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

Development and validation of moderate to severe obstructive sleep apnea screening test (ColTon) in a pediatric population

OBJECTIVE

Development and validation of a machine learning algorithm to predict moderate to severe obstructive sleep apnea syndrome (OSAS) in otherwise healthy children.

DESIGN

Multivariable logistic regression and cforest algorithm of a large cross-sectional data set of children with sleep-disordered breathing.

SETTING

An university pediatric sleep centre.

PARTICIPANTS

Children underwent clinical examination, acoustic rhinometry and pharyngometry, and surveying through parental sleep questionnaires, allowing the recording of 14 predictors that have been associated with OSAS. The dataset was nonrandomly split into a training (development) versus test (external validation) set (2:1 ratio) based on the time of the polysomnography. We followed the TRIPOD checklist.

RESULTS

We included 336 children in the analysis: 220 in the training set (median age [25th-75th percentile]: 10.6 years [7.4; 13.5], z-score of BMI: 1.96 [0.73; 2.50], 89 girls) and 116 in the test set (10.3 years [7.8; 13.0], z-score of BMI: 1.89 [0.61; 2.46], 51 girls). The prevalence of moderate to severe OSAS was 106/336 (32%). A machine learning algorithm using the cforest with pharyngeal collapsibility (pharyngeal volume reduction from sitting to supine position measured by pharyngometry) and tonsillar hypertrophy (Brodsky scale), constituting the ColTon index, as predictors yielded an area under the curve of 0.89, 95% confidence interval [0.85-0.93]. The ColTon index had an accuracy of 76%, sensitivity of 63%, specificity of 81%, negative predictive value of 84%, and positive predictive value of 59% on the validation set.

CONCLUSION

A cforest classifier allows valid predictions for moderate to severe OSAS in mostly obese, otherwise healthy children.

Nocturnal oximetry parameters as predictors of sleep apnea severity in resource-limited settings

Nocturnal oximetry is an alternative modality for evaluating obstructive sleep apnea syndrome (OSAS) severity when polysomnography is not available. The Oxygen Desaturation (≥3%) Index (ODI3) and McGill Oximetry Score (MOS) are used as predictors of moderate-to-severe OSAS (apnea-hypopnea index-AHI >5 episodes/h), an indication for adenotonsillectomy. We hypothesised that ODI3 is a better predictive parameter for AHI >5 episodes/h than the MOS. All polysomnograms performed in otherwise healthy, snoring children with tonsillar hypertrophy in a tertiary hospital (November 2014 to May 2019) were analysed. The ODI3 and MOS were derived from the oximetry channel of each polysomnogram. Logistic regression was applied to assess associations of ODI3 or MOS (predictors) with an AHI >5 episodes/h (primary outcome). Receiver operating characteristic (ROC) curves and areas under ROC curves were used to compare the ODI3 and MOS as predictors of moderate-to-severe OSAS. The optimal cut-off value for each oximetry parameter was determined using Youden's index. Polysomnograms of 112 children (median [interquartile range] age 6.1 [3.9-9.1] years; 35.7% overweight) were analysed. Moderate-to-severe OSAS prevalence was 49.1%. The ODI3 and MOS were significant predictors of moderate-to-severe OSAS after adjustment for overweight, sex, and age (odds ratio [OR] 1.34, 95% confidence interval [CI] 1.19-1.51); and OR 4.10, 95% CI 2.06-8.15, respectively; p < 0.001 for both). Area under the ROC curve was higher for the ODI3 than for MOS (0.903 [95% CI 0.842-0.964] versus 0.745 [95% CI 0.668-0.821]; p < 0.001). Optimal cut-off values for the ODI3 and MOS were ≥4.3 episodes/h and ≥2, respectively. The ODI3 emerges as preferable or at least a complementary oximetry parameter to MOS for detecting moderate-to-severe OSAS in snoring children when polysomnography is not available.

Accuracy of the sleep clinical record for the diagnosis of pediatric moderate-to-severe obstructive sleep apnea syndrome

PURPOSE

The sleep clinical record (SCR) has been used to diagnose obstructive sleep apnea syndrome (OSAS) in children when access to polysomnography (PSG) is limited. Our aim was to determine the best SCR score that could facilitate diagnosis of moderate-to-severe OSAS in children with snoring.

METHODS

Healthy children with history of snoring, who were referred for PSG, were prospectively recruited. The SCR score was calculated. Receiver operating characteristic curves (ROCs) were plotted to determine the area under curve (AUC), and the optimum SCR cutoff value was determined using the Youden index (J).

