Referral indications and prevalence of sleep abnormalities in children with early onset scoliosis.

This study describes the utility of overnight sleep studies in children with early onset scoliosis (EOS). Children with EOS have diminished respiratory reserve which is associated with abnormal breathing and sleep quality in children. Currently, there are no criteria for referral of these children to evaluate breathing during sleep or data on the use of sleep treatments as part of their supportive care. A review of the 159 patients with EOS who were followed at a single institution from 2003 to 2016 identified 68 who underwent overnight polysomnograms (PSGs). Sixty-five of 68 (96%) had elevated apnea-hypopnea index (AHI) and a majority (56%) were prescribed nighttime respiratory support. A majority of young children (< 5 years) with PSG were referred for a history of snoring, apnea, or restless sleep; all 30 had abnormal PSGs. Twenty-seven (90%) had nighttime hypoxemia (nadir oxygen saturation values < 92%). Eighteen (60%) were referred to otolaryngology, of whom 11 (37%) subsequently underwent tonsil and/or adenoid removal. In older children (≥ 5 years), those referred for PSGs had more severe restrictive chest wall disease [lower forced vital capacity (FVC) values] than those who were not sent for PSG. Correlation between FVC and apnea-hypopnea index, however, was not significant. Pre-operative coronal curve magnitude did not strongly correlate with nadir SaO2 or AHI in either age group. These results suggest that sleep studies are underutilized in the management of children with EOS. Inadequate and poor-quality sleep adversely affects growth, behavior, and cognitive function in children. This study suggests that screening for sleep abnormalities should be incorporated into assessment and treatment of more patients with EOS.

Lung disease in indigenous children.

Children in indigenous populations have substantially higher respiratory morbidity than non-indigenous children. Indigenous children have more frequent respiratory infections that are, more severe and, associated with long-term sequelae. Post-infectious sequelae such as chronic suppurative lung disease and bronchiectasis are especially prevalent among indigenous groups and have lifelong impact on lung function. Also, although estimates of asthma prevalence among indigenous children are similar to non-indigenous groups the morbidity of asthma is higher in indigenous children. To reduce the morbidity of respiratory illness, best-practice medicine is essential in addition to improving socio-economic factors, (eg household crowding), tobacco smoke exposure, and access to health care and illness prevention programs that likely contribute to these issues. Although each indigenous group may have unique health beliefs and interfaces with modern health care, a culturally sensitive and community-based comprehensive care system of preventive and long term care can improve outcomes for all these conditions. This article focuses on common respiratory conditions encountered by indigenous children living in affluent countries where data is available.

Exhaled nitric oxide predicts persistence of wheezing, exacerbations, and decline in lung function in wheezy infants and toddlers.

BACKGROUND: There are limited data assessing the predictive value of fraction of exhaled nitric oxide (FENO ) for persistence of wheezing, exacerbations, or lung function change over time in infants/toddlers with recurrent wheezing. OBJECTIVES: In an ongoing longitudinal cohort of infants and toddlers with recurrent wheezing, we compared predictive values of single-breath FENO (SB-FENO ), tidal-breathing mixed expired FENO (tidal-FENO ), bronchodilator responsiveness (BDR) and the Castro-Rodriquez Asthma Predictive Index (API) for persistence of wheezing, exacerbations and lung function change through age 3 years. METHODS: Enrolment forced expiratory flows and volumes infant pulmonary function tests (iPFTs) were measured in 44 infants/toddlers using the raised volume rapid thoracoabdominal compression method. SB-FENO was measured at 50 mL/s, and tidal-FENO was measured during awake tidal breathing. Clinical outcomes were assessed at age 3 years in 42 infants. Follow-up iPFTs were completed between ages 2.5-3 years in 32 subjects. RESULTS: An enrolment SB-FENO concentration ≥ 30 p.p.b. predicted persistence of wheezing at age 3 years with a sensitivity of 77%, a specificity of 94%, and an area under the curve (AUC) of 0.86 (95% CI: 0.74-0.98). The sensitivity, specificity, positive predictive, and negative predictive values of SB-FENO for persistence of wheezing and exacerbations were superior to tidal-FENO , BDR, and the API. SB-FENO ≥ 30 p.p.b. and tidal-FENO ≥ 7 p.p.b. measured at enrolment was associated with a decline in both FEV0.5 and FEF25-75 between enrolment and age 3 years. CONCLUSIONS: In wheezy infants/toddlers, SB-FENO was superior to tidal-FENO , BDR, and the API in predicting future exacerbations and persistence of wheezing at age 3 years. Both SB-FENO and tidal-FENO were associated with lung function decline over time.

Temporal and spatial metabolic rate variation in the Antarctic springtail Gomphiocephalus hodgsoni.

Spatial and temporal environmental variation in terrestrial Antarctic ecosystems are known to impact species strongly at a local scale, but the ways in which organisms respond (e.g. physiologically, behaviourally) to such variation are poorly understood. Further, very few studies have attempted to assess inter-annual variability of such responses. Building on previous work demonstrating intra-seasonal variation in standard metabolic rate in the springtail Gomphiocephalushodgsoni, we investigated variation in metabolic activity of G. hodgsoni across two austral summer periods at Cape Bird, Ross Island. We also examined the influence of spatial variation by comparing metabolic rates of G. hodgsoni at Cape Bird with those from two other isolated continental locations within Victoria Land (Garwood and Taylor Valleys). We found significant differences between metabolic rates across the 2 years of measurement at Cape Bird. In addition, standard metabolic rates of G. hodgsoni obtained from Garwood and Taylor Valleys were significantly higher than those at Cape Bird where habitats are comparable, but environmental characteristics differ (e.g. microclimatic temperatures are higher). We discuss potential underlying causes of these metabolic rate variation patterns, including those related to differences among individuals (e.g. physiological and genetic differences), locations (e.g. habitat quality and microclimatic regime differences) and populations (e.g. acclimation differences among G. hodgsoni populations in the form of metabolic cold adaptation (MCA)).

