Enhanced interleukin-8 production in mononuclear cells in severe pediatric obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea (OSA) is a risk factor for cardiovascular disease, metabolic disorders, and cognitive dysfunction. Current thinking links chronic intermittent hypoxia (CIH) with oxidative stress and systemic inflammation. However, the sequence of events leading to the morbidities associated with OSA is poorly understood in children. Monocytes are known to be altered by chronic hypoxia. Thus in this prospective study, we investigated inflammatory cytokine profiles from cultures of peripheral blood mononuclear cells (PBMC) obtained from children with severe OSA and sleep-related CIH. METHODS: Ten children with OSA (cases) and 5 age-matched children without OSA (controls) were recruited for study. Samples of plasma and PBMC were obtained before and after adenotonsillectomy. The levels of the inflammatory cytokines, interleukin (IL)-1ß, IL-6, IL-8, IL-10, IL-12p70, and tumor necrosis factor-α (TNFα), were measured in both plasma and ex vivo culture supernatants of PBMC incubated with lipopolysaccharide (LPS) using the cytometric bead assay. RESULTS: Upon activation of PBMC by LPS, the levels of IL-8 in the culture supernatants from cases were threefold higher than in controls. The levels of the other cytokines including IL-1ß, IL-6, and TNFα, in culture supernatant of PBMC from cases showed no difference from controls; nor were there significant differences in plasma cytokine levels. CONCLUSION: We speculate that in young children with sleep-related CIH, an enhanced production capacity of IL-8 precedes the development of systemic inflammatory markers. Future work should evaluate IL-8 production capacity as a potential biomarker for OSA severity.

Training, knowledge, attitudes and practices of Canadian health care providers regarding sleep and sleep disorders in children.

BACKGROUND: Sleep disorders are prevalent in children and are associated with significant comorbidity. OBJECTIVE: To assess the training, knowledge, attitudes and practices of Canadian health care providers (HCPs) regarding sleep disorders in children. METHOD: A 42-item survey, designed to collect information on frequency of paediatric sleep disorders-related screening and diagnosis, implementation of evidence-based interventions and related knowledge base, was completed by HCPs. RESULTS: Ninety-seven HCPs completed the survey. One per cent obtained training in paediatric sleep during undergraduate training and 3% obtained such training during their residencies, yet 34.9% estimated that 25 to 50% of their patients suffered from sleep disorders. Most HCPs thought that sleep disorders significantly impacted children's health and daytime function. Most HCPs screened for developmental sleep issues, but not consistently for sleep disorders. Most recommended evidence-based behavioural interventions for behavioural sleep disorders, but some also reported behavioural interventions that were not first-line or recommended. Inadequate knowledge regarding melatonin use was evident. Most participants reported rarely/never ordering a sleep study for a child with suspected obstructive sleep apnea (OSA). Most were familiar with surgical and weight loss management options for OSA; many were unfamiliar with benefits of continuous positive airway pressure. Participants' knowledge scores were highest on developmental and behavioural aspects of sleep, and lowest on sleep disorders. CONCLUSIONS: HCPs exhibit significant gaps in their knowledge, screening, evaluation and treatment practices for paediatric sleep disorders. Training at the undergraduate, graduate and postgraduate levels, as well as Continuing Medical Education are needed to optimize recognition, treatment and follow-up of paediatric sleep disorders.

Testing for pediatric obstructive sleep apnea when health care resources are rationed.

