was examined in 432 subjects (6.5±3.2 years), with 343 having AHIPSG >1 event·h−1. The accuracies of AHIOXI were consistently >79% for all levels of OSAS severity, and specificity was particularly favourable for AHI >10 events·h−1 (92.7%). Using the criterion of AHIPSG >1 event·h−1, only 4.7% of false-negative cases emerged, from which only 0.6% of cases showed moderate or severe OSAS.

Overnight oximetry processed via Bluetooth technology by a cloud-based machine learning-derived algorithm can reliably diagnose OSAS in children with clinical symptoms suggestive of the disease. This approach provides virtually limitless scalability and should alleviate the substantial difficulties in accessing paediatric sleep laboratories while markedly reducing the costs of OSAS diagnosis.

Improving the Diagnostic Ability of Oximetry Recordings in Pediatric Sleep Apnea-Hypopnea Syndrome by Means of Multi-Class AdaBoost

Pediatric sleep apnea-hypopnea syndrome (SAHS) is a highly prevalent respiratory disorder that may impose many negative effects on the health and development of children. Due to the drawbacks of overnight polysomnography (PSG), the gold standard diagnosis technique, automated analysis of nocturnal oximetry has emerged as a simplified alternative. In order to improve diagnosis ability of oximetry, we propose to evaluate the usefulness of AdaBoost, a classification boosting algorithm, in the context of pediatric SAHS. A database composed of 981 SpO₂ recordings from pediatric subjects was used. For this purpose, a signal processing approach divided into two main stages was conducted: (i) feature extraction, where 3% oxygen desaturation index (ODI3), spectral, and nonlinear features were computed from the oximetry signal, and (ii) AdaBoost classification, where an AdaBoost.M2 model was trained with these features in order to determine the severity of pediatric SAHS according to the apnea-hypopnea index (AHI): AHI<1 events per hour (e/h), 1≤AHI<5 e/h, and AHI≥5 e/h. Our AdaBoost.M2 model achieved a Cohen's kappa of 0.474 in an independent test set in the 3-class classification task. In addition, high accuracies were obtained when using the AHI cutoffs for diagnosis of mild (AHI=1 e/h) and moderate-to-severe (AHI=5 e/h) SAHS: 80.9% and 82.9%, respectively. These results achieved slightly higher diagnostic accuracies than ODI3 as well as state-of-the-art studies. Therefore, AdaBoost could help to enhance the diagnostic ability of the oximetry signal to assess pediatric SAHS severity.

Detrended fluctuation analysis of the oximetry signal to assist in paediatric sleep apnoea-hypopnoea syndrome diagnosis

OBJECTIVE

To evaluate whether detrended fluctuation analysis (DFA) provides information that improves the diagnostic ability of the oximetry signal in the diagnosis of paediatric sleep apnoea-hypopnoea syndrome (SAHS).

APPROACH

A database composed of 981 blood oxygen saturation (SpO₂) recordings in children was used to extract DFA-derived features in order to quantify the scaling behaviour and the fluctuations of the SpO₂ signal. The 3% oxygen desaturation index (ODI3) was also computed for each subject. Fast correlation-based filter (FCBF) was then applied to select an optimum subset of relevant and non-redundant features. This subset fed a multi-layer perceptron (MLP) neural network to estimate the apnoea-hypopnoea index (AHI).

MAIN RESULTS

ODI3 and four features from the DFA reached significant differences associated with the severity of SAHS. An optimum subset composed of the slope in the first scaling region of the DFA profile and the ODI3 was selected using FCBF applied to the training set (60% of samples). The MLP model trained with this feature subset showed good agreement with the actual AHI, reaching an intra-class correlation coefficient of 0.891 in the test set (40% of samples). Furthermore, the estimated AHI showed high diagnostic ability, reaching an accuracy of 82.7%, 81.9%, and 91.1% using three common AHI cut-offs of 1, 5, and 10 events per hour (e h^-1), respectively. These results outperformed the overall performance of ODI3.

SIGNIFICANCE

DFA may serve as a reliable tool to improve the diagnostic performance of oximetry recordings in the evaluation of paediatric patients with symptoms suggestive of SAHS.

The OSA-5: Development and validation of a brief questionnaire screening tool for obstructive sleep apnea in children

OBJECTIVE

To develop and test a screening tool based on the OSA-18 questionnaire for triage of referrals for sleep-disordered breathing (SDB) in children.

STUDY DESIGN

Consecutive children aged >2y without major comorbidities referred for polysomnography (PSG) or overnight oximetry for suspected obstructive sleep apnea (OSA) between 11 January and 31 May 2017 were included. OSA was defined by an obstructive apnea/hypopnea index (OAHI) >1event/h on PSG or an abnormal overnight oximetry (McGill Oximetry Score 2-4). An 11-item questionnaire derived from a previous validation study of the OSA-18 underwent exploratory factor analysis (EFA) with varimax rotation. ANOVA identified questions associated with the presence of OSA. This informed a 5-question, 4-category instrument, scored 0-15 (the OSA-5), that was tested prospectively on 112 children having PSG.

