Severity assessment of obstructive sleep apnea syndrome (OSAS) in pediatric patients

Effect of positive end-expiratory pressure ventilation on plasma nitric oxide, endothelin-1 and vascular celladhesion molecule-1 levels in patients undergoing uvulopalatopharyngoplasty

BACKGROUND

During uvulopalatopharyngoplasty (UPPP), cardiovascular adverse events may occur which can be harmful to patients.

OBJECTIVE

To evaluate the effect of the protective ventilation strategy on the function of vascular endothelial cells.

METHODS

Forty obstructive apnea syndrome (OSA) patients who underwent uvulopalatopharyngoplasty (UPPP) were enrolled. Patients were randomly divided into the control group (group C, PEEP = 0 cm H2O) and PEEP group (group P, PEEP = 5 cm H2O). Each group (n= 20) received intermittent volume controlled ventilation (VCV) with tidal volume 6 ml/kg of the predicted body weight, I:E 1:2, rate titrated for ETCO2 35-45, FiO2 0.7. Blood from the radial artery was sampled for blood gas analysis at four time points: the fifth minute of inhaling pure oxygen (T0), after tracheal intubation (T1), at the end of the operation (T2), and 20 minutes after extubation (T3). Three ml of arterial blood was retained, preserved at -20∘C after serum isolation, and plasma nitric oxide (NO), endothelin-1 (ET-1) and vascular celladhesion molecule-1 (VCAM-1) levels were determined by enzyme linked immunosorbent assay (ELISA).

RESULTS

Compared with group C, plasma ET-1 at T3 decreased in group P, and plasma NO levels at T2 and T3 increased (P< 0.05). Compared with samples collected at T0, plasma VCAM-1 levels at T1, T2 and T3 increased in group C, while plasma VCAM-1 levels at T2 and T3 decreased in group P (P< 0.05). Compared with group C, plasma VCAM-1 levels T2 and T3 decreased in group P (P< 0.05).

CONCLUSIONS

Positive end-expiratory pressure (PEEP) ventilation has a protective effect on vascular endothelial cell function in patients during UPPP.

Electrocardiographic variables in children with syndromic craniosynostosis and primary snoring to mild obstructive sleep apnea: significance of identifying respiratory arrhythmia during sleep

BACKGROUND

In the spectrum of children with symptomatic sleep disordered breathing (SDB), some individuals - such as those with upper airway resistance syndrome (UARS) - do not have abnormalities on polysomnography (PSG). In this study we have assessed whether assessment of respiratory arrhythmia (RA) and heart rate variability (HRV) analysis helps in management of children with syndromic craniosynostosis and none-to-mild obstructive sleep apnea (OSA).

METHODS

Prospective cohort study in children aged 1-18 years old with syndromic craniosynostosis. Children were selected for HRV analysis from the ECG if their obstructive apnea-hypopnea index (oAHI) was between zero and five per hour (ie, oAHI ≤5/hour). Subjects were divided into groups based on the presence or absence of respiratory arrhythmia (with or without RA respectively) using the electrocardiogram (ECG). The main analysis included studying the relationship between RA and HRV, symptoms, interventions, and sleep architecture.

RESULTS

We identified 42 patients with, at worst, mild OSA. We found higher parasympathetic control and higher total power in children with RA during the non-rapid eye movement (non-REM) sleep. Children with RA also have a relatively higher percentage of paradoxical breathing during non-REM sleep (P = 0.042). Intracranial hypertension was distributed equally between groups. Last, RA patients showed increased parasympathetic activity that further increased in non-REM sleep.

CONCLUSION

In syndromic craniosynostosis cases with SDB and PSG showing oAHI ≤5/hour, the presence of RA may indicate subsequent need for treatment interventions, and a trend toward higher occurrence of clinical symptoms. ECG analyses of HRV variables in subjects with RA demonstrate increased parasympathetic activity and total power. Such findings may add to the diagnosis of apparently asymptomatic children.