IMPORTANCE: Evaluation of pediatric obstructive sleep apnea in resource-limited health care systems necessitates testing modalities that are accurate and more cost-effective than polysomnography. OBJECTIVE: To trace the clinical pathway of children referred to our sleep laboratory for possible obstructive sleep apnea who were evaluated using nocturnal pulse oximetry and the McGill Oximetry Score. DESIGN, SETTING, AND PARTICIPANTS: This was a retrospective cohort study of children 2 to 17 years old with suspected obstructive sleep apnea due to adenotonsillar hypertrophy, conducted at a Canadian pediatric tertiary care center. INTERVENTIONS: Nocturnal pulse oximetry studies scored using the McGill Oximetry Score. MAIN OUTCOMES AND MEASURES: For children who underwent adenotonsillectomy we determined the length of time from oximetry to surgery, postoperative length of stay, postoperative readmissions, and emergency department visits in the month following surgery and major surgical complications. We analyzed these outcomes by oximetry result. We compared the cost savings of our diagnostic approach with those of other diagnostic models. RESULTS: Among 362 children, the median age was 4.8 years (interquartile range, 3.3-6.7), and 61% were male. Two-hundred-sixty-six (73%) and 96 (27%), respectively, had inconclusive and abnormal oximetry results. Eighty of 96 of children with abnormal oximetry results (83%) and 81 of 266 children with inconclusive oximetry results (30%) underwent adenotonsillectomy. Thirty-three of 266 children (12%) underwent further evaluation with polysomnography; of 14 diagnosed as having OSA, 12 underwent adenotonsillectomy. Children with abnormal oximetry results were operated on soonest after testing and triaged based on oximetry results. No child with an inconclusive oximetry result required hospitalization for more than 1 night postoperatively; 14% of children (11 of 80) with an abnormal oximetry result required hospitalization for 2 or 3 nights (χ2 = 12.0; P = .001). Rates of readmissions and emergency department visits were low, irrespective of oximetry results (whether inconclusive or abnormal). We show that our oximetry-based diagnostic approach results in considerable cost savings compared with a polysomnography-for-all approach. CONCLUSIONS AND RELEVANCE: Oximetry studies evaluated with the McGill Oximetry Score expedite diagnosis and treatment of children with adenotonsillar hypertrophy referred for suspected sleep-disordered breathing. When resources for testing for sleep-disordered breathing are rationed or severely limited, our proposed diagnostic approach can help maximize cost-savings and allows sleep laboratories to focus resources on medically complex children requiring polysomnographic evaluation of suspected sleep disorders.

Night-to-night consistency of at-home nocturnal pulse oximetry testing for obstructive sleep apnea in children.

RATIONALE: At-home nocturnal pulse oximetry has a high positive predictive value (PPV) for polysomnographically-diagnosed obstructive sleep apnea (OSA) but no studies have been published testing the night-to-night consistency of at-home nocturnal pulse oximetry for the evaluation of suspected OSA in children. We therefore determined the night-to-night consistency of nocturnal pulse oximetry as a diagnostic test for OSA in children. METHODS: We prospectively studied 148 children (96 male) aged 4.9 ± 2.4 (1.2-11.8) years, referred for suspected OSA. To evaluate night-to-night consistency, we compared an oximetry analysis method, the McGill Oximetry Score (MOS), from two consecutive at-home nocturnal pulse oximetry recordings. RESULTS: Pulse oximetry metrics were similar on the two nights. The MOS on the two nights showed excellent night-to-night consistency when analyzed as positive for OSA versus inconclusive, 143/148 (Spearman's correlation coefficient = 0.90). A more detailed analysis using four categories (MOS 1, 2, 3, and 4) of OSA severity showed very good night-to-night agreement, 133/148 (Spearman's correlation coefficient = 0.91). Variability was increased in children younger than 4 years of age compared to older children. CONCLUSIONS: Night-to-night consistency of nocturnal pulse oximetry as a diagnostic test for OSA showed excellent agreement. Night-to-night consistency of pulse oximetry, as analyzed by the MOS, for diagnosis and severity evaluation further validates this abbreviated testing method for pediatric OSA. Polysomnography (PSG) is required to rule in or rule out OSA in children if a single night oximetry testing is inconclusive.

Sleep in children with cerebral palsy: a review.

Children with neurodevelopmental disabilities, such as cerebral palsy, are considered to be a population at risk for the occurrence of sleep problems. Moreover, recent studies on children with cerebral palsy seem to indicate that this population is at higher risk for sleep disorders. The importance of the recognition and treatment of sleep problems in children with cerebral palsy cannot be overemphasized. It is well known that the consequences of sleep disorders in children are broad and affect both the child and family. This review article explores the types and possible risk factors associated with the development of sleep problems in children with cerebral palsy and the impact of this disorder on the child and family. In addition, a brief summary of current diagnostic and treatment modalities is provided. Finally, the characteristics, diagnostic techniques, and management of sleep-related breathing disorders in children with cerebral palsy are discussed.

Childhood sleep apnea and neighborhood disadvantage.

