Robert T Brouillette

McGill University | McGill · McGill University Health Centre

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-n...

Obstructive sleep apnea is common among children, with an estimated point prevalence of 1 to 5%.(1) Important sequelae include cardiovascular, growth, cognitive, and behavioral deficits. Adenotonsillectomy, the usual first-line treatment, most often cures or ameliorates the disorder. Each year, 77% of the 530,000 tonsillectomies in the United State...

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 t...

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...

To determine whether neighborhood characteristics or socioeconomic status are risk factors for obstructive sleep apnea (OSA) in young children. 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...

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 recu...

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 polys...

A newborn with acute spinal-cord dysfunction associated with disseminated intravascular coagulation (DIC) is presented. Spinal-cord dysfunction in the newborn resulting from DIC or any other coagulopathy has not been previously reported in the English literature. This association should be considered in the differential diagnoses of neonatal hypoto...

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...

Current scoring systems, which adjust prediction for severity of illness, do not account for higher observed mortality in neonatal intensive care units (NICUs) of children's hospitals than that of perinatal centers. We hypothesized that three potential predictors, (a) admission from another NICU, (b) presence of congenital anomalies and (c) need fo...

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...

To obtain parental perspectives on changes in sleep, breathing, quality of life (QOL), and neurobehavioral measures after adenotonsillectomy. 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 t...

Since 1976 we have implanted bilateral diaphragm pacers in 34 infants and children: 26 with central hypoventilation syndrome (CHS), three with myelomeningocele, and five with quadriplegia. Compared to adults, several modifications have been necessary to achieve effective ventilation in infants and younger children. In all instances, a tracheostomy...

Pulmonary lymphangiectasia is a rare cause of respiratory distress in the newborn associated with a very poor outcome. We describe three premature newborns presenting at birth with nonimmune hydrops, bilateral chylothorax, and severe respiratory distress in the immediate newborn period secondary to pulmonary lymphangiectasia. We review the similari...

In the past 25 years there has been increasing recognition of obstructive sleep apnoea (OSA) as a common condition of childhood. Morbidity includes impairment of growth, cardiovascular complications, learning impairment, and behavioural problems. Diagnosis and treatment of this condition in children differs in many respects from that in adults. We...

Adenotonsillectomy (T&A) has established effectiveness for the treatment of obstructive sleep apnea (OSA). However, more than 20% of children with OSA have respiratory compromise requiring medical intervention in the postoperative period. The reasons for this complication are not well-defined. We aimed to compare the nature and severity of sleep-di...

To 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. Children having adenotonsillectomy were included if they had a polysomnographic diagnosis of severe OSAS within six...

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 a...

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...

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 co...

Arousals from sleep and consequent sleep disruption may be a causal link between sleep-disordered breathing and its sequellae in children. Quantification of arousals therefore makes an important contribution to the overall assessment of the sleep of a child with suspected obstructive sleep apnea (OSA) or other sleep disorders. Arousals are classica...

Prader-Willi syndrome (PWS) is a genetic disorder, with hypotonia being the predominant feature in infancy, and developmental delay, obesity, and behavioral problems becoming more prominent in childhood and adolescence. Children with this disorder frequently suffer from excessive daytime sleepiness and have a primary abnormality of the circadian rh...

Obstructive sleep apnoea (OSA) is a common condition of childhood with significant associated morbidity. The comprehensive evaluation of children who present with suggestive symptoms involves the overnight recording and assessment of both sleep and respiration by polysomnography in a sleep laboratory. These studies require resources and facilities...

Unlabelled: Newer pulse oximeters have been developed to be motion resistant and thus have few false alarms. However, they have not yet been evaluated in a pediatric sleep laboratory setting. While evaluating new oximeters for use in our laboratory, we obtained simultaneous pulse oximetry data from two Masimo oximeters and from two Nellcor oximete...

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. Children referred for sleep studies between 1992 and 1998, who underwent adenotonsillectomy...

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 t...

We tested the hypothesis that a 6-week course of a nasal glucocorticoid spray would decrease the severity of obstructive sleep apnea in children with adenotonsillar hypertrophy. We conducted a randomized, triple-blind, placebocontrolled, parallel-group trial of nasal fluticasone propionate versus placebo in 25 children aged 1 to 10 years with obstr...