Obstructive sleep apnoea in craniofacial microsomia: analysis of 755 patients

A retrospective cohort study was set up to analyse the prevalence and treatment of obstructive sleep apnoea (OSA) in relation to the severity of the deformity in patients with craniofacial microsomia (CFM). This study included a population of 755 patients with CFM from three craniofacial centres. Medical charts were reviewed for severity of the deformity, types of breathing difficulty, age at which breathing difficulty first presented, treatment for OSA, and treatment outcome. In total, 133 patients (17.6%) were diagnosed with OSA. Patients with Pruzansky IIB/III classification or bilateral craniofacial microsomia were significantly more often diagnosed with OSA than unilaterally affected patients of Pruzansky I/IIA classification. The initial treatment of OSA consisted of adenotonsillectomy, tracheotomy, or non-invasive positive pressure ventilation. Thirty-seven patients received more than one treatment (range 1-3). In this study, the prevalence of OSA in patients with CFM was higher than the prevalence in the healthy population described in the literature. Although several treatment modalities are available for the treatment of OSA in patients with CFM, treatment should be individualized and based on clinical symptoms, the severity of the deformity, and comorbidities.

Sleep Architecture Linked to Airway Obstruction and Intracranial Hypertension in Children with Syndromic Craniosynostosis

BACKGROUND

Children with syndromic craniosynostosis often have obstructive sleep apnea and intracranial hypertension. The authors aimed to evaluate (1) sleep architecture, and determine whether this is influenced by the presence of obstructive sleep apnea and/or intracranial hypertension; and (2) the effect of treatment on sleep architecture.

METHODS

This study included patients with syndromic craniosynostosis treated at a national referral center, undergoing screening for obstructive sleep apnea and intracranial hypertension. Obstructive sleep apnea was identified by polysomnography, and categorized into no, mild, moderate, or severe. Intracranial hypertension was identified by the presence of papilledema on funduscopy, supplemented by optical coherence tomography and/or intracranial pressure monitoring. Regarding sleep architecture, sleep was divided into rapid eye movement or non-rapid eye movement sleep; respiratory effort-related arousals and sleep efficiency were scored.

RESULTS

The authors included 39 patients (median age, 5.9 years): 19 with neither obstructive sleep apnea nor intracranial hypertension, 11 with obstructive sleep apnea (four moderate/severe), six with intracranial hypertension, and three with obstructive sleep apnea and intracranial hypertension. Patients with syndromic craniosynostosis, independent of the presence of mild obstructive sleep apnea and/or intracranial hypertension, have normal sleep architecture compared with age-matched controls. Patients with moderate/severe obstructive sleep apnea have a higher respiratory effort-related arousal index (p < 0.01), lower sleep efficiency (p = 0.01), and less rapid eye movement sleep (p = 0.04). An improvement in sleep architecture was observed following monobloc surgery (n = 5; rapid eye movement sleep, 5.3 percent; p = 0.04).

CONCLUSIONS

Children with syndromic craniosynostosis have in principle normal sleep architecture. However, moderate/severe obstructive sleep apnea does lead to disturbed sleep architecture, which fits within a framework of a unifying theory for obstructive sleep apnea, intracranial hypertension, and sleep.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Upper airway endoscopy to optimize obstructive sleep apnea treatment in Apert and Crouzon syndromes

INTRODUCTION

Obstructive sleep apnea (OSA) is highly prevalent in children with Apert and Crouzon syndromes. Although often related to midface hypoplasia, it is a multi-level problem for which routine midface advancement might be a suboptimal treatment choice. We therefore wished to: 1.) use upper airway endoscopy to examine the level of obstruction in children with OSA; 2.) determine the relationship between endoscopic assessment and OSA severity; and 3.) evaluate the effect of surgery on endoscopic assessment and OSA severity.

METHODS

Prospective observational cohort study of patients considered for midface advancement, underwent upper airway endoscopy. Endoscopy findings were scored according to the system of Bachar, based on level (nose, uvulopalatine plane, tongue base, hypopharynx and larynx); and severity (no, partial or complete obstruction). Polysomnography was used to diagnose OSA.

RESULTS

We included 22 children (Apert N = 10, Crouzon N = 12), 17 had OSA, 14 of whom had multilevel obstruction and 3 single-level obstruction. The endoscopy findings were correlated with OSA severity: R = 0.56, P = 0.01. Midface advancement (N = 8) reduced Bachar's severity index in 7 of 8 patients, and OSA in all patients.

CONCLUSIONS

OSA in children with Apert or Crouzon syndrome is often a multi-level problem. Upper airway endoscopy is essential to optimizing OSA treatment.