OBJECTIVE: To determine whether neighborhood characteristics or socioeconomic status are risk factors for obstructive sleep apnea (OSA) in young children. STUDY DESIGN: In this observational study, we compared residential census tract metrics in Montreal, Canada for 436 children aged 2-8 years who were evaluated for OSA, hypothesizing that the children with proven OSA (OSA group; n = 300) would come from more disadvantaged neighborhoods compared with those children without OSA (no OSA group; n = 136). Children who had undergone previous adenotonsillectomy and those with comorbid disorders were excluded from the analysis. RESULTS: Compared with the no OSA group, the OSA group lived in census tracts with lower median family incomes, higher proportions of children living below the Canadian low-income cutoff (indicating poverty), higher proportions of single-parent families, and greater population densities. The highest probability of having OSA was seen in children referred from the most disadvantaged census tracts and was due primarily to moderate/severe OSA. Group differences remained significant when adjusted for age, race/ethnicity, and obesity. CONCLUSIONS: Compared with the children without OSA, those with OSA were more likely to reside in disadvantaged neighborhoods. Future studies should examine whether these results can be replicated in other settings, especially those with large socioeconomic disparities.

An anesthetic management protocol to decrease respiratory complications after adenotonsillectomy in children with severe sleep apnea.

BACKGROUND: A high incidence of respiratory morbidity after adenotonsillectomy is reported in children with obstructive sleep apnea syndrome (OSAS). In an effort to decrease this morbidity, we implemented perioperative guidelines recommending an adjustment in the administration of opioids, dexamethasone, and atropine in children with OSAS who demonstrated recurrent episodes of profound hypoxemia during the perioperative sleep study. METHODS: We performed a retrospective review and compared results with historic data from 2001. The primary outcome variable was a major respiratory medical intervention (MMI(Respiratory)). The severity of OSAS was classified with the McGill Oximetry Scoring (MOS) system, and our focus was on those children demonstrating repetitive desaturation <80% (MOS4). RESULTS: The medical records of 292 children who underwent adenotonsillectomy between October 2002 and February 2006 met the inclusion criteria and 97 had been assigned MOS4. Eleven children (11.3%) required an MMI(Respiratory). In 2001, 8 children (29.6%), assigned MOS4, required an MMI(Respiratory). Comparing the new and old guidelines, the adjusted odds ratio for MMI(Respiratory) in MOS4 was 0.30 (95% CI: 0.10-0.85). The key elements achieving this reduction in MMI(Respiratory) were dexamethasone administration and a reduced opioid dosage. In 2002 to 2006, the intraoperative opioid dose, expressed in morphine equivalents, administered to the MOS4 group was 0.10 mg . kg(-1) (0.06-0.12 mg . kg(-1)), and the postoperative morphine dose was 0.02 mg . kg(-1) (0-0.07 mg . kg(-1)). Both doses were lower than the ones administered to the concurrent comparison group, P values <0.001. CONCLUSIONS: A change in practice that included a dexamethasone administration and a reduction in opioid administration to children with profound recurrent hypoxia reduced the incidence of MMI(Respiratory) by >50%.

Can the OSA-18 quality-of-life questionnaire detect obstructive sleep apnea in children?

BACKGROUND: Polysomnography is the best tool available for diagnosing obstructive sleep apnea (OSA) in children. However, polysomnography is relatively inaccessible and costly, and studies are needed to evaluate other diagnostic approaches. It has been suggested that the OSA-18 quality-of-life questionnaire (OSA-18) is a useful measure that could replace polysomnography. The purpose of our study was to determine if the OSA-18, is an accurate measure for the detection of moderate-to-severe OSA. PATIENTS AND METHODS: Children who were referred to our sleep laboratory for evaluation of suspected OSA and who had a nocturnal pulse oximetry study were included in our cross-sectional study. The results of the oximetry study were interpreted by using the McGill oximetry score (MOS). Abnormal scores were consistent with moderate-to-severe OSA. We analyzed demographic and medical data in addition to the OSA-18 results. We estimated sensitivity and negative predictive values for the OSA-18 to detect an abnormal MOS. We also conducted logistic regression analyses with MOS as the dependent variable and the OSA-18 score, age, gender, comorbidities, and race as independent variables. RESULTS: We studied 334 children (mean age: 4.6 years; 58% male). The OSA-18 had a sensitivity of 40% and a negative predictive value of 73% for detecting an abnormal MOS. While controlling for other variables in the regression model, for each unit increase in the OSA-18 score, the odds of having an abnormal MOS were increased by 2%. For each 1-year increase in age, the odds of having an abnormal MOS were decreased by 17%. CONCLUSIONS: Among children who are referred to a sleep laboratory, the OSA-18 does not accurately detect which children will have an abnormal MOS and cannot be used to exclude moderate-to-severe OSA. The OSA-18 should not be used in the place of objective testing to identify moderate-to-severe OSA in children.

