Sadasivam Suresh

Sleep-related breathing disorder in Duchenne muscular dystrophy: Disease spectrum in the paediatric population

Duchenne muscular dystrophy (DMD) is a progressive neuromuscular disease with death usually occurring because of respiratory failure. Signs of early respiratory insufficiency are usually first detectable in sleep.

Bacterial causes of empyema in children, Australia, 2007-2009

Most infections were caused by non–7-valent pneumococcal conjugate vaccine serotypes.

Central sleep-disordered breathing and the effects of oxygen therapy in infants with Prader-Willi syndrome

Objectives To describe breathing patterns in infants with Prader-Willi Syndrome (PWS), as well as the effects of supplemental oxygen (O2) on breathing patterns. Children with PWS commonly have sleep-disordered breathing, including hypersomnolence and obstructive sleep apnoea, as well as central sleep breathing abnormalities that are present from infancy. Design Retrospective cohort study. Patients Infants with a diagnosis of PWS. Setting Tertiary childrens hospital. Interventions Infants with PWS underwent full polysomnography, and in those with frequent desaturations associated with central events, supplemental O2 during sleep was started and followed with regular split-night studies (periods in both air and O2). Results Thirty split-night studies on 10 infants (8 female) aged 0.06–1.79 (median 0.68, IQR 0.45, 1.07) years were undertaken. At baseline (ie, air), children with PWS had a median (IQR) central apnoea index (CAI) of 4.7 (1.9, 10.6) per hour, with accompanying falls in oxygen saturation (SpO2). O2 therapy led to statistically significant reductions in CAI to 2.5/hour (p=0.002), as well as a reduced central event index (CEI) and improved SpO2. No change in the number of obstructive events was noted. Central events were more prevalent in rapid-eye movement/active sleep. Conclusions It is concluded that infants with PWS may have central sleep-disordered breathing, which, in some children, may cause frequent desaturations. Improvements in CAI and CEI as well as oxygenation were noted with O2 therapy. Longitudinal work with this patient group would help to establish the timing of onset of obstructive symptoms.

Attractor Structure Discriminates Sleep States: Recurrence Plot Analysis Applied to Infant Breathing Patterns

Breathing patterns are characteristically different between infant active sleep (AS) and quiet sleep (QS), and statistical quantifications of interbreath interval (IBI) data have previously been used to discriminate between infant sleep states. It has also been identified that breathing patterns are governed by a nonlinear controller. This study aims to investigate whether nonlinear quantifications of infant IBI data are characteristically different between AS and QS, and whether they may be used to discriminate between these infant sleep states. Polysomnograms were obtained from 24 healthy infants at six months of age. Periods of AS and QS were identified, and IBI data extracted. Recurrence quantification analysis (RQA) was applied to each period, and recurrence calculated for a fixed radius in the range of 0-8 in steps of 0.02, and embedding dimensions of 4, 6, 8, and 16. When a threshold classifier was trained, the RQA variable recurrence was able to correctly classify 94.3% of periods in a test dataset. It was concluded that RQA of IBI data is able to accurately discriminate between infant sleep states. This is a promising step toward development of a minimal-channel automatic sleep state classification system.

Pleural fluid nucleic acid testing enhances pneumococcal surveillance in children

Background and objective:  National surveillance of invasive pneumococcal disease (IPD) includes serotyping Streptococcus pneumoniae (SP) isolates from sterile site cultures. PCR is more sensitive and can identify more SP serotypes (STs) in culture‐negative samples. The aim of this study was to determine whether enhanced surveillance of childhood empyema, using PCR, provides additional serotype information compared with conventional surveillance.

Impact of childhood anthropometry trends on adult lung function

BACKGROUND Poor fetal growth rate is associated with lower respiratory function; however, there is limited understanding of the impact of growth trends and BMI during childhood on adult respiratory function. METHODS The current study data are from the Mater-University of Queensland Study of Pregnancy birth cohort. Prospective data were available from 1,740 young adults who performed standard spirometry at 21 years of age and whose birth weight and weight, height, and BMI at 5, 14, and 21 years of age were available. Catch-up growth was defined as an increase of 0.67 Z score in weight between measurements. The impact of catch-up growth on adult lung function and the relationship between childhood BMI trends and adult lung function were assessed using regression analyses. RESULTS Lung function was higher at 21 years in those demonstrating catch-up growth from birth to 5 years (FVC, men: 5.33 L vs 5.54 L; women: 3.78 L vs 4.03 L; and FEV1, men: 4.52 L/s vs 4.64 L/s; women: 3.31 L/s vs 3.45 L/s). Subjects in the lowest quintile of birth (intrauterine growth retardation) also showed improved lung function if they had catch-up growth in the first 5 years of life. There was a positive correlation between increasing BMI and lung function at 5 years of age. However, in the later measurements when BMI increased into the obese category, a drop in lung function was observed. CONCLUSIONS These data show evidence for a positive contribution of catch-up growth in early life to adult lung function. However, if weight gain or onset of obesity occurs after 5 years of age, an adverse impact on adult lung function is noted.