Is there an effect of obstructive sleep apnea syndrome on oxidative stress and inflammatory parameters in patients with craniofacial anomalies?

The aim of this study was to test the hypothesis that obstructive sleep apnea syndrome (OSAS) exhibits oxidative stress and inflammation in patients who have a congenital, craniofacial anomaly.This prospective, cross-sectional cohort study included ambulant sleep study data to asses OSAS in patients with syndromic craniosynostosis and Treacher Collins syndrome. Laboratory analyses were performed including malondialdehyde, tumor necrosis factor α (TNF-α), interleukin 6, and high-sensitivity C-reactive protein.Forty-eight patients were included; 11 were adults; 37 were children. The patients' body mass indexes were normal, with a median (SD) of 0.7 (-1.82 to 2.48) in children and 20.5 (15.2-29.4) in adults. Obstructive sleep apnea syndrome was diagnosed in 23 of 48 patients. It was mild (median obstructive apnea-hypopnea index [oAHI], 2.3; oxygenation-desaturation index [ODI], 0.9) in 16 patients and moderate/severe in 7 patients (median oAHI, 10.8; ODI, 5.0). Neither oxidative stress nor inflammation had a correlation with the oAHI and ODI. Only TNF-α was found significantly higher in both the OSAS and non-OSAS groups compared with the reference values (median, 15.1 pg/mL and 12.3 pg/mL versus 4.05 [0.0-8.1 pg/mL], P < 0.001 and P < 0.001, respectively).Based on our findings we conclude that (mainly mild) OSAS, oxidative stress, as well as high-sensitivity C-reactive protein and interleukin 6 levels are not abnormal in the day time in a population of nonobese patients with a craniofacial anomaly. The increased level of TNF-α cannot be explained by OSAS. Future research should focus on mapping chronobiologic changes for further interpretation of the results.

Obstructive sleep apnea in young infants with Down syndrome evaluated in a Down syndrome specialty clinic

Children with Down syndrome (DS) experience congenital and functional medical issues that predispose them to obstructive sleep apnea (OSA). Research utilizing stringent age criteria among samples of infants with DS and OSA is limited. This study examines clinical correlates of OSA among infants with DS. A retrospective chart review was conducted of infants ≤6 months of age referred to a DS clinic at a tertiary children's hospital over five-years (n = 177). Chi-square tests and binary logistic regression models were utilized to analyze the data. Fifty-nine infants underwent polysomnography, based on clinical concerns. Of these, 95% (56/59) had studies consistent with OSA. Among infants with OSA, 71% were identified as having severe OSA (40/56). The minimum overall prevalence of OSA among the larger group of infants was 31% (56/177). Significant relationships were found between OSA and dysphagia, congenital heart disease (CHD), prematurity, gastroesophageal reflux disease (GERD), and other functional and anatomic gastrointestinal (GI) conditions. Results indicate that odds of OSA in this group are higher among infants with GI conditions in comparison to those without. Co-occurring dysphagia and CHD predicted the occurrence of OSA in 36% of cases with an overall predictive accuracy rate of 71%. Obstructive sleep apnea is relatively common in young infants with DS and often severe. Medical factors including GI conditions, dysphagia and CHD may help to identify infants who are at greater risk and may warrant evaluation. Further studies are needed to assess the impact of OSA in infants with DS.

Usefulness of cerebral NIRS in detecting the effects of pediatric sleep apnea

BACKGROUND

Children with sleep apnea have increased morbidity if the sleep apnea is untreated. Polysomnography (PSG) is used to detect sleep apnea, but in children, there are technical difficulties that make the diagnosis more difficult. Cerebral near infrared spectroscopy (NIRS) has the ability to detect tissue hypoxia by measuring regional oxygen saturation (rSO2 ). We hypothesized that when used as an adjunct to PSG testing, cerebral NIRS would better detect the effects of sleep apnea in children than arterial pulse oximetry (SpO2 ). Specifically, we aimed to show that the apnea/hypopnea index (AHI) calculated with rSO2 from the NIRS would be greater than that calculated with SpO2 .

METHODS

Forty-seven patients under 18 years of age who underwent PSG testing for sleep apnea were evaluated. Cerebral NIRS was utilized in addition to PSG. The AHI was calculated using SpO2 and compared to the AHI calculated using the rSO2 . A pediatric pulmonologist who was unaware of the NIRS data evaluated each patient for sleep apnea. Data are median (interquartile range).

