Geographic disparities in performance of pediatric polysomnography to diagnose obstructive sleep apnea in a universal access health care system.

BACKGROUND: Diagnostic polysomnography (PSG) is recommended prior to adenotonsillectomy (AT) for children with obstructive sleep apnea (OSA) and certain high-risk characteristics, but resource limitations often prevent this practice. OBJECTIVE: We performed a population-based assessment of children across Ontario, Canada to describe and quantify disparities in PSG. METHODS AND MATERIALS: This retrospective cohort study was performed using provincial health administrative data held at ICES. We identified children 0-10 years old who underwent PSG and AT between 2009 and 2018, and those with a PSG within 18 months prior to and/or 12 months following AT. We calculated the odds of PSG prior to/following AT after adjustment for demographics, medical comorbidities, geographic and socioeconomic characteristics. Our main predictor was driving time/distance to the nearest pediatric sleep centre ascertained using spatial analysis and geographic information systems. RESULTS: We identified 27,837 children <10 years old who underwent AT for OSA in Ontario. Only 12.8% had a PSG within 18 months prior and 5.7% had a PSG within 12 months following AT. Shorter driving time/distance, older age, male sex and certain comorbidities were associated with increased odds of PSG. CONCLUSION: Only a small proportion of children in our cohort underwent PSG prior to or following AT surgery despite universal access to healthcare. This study suggests a need to increase overall PSG access, particularly for those living distant from existing pediatric sleep centres. Future studies could determine if increased PSG testing in 'underserviced areas' would reduce overall surgery rates and/or improve health outcomes.

Screening for pulmonary and cerebral arteriovenous malformations in children with hereditary haemorrhagic telangiectasia.

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disease characterised by vascular dysplasia complicated by visceral arteriovenous malformations (AVMs). To date, the diagnostic yield of screening procedures for pulmonary and cerebral AVMs in children with definite or potential HHT is not well defined. The aim of the present study was to prospectively evaluate the diagnostic yield of a screening protocol for pulmonary and cerebral AVMs in children with either a definite or potential HHT diagnosis. All children referred for evaluation for HHT between 1996 and 2008 were included in the present analysis. Screening tests for AVMs included chest computed tomography and brain magnetic resonance imaging. 61 children with a definite clinical and/or genetic diagnosis of HHT were asymptomatic for visceral AVMs at their first baseline assessment (mean+/-SD age 8.7+/-4.7 yrs; range 0-17.0 yrs). Of these, 15 (25%) had pulmonary and/or cerebral AVMs diagnosed on initial screening tests. Pulmonary AVMs predominated in paediatric HHT patients (14 out of 15 patients) and were found in eight children aged <10 yrs. 55 children had a potential HHT diagnosis as they fulfilled only one or two HHT clinical diagnostic criteria and did not have a confirmatory genetic diagnosis (age 10.9+/-4.8 yrs; range 0-17.9 yrs). None of these children had pulmonary or cerebral AVMs on initial screening tests. The present data suggest that children with a definite HHT diagnosis have a high frequency of pulmonary AVMs even when clinically asymptomatic. In contrast, no AVMs were observed in children not fulfilling HHT diagnostic criteria. Genetic testing appears to be useful in defining an at-risk group for pulmonary AVMs in childhood.

Sleep-related breathing in children with mucopolysaccharidosis.

BACKGROUND: The mucopolysaccharidoses (MPSs), a group of genetic lysosomal storage disorders, are associated with significant morbidity. Secondarily to specific associated anatomical abnormalities, MPS is associated with sleep disordered breathing (SDB), specifically obstructive sleep apnoea (OSA) that may confer additional morbidity. Few studies have examined SDB in children with MPS using full polysomnography (PSG) and thus the exact prevalence and severity of SDB is unknown. Further, successful treatments for SDB in this population have not been explored. OBJECTIVES: This study evaluated both SDB and the efficacy of treatments offered to children with MPS using PSG data. PATIENTS AND METHODS: A retrospective chart review was conducted on all children with MPS and a history of suspected OSA who were referred to the Hospital for Sick Children, Toronto. Both baseline and follow up treatment PSG data were analysed. PSG data recorded included obstructive apnoea-hypopnoea index (OAHI) and central apnoea index (CAI). RESULTS: Fourteen patients (10 male) underwent a baseline PSG. Three of 14 children on ERT were excluded from the main analyses. The median (range) baseline parameters of the population (n = 11) were recorded. The age was 5.2 years (0.8-17.8) and the body mass index (BMI) was 19.9 (13.7-22.2). The OAHI was 6.6 (0.0-54.8); the CAI was 0.6 (0.0-2.6). Seven of 11 (64%) had evidence for OSA and 3/7 children were classified as having severe OSA (OAHI > 10). Of these, 5/7 children underwent treatment for OSA with 3/5 children showing a significant reduction in their OAHI. Further, the 2 patients on ERT therapy with OSA were also both successfully treated. CONCLUSIONS: Children with MPS have a high prevalence of significant OSA and thus should be carefully screened for OSA using full polysomnography and treated accordingly.