RESULTS

420 children (2.0-17.9y, 43% female) met the inclusion criteria, including 366 complete questionnaires. EFA resulted in a 3-factor structure. ANOVA identified 5 questions from one factor that were independently associated with a diagnosis of OSA: snoring, breath holding, choking, mouth breathing and parental concern. Mean OSA-5 scores with and without OSA were 7.7 vs 4.5 (p < 0.001). Thirty-four percent (60/178) had a total score <5/15, with a sensitivity at this threshold for OSA of 82% and negative predictive value (NPV) of 70%. Similar results were obtained when tested prospectively, including a sensitivity of 82% and NPV of 81% for the presence of moderate/severe OSA (OAHI>5/h).

CONCLUSION

The OSA-5 is a simple questionnaire that performs well as a triage screening tool to identify those children at risk of OSA among large numbers of referrals for SDB.

Symbolic dynamics to enhance diagnostic ability of portable oximetry from the phone oximeter in the detection of paediatric sleep apnoea

OBJECTIVE

This study is aimed at assessing symbolic dynamics as a reliable technique to characterise complex fluctuations of portable oximetry in the context of automated detection of childhood obstructive sleep apnoea-hypopnoea syndrome (OSAHS).

APPROACH

Nocturnal oximetry signals from 142 children with suspected OSAHS were acquired using the Phone Oximeter: a portable device that integrates a pulse oximeter with a smartphone. An apnoea-hypopnoea index (AHI) ≥5 events/h from simultaneous in-lab polysomnography was used to confirm moderate-to-severe childhood OSAHS. Symbolic dynamics was used to parameterise non-linear changes in the overnight oximetry profile. Conventional indices, anthropometric measures, and time-domain linear statistics were also considered. Forward stepwise logistic regression was used to obtain an optimum feature subset. Logistic regression (LR) was used to identify children with moderate-to-severe OSAHS.

MAIN RESULTS

The histogram of 3-symbol words from symbolic dynamics showed significant differences (p <0.01) between children with AHI <5 events/h and moderate-to-severe patients (AHI ≥5 events/h). Words representing increasing oximetry values after apnoeic events (re-saturations) showed relevant diagnostic information. Regarding the performance of individual characterization approaches, the LR model composed of features from symbolic dynamics alone reached a maximum performance of 78.4% accuracy (65.2% sensitivity; 86.8% specificity) and 0.83 area under the ROC curve (AUC). The classification performance improved combining all features. The optimum model from feature selection achieved 83.3% accuracy (73.5% sensitivity; 89.5% specificity) and 0.89 AUC, significantly (p-value <0.01) outperforming the other models.

SIGNIFICANCE

Symbolic dynamics provides complementary information to conventional oximetry analysis enabling reliable detection of moderate-to-severe paediatric OSAHS from portable oximetry.

Use of Oximetry to Determine Need for Adenotonsillectomy for Sleep-Disordered Breathing

: media-1vid110.1542/5802711151001PEDS-VA_2017-3382Video Abstract OBJECTIVES: We evaluated the efficacy of adenotonsillectomy (T/A) in children with sleep-disordered breathing (SDB) in a controlled study using oximetry. We hypothesized that children with SDB and abnormal nocturnal oximetry in a community setting will have improved hypoxemia indices after T/A.

METHODS

Children with snoring and tonsillar hypertrophy (4-10 years old) who were candidates for T/A were randomly assigned to 2 oximetry sequences (baseline and 3-month follow-up): (1) oximetry immediately before T/A and at the 3-month follow-up, which occurred postoperatively (T/A group); or (2) oximetry at the initial visit and at the end of the usual 3-month waiting period for surgery (control group). Outcomes were (1) proportion of subjects with McGill oximetry score (MOS) >1 at baseline acquiring MOS of 1 at follow-up and (2) proportion of subjects achieving oxygen desaturation (≥3%) of hemoglobin index (ODI3) <2 episodes per hour at follow-up if they had ODI3 ≥3.5 episodes per hour at baseline.

RESULTS

One hundred and forty children had quality oximetry tracings. Twelve of 17 (70.6%) children with MOS >1 in the T/A group and 10 of 21 (47.6%) children with MOS >1 in the control group had MOS of 1 at follow-up (P = .14). More subjects in the T/A than in the control group achieved ODI3 <2 episodes per hour at follow-up (14 of 32 [43.8%] vs 2 of 38 [5.3%]; P < .001). Three children with elevated ODI3 were treated to prevent persistently abnormal ODI3 in 1 child at follow-up.

CONCLUSIONS

An ODI3 ≥3.5 episodes per hour in nocturnal oximetry is related to increased resolution rate of nocturnal hypoxemia after T/A for SDB compared with no intervention.

Fast Convolutional Method for Automatic Sleep Stage Classification

Objectives

Polysomnography is essential to diagnose sleep disorders. It is used to identify a patient's sleep pattern during sleep. This pattern is obtained by a doctor or health practitioner by using a scoring process, which is time consuming. To overcome this problem, we developed a system that can automatically classify sleep stages.

Methods

This paper proposes a new method for sleep stage classification, called the fast convolutional method. The proposed method was evaluated against two sleep datasets. The first dataset was obtained from physionet.org, a physiologic signals data centers. Twenty-five patients who had a sleep disorder participated in this data collection. The second dataset was collected in Mitra Keluarga Kemayoran Hospital, Indonesia. Data was recorded from ten healthy respondents.