RESULTS

The median AHI(rSO2 ) was 2.4(1.2,5.1), significantly greater (P < 0.0001) than the AHI(SpO2 ) of 0.7(0.4,1.2). Four patients were diagnosed with sleep apnea; however, only one had an AHI(SpO2 ) ≥ 5, a typical threshold for the diagnosis of sleep apnea. All 4 subjects had an AHI(rSO2 ) ≥ 5 but 10 patients without sleep apnea had a value ≥5. The sensitivity and specificity for using the AHI(rSO2 ) to diagnose sleep apnea was 100% and 76.7%, respectively.

CONCLUSION

Consistent with the ability of NIRS to detect tissue hypoxia, we found that the AHI calculated with rSO2 was greater than that using SpO2 . We conclude that NIRS has potential as a valuable adjunct to PSG in evaluating patients for sleep apnea and warrants further investigation for this purpose.

How does obstructive sleep apnoea evolve in syndromic craniosynostosis? A prospective cohort study

OBJECTIVE

To describe the course of obstructive sleep apnoea syndrome (OSAS) in children with syndromic craniosynostosis.

DESIGN

Prospective cohort study.

SETTING

Dutch Craniofacial Centre from January 2007 to January 2012.

PATIENTS

A total of 97 children with syndromic craniosynostosis underwent level III sleep study. Patients generally undergo cranial vault remodelling during their first year of life, but OSAS treatment only on indication.

MAIN OUTCOME MEASURES

Obstructive apnoea-hypopnoea index, the central apnoea index and haemoglobin oxygenation-desaturation index derived from consecutive sleep studies.

RESULTS

The overall prevalence of OSAS in syndromic craniosynostosis was 68% as defined by level III sleep study. Twenty-three patients were treated for OSAS. Longitudinal profiles were computed for 80 untreated patients using 241 sleep studies. A mixed effects model showed higher values for the patients with midface hypoplasia as compared to those without midface hypoplasia (Omnibus likelihood ratio test=7.9). In paired measurements, the obstructive apnoea-hypopnoea index (Z=-3.4) significantly decreased over time, especially in the first years of life (Z=-3.3), but not in patients with midface hypoplasia (Z=-1.5). No patient developed severe OSAS during follow-up if it was not yet diagnosed during the first sleep study.

CONCLUSIONS

OSAS is highly prevalent in syndromic craniosynostosis. There is some natural improvement, mainly during the first 3 years of life and least in children with Apert or Crouzon/Pfeiffer syndrome. In the absence of other co-morbid risk factors, it is highly unlikely that if severe OSAS is not present early in life it will develop during childhood. Ongoing clinical surveillance is of great importance and continuous monitoring for the development of other co-morbid risk factors for OSAS should be warranted.

Pediatric obstructive sleep apnea assessment using pulse oximetry and dual RIP bands

The diagnosis of Obstructive Sleep Apnea (OSA) in children presents a challenging diagnostic problem given the high prevalence (2-3%), the resource intensity of the overnight polysomnography investigation, and the realisation that OSA poses a serious threat to the healthy growth and development of children. Previous attempts to develop OSA diagnostic systems using home pulse oximetry studies have failed to meet the accuracy requirements - particularly the low false normal rate (FNR) - required for a pre-PSG screening test. Thus the aim of this study is to investigate the feasibility of an OSA severity diagnostic system based on both oximetry and dual respiratory inductance plethysmography (RIP) bands. A total of 90 PSG studies (30 each of normal, mild/moderate and severe OSA) were retrospectively analyzed. Quantifications of oxygen desaturations (S), respiratory events (E) and heart rate arousals (A) were calculated and extracted and an empirical rule-based SEA classifier model for normal, mild/moderate and severe OSA defined and developed. In addition, an automated classifier using a decision tree algorithm was trained and tested using a 10-fold cross-validation. The empirical classification system showed a correct classification rate (CCR) of 0.83 (Cohen's Kappa κ=0.81, FNR=0.08), and the decision tree classifier achieved a CCR of 0.79 (κ=0.73, FNR=0.08) when compared to gold standard PSG assessment. The relatively high CCR, and low FNR indicate that a OSA severity system based on dual RIP and oximetry is feasible for application as a pre-PSG screening tool.