Robert T. Brouillette

Can assessment for obstructive sleep apnea help predict postadenotonsillectomy respiratory complications

Background The aim of this study was to determine the frequency and type of respiratory complications after adenotonsillectomy in children. A second aim was to assess the ability of preoperative sleep studies to identify children at risk for respiratory complications. Methods Children referred for sleep studies between 1992 and 1998, who underwent adenotonsillectomy within 6 months of the preoperative study, were reviewed. The study focused on two variables: the obstructive apnea and hypopnea index and the oxygen saturation nadir. Medical charts were reviewed for postoperative respiratory complications. Results Three hundred forty-nine children were referred for sleep studies, and 163 met the inclusion criteria. Thirty-four children (21%) had postoperative respiratory complications requiring a medical intervention. Children experiencing respiratory complications were younger (aged < 2 yr; adjusted odds ratio, 4.3; 95% confidence interval, 1.7–11) and had an associated medical condition (odds ratio, 3; 95% confidence interval, 1.4–6.5). A preoperative obstructive apnea and hypopnea index of 5 or more events per hour increased the chance of postoperative respiratory complications (odds ratio, 7.2; 95% confidence interval, 2.7–19.3), as did a preoperative oxygen saturation nadir of 80% or less (odds ratio, 6.4; 95% confidence interval, 2.8–14.5). A preoperative oxygen saturation nadir of 80% or less had a likelihood ratio of 3.1, increasing the probability of postoperative respiratory complications from 20 to 50%. Conclusions The data suggest, but do not prove, that preoperative nocturnal oximetry could be a useful preoperative test to identify children who are at increased risk for postoperative respiratory complications.

Face-straight-down and face-near-straight-down positions in healthy, prone-sleeping infants

OBJECTIVEnTo determine the frequency and physiologic consequences of the face-straight-down (FSD) position, a postulated mechanism for the sudden infant death syndrome in prone-sleeping infants.nnnSTUDY DESIGNnA survey of 151 infants, aged 1 to 7 months, in Montreal showed that 33% slept prone. Ten healthy prone-sleeping infants were studied in their homes at age 10 to 22 weeks. Infrared video and cardiorespiratory recordings were made on 3 consecutive nights in the prone (nights 1 and 3) and lateral (night 2) positions.nnnRESULTSnInfants maintained the prone position during 17 of 19 studies, but only 4 of 9 infants maintained the lateral position. The FSD position was observed 27 times in 17 prone nights: median frequency, 0.6 times per night (interquartile range, 0 to 4), and median total duration, 3.3 minutes (0.8% of total sleep time). A related position, the face-near-straight-down (FNSD) position, occurred more often, 5.3 (1 to 10) time per prone night, for 22.4 minutes (5.8% of total sleep time). Most periods in the FSD and FNSD position had no physiologic consequences; however, 14% of FSD and 3% of FNSD episodes were associated with airway obstruction as indicated by snoring, paradoxical respiratory movements, apnea, and/or increased partial pressure of transcutaneous carbon dioxide. Spontaneous arousal and head turning terminated the FSD and FNSD episodes.nnnCONCLUSIONnThe FSD and FNSD positions occur commonly in healthy prone-sleeping infants, and these positions can cause airway obstruction. We speculate that those infants with sudden infant death syndrome found in the FSD or FNSD position either have a congenital or an acquired defect in the arousal-head turning response or have encountered insurmountable environmental factors that prevent effective head turning.

Do Systemic Corticosteroids Effectively Treat Obstructive Sleep Apnea Secondary to Adenotonsillar Hypertrophy

To determine if pediatric obstructive sleep apnea syndrome (OSAS) caused by adenotonsillar hypertrophy (ATH) could be treated by a short course of systemic corticosteroids, we conducted an openlabel pilot study in which standardized assessments of symptomatology, OSAS severity, and adenotonsillar size were performed before and after a 5‐day course of oral prednisone, 1.1 ± 0.1(± SE) mg/kg per day. Outcome measures included symptom severity, adenotonsillar size, and polysomnographic measures of OSAS. Selection criteria included age from 1 to 12 years, ATH, symptomatology suggesting OSAS, an apnea/hypopnea index (AHI) ≥ 3/hour, and intent to perform adenotonsillectomy. Only one of nine children showed enough improvement to avoid adenotonsillectomy. Symptomatology did not improve after corticosteroid treatment but did after removal of tonsils and adenoids. Polysomnographic indices of OSAS severity did not improve after corticosteroid treatment. After corticosteroids, tonsillar size decreased in only two patients, adenoidal size was only marginally reduced, and the size of the nasopharyngeal airway was not significantly increased. These results suggest that a short course of prednisone is ineffective in treating pediatric OSAS caused by ATH.