Results

The proposed method reached 73.50% and 56.32% of the F-measures for the PhysioNet and Mitra Keluarga Kemayoran Hospital data, respectively. Both values were the highest among all the machine learning methods considered in this study. The proposed method also had an efficient running time. The fast convolutional models of the PhysioNet and Mitra Keluarga Kemayoran Hospital data needed 42.60 and 0.06 seconds, respectively.

Conclusions

The fast convolutional method worked well on the tested datasets. It achieved a high F-measure result and an efficient running time. Thus, it can be considered a promising tool for sleep stage classification.

Pre-operative parameters do not reliably identify post-operative respiratory risk in children undergoing adenotonsillectomy

AIM

Adenotonsillectomy is performed in children with recurrent tonsillitis or obstructive sleep apnoea. Children at risk of post-operative respiratory complications are recommended to be monitored in paediatric intensive care unit (PICU). The aim of the study is to review the risk factors for post-operative complications and admissions to PICU.

METHODS

A review of medical records of children who underwent adenotonsillectomy between January 2011 and December 2014 was performed. Association between demographic variables and post-operative complications were examined using chi-square and Mann-Whitney tests.

RESULTS

A total of 214 children were identified, and of these, 19 (8.8%) experienced post-operative complications. Six children (2.8%) had respiratory complications: hypoxaemia in four and laryngospasm requiring reintubation in a further two. Both of the latter patients were extubated upon arrival to PICU and required no escalation of therapy. A total of 13 (6.1%) children had non-respiratory complications: 8 (3.7%) had infection and 5 (2.3%) had haemorrhage. A total of 26 (12.1%) children were electively admitted to PICU and mean stay was 19.5 (SD ± 13) h. No association between demographic characteristics, comorbid conditions or polysomnographic parameters and post-operative complications were noted. A total of 194 (90.7%) children stayed only one night in hospital (median 1 day, range 1-5 days).

CONCLUSION

The previously identified risk factors and criteria for PICU admission need revision, and new recommendations are necessary.

Utility of bispectrum in the screening of pediatric sleep apnea-hypopnea syndrome using oximetry recordings

BACKGROUND AND OBJECTIVE

The aim of this study was to assess the utility of bispectrum-based oximetry approaches as a complementary tool to traditional techniques in the screening of pediatric sleep apnea-hypopnea syndrome (SAHS).

METHODS

298 blood oxygen saturation (SpO₂) signals from children ranging 0-13 years of age were recorded during overnight polysomnography (PSG). These recordings were divided into three severity groups according to the PSG-derived apnea hypopnea index (AHI): AHI < 5 events per hour (e/h), 5 ≤ AHI < 10 e/h, AHI ≥ 10 e/h. For each pediatric subject, anthropometric variables, 3% oxygen desaturation index (ODI3) and spectral features from power spectral density (PSD) and bispectrum were obtained. Then, the fast correlation-based filter (FCBF) was applied to select a subset of relevant features that may be complementary, excluding those that are redundant. The selected features fed a multiclass multi-layer perceptron (MLP) neural network to build a model to estimate the SAHS severity degrees.

RESULTS

An optimum subset with features from all the proposed methodological approaches was obtained: variables from bispectrum, as well as PSD, ODI3, Age, and Sex. In the 3-class classification task, the MLP model trained with these features achieved an accuracy of 76.0% and a Cohen's kappa of 0.56 in an independent test set. Additionally, high accuracies were reached using the AHI cutoffs for diagnosis of moderate (AHI = 5 e/h) and severe (AHI = 10 e/h) SAHS: 81.3% and 85.3%, respectively. These results outperformed the diagnostic ability of a MLP model built without using bispectral features.

CONCLUSIONS

Our results suggest that bispectrum provides additional information to anthropometric variables, ODI3 and PSD regarding characterization of changes in the SpO₂ signal caused by respiratory events. Thus, oximetry bispectrum can be a useful tool to provide complementary information for screening of moderate-to-severe pediatric SAHS.

Assessment of oximetry-based statistical classifiers as simplified screening tools in the management of childhood obstructive sleep apnea

PURPOSE

A variety of statistical models based on overnight oximetry has been proposed to simplify the detection of children with suspected obstructive sleep apnea syndrome (OSAS). Despite the usefulness reported, additional thorough comparative analyses are required. This study was aimed at assessing common binary classification models from oximetry for the detection of childhood OSAS.

METHODS

Overnight oximetry recordings from 176 children referred for clinical suspicion of OSAS were acquired during in-lab polysomnography. Several training and test datasets were randomly composed by means of bootstrapping for model optimization and independent validation. For every child, blood oxygen saturation (SpO₂) was parameterized by means of 17 features. Fast correlation-based filter (FCBF) was applied to search for the optimum features. The discriminatory power of three statistical pattern recognition algorithms was assessed: linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), and logistic regression (LR). The performance of each automated model was evaluated for the three common diagnostic polysomnographic cutoffs in pediatric OSAS: 1, 3, and 5 events/h.

RESULTS

Best screening performances emerged using the 1 event/h cutoff for mild-to-severe childhood OSAS. LR achieved 84.3% accuracy (95% CI 76.8-91.5%) and 0.89 AUC (95% CI 0.83-0.94), while QDA reached 96.5% PPV (95% CI 90.3-100%) and 0.91 AUC (95% CI 0.85-0.96%). Moreover, LR and QDA reached diagnostic accuracies of 82.7% (95% CI 75.0-89.6%) and 82.1% (95% CI 73.8-89.5%) for a cutoff of 5 events/h, respectively.