RESULTS

Two hundred and seventy-three children were recruited (mean age 6.3 ± 2.5 years; median obstructive apnea-hypopnea index 1.5 episodes/h; range 0-61.1). The mean SCR score was 6.9 ± 3.6. Forty-six children had moderate-to-severe OSAS. Subjects with moderate-to-severe OSAS had a significantly higher mean SCR score (10.2 ± 2.9) than those with mild OSAS (6.2 ± 3.3; P < 0.001). Based on the plotted ROC, the AUC was 0.811 (95% confidence interval: 0.747-0.876; P < 0.001). Calculation of J, based on its ROC coordinates, indicated that the optimum cutoff SCR score to predict moderate-to-severe OSAS was 8.25, corresponding to a sensitivity of 83% and a specificity of 70%.

CONCLUSION

Among children with history of snoring, an SCR score above 8.25 can identify those with moderate-to-severe OSAS.

Systemic corticosteroids could be used as bridge treatment in children with obstructive sleep apnea syndrome waiting for surgery

PURPOSE

Local and systemic inflammatory markers and pro-inflammatory cytokines are increased in children with obstructive sleep apnea syndrome (OSAS). Therefore, systemic or topical anti-inflammatory agents are used to treat this syndrome. We evaluated the treatment with systemic corticosteroids in children with severe OSAS and adenotonsillar hypertrophy before surgery.

METHODS

This was an unblinded open label study. Children with severe OSAS (diagnosed through polysomnography, obstructive apnea-hypopnea index [AHI] > 10 eV/h) were recruited. Exclusion criteria included age < 3 years, history of acute or chronic cardiorespiratory or neuromuscular or metabolic disease; major craniofacial abnormalities; and chromosomal syndromes and epilepsy. Computer-generated random numbers were used for simple randomization of subjects. All children were treated with intranasal beclomethasone spray, and 15 children additionally received oral betamethasone and 0.1 mg/kg per day for 7 days. Sleep clinical record (SCR) and pulsoximetry were performed before and after 7 days in all children.

RESULTS

Among 28 children with severe OSAS mean age was 4.5 ± 1.8 years, AHI 20.4 ± 1.8 eV/h). In children treated with intranasal and oral corticosteroids, mean (95.3 ± 1.1 vs 97.0 ± 0.8%, p = 0.0001) and minimum oxygen saturation (78.8 ± 6.3 vs 89.2 ± 4.2, p = 0.001) improved, and the SCR score (12.6 ± 1.2 vs 8.3 ± 1.1, p = 0.0001) was reduced. Children treated only with intranasal beclomethasone spray showed no differences in outcome measures before and after treatments. When we considered the oximetry measures, after corticosteroid treatment, we obtained statistical differences between the 2 groups (p < 0.01).

CONCLUSIONS

These results seem to suggest that a short course of oral betamethasone could be useful to treat children with severe OSAS and adenotonsillar hypertrophy waiting for surgery.

Screening Severe Obstructive Sleep Apnea in Children with Snoring

Efficient screening for severe obstructive sleep apnea (OSA) is important for children with snoring before time-consuming standard polysomnography. This retrospective cross-sectional study aimed to compare clinical variables, home snoring sound analysis, and home sleep pulse oximetry on their predictive performance in screening severe OSA among children who habitually snored. Study 1 included 9 (23%) girls and 30 (77%) boys (median age of 9 years). Using univariate logistic regression models, 3% oxygen desaturation index (ODI3) ≥ 6.0 events/h, adenoidal-nasopharyngeal ratio (ANR) ≥ 0.78, tonsil size = 4, and snoring sound energy of 801–1000 Hz ≥ 22.0 dB significantly predicted severe OSA in descending order of odds ratio. Multivariate analysis showed that ODI3 ≥ 6.0 events/h independently predicted severe pediatric OSA. Among several predictive models, the combination of ODI3, tonsil size, and ANR more optimally screened for severe OSA with a sensitivity of 91% and a specificity of 94%. In Study 2 (27 (27%) girls and 73 (73%) boys; median age, 7 years), this model was externally validated to predict severe OSA with an accuracy of 76%. Our results suggested that home sleep pulse oximetry, combined with ANR, can screen for severe OSA more optimally than ANR and tonsil size among children with snoring.

Measures of nocturnal oxyhemoglobin desaturation in children with neuromuscular disease or Prader-Willi syndrome

OBJECTIVES

Evidence for nocturnal oximetry interpretation in patients with abnormal neuromuscular function is limited. We aimed to compare children with neuromuscular disease (NMD) or Prader-Willi syndrome (PWS) to otherwise healthy subjects with obstructive sleep-disordered breathing (SDB) or without respiratory disorder (controls) regarding nocturnal oximetry parameters.

METHODS

We analyzed recordings from children with: (a) NMD; (b) PWS; (c) snoring and adenotonsillar hypertrophy and/or obesity (SDB); and (d) controls. Outcomes included: (a) basal SpO₂ ; (b) proportions of subjects with McGill oximetry score (MOS) >1 (clusters of desaturations); and (c) desaturation index (SpO₂ drops ≥3%/h-ODI3).