Long-term effects of inhaled tobramycin in patients with cystic fibrosis colonized with Pseudomonas aeruginosa.

Twenty-seven patients with cystic fibrosis and endobronchial colonization with Pseudomonas aeruginosa were randomly assigned to inhale either 2 mL saline (12 patients) or 80 mg tobramycin solution (15 patients) 3 times daily. One control patient died; all others completed the study (mean duration 32 months). No significant differences were found between the two groups at enrollment. The treatment group showed no change, while the control group had a significant decline in both pulmonary function and clinical status over the study period. Individually, 11 of 12 patients in the control group showed deterioration, while 9 of 15 in the treatment group with susceptible P. aeruginosa at enrollment acquired resistant organisms. There was no evidence of significant nephro- or ototoxicity. Although inhaled tobramycin appeared to arrest the decline in pulmonary status, further work is required to identify patients most likely to respond.

Cardiorespiratory status in long-term survivors of prematurity, with and without hyaline membrane disease.

Forty-eight children, born at less than 33 weeks' gestation and without bronchopulmonary dysplasia (BPD) or Wilson-Mikity syndrome (WM) were studied at a mean age of 9.1 years, to identify the incidence and possible factors contributing to the development of long-term abnormalities in pulmonary function. As neonates, 30 children had hyaline membrane disease (HMD) of whom 21 required ventilation. Eighteen did not have HMD, of whom 9 required ventilation for nonrespiratory reasons. All patients had grown normally. Four of the 48 (8.3%) had clinical asthma, 5 had persisting chest x-ray abnormalities (10.6% of 47 chest x-rays performed), each having been ventilated for HMD. There was a close association between duration of ventilation, oxygen administration, and subsequent abnormal chest x-ray. Electrocardiogram and M-mode echocardiograms were normal in all but 2 patients. Only 3 patients had significant restrictive lung disease, 3 had evidence of significant airways obstruction, and 13 (27.7%) had signs of air trapping. Methacholine challenge was positive in 30 of 46 patients (65.2%). The incidence of a positive methacholine challenge did not correlate with history of HMD, duration of ventilation, or high oxygen administration. There is an increased incidence of airway hyperreactivity in survivors of prematurity, not associated with any identified therapeutic maneuver during the neonatal period.

Comparison of airway reactivity induced by cold air and metacholine challenges in asthmatic children.

Bronchial responsiveness to isocapnic hyperventilation with cold air (CAH) and to inhaled methacholine (MCH) was compared in 17 children with bronchial asthma. The response to cold air was expressed as the percent drop in FEV1 from baseline at 4 min. after the challenge (delta % FEV1 CAH), and the response to methacholine as the provocative concentration required to reduce the FEV1 by 20% from baseline (PC20MCH). Both tests were sensitive (94%) for detecting airway hyperreactivity. There was no statistically significant relationship between delta % FEV1 CAH and the log PC20MCH (r = 0.39; P = 0.12). In clinical practice, methacholine test is easier to perform, but in the research field cold air challenge may be preferable because it avoids potential drug effects.

Prediction of preschool behavioral problems in healthy and pediatric samples.

In a prospective study of 137 children (47 with cystic fibrosis, 48 with congenital heart disease, 42 with no chronic illness), four domains were examined as predictors of parent-reported behavioral problems, particularly internalizing problems, at 4 years of age: child health, child temperament, parent-child relationships, and family environment. Family environment, as measured by the Parenting Stress Index at 1,2, and 3 years, was the most powerful predictor. This suggests that this index is useful as an early screen for children at risk for behavioral problems and that a reduction of parenting stress is an appropriate target of preventive interventions.