CONCLUSIONS

Automated analysis of overnight oximetry may be used to develop reliable as well as accurate screening tools for childhood OSAS.

Paediatric obstructive sleep apnoea: can our identification of surgical candidates be evidence-based?

BACKGROUND

Paediatric obstructive sleep apnoea is a common clinical condition managed by most ENT clinicians. However, despite the plethora of publications on the subject, there is wide variability, in the literature and in practice, on key aspects such as diagnostic criteria, the impact of co-morbidities and the indications for surgical correction.

METHODS

A systematic review is presented, addressing four key questions from the available literature: (1) what is the evidence base for any definition of paediatric obstructive sleep apnoea?; (2) does it cause serious systemic illness?; (3) what co-morbidities influence the severity of paediatric obstructive sleep apnoea?; and (4) is there a medical answer?

RESULTS AND CONCLUSION

There is a considerable lack of evidence regarding most of these fundamental questions. Notably, screening measures show low specificity and can be insensitive to mild obstructive sleep apnoea. There is a surprising lack of clarity in the definition (let alone estimate of severity) of sleep-disordered breathing, relying on what may be arbitrary test thresholds. Areas of potential research might include investigation of the mechanisms through which obstructive sleep apnoea causes co-morbidities, whether neurocognitive, behavioural, metabolic or cardiovascular, and the role of non-surgical management.

Nocturnal Oximetry-based Evaluation of Habitually Snoring Children

RATIONALE

The vast majority of children around the world undergoing adenotonsillectomy for obstructive sleep apnea-hypopnea syndrome (OSA) are not objectively diagnosed by nocturnal polysomnography because of access availability and cost issues. Automated analysis of nocturnal oximetry (nSp_O2), which is readily and globally available, could potentially provide a reliable and convenient diagnostic approach for pediatric OSA.

METHODS

Deidentified nSp_O2 recordings from a total of 4,191 children originating from 13 pediatric sleep laboratories around the world were prospectively evaluated after developing and validating an automated neural network algorithm using an initial set of single-channel nSp_O2 recordings from 589 patients referred for suspected OSA.

MEASUREMENTS AND MAIN RESULTS

The automatically estimated apnea-hypopnea index (AHI) showed high agreement with AHI from conventional polysomnography (intraclass correlation coefficient, 0.785) when tested in 3,602 additional subjects. Further assessment on the widely used AHI cutoff points of 1, 5, and 10 events/h revealed an incremental diagnostic ability (75.2, 81.7, and 90.2% accuracy; 0.788, 0.854, and 0.913 area under the receiver operating characteristic curve, respectively).

CONCLUSIONS

Neural network-based automated analyses of nSp_O2 recordings provide accurate identification of OSA severity among habitually snoring children with a high pretest probability of OSA. Thus, nocturnal oximetry may enable a simple and effective diagnostic alternative to nocturnal polysomnography, leading to more timely interventions and potentially improved outcomes.

Age and seasons influence on at-home pulse oximetry results in children evaluated for suspected obstructive sleep apnea

Background

Seasonal variability on obstructive sleep apnea has already been studied by polysomnography in children. Winter and spring season emerged as critical periods. No data are currently available for pulse oximetry performed at home. The aim of our study was to evaluate the effect of seasonality and age on the results of at-home pulse oximetry performed in children referred for suspected OSA.

Methods

We retrospectively studied 781 children (64.3% Males), aged 4.9 ± 2.5 years. For all patients, we evaluated both pulse oximetry metrics and the McGill Oximetry Score. Variables for seasonal groups were assessed using Kruskal-Wallis test. A logistic regression model was performed to assess the relationship between patients’ main characteristics, season period and the likelihood to have an abnormal McGill Oximetry Score.

Results

Patients recorded during winter were significantly younger (p < 0.02), nadir SpO₂ was significantly lower (p < 0.002) and DI₄ significantly higher than during others seasons (p < 0.005). Moreover, patients recorded during winter were nearly 2 times more likely to have an abnormal MOS (aOR 1.949). The logistic regression showed that also younger age (p < 0.0001) was associated with a higher risk to find an abnormal pulse oximetry.

Conclusions

In our study, the winter season confirms to be a critical period for pulse-oximetry and it should be taken into account by clinicians for a correct interpretation of tests. Our data show that also younger age affects the prevalence of abnormal at-home pulse oximetry in children.

Evaluation of behavioral change after adenotonsillectomy for obstructive sleep apnea in children with autism spectrum disorder

BACKGROUND AND OBJECTIVE

Obstructive sleep apnea (OSA) may affect daily cognitive functioning in children. The aims of our study were two-fold. The first aim was to detect, using the Child Behavior Checklist (CBCL), whether adenotonsillectomy (AT) for the treatment of OSA improved the behavior of children with autism spectrum disorder (ASD). The second aim was to identify characteristics for behavioral improvement following the treatment of OSA in these children with ASD.