In addition to usual prone sleeping, unaccustomed prone sleeping represents a significant risk factor for sudden infant death syndrome (SIDS). However, little information is available regarding the circumstances leading caretakers to change the infant's sleep position to prone position in SIDS victims. To determine, in a population of SIDS victims,...

The prevalence of moderate to severe sleep-disordered breathing (SDB) in patients with myelomeningocele may be as high as 20%, but little information is available regarding treatment of these patients. To assess the efficacy and complications of treatments for these children, we collected data on 73 patients from seven pediatric sleep laboratories....

Event recording, by differentiating between true and false events, has advanced the diagnosis and management of infants on home cardiorespiratory monitors; however, the pathogenesis of many events remains obscure. To clarify infant behaviours around the time of apnoea/bradycardia alarms, a computerised audiovisual event recording system (CAVERS) tr...

To determine the utility of pulse oximetry for diagnosis of obstructive sleep apnea (OSA) in children. We performed a cross-sectional study of 349 patients referred to a pediatric sleep laboratory for possible OSA. A mixed/obstructive apnea/hypopnea index (MOAHI) greater than or equal to 1 on nocturnal polysomnography (PSG) defined OSA. A sleep lab...

Term infants may die of sudden infant death syndrome (SIDS) when they assume the face-straight-down or the face-near-straight-down head positions. Preterm infants have a higher SIDS rate, but it is not known how often they assume the face-straight-down and face-near-straight-down positions. To determine the frequency and cardiorespiratory consequen...

Background: Full-term infants may die from the sudden infant death syndrome (SIDS) when they assume the face-straight-down (FSD) or the face-near-straight-down (FNSD) head positions. Preterm infants have a higher SIDS rate but it is not known how often they assume the FSD and FNSD positions. Objectives: To determine the frequency and cardiorespirat...

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 Children's 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 wer...

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 dur...

Hunter syndrome is one of the mucopolysaccharidoses, characterized by a deficiency of the lysosomal enzyme iduronate sulfatase. Among its physical manifestations, there are numerous head and neck signs, including characteristic facial features, macroglossia and short neck. The accumulation of glycosaminoglycans in the soft tissues of the head and n...

To determine the incidence, type, timing, and factors predictive of recurrent significant events in infants with home cardiorespiratory monitors. We reviewed data accumulated for 147 patients with an event-recorder type of monitor. The infants were allocated to one of four diagnostic categories: apparent life-threatening events (ALTE, n = 73), form...

Although patients with myelomeningocele and the Chiari II malformation are known to have sleep apnea and respiratory control deficits, the prevalence, types, severities, and associations of sleep-disordered breathing (SDB) have not been adequately defined. A cross-sectional study of our myelomeningocele clinic population was undertaken to correlate...

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 open-label pilot study in which standardized assessments of symptomatology, OSAS severity, and adenotonsillar size were performed before and after a 5-day course...

Blood gas measurements and complementary, noninvasive monitoring techniques provide the clinician with information essential to patient assessment, therapeutic decision making, and prognostication. Blood gas measurements are as important for ill newborns as for other critically ill patients, but rapidly changing physiology, difficult access to arte...

We developed a portable recording system, suitable for unattended use in a patient's home, that quantitates the essential diagnostic elements of pediatric obstructive sleep apnea syndrome (OSAS): obstructive, mixed and central apneas and hyponeas; hemoglobin saturation, sleep vs. wakefulness; body and head positions; snoring: and sleep disturbance....

To 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. A 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...

Polysomnography, including EEG recording, is the standard method to diagnose obstructive sleep apnea (OSA) in children and adults. Diagnosis of OSA would be considerably simplified if it was shown that sleep could be distinguished from wakefulness without EEG recordings. Therefore, we compared sleep/wakefulness classification using a simplified car...

There is reason to suspect that pediatric OSA due to ATH could be treated by a short course of systemic steroids. For instance, steroids can reduce tonsillar size in infectious mononucleosis. We therefore performed assessments of symptomatology, ATH, and OSA severity before and after a 5 day course of 1 mg/kg/day of oral prednisone in 9 children (6...

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...

The objective of this study was to determine the accuracy and practicality of home testing for pediatric obstructive sleep apnea syndrome (OSAS) secondary to adenotonsillar hypertrophy. Twenty-one children aged 2-12 years and referred for possible OSAS were studied twice, once at home and once in the sleep laboratory. The home test consisted of two...