Infant-mother attachment and nutrition in children with cystic fibrosis.

The association between nutritional status (percentage of weight for height) and infant-mother relationship was studied over 4 years in 38 children diagnosed with cystic fibrosis in the first year of life. Infant-mother relationship was assessed in a standardized laboratory observation. Although they could not be distinguished medically from the others at the time of diagnosis, infants showing a specific form of insecure relationship with their mothers (insecure-avoidant) differed from the others in: (1) failure to improve in nutritional status in the first year; (2) continuing decline in weight for height in the first 3 years; and (3) significantly lower weight for height at 1, 2, and 3 years of age. These data suggest that attention to mother-infant relationships, particularly feeding interactions, may improve nutritional status in children with cystic fibrosis.

Assessing the efficacy of a school-based asthma education program for children: a pilot study.

BACKGROUND: Asthma diminishes the health-related quality of life for many school-aged children. This study sought to explore the effect of a School-Based Asthma Education Program (SBAEP) on quality of life. METHODS: Children with asthma who attended grades 1-5 at two selected schools were requested to participate in this pilot study. Participants at one school were provided with a SBAEP, those at another school (control group) were provided with written educational material about asthma. The children completed the Paediatric Asthma Quality of Life Questionnaire (PAQLQ) before and one month after the educational interventions. RESULTS: There were clinically important improvements in the SBAEP group in quality of life, specifically in the symptom subdomain. CONCLUSIONS: The "Air Force" SBAEP appears to result in a favourable trend in quality of life for children. A larger scale trial is required following revisions to the program.

Inhaled antibiotics in cystic fibrosis: is there a therapeutic effect?

Antibiotics are administered to patients with cystic fibrosis to eliminate or suppress sputum bacteria. Aerosol administration is attractive because it delivers antibiotic directly to the site of infection. Effective aerosol administration is compromised by the inefficiency of nebulizers to generate small-particle aerosols, adverse airway reaction to the drug, potential emergence of resistant bacteria, and cost. Studies evaluating aerosol treatment have not always controlled for confounding factors and have used a variety of outcome indicators. Results of controlled studies are contradictory with regard to the beneficial effect of aerosol therapy on pulmonary function, sputum bacterial density, and frequency of hospitalization. Therefore, until additional well-controlled trials are completed, routine aerosol administration of antibiotics in cystic fibrosis is not warranted because of cost, potential side effects, and the propensity to select resistant organisms.

Utility of gram stain in evaluation of sputa from patients with cystic fibrosis.

The utility of sputum Gram stain in assessing salivary contamination and in predicting the presence of pathogens on the basis of morphology was investigated in 287 respiratory specimens from patients with cystic fibrosis. Where acceptability for culture was defined as a leukocyte/squamous epithelial cell ratio of > 5, 76.6% (220 of 287) of respiratory specimens received in the laboratory were considered acceptable. Unacceptable specimens were more common in younger patients. The positive predictive value of the Gram stain for growth from acceptable sputum samples was 98% for Pseudomonas aeruginosa, 84.4% for Pseudomonas cepacia, 86.3% for Staphylococcus aureus, and 100% for Haemophilus influenzae. In cystic fibrosis patients, as has been reported for respiratory specimens in general, Gram stain of respiratory specimens in helpful for interpreting culture results.

Respiratory function in the prune-belly syndrome.

Respiratory function was evaluated in 11 patients with prune-belly syndrome. Nine had evidence of gas trapping and six of restrictive lung disease. These abnormalities of lung function appear to be secondary to the musculoskeletal disorder associated with prune-belly syndrome rather than parenchymal lung disease.

Outcome of non-invasive positive pressure ventilation in paediatric neuromuscular disease.