METHODS

The behaviors of ASD children aged 5-14 years diagnosed as having OSA (n=30) were evaluated using CBCL before and after AT. CBCL evaluation of ASD children without OSA at two time points with the same interval served as a control (n=24). We statistically examined the two groups. In addition, we conducted a paired t-test to assess changes in CBCL Tscores between the improved group and unchanged/deteriorated group to identify characteristics that may affect behavioral changes following OSA treatment.

RESULTS

After AT, T-scores of the CBCL scales were significantly improved in the OSA group, but no change was observed in the control. A paired t-test revealed that the improved group had significantly higher scores on the CBCL pre-AT than the unchanged/deteriorated group in ASD children with OSA after OSA treatment.

CONCLUSIONS

Behavioral problems were significantly improved following AT in ASD children with OSA. Early detection and treatment of children with OSA is essential to prevent behavioral problems and to support mental development.

The watch-pat in pediatrics sleep disordered breathing: Pilot study on children with negative nocturnal pulse oximetry

OBJECTIVES

The main purpose of this study was to determine the efficacy of Watch-PAT in Pediatric Sleep Disordered Breathing (PSDB) diagnosis in children with symptoms suggestive of PSDB, in which the nocturnal pulse oximetry was negative according to the Brouilette criteria.

METHODS

We enrolled 28 patients aged between 5 and 12 years (mean age: 7.75 ± 1.69), who underwent the registration with Watch-PAT, that utilizes the Peripheral Arterial Tone (PAT), AHI, RDI, body position, snoring, pulse oximetry and actigraphy.

RESULTS

Recording Watch-PAT was indicative of PSDB in 10/28 (35.7%) patients; when it was placed the threshold of AHI > 1 the number of positive patients for PSDB increased to 17/28 (60.7%). Exists a positive correlation between pat-RDI (rho = 0.798, p = 0.005) and the snoring > 40% of the time (rho = 0.656, p < 0.001) were correlated with the pat-AHI values.

CONCLUSION

The recording Watch-PAT appears to permit the defection of a certain number of SDB that might escape to the clinical evaluation and pulse oximetry only.

Automated Screening of Children With Obstructive Sleep Apnea Using Nocturnal Oximetry: An Alternative to Respiratory Polygraphy in Unattended Settings

STUDY OBJECTIVES

Nocturnal oximetry has become known as a simple, readily available, and potentially useful diagnostic tool of childhood obstructive sleep apnea (OSA). However, at-home respiratory polygraphy (HRP) remains the preferred alternative to polysomnography (PSG) in unattended settings. The aim of this study was twofold: (1) to design and assess a novel methodology for pediatric OSA screening based on automated analysis of at-home oxyhemoglobin saturation (SpO₂), and (2) to compare its diagnostic performance with HRP.

METHODS

SpO₂ recordings were parameterized by means of time, frequency, and conventional oximetric measures. Logistic regression models were optimized using genetic algorithms (GAs) for three cutoffs for OSA: 1, 3, and 5 events/h. The diagnostic performance of logistic regression models, manual obstructive apnea-hypopnea index (OAHI) from HRP, and the conventional oxygen desaturation index ≥ 3% (ODI3) were assessed.

RESULTS

For a cutoff of 1 event/h, the optimal logistic regression model significantly outperformed both conventional HRP-derived ODI3 and OAHI: 85.5% accuracy (HRP 74.6%; ODI3 65.9%) and 0.97 area under the receiver operating characteristics curve (AUC) (HRP 0.78; ODI3 0.75) were reached. For a cutoff of 3 events/h, the logistic regression model achieved 83.4% accuracy (HRP 85.0%; ODI3 74.5%) and 0.96 AUC (HRP 0.93; ODI3 0.85) whereas using a cutoff of 5 events/h, oximetry reached 82.8% accuracy (HRP 85.1%; ODI3 76.7) and 0.97 AUC (HRP 0.95; ODI3 0.84).

CONCLUSIONS

Automated analysis of at-home SpO₂ recordings provide accurate detection of children with high pretest probability of OSA. Thus, unsupervised nocturnal oximetry may enable a simple and effective alternative to HRP and PSG in unattended settings.

When and why to treat the child who snores?

Obstructive sleep-disordered breathing (SDB) can result in cardiovascular and neurocognitive morbidity as well as adversely affect behavior, growth, quality of life, and nocturnal continence. This article summarizes the latest evidence regarding the morbidity related to obstructive SDB, commenting on the impact of severity of obstruction, that is, the difference in effects seen of moderate to severe obstructive sleep apnea syndrome (OSAS) compared to those of mild OSAS or primary snoring. The impact of therapy is discussed, focusing on which children are likely to benefit from treatment interventions; namely those with moderate or severe OSAS irrespective of the presence of morbidity, children with mild OSAS with associated morbidity or predictors of SDB persistence such as obesity, and children with complex conditions accompanied by upper airway obstruction like craniosynostosis and Prader-Willi syndrome. The co-existing conditions which may improve when treatment for obstructive SDB is offered are reviewed, while the clinical parameters associated with spontaneous improvement or resolution of obstructive SDB are discussed. The intention being to enable clinicians to make informed decisions on who should be treated, when and why. Pediatr Pulmonol. 2017;52:399-412. © 2016 Wiley Periodicals, Inc.