Pulse rate and pulse rate variability decrease after adenotonsillectomy for obstructive sleep apnea.

BACKGROUND: Data suggest that obstructive sleep apnea syndrome (OSA) results in sympathetic stimulation, brady/tachycardia and cardiac stress. Heart rate variability, but not baseline heart rate, is known to be elevated in pediatric OSA. Our patients with moderate to severe OSA (McGill Oximetry Scores of 3 or 4) have been re-evaluated with pulse oximetry after adenotonsillectomy (T&A). We hypothesized that pulse rate (PR) and pulse rate variability (PRV) would decrease after treatment of OSA with T&A. METHODS: This retrospective before-after study comprised pre- and post-operative oximetries and parental questionnaires of children 1-18 years old with moderate to severe OSA from September 2004 to August 2005, inclusive. We excluded patients with significant comorbidities. RESULTS: In 25 subjects, age at surgery was 4.3 +/- 3.6 years (mean +/- SD). OSA symptoms decreased or resolved, saturation metrics improved, and parental concern about breathing during sleep decreased following T&A. PR decreased in 21 of 25 patients after T&A (mean PR from 99.7 +/- 11.2 to 90.1 +/- 10.7 bpm, P < 0.001; maximum PR from 150.6 +/- 14.5 to 137.4 +/- 15.6 bpm, P < 0.001). PRV, as measured by the standard deviation of the PR, decreased in 23 of 25 patients after T&A (from 10.3 +/- 2.1 to 8.2 +/- 1.6 bpm, [P < 0.001]). Pulse accelerations greater than 6, 7, 8 bpm also decreased post-operatively. CONCLUSIONS: Nocturnal pulse oximetry complements clinical history to document improvement and/or resolution of moderate to severe OSA in children. Resolution of tachycardia and diminished PRV after T&A illustrate the stress that recurrent airway obstruction during sleep places on the cardiovascular system. Further work will be required to determine if PR and PRV as measured by pulse oximetry would be useful in the diagnosis and follow-up of OSA in children.

Respiratory-swallowing interactions during sleep in premature infants at term.

Non-nutritive swallowing occurs frequently during sleep in infants and is vital for fluid clearance and airway protection. Swallowing has also been shown to be associated with prolonged apnea in some clinical populations. What is not known is whether swallowing contributes to apnea or may instead help resolve these clinically significant events. We studied the temporal relationships between swallowing, respiratory pauses and arousal in six preterm infants at term using multi-channel polysomnography and a pharyngeal pressure transducer. Results revealed that swallows occurred more frequently during respiratory pauses and arousal than during control periods. They did not trigger the respiratory pause, however, as most swallows (66%) occurred after respiratory pause onset and were often tightly linked to arousal from sleep. Swallows not associated with respiratory pauses (other than the respiratory inhibition to accommodate swallowing) and arousal occurred consistently during the expiratory phase of the breathing cycle. Results suggest that swallowing and associated arousal serve an airway protective role during sleep and medically stable preterm infants exhibit the mature pattern of respiratory-swallowing coordination by the time they reach term.

Adenotonsillectomy improves sleep, breathing, and quality of life but not behavior.

OBJECTIVE: To obtain parental perspectives on changes in sleep, breathing, quality of life (QOL), and neurobehavioral measures after adenotonsillectomy. STUDY DESIGN: This retrospective cohort study comprised otherwise healthy children evaluated for obstructive sleep apnea syndrome (OSAS) from 1993 to 2001. We compared those children who underwent adenotonsillectomy with those children who did not. The parents of 473 children (292 boys) 2 years of age and older were sent questionnaires to evaluate QOL and clinical and behavioral changes. For 94 children 3 years of age and older, behavioral changes were evaluated using the Conners' Parent Rating Scale-Revised (CPRS-R) for three different periods: pre-operatively/pre-polysomnography, postoperatively/postpolysomnography, and recently. RESULTS: One hundred and sixty-six questionnaires were returned (35%), 138 of which were complete with written consent provided. Compared with parents of unoperated children, parents of children who had adenotonsillectomy were more likely to report improvements in sleep, breathing, and QOL but not improvements in concentration, school performance, and intellectual or developmental progress. Both short and long term, there were no significant effects of adenotonsillectomy on any of the CPRS-R behavior subscales. CONCLUSION: From a parental perspective, adenotonsillectomy frequently improves sleep, breathing, and QOL but does not often improve neurobehavioral outcomes.