Sleep disorders in children.

Sleep disorders are very common in childhood and are often amenable to simple advice and parental education. Questions about sleep should be an integral part of every paediatric consultation. Children with underlying syndromes or complex medical conditions often have multiple sleep issues. Excessive sleepiness in children requires careful history‐taking and consideration of specialised investigation. Obstructive sleep apnoea (OSA) is a common condition in childhood with important health implications. The high prevalence of OSA warrants rigorous attempts to identify children at higher risk and manage them appropriately. Adenotonsillectomy is a highly efficacious therapy for paediatric OSA. A current major issue is to improve ways of distinguishing mild from severe OSA before a child undergoes adenotonsillectomy, as those with more severe disease are at increased risk of postoperative complications and should undergo adenotonsillectomy in a tertiary centre. Children with obesity and other comorbid conditions are at increased risk of persisting OSA despite adenotonsillectomy. Topical (nasal) steroids and/or anti‐inflammatory agents have a role in the non‐surgical treatment of mild OSA. Continuous positive airway pressure and orthodontic interventions are treatment options for treatment of persisting OSA in children.

The Impact of Birth Weight on Peak Lung Function in Young Adults

BACKGROUND Poor fetal growth rate, as indicated by lower birth weight, is associated with lower respiratory function in childhood; however, findings in adult life remain inconsistent. A birth cohort provides the opportunity to study the association between birth weight and adult respiratory function. METHODS The present study data are from a longitudinal birth cohort, the Mater-University of Queensland Study of Pregnancy. Prospective data were available from 2,368 young adults who underwent standard spirometry when 21 years old. Pregnancy and birth-related variables collected were birth weight, placental weight, parental height, maternal educational status, maternal smoking history in pregnancy, and maternal history of alcohol, tea, and coffee consumption during pregnancy. The impact of birth weight on adult lung function was assessed using univariate and multivariate analyses. RESULTS For every 100-g increase in birth weight, FVC (95% CI) at 21 years increased by 24 mL (15-32) in men and 20 mL (13-27) in women, and the increase in FEV1 (CI) was 22 mL (15-30) and 16 mL (11-22), respectively. These associations remain after adjusting for lifestyle factors during pregnancy, current smoking, and parental height. However, further adjustment for adult height reduces the strength of association and remains significant for FEV1: 8 mL (1-14) in men and 5 mL (1-10) in women, but not for FVC: 7 mL (-1-14) in men and 5 mL (-1-11) in women. CONCLUSION Our longitudinal cohort study provides evidence of robust links between birth weight and adult lung function at the age of 21 years. Various estimates of the effect size in the literature may be related to the age at assessment.

A bedside assay to detect streptococcus pneumoniae in children with empyema

Empyema is a complication of pneumonia, commonly caused by Streptococcus pneumoniae.

Congenital central hypoventilation syndrome: four families.

BackgroundCongenital central hypoventilation syndrome (CCHS) is a rare condition that usually presents soon after birth and is potentially life-shortening if not treated. The defining abnormality is hypoventilation during sleep which requires life-long treatment with artificial ventilation. This syndrome may also be associated with generalised dysfunction of the autonomic nervous system and a sub-group with associated Hirschsprung’s disease. The genetic basis of CCHS has been identified as mutations in the PHOX2B gene.MethodsWe present four families, three with autosomal dominant inheritance and familial clustering, and one with a de novo mutation resulting in CCHS.ConclusionsWe demonstrate that nasal mask ventilation from birth can provide adequate treatment and improved quality of life for these children. Phenotypic variability in expression of disease is seen in families with the same mutations in PHOX2B gene. The psychosocial costs of the disease and the unrecognised ‘morbidity barter’ that is part of current management needs to be factored into in all stages of management from childhood to adolescence to adulthood.