Parental Snoring and Environmental Pollutants, but Not Aeroallergen Sensitization, Are Associated with Childhood Snoring in a Birth Cohort

The objective of this study was to determine whether atopy and other clinical and environmental variables predict the risk of childhood habitual snoring (HS) in a birth cohort born to atopic parents. Participants completed clinical evaluations and questionnaires at ages 1-4 and age 7. HS was defined as snoring ≥3 nights/week. Traffic-related air pollution (TRAP) exposure was estimated using land-use regression. The association between early (≤age 4) and current (age 7) allergic disease, environmental exposures, and snoring at age 7 was examined using adjusted logistic regression. Of the 609 children analyzed the prevalence of HS at age 7 was 21%. Early tobacco smoke exposure [environmental tobacco smoke (ETS)] [odds ratio (OR) 1.79, 95% CI (confidence interval) 1.12-2.84], rhinitis (OR 1.74, 95% CI 1.06-2.92), wheezing (OR 1.63, 95% CI 1.05-2.53), maternal HS (OR 2.08, 95% CI 1.36-3.18), and paternal HS (OR 1.83, 95% CI 1.14-3.00) were significantly associated with HS at age 7. Current TRAP (OR 1.93, 95% CI 1.13-3.26), respiratory infections (OR 1.16, 95% 1.03-1.35), maternal HS (OR 2.86, 95% CI 1.69-4.84), and paternal HS (OR 3.01, 95% CI 1.82-5.09) were significantly associated with HS at age 7. To our knowledge, this is the largest birth cohort examining longitudinal predictors of snoring in children born to atopic parents. Parental HS was the only variable consistently associated with childhood HS from ages 1 to 7. Early rhinitis, early ETS exposure, and concurrent traffic pollution exposure increased the risk of HS at age 7, while aeroallergen sensitization did not. Children with these characteristics should be considered for screening of sleep disorders.

How do we recognize the child with OSAS?

Obstructive sleep-disordered breathing includes a spectrum of clinical entities with variable severity ranging from primary snoring to obstructive sleep apnea syndrome (OSAS). The clinical suspicion for OSAS is most often raised by parental report of specific symptoms and/or abnormalities identified by the physical examination which predispose to upper airway obstruction (e.g., adenotonsillar hypertrophy, obesity, craniofacial abnormalities, neuromuscular disorders). Symptoms and signs of OSAS are classified into those directly related to the intermittent pharyngeal airway obstruction (e.g., parental report of snoring, apneic events) and into morbidity resulting from the upper airway obstruction (e.g., increased daytime sleepiness, hyperactivity, poor school performance, inadequate somatic growth rate or enuresis). History of premature birth and a family history of OSAS as well as obesity and African American ethnicity are associated with increased risk of sleep-disordered breathing in childhood. Polysomnography is the gold standard method for the diagnosis of OSAS but may not be always feasible, especially in low-income countries or non-tertiary hospitals. Nocturnal oximetry and/or sleep questionnaires may be used to identify the child at high risk of OSAS when polysomnography is not an option. Endoscopy and MRI of the upper airway may help to identify the level(s) of upper airway obstruction and to evaluate the dynamic mechanics of the upper airway, especially in children with combined abnormalities. Pediatr Pulmonol. 2017;52:260-271. © 2016 Wiley Periodicals, Inc.

Safe sleeping positions: practice and policy for babies with cleft palate

Guidance recommends 'back to sleep' positioning for infants from birth in order to reduce the risk of sudden infant death. Exceptions have been made for babies with severe respiratory difficulties where lateral positioning may be recommended, although uncertainty exists for other conditions affecting the upper airway structures, such as cleft palate. This paper presents research of (i) current advice on sleep positioning provided to parents of infants with cleft palate in the UK; and (ii) decision making by clinical nurse specialists when advising parents of infants with cleft palate. A qualitative descriptive study used data from a national survey with clinical nurse specialists from 12 regional cleft centres in the UK to investigate current practice. Data were collected using semi-structured telephone interviews and analysed using content analysis. Over half the regional centres used lateral sleep positioning based on clinical judgement of the infants' respiratory effort and upper airway obstruction. Assessment relied upon clinical judgement augmented by a range of clinical indicators, such as measures of oxygen saturation, heart rate and respiration.

CONCLUSION

Specialist practitioners face a clinical dilemma between adhering to standard 'back to sleep' guidance and responding to clinical assessment of respiratory effort for infants with cleft palate. In the absence of clear evidence, specialist centres rely on clinical judgement regarding respiratory problems to identify what they believe is the most appropriate sleeping position for infants with cleft palate. Further research is needed to determine the best sleep position for an infant with cleft palate. What is Known • Supine sleep positioning reduces the risk of sudden infant death in new born infants. • There is uncertainty about the benefits or risks of lateral sleep positioning for infants with upper airway restrictions arising from cleft palate. What is New • Variability exists in the information/advice provided to parents of infants with cleft palate regarding sleep positioning. • Over half the national specialist centres for cleft palate in the UK advise positioning infants with CP in the lateral position as a routine measure to reduce difficulties with respiration.

Sleep disordered breathing in childhood

Sleep disordered breathing (SDB) in childhood is linked with significant end-organ dysfunction across various systems, particularly with cardiovascular, neurocognitive and metabolic consequences. If we understand the pathophysiology of SDB, diagnose it promptly and treat appropriately, we may be able to prevent morbidity associated with SDB and also save health resources around the world. In this article, we highlight articles on this topic published in medical journals in the past year.