RESULTS

Data of 12 subjects with NMD (median age, 5.2 years; IQR, 2.7, 8.2), 14 children with PWS (5 years; 2.3, 6.9), 21 children with SDB (5.8 years; 4.6, 9.6), and 20 controls (6.2 years; 5.4, 11.2) were analyzed. Children with NMD, PWS, and SDB had lower basal SpO₂ than controls (95.6% [94.5%, 96.9%], 96.2% [95.1%, 97.4%], 96.1% [95.8%, 97.5%] vs 97.8% [97.2%, 97.9%], respectively; (P < .01). NMD and PWS showed the greatest negative effect on basal SpO₂ (P < .05). Children with SDB or PWS had a higher risk of MOS >1 than patients with NMD (OR, 25.9 [95% CI, 3.4-200.4] and 9.5 [1.5-62.6]). NMD, PWS, and SDB were similar regarding ODI3, which was elevated compared to ODI3 in controls (P < .05). Frequent desaturations predominated in NMD, while periods of sustained desaturation were noted in NMD and PWS.

CONCLUSION

PWS and NMD have a negative effect on basal SpO₂ , while clusters of desaturations are prevalent in patients with PWS or obstructive SDB.

Pediatric pulmonology year in review 2019: Sleep medicine

Pediatric Pulmonology publishes original research, review articles as well as case reports on a wide variety of pediatric respiratory disorders. In this article, we summarize the past year's publications in sleep medicine and we review selected literature from other journals within this field. Articles highlighted are topics on risk factors of sleep-disordered breathing, diagnosis, and treatment of obstructive sleep apnea as well as the utility of polysomnography in various complex conditions.

Preoperative identification of children at high risk of obstructive sleep apnea

Obstructive sleep apnea is a common childhood disorder which can lead to serious health problems if left untreated. Enlarged adenoid and tonsils are the commonest causes, and adenotonsillectomy is the recommended first line of treatment. Obstructive sleep apnea poses as an anesthetic challenge, and it is a well-known risk factor for perioperative adverse events. The presence and severity of an obstructive sleep apnea diagnosis will influence anesthesia, pain management, and level of monitoring in recovery period. Preoperative obstructive sleep apnea assessment is necessary, and anesthetists are ideally placed to do so. Currently, there is no standardized approach to the best method of preoperative screening for obstructive sleep apnea. Focused history, clinical assessments, and knowledge regarding the strengths and limitations of available obstructive sleep apnea assessment tools will help recognize a child with obstructive sleep apnea in the preoperative setting.

Assessing the need for adenotonsillectomy for sleep-disordered breathing in a community setting: A secondary outcome measures analysis of a randomized controlled study

OBJECTIVE

To assess whether children with sleep-disordered breathing (SDB) symptom severity above a certain level, measured by a validated questionnaire, improve after adenotonsillectomy (AT) compared to no intervention.

METHODS

Children with snoring and tonsillar hypertrophy (4 to 10-years old), who were candidates for AT, were randomly assigned to two evaluation sequences (baseline and 3-month follow-up): (a) evaluation immediately before AT and at 3 months postoperatively (AT group); or (b) evaluation at the initial visit and at the end of the usual 3-month waiting period for surgery (control group). Outcomes were (a) Pediatric Sleep Questionnaire sleep-related breathing disorder scale (PSQ-SRBD); (b) modified Epworth Sleepiness Scale (mESS); and (c) proportion of subjects achieving PSQ-SRBD <0.33 (low-risk for apnea-hypopnea index ≥5/h) if they had score ≥0.33 at baseline.

RESULTS

Sixty-eight children were assigned to the AT and 72 to the control group and two-thirds of them had PSQ-SRBD ≥0.33. The AT group experienced significantly larger improvement between follow-up and baseline than controls (between-group difference [95% CI] for PSQ-SRBD: -0.31 [-0.35 to -0.27]; and mESS: -2.76 [-3.63 to -1.90]; P < .001 for both). Children with baseline PSQ-SRBD ≥0.33 in the AT group had an eight-times higher probability of achieving PSQ-SRBD <0.33 at follow-up than controls with similar baseline score (risk ratio [95% CI]: 8.33 [3.92-17.54]; P < .001).

CONCLUSION

Among children with snoring, tonsillar hypertrophy, and clinical indications for AT, those with preoperative PSQ-SRBD score ≥0.33 show measurable clinical benefit postoperatively.

Pediatric pulmonology year in review 2018: Sleep medicine

Pediatric Pulmonology publishes original research, case reports, and review articles on topics related to a wide range of children's respiratory disorders. In this article (Part 4 of a five-part series), we summarize the past year's publications in sleep medicine, in the context of selected literature in this area from other journals. Articles are highlighted on topics including infant sleep, diagnosis, and treatment of obstructive sleep apnea, and sleep disorders in chronic disease.

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.

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.