BACKGROUND: Non-invasive positive pressure ventilation (NPPV) has a beneficial effect on nocturnal hypoventilation and hospitalisation rates in adults with static or slowly progressive neuromuscular disease and respiratory failure. Its role in children affected with similar disease processes, however, remains unclear. AIMS: To investigate the impact of NPPV on hospitalisations and sleep related respiratory parameters in children with neuromuscular disease. METHODS: Fifteen children (mean age 11.7, range 3.4-17.8 years) diagnosed with neuromuscular disease who had been started on nocturnal NPPV and had at least one year of follow up since the initiation of such therapy were studied. Patients served as their own controls and comparison was made of the years preceding and following the initiation of NPPV. RESULTS: Children spent 85% fewer days in hospital (mean pre-NPPV 48.0 days, mean post-NPPV 7.0 days) and 68% less days in intensive care after initiation of NPPV (mean pre-NPPV 12.0 days, mean post-NPPV 3.9 days). Sleep study parameters including number of desaturations, apnoea-hypopnoea index and transcutaneous pCO2 levels improved after initiation of NPPV. CONCLUSIONS: NPPV can decrease hospitalisations for children with neuromuscular disease and improves sleep related respiratory parameters. A prospective study is now needed to further delineate the role of NPPV in this population of children.

Pseudomonas cepacia infection in cystic fibrosis: an emerging problem.

The prevalence of Pseudomonas cepacia infection increased from 10% in 1971 to 18% by 1981 in a population of approximately 500 patients with cystic fibrosis. Carriage of P. aeruginosa has remained unchanged at 70% to 80% over the same period. Patients infected with P. cepacia have greater impairment of pulmonary function than those with P. aeruginosa. A syndrome characterized by high fever, severe progressive respiratory failure, leukocytosis, and elevated erythrocyte sedimentation rate has occurred in eight patients over the past 3 years, with a 62% fatality rate. Because P. cepacia strains are uniformly resistant to ticarcillin, piperacillin, and aminoglycosides, and because ceftazidime is ineffective despite in vitro activity, treatment of these infections is very difficult. Prevention of acquisition and effective treatment of P. cepacia in patients with cystic fibrosis are now major clinical problems in our clinic.

Pulmonary syndrome in patients with thalassemia major receiving intravenous deferoxamine infusions.

Eight patients with transfusion-dependent thalassemia major were given continuous intravenous infusions of the chelator, deferoxamine mesylate, to reduce iron overload. Within 5 to 9 days of starting the infusions, four patients developed a pulmonary syndrome of moderate to life-threatening severity characterized by tachypnea, hypoxemia, and a diffuse interstitial pattern on chest roentgenogram. Pulmonary function studies showed restrictive dysfunction. Lung biopsy showed diffuse abnormalities with alveolar damage, interstitial fibrosis, and inflammation. The inflammatory infiltrate comprised lymphocytes, eosinophils, and mast cells. Exposure of the biopsy specimen to fluorescein-conjugated anti-IgE antibody showed fixation of IgE to the mast cell surface, suggesting a hypersensitivity reaction. Detailed studies failed to identify an infectious agent. The temporal relationship between drug administration and lung disease, and the clinical similarities in the four affected patients, strongly suggested a cause and effect relationship. We recommend that therapy with continuous intravenous infusions of deferoxamine be monitored carefully with respect to pulmonary status.

Diffuse pulmonary angiomatosis.

A six year old girl with diffuse pulmonary angiomatosis presented with haemoptysis and diffuse interstitial changes with bilateral pleural effusions on the chest radiograph. The lung lesion as seen on biopsy specimens (and confirmed at necropsy) consisted of bloodless, thin walled, endothelium lined channels, affecting the interstitial septae, pleura, bronchi, and adventitia of large vessels. There was no response to oral corticosteroids or a trial of cyclosphamide. This lesion may be an example of an angiogenic disease.

A broader spectrum of abnormalities in the prune belly syndrome.

The clinical course of 25 children with the prune belly syndrome was reviewed retrospectively to assess the over-all morbidity associated with this disorder. There were 3 neonatal deaths of renal or pulmonary disease. Chronic renal insufficiency or end stage renal disease developed in 5 survivors, all of whom had impaired kidney function in early infancy. An additional 17 patients survived with only mild renal insufficiency. Growth retardation, which correlated poorly with renal function, was present in a third of the patients. Clinically significant pulmonary and orthopedic problems were noted in 55 per cent of the survivors. Chronic constipation was another common, although less serious, feature. This report emphasizes the severity of the extrarenal problems associated with the prune belly syndrome.