Prematurity, obesity and adenotonsillar hypertrophy are risk factors for sleep disordered breathinghttp://ow.ly/W47FU

Oximetry for suspected obstructive sleep apnea-Does removal of awake data affect the result?

Frequency of dips below 90% on overnight oximetry can be used to estimate severity of obstructive sleep apnea (OSA) in children. Movement can result in artifact on oximetry recordings. Clinicians may therefore be tempted to remove periods of wakefulness from the recording to improve accuracy, but removal of such periods of potential artifact is time consuming. The aim of this study was to determine whether removing periods of wakefulness had a significant impact on analysis of overnight oximetry. Children aged 2-18 years (N = 108) with suspected OSA underwent overnight simultaneous oximetry and actigraphy at home on a single night. Actigraphy defined awake periods were "trimmed" from the oximetry data and oximetry variables compared between full and trimmed analysis. There was a statistically but not clinically significant difference between the full and trimmed data for mean SpO₂ , minimum SpO₂ , 4% desaturation index, and 3% desaturation index (all P < 0.05). There was no difference between the two analyses for median SpO₂ or the frequency of dips below 90%, 85%, or 80%. In conclusion, removal of periods of wakefulness at the start and end of overnight oximetry recordings does not affect the result in the context of testing for suspected OSA in children. Pediatr Pulmonol. 2016;51:1409-1413. © 2016 Wiley Periodicals, Inc.

Oximetry in obese children with sleep-disordered breathing

BACKGROUND

Obesity is an important risk factor for obstructive sleep apnea syndrome (OSAS), and obese children with OSAS have frequently shown oxygen desaturations when compared with normal-weight children. The aim of our study was to investigate the oximetry characteristics in children with obesity and sleep-disordered breathing (SDB).

METHODS

Children referred for suspected OSAS were enrolled in the study. All children underwent sleep clinical record (SCR), pulse oximetry, and polysomnography (PSG).

RESULTS

A total of 248 children with SDB were recruited (128 obese and 120 normal-weight children). Obese children showed higher oxygen desaturation index (ODI) and lower nadir oxygen saturation (nadir SaO₂) compared to non-obese children (p < 0.05). ODI and nadir SaO₂ correlated with obesity (p < 0.05). The SCR evaluation showed that deep bite and overjet were more common among obese children (p < 0.05), whereas habitual nasal obstruction and arched palate were more common among non-obese children (p < 0.05). Furthermore, skeletal malocclusion and tonsillar hypertrophy were significant risk factors in obese children associated with severe desaturation (p < 0.05).

CONCLUSION

Obese children with SDB have a more significant oxygen desaturation; adeno-tonsillar hypertrophy is not the only important risk factor for its development but also the presence of malocclusions.

Application of desaturation index in post-surgery follow-up in children with obstructive sleep apnea syndrome

Adenotonsillectomy is recommended for children who need surgery for obstructive sleep apnea syndrome (OSAS). Overnight, polysomnography (PSG) is suggested for post-surgery follow-up, but this diagnostic technique is time consuming and inconvenient. Desaturation index (DI) has been reported as a good tool for predicting both the presence and severity of OSAS in children. The purpose of this study was to determine the usefulness of the DI for post-surgery follow-up of children with OSAS. This retrospective study enrolled 42 children, aged 3-12 years, who were snorers diagnosed with OSAS by overnight PSG and who underwent an adenotonsillectomy. Pre- and postoperative PSG parameters, nocturnal pulse oximetry data, and modified Epworth sleepiness scale scores were assessed. Previously determined cut-off DI values (2.05, 3.50, and 4.15 for mild, moderate, and severe OSAS, respectively) were used to predict residual OSAS. Of the 42 children, obvious improvements were observed in apnea-hypopnea index (AHI, decreased 45.5 %), arousal index (decreased 30.5 %), DI (decreased 40.4 %), and snore index (decreased 100.3 %) compared with the preoperative measurements. Among these objective PSG measures, DI had the strongest correlation with AHI both pre- and post-surgeries (r = 0.947 and r = 0.954, respectively; p all <0.001). The DI change, before and after surgery, also had the strongest positive correlation to the AHI change (r = 0.482 and p = 0.001). Using the previously determined DI cut-off values to predict postoperative residual OSAS, there was a good positive predictive value (92.6 %) for mild residual OSAS and a good negative predictive value for moderate and severe residual OSAS (85.2 and 89.7 %, respectively). These findings suggest that DI, as determined using a nocturnal pulse oximeter, may be an alternative tool for postoperative evaluation and follow-up of children with OSAS.

The STBUR questionnaire for identifying children at risk for sleep-disordered breathing and postoperative opioid-related adverse events

BACKGROUND

Children with symptoms of sleep-disordered breathing (SDB) appear to be at risk for perioperative respiratory events (PRAE). Furthermore, these children may be more sensitive to the respiratory-depressant effects of opioids compared with children without SDB.

AIMS

The aim of this prospective observational study was to confirm that otherwise healthy children with symptoms of SDB are at greater risk for PRAE compared with children with no symptoms and to determine if these children are also at increased risk for postoperative opioid-related adverse events (ORAE).