To determine the safety and efficacy of nasal continuous positive airway pressure (CPAP) for obstructive sleep apnea (OSA) during childhood and the effects of growth and maturation on CPAP requirements. Retrospective study with use of a written questionnaire administered to pediatric practitioners treating sleep disorders. Nine academic pediatric s...

Movement/arousal has been described as a characteristic of adult obstructive sleep apnea syndrome (OSAS), but opinions differ as to whether or not OSAS in children increases the frequency of movement/arousal. The problem that we decided to address was the lack of a comprehensive definition and characterization of movement/arousals in children. We t...

Over the last 26 years diaphragm pacing has been used in over 400 adults and 70 children to support ventilation and oxygenation. Diaphragm pacing can be useful for conditions in which the brain stem respiratory centers provide little or no stimulation to the respiratory muscles, i.e. central hypoventilation syndrome, Arnold-Chiari malformation/brai...

Pediatric obstructive sleep apnea (OSAS) is characterized by partial airway obstruction, alveolar hypoventilation, and elevated arterial CO2 (PaCO2). Thus, a reliable, practical method of estimating CO2 is needed for pediatric polysomnography. Therefore, we measured both transcutaneous CO2 (PtcCO2) and end-tidal CO2 (PETCO2) in 15 pediatric polysom...

• Congenital dysplasia of the hip (CDH) continues to be missed by routine physical screening examinations in the early months when treatment is most effective. Real-time ultrasonography (US) is valuable in the detection of CDH in the young infant. We performed a prospective study to evaluate one US screening strategy that targets a select "high-ris...

Using event recording, we determined how often apnea exceeding 15 seconds in duration was associated with bradycardia and how often patients with apnea resumed breathing spontaneously. Of 1306 documented apnea events exceeding 15 seconds (54 patients), 926 lasted 16 to 20 seconds, 262 lasted 21 to 25 seconds, and 118 exceeded 25 seconds. Of these e...

Although diaphragm pacing has been shown to be a practical method of supporting ventilation in children, its usefulness has been limited because of concern that continuous (24 h/day) diaphragm pacing would fatigue and damage the diaphragm. We examined the functional and structural effects of continuous low-frequency diaphragm pacing on the left hem...

Pediatric breathing control disorders can be disastrous if not promptly recognized and treated. Diagnostic techniques and management options are discussed in the context of essential clinical features of five major entities: neonatal apnea, obstructive sleep apnea, central hypoventilation syndrome, "apparent life-threatening events," and sudden inf...

Patients using diaphragm pacemakers have several respiratory-related problems placing them at high risk for death during sleep, including central hypoventilation, abnormal arousal responses, upper airway and/or tracheostomy obstruction, and, in the case of high quadriplegia, lack of motor response to airway obstruction. The recent death from airway...

We evaluated the performance of an event recorder system in a large, consecutive series of referred monitored patients to determine the relative incidence of true apnea and true bradycardia, false alarms, and alarms for movement or a loose lead. In addition, we developed an event classification system based on the reason for the event being recorde...

Fifteen children with renovascular hypertension as a result of aortic thrombosis were followed for a mean of 26 months (range 5 to 58 months) to determine outcome. As neonates, all patients had hypertension and elevated plasma renin activity. Of 11 patients studied with radionuclide renography and scintigraphy, 10 had abnormal renal blood flow; thr...

Since 1976, we have implanted bilateral phrenic nerve electrodes for diaphragm pacing in 33 infants and children. This population includes 23 patients with congenital central hypoventilation syndrome (CHS), two with late onset CHS and hypothalamic dysfunction, three with hypoventilation associated with Chiari II malformation and myelomeningocele, a...

Records were reviewed of 477 patients who had diaphragm pacemakers implanted for treatment of chronic hypoventilation. Three groups were established for comparison. (1) Center group: 165 patients operated on in six medical centers participating in a cooperative study; (2) Noncenter group, sufficient data available: 203 patients operated on by surge...

Since 1976 we have implanted bilateral diaphragm pacers in 34 infants and children: 26 with central hypoventilation syndrome (CHS), three with myelomeningocele, and five with quadriplegia. Compared to adults, several modifications have been necessary to achieve effective ventilation in infants and younger children. In all instances, a tracheostomy...

Pneumogram (PG) scoring methods have not been standardized. To determine the extent to which varying definitions for apnea-onset and apnea-termination will result in clinically significant differences in calculated apnea density (A6/D%) and periodic breathing, we analyzed 40 randomly selected PGs. All PGs were initially scored using end-expiration...