Planning adenotonsillectomy in children with obstructive sleep apnea: the role of overnight oximetry.

OBJECTIVE: Obstructive sleep apnea (OSA) in children is usually effectively treated by adenotonsillectomy (T&A). However, there may be a waiting list for T&A, and the procedure is associated with an increased risk of postoperative complications in children with OSA. Needed is a simple test that will facilitate logical prioritization of the T&A surgical list and help to predict children who are at highest risk of postoperative complications. The objective of this study was to develop and validate a severity scoring system for overnight oximetry and to evaluate the score as a tool to prioritize the T&A surgical list. METHODS: This study comprised 3 phases. In phase 1, a severity score was developed by review of preoperative overnight oximetry in children who had urgent T&A in 1999-2000. In phase 2, the score was validated retrospectively in 155 children who had polysomnography (PSG) before T&A in 1992-1998. In a phase 3, a 12-month prospective evaluation of a protocol based on the score was conducted. RESULTS: In phase 1, a 4-level severity score was developed on the basis of the number and the depth of desaturation events (normal to severely abnormal, categories 1-4). In phase 2, the McGill oximetry score correlated with severity of OSA by PSG criteria. In phase 3, a clinical management protocol was developed based on the score. Of 230 children tested, 179 (78%) had a normal/inconclusive oximetry (category 1) and went on to have PSG. Those with a positive oximetry (categories 2-4; 22%) had no additional sleep studies before T&A. Timing of T&A was based on oximetry score, leading to a significant reduction in waiting time for surgery for those with higher oximetry scores. Postoperative respiratory complications were more common with increasing oximetry score. CONCLUSIONS: Overnight pulse oximetry can be used to estimate the severity of OSA, to shorten the diagnostic and treatment process for those with more severe disease, and to aid clinicians in prioritization of T&A and planning perioperative care.

Urgent adenotonsillectomy: an analysis of risk factors associated with postoperative respiratory morbidity.

BACKGROUND: The aim of this study was to determine the frequency and type of respiratory complications after urgent adenotonsillectomy (study group) for comparison with a control group of children undergoing a sleep study and adenotonsillectomy for obstructive sleep apnea syndrome. A second aim was to assess risk factors predictive of respiratory complications after urgent adenotonsillectomy. METHODS: The perioperative course of children who underwent adenotonsillectomy between January 1, 1999, and March 31, 2001, was reviewed. Two groups of children were identified from two different databases: the hospital database for surgical procedures (the study group) and the sleep laboratory database (the control group). The retrospective chart review focused on the preoperative status (including an evaluation for obstructive sleep apnea), anesthetic management, and need for postoperative respiratory interventions. RESULTS: A total of 64 consecutive cases for urgent adenotonsillectomy were identified, and 54 children met the inclusion criteria. Thirty-three children (60%) had postoperative respiratory complications necessitating a medical intervention; 11 (20.3%) required a major intervention (reintubation, ventilation, and/or administration of racemic epinephrine or Ventolin), and 22 (40.7%) required a minor intervention (oxygen administration). Six children (11.1%) required reintubation in the recovery room for respiratory compromise. Risk factors for respiratory complications were an associated medical condition (odds ratio, 8.15; 95% confidence interval, 1.81-36.73) and a preoperative saturation nadir less than 80% (odds ratio, 5.54; 95% confidence interval, 1.15-26.72). Sixteen (49%) of the medical interventions were required within the first postoperative hour. Atropine administration, at induction, decreased the risk of postoperative respiratory complications (odds ratio, 0.18; 95% confidence interval, 0.11-1.050. CONTROL GROUP: Of 75 children who underwent a sleep study and adenotonsillectomy, 44 had sleep apnea and were admitted to hospital after elective adenotonsillectomy. Sixteen (36.4%) children had postoperative respiratory complications necessitating a medical intervention. Six percent of the children (n = 3) required a major medical intervention. No child required reintubation for respiratory compromise. CONCLUSIONS: Severe obstructive sleep apnea syndrome and an associated medical condition are risk factors for postadenotonsillectomy respiratory complications. Risk reductions strategies should focus on their assessment.