METHODS

Six hundred and seventy-eight parents of children scheduled for surgery completed the Snoring, Trouble Breathing, and Un-Refreshed (STBUR) questionnaire preoperatively. Data regarding the incidence of PRAE were collected prospectively. Postoperative pulse oximetry desaturation alarm events were downloaded from the institutional secondary alarm notification system.

RESULTS

Children with symptoms of SDB per STBUR (≥3 symptoms) had a two-fold increased likelihood of PRAE compared with children without SDB (52.8% vs 27.9% respectively, LR(+) = 2.00, 95% CI = 1.60-2.49, P = 0.0001). A subset analysis of children undergoing airway procedures requiring hospital admittance (n = 179) showed that those with SDB were given the same postoperative opioid doses as children without SDB. However, children with SDB symptoms generated a greater number of postoperative oxygen desaturation alarms (14.14 ± 29.3 vs 7.12 ± 13.2, mean difference = 7.02, 95% CI = 0.39-13.64, P = 0.038) and more frequently required escalation of care (15.3% vs 7.1%, LR(+) = 1.67, 95% CI = 1.22-2.16, P = 0.001) compared with children with no SDB symptoms.

CONCLUSIONS

Children presenting for surgery with SDB symptoms are at increased risk for PRAE. Children undergoing airway-related procedures also appear to be at increased risk for ORAE. Furthermore, regardless of the preoperative assessment of risk using the STBUR questionnaire, children received the same doses of opioids postoperatively. Given the increased incidence of postoperative oxygen desaturations among children with SDB symptoms, it would seem prudent to consider titration of opioid doses according to identified risk.

Pediatric Pulmonology year in review 2015: Part 2

Pediatric Pulmonology covers a broad range of research and scholarly topics related to children's respiratory disorders. For updated perspectives on the rapidly expanding knowledge in our field, we will summarize the past year's publications in our major topic areas, as well as selected publications in these areas from the core clinical journal literature outside our own pages. The current review (Part 2) covers articles on sleep-disordered breathing. Pediatr Pulmonol. 2016;51:740-746. © 2016 Wiley Periodicals, Inc.

Chronic Intermittent Hypoxia Alters Local Respiratory Circuit Function at the Level of the preBötzinger Complex

Chronic intermittent hypoxia (CIH) is a common state experienced in several breathing disorders, including obstructive sleep apnea (OSA) and apneas of prematurity. Unraveling how CIH affects the CNS, and in turn how the CNS contributes to apneas is perhaps the most challenging task. The preBötzinger complex (preBötC) is a pre-motor respiratory network critical for inspiratory rhythm generation. Here, we test the hypothesis that CIH increases irregular output from the isolated preBötC, which can be mitigated by antioxidant treatment. Electrophysiological recordings from brainstem slices revealed that CIH enhanced burst-to-burst irregularity in period and/or amplitude. Irregularities represented a change in individual fidelity among preBötC neurons, and changed transmission from preBötC to the hypoglossal motor nucleus (XIIn), which resulted in increased transmission failure to XIIn. CIH increased the degree of lipid peroxidation in the preBötC and treatment with the antioxidant, 5,10,15,20-Tetrakis (1-methylpyridinium-4-yl)-21H,23H-porphyrin manganese(III) pentachloride (MnTMPyP), reduced CIH-mediated irregularities on the network rhythm and improved transmission of preBötC to the XIIn. These findings suggest that CIH promotes a pro-oxidant state that destabilizes rhythmogenesis originating from the preBötC and changes the local rhythm generating circuit which in turn, can lead to intermittent transmission failure to the XIIn. We propose that these CIH-mediated effects represent a part of the central mechanism that may perpetuate apneas and respiratory instability, which are hallmark traits in several dysautonomic conditions.

Pediatric Home Sleep Apnea Testing: Slowly Getting There!

Pediatric OSA can result in significant neurocognitive, behavioral, cardiovascular, and metabolic morbidities. Prompt diagnosis and treatment are, therefore, of paramount importance. The current gold standard for diagnosis of OSA in children is in-laboratory polysomnography (PSG). Home sleep apnea testing has been considered as an alternative as it is potentially more cost effective, convenient, and accessible. This review concentrates mainly on the use of type 2 and 3 portable monitoring devices. The current evidence on the feasibility and diagnostic accuracy of home testing in the diagnosis of pediatric OSA was examined. Overall, the evidence in children is limited. Feasibility studies that have been performed have on the whole shown good results, with several reporting > 90% of their home recordings as meeting predetermined quality criteria regarding signal artifact and minimum recording time. The limited data comparing type 2 studies with in-laboratory PSG have shown no significant differences in respiratory parameters. The results pertaining to diagnostic accuracy of type 3 home sleep apnea testing devices are conflicting. Although more research is needed, home testing with at least a type 3 portable monitor offers a viable alternative in the diagnosis of otherwise healthy children with moderate to severe OSA, particularly in settings where access to polysomnography is scarce or unavailable. Of note, since most studies have been performed in habitually snoring healthy children, home sleep apnea testing may not be applicable to children with other comorbid conditions. In particular, CO2 monitoring is important in children in whom there is concern regarding nocturnal hypoventilation, such as children with neuromuscular disease, underlying lung disease, or obesity hypoventilation, and most home testing devices do not include a transcutaneous or end-tidal CO2 channel.