Central hypoventilation syndrome (CHS) is a disorder of respiratory control. It may be an idiopathic primary disease or it may be the secondary consequence of an infectious process or Chiari II malformation. Clinical data suggest that the primary defect involves the brainstem respiratory centers. To date, pathologic evaluation has linked primary CH...

We previously demonstrated that almitrine, a peripheral chemoreceptor stimulant, increased tidal volume (VT), expired minute ventilation (VE), and respiratory frequency (f) and decreased inspiratory (TI) and expiratory time (TE) in sleeping adult cats. We now hypothesized that almitrine would induce an increase in ventilation in a young animal mode...

In summary, theophylline treatment appears to be effective in significantly improving the respiratory pattern, in preventing recurrent symptoms in apnea of infancy, and in preventing life-threatening events in asymptomatic at-risk infants. To resolve the question of whether methylxanthine treatment is an effective alternative to a home monitor in a...

Phrenic nerve pacing has been used since 1966 to support breathing in quadriplegics and patients with central hypoventilation syndrome (CHS). Recently, using low-frequency, long-inspiratory-time (Ti) stimulation, phrenic nerve pacing has been used successfully to support breathing 24 hours per day in adults and older children. However, no similar e...

Thoracic impedance apnea monitors may fail to detect obstructive apnea, may falsely alarm when the infant is breathing, and may confuse cardiac artifact with respiratory impedance. Therefore, we compared the performance of a respiratory inductive plethysmograph and a thoracic impedance monitor with a reliable measure of airflow, either nasal CO2 or...

The pathophysiology of SIDS remains unknown. Although a multifactorial cause appears plausible on the basis of available data, new data are needed to determine which components of this multifactorial hypothesis are most important and whether other factors need to be added. We need to better understand control of breathing in the newborn infant and...

Systemic candidiasis, especially candidemia, is an increasing problem among high risk neonates. Although possible predisposing factors have been suggested, no case-control study has evaluated potential risk factors. By retrospective chart review we identified 21 infants admitted to the neonatal intensive care unit between 1976 and 1983 (0.9% of all...

We previously demonstrated dose-dependent increases in both hypoglossal and phrenic electroneurograms after almitrine in anesthetized, paralyzed, and vagotomized cats. We have now investigated the effect of this peripheral chemoreceptor stimulant on diaphragmatic and genioglossal (GG, an upper airway-maintaining muscle) electromyograms in five unan...

Patients with congenital central hypoventilation syndrome (CCHS) lack hypercapnic and hypoxic stimulation of ventilation but have demonstrated carotid body function in response to hyperoxia and to pharmacological stimulation with doxapram. This study investigated the ventilatory effects of almitrine bismesylate, a carotid body stimulant, in 12 pati...

An infant developed chronic respiratory failure after aseptic meningoencephalitis at 5 months of age. Neurologic evaluations at 16 and 17 months were normal except for an abnormal pharyngeal stage of swallowing, lower extremity hypotonia, and a mild left hemiparesis. Spontaneous breathing during sleep at 16 months was characterized by alveolar hypo...

To evaluate the course, use of diagnostic modalities, management, and outcome of aortic thrombosis associated with umbilical artery catheterization, we reviewed 20 cases of aortic thrombosis diagnosed by ultrasonography (n = 16) or aortography (n = 4) over 4 years. Fourteen of 20 infants had severe perinatal asphyxia, suggesting that asphyxia predi...

Sudden infant death syndrome occurs with increased frequency in low birth weight infants and in black infants. The degree to which the higher LBW rate among blacks might explain this higher SIDS rate is unknown. To address this question, we analyzed the 1233 SIDS deaths that occurred among 252,376 neonatal survivors in Cook County from 1975 to 1980...

A 16-month-old infant presented with bilateral diaphragmatic paralysis and respiratory failure after removal of a thoracic teratoma. Right diaphragmatic function recovered after end-to-end anastomosis of a transected phrenic nerve. We conclude that phrenic nerve repair can restore diaphragmatic function and should be attempted in selected cases of...

Phrenic nerve pacing was employed in 8 infants with central hypoventilation syndrome. Their ages ranged from 2.5 to 8.5 months. Preoperative diagnosis was established by demonstrating inadequate ventilatory response to hypercapnia and hypoxia. Percutaneous measurements of phrenic nerve conduction time and diaphragmatic action potentials were perfor...