Children with severe OSAS who have adenotonsillectomy in the morning are less likely to have postoperative desaturation than those operated in the afternoon

PurposeTo determine, in a subset of children previously reported, if the time of day when adenotonsillectomy for severe obstructive sleep apnea syndrome (OSAS) was performed affected the incidence of postoperative respiratory complications.Clinical featuresChildren having adenotonsillectomy were included if they had a polysomnographic diagnosis of severe OSAS within six months prior to operation. Patients who met the inclusion criteria were grouped by the occurrence of postoperative desaturation into a saturated (SAT) and desaturated (deSAT) group. The charts of children in group deSAT were reviewed. The clock time of the surgical procedure was recorded and categorized as morning (AM) or afternoon (PM).ResultsEighty-eight patients met the inclusion criteria. There were 31 girls and 57 boys. The mean ± SD age (yr) and weight (kg) were 4.6 ± 2.9 yr and 20.8 ± 14.5 kg respectively. There were 63 children in the SATgroup and 25 in the deSATgroup. Differences in age, weight and gender were not significant. The preoperative oxygen saturation (SaO2) nadir for the SAT and deSAT groups was 80.8 ± 10.2% and 67.6 ± 17.5% (P < 0.05) respectively. The preoperative obstructive apnea and hypopnea index was 15.8 ± 10.2 and 35.7 ± 34.6 events · hr−1 (P < 0.05), respectively. Surgery in 63 (71.6%) children was performed in the AM. Univariate logistic regression identified PM surgery [odds ratio (OR) 4.6, 95% confidence interval (CI) 1.7 to 12.6,P = 0.002] and a preoperative SaO2 nadir < 80% (OR 3.6, 95% CI 1.4 to 9.4,P = 0.009) as risk factors predicting postadenotonsillectomy desaturation.ConclusionChildren with severe OSAS whose surgery is performed in the AM are less likely to desaturate following adenotonsillectomy than children whose surgery is performed in the PM.RésuméObjectifDéterminer, chez un sous-groupe connu d’enfants, si i’heure à iaqueiie i’amygdaiectomie a été réalisée pour un syndrome sévère d’apnée obstructive du sommeil (SAOS) a un effet sur l’incidence de complications respiratoires postopératoires.Éléments cliniquesDes enfants subissant une amygdalectomie ont été inclus dans notre étude si un diagnostic polysomnographique de SAOS sévère avait été établi dans les six mois avant l’opération. Les patients admis ont été répartis selon l’occurrence de désaturation postopératoire dans un groupe de saturation (SAT) ou de désaturation (deSAT). Les dossiers des enfants du groupe deSAT ont été révisés. L’heure de l’opération a été notée sous matin (AM) ou après-midi (PM).RésultatsOnt été admis à l’étude, 88 patients dont 31 files et 57 garçons. La moyenne d’âge et de poids ± l’écart type étaient respectivementde 4,6 ± 2,9 ans et 20,8 ± 14,5 kg. Il y a eu 63 enfants dans le groupe SAT et 25 dans le groupe deSAT. Les différences d’âge, de poids et de sexe n’étaient pas signifcatives. Le niveau préopératoire minimal de saturation en oxygène (SaO2) a été de 80,8 ± 10,2 % et de 67,6 ± 17,5 % (P < 0,05) dans les groupes SAT et deSAT respectivement. Les indices d’apnée obstructive et d’hypopnée préopératoires étaient de 15,8 ± 10,2 et de 35,7 ± 34,6 événements · h−1 (P < 0,05), respectivement. L’opération de 63 (71,6 %) enfants s’est faite en AM. Une analyse univariée de régression logistique a considéré l’opération réalisée en PM [risque relatif (RR) de 4,6, intervalle de confiance (IC) de 95 %, 1,7 à 12,6, P = 0,002] et un niveau minimal de SaO2 préopératoire < 80 % (RR de 3,6, IC de 95 %, 1,4 à 9,4, P = 0,009) comme des facteurs de risque prédictifs de désaturation postamygdalectomie.ConclusionLes enfants atteints d’un SAOS sévère, opérés en AM, sont moins susceptibles de subir une désaturation postamygdalectomie que les enfants opérés en PM.

Diagnostic approach to obstructive sleep apnea in children

Obstructive sleep apnea syndrome (OSAS) in childhood is a disorder of breathing during sleep characterized by prolonged partial upper airway obstruction and/or intermittent complete obstruction that disrupts normal ventilation during sleep and normal sleep patterns. A spectrum of severity related to the degree of upper airway resistance, to the duration of the disease, to the presence or absence of hypoxemia episodes, and to certain clinical features can be described. Symptomatic children may not fit the criteria for diagnosis established for OSAS in adults; age-specific standards are needed. Both anatomical factors that increase upper airway resistance, e.g. adenotonsillar hypertrophy, and functional processes that decrease upper airway tone, e.g. REM sleep, contribute to the pathogenesis of pediatric OSAS. Sequelae of OSAS in children include neurobehavioural abnormalities, stunting of growth, and cor pulmonale. Both the history and physical examination should target the sleeping child; parents often report loud snoring, difficulty breathing, and obstructive apneas. The gold standard investigation to establish the diagnosis and to quantitate disease severity is overnight polysomnography. Home cardiopulmonary sleep studies have been shown to be an accurate and practical alternative to overnight laboratory polysomnography for routine evaluation of non-complex children with adenotonsillar hypertrophy. Children with documented severe OSAS are at increased post-operative risk for airway compromise and should be observed and monitored carefully. Adenotonsiliectomy is the most common therapy for OSAS in children; as a second-line treatment, the use of nasal CPAP in children with OSAS has been very successful in experienced hands.

Obstructive Sleep Apnea in Children

Obstructive sleep apnea (OSA) is a common condition of childhood, and is associated with significant morbidity. Prevalence of the condition peaks during early childhood, due in part to adenoidal and tonsillar enlargement within a small pharyngeal space. The lymphoid tissues regress after 10 years of age, in the context of ongoing bony growth, and there is an associated fall in the prevalence of OSA. Obstruction of the nasopharynx by adenoidal enlargement promotes pharyngeal airway collapse during sleep, and the presence of large tonsils contributes to airway obstruction. Administration of systemic corticosteroids leads to a reduction in the size of lymphoid tissues due to anti-inflammatory and lympholytic effects. However, a short course of systemic prednisone has been demonstrated not to have a significant effect on adenoidal size or the severity of OSA, and adverse effects preclude the long-term use of this therapy. Intranasal corticosteroids are effective in relieving nasal obstruction in allergic rhinitis, and allergic sensitization is more prevalent among children who snore than among those who do not snore. Intranasal corticosteroids have also been demonstrated to reduce adenoidal size, independent of the individual’s atopic status. There is preliminary evidence of an improvement in the severity of OSA in children treated with intranasal corticosteroids, but further studies are needed before such therapy can be routinely recommended. Prescribing clinicians should take into account the potential benefits to the patient, the age of the child, the presence of comorbidities such as allergic rhinitis, the agent used, and the dose and duration of treatment when considering such therapy.

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.

SLEEP-DISORDERED BREATHING IN PATIENTS WITH MYELOMENINGOCELE : THE MISSED DIAGNOSIS

Moderate to severe sleep‐disordered breathing (SDB) was identified in 20% (17 of 83) of children with spina bifida/myelomeningocele (SB/MM) at the Montreal Childrens Hospital. The prevalence of SDB in patients with SB/MM elsewhere has not been determined. To establish current practices for identifying SDB in patients with SB/MM, questionnaires were sent to the coordinators of the 212 spina‐bifida clinics in Canada and in the United States. Eighty‐six (41%) questionnaires were returned, representing data on 13 349 patients. Although 67% of the responding centers reported availability of cardiorespiratory sleep studies, only 996 (7.5%) patients with SB/MM had been tested and only 418 (3.1%) patients had been diagnosed with SDB. Across clinics, the prevalence of SDB was directly related to the frequency of testing. Of 380 deaths over the past 10 years, SDB and sudden unexplained death during sleep were identified as the cause of death in 49 (12.8%) and 34 (8.9%) patients, respectively. Moderate to severe SDB may not have been identified in a significant number of patients with SB/MM because they have not been tested.

Pulse oximetry: Accuracy of methods of interpreting graphic summaries

Although pulse oximetry has been used to determine the frequency and extent of hemoglobin desaturation during sleep, movement artifact can result in overestimation of desaturation unless valid desaturations can be identified accurately. Therefore, we determined the accuracy of pulmonologists and technicians interpretations of graphic displays of desaturation events, derived an objective method for interpreting such events, and validated the method on an independent data set. Eighty‐seven randomly selected desaturation events were classified as valid (58) or artifactual (29) based on cardiorespiratory recordings (gold standard) that included pulse waveform and respiratory inductive plethysmography signals. Using oximetry recordings (test method), nine pediatric pulmonologists and three respiratory technicians (“readers”) averaged 50 ± 11% (SD) accuracy for event classification. A single variable, the pulse amplitude modulation range (PAMR) prior to desaturation, performed better in discriminating valid from artifactual events with 76% accuracy (P < 0.05). Following a seminar on oximetry and the use of the PAMR method, the readers accuracy increased to 73 ± 2%. In an independent set of 73 apparent desaturation events (74% valid, 26% artifactual), the PAMR method of assessing oximetry graphs yielded 82% accuracy; transcutaneous oxygen tension records confirmed a drop in oxygenation during 49 of 54 (89%) valid desaturation events. In conclusion, the most accurate method (91%) of assessing desaturation events requires recording of the pulse and respiratory waveforms. However, a practical, easy‐to‐use method of interpreting pulse oximetry recordings achieved 76–82% accuracy, which constitutes a significant improvement from previous subjective interpretations. Pediatr Pulmonol. 1996; 21:121–131.

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.