Temporal metabolic rate variation in a continental Antarctic springtail.

Terrestrial systems in Antarctica are characterized by substantial spatial and temporal variation. However, few studies have addressed the paucity of data on metabolic responses to the unpredictable Antarctic environment, particularly with regard to terrestrial biota. This study measured metabolic rate variation for individual springtails at a continental Antarctic site using a fiber-optic closed respirometry system incorporating a custom-made respiration chamber. Concurrent measures of (behavioural) activity were made via daily pitfall counts. Metabolic rate of Gomphiocephalus hodgsoni measured at constant temperature varied systematically with progression through the austral summer, and was greatest mid-season. This finding of clear intra-seasonal and temperature-independent variation in mass-specific metabolic rate in G. hodgsoni is one of very few such reports for a terrestrial invertebrate (and the only such study for Antarctica), and parallels physiological studies in the Antarctic marine environment linking metabolic rate elevation with biological function rather than temperature adaptation per se. However, response to temperature at relatively short time-scales is also likely to be an important part of the life history strategy of Antarctic terrestrial invertebrates such as G. hodgsoni, which appears capable of both physiologically and behaviourally 'tuning' in to short-term thermal variability to respond appropriately to the local unpredictable Antarctic habitat.

Chronic wet cough: Protracted bronchitis, chronic suppurative lung disease and bronchiectasis.

The role of persistent and recurrent bacterial infection of the conducting airways (endobronchial infection) in the causation of chronic respiratory symptoms, particularly chronic wet cough, has received very little attention over recent decades other than in the context of cystic fibrosis (CF). This is probably related (at least in part) to the (a) reduction in non-CF bronchiectasis in affluent countries and, (b) intense focus on asthma. In addition failure to characterize endobronchial infections has led to under-recognition and lack of research. The following article describes our current perspective of inter-related endobronchial infections causing chronic wet cough; persistent bacterial bronchitis (PBB), chronic suppurative lung disease (CSLD) and bronchiectasis. In all three conditions, impaired muco-ciliary clearance seems to be the common risk factor that provides organisms the opportunity to colonize the lower airway. Respiratory infections in early childhood would appear to be the most common initiating event but other conditions (e.g., tracheobronchomalacia, neuromuscular disease) increases the risk of bacterial colonization. Clinically these conditions overlap and the eventual diagnosis is evident only with further investigations and long term follow up. However whether these conditions are different conditions or reflect severity as part of a spectrum is yet to be determined. Also misdiagnosis of asthma is common and the diagnostic process is further complicated by the fact that the co-existence of asthma is not uncommon. The principles of managing PBB, CSLD and bronchiectasis are the same. Further work is required to improve recognition, diagnosis and management of these causes of chronic wet cough in children.

Mathematical modelling of oxygen transport-limited follicle growth.

Mathematical modelling was used to investigate oxygen transport in the developing ovarian follicle. In contrast to previous findings, the results show that oxygen can reach the oocyte in large preantral follicles. This is largely due to the inclusion of fluid voidage in the model and improved estimates of oxygen diffusion coefficients through the granulosa. The results also demonstrate that preantral follicles will eventually reach a size beyond which further growth will result in the follicle becoming increasingly anoxic. The predicted size range at which this occurs is consistent with the size range at which antrum formation is observed in many mammals. This suggests that the antrum formation stage of follicular growth may be pivotal to the further development and ultimate fate of the follicle, and that antrum formation itself may represent a mechanism by which the follicle can overcome oxygen limitations. This was supported through extension of the model to the antral follicle, which showed that antrum formation can provide a way in which the follicle can continue to grow and yet avoid becoming hypoxic. The results of the model were consistent with observed follicle development.

Comparison of local risk factors for children's atopic symptoms in Hanoi, Vietnam.

BACKGROUND: A 1999 study in Hanoi, Vietnam using the International Study on Asthma and Allergies in Childhood (ISAAC) questionnaire showed a high prevalence of atopic symptoms. Identifying risk factors for symptoms in these children may help in understanding the causes for these high estimates. METHODS: An ISAAC questionnaire with supplemental questions on environmental variables was distributed to 5495 school children in Hanoi and a suburban district, Dong Anh. The response rate was 65.7%. RESULTS: In Dong Anh, the following were among the significant age and gender adjusted associations: pig ownership [odds ratio (OR) (95% confidence interval), OR = 1.79 (1.18-2.70) for doctor-diagnosed asthma (DDA), OR = 1.72 (1.08-2.78) for doctor diagnosed hay fever (DDHF)] and farming [OR = 1.67 (1.27-2.19) for ever asthma, OR = 1.51 (1.09-2.09) for DDHF]. In multivariate models, tuberculosis (TB) was a significant predictor of atopic symptoms [Hanoi: OR = 3.09 (1.10-8.70) for DDA, Dong Anh: OR = 3.71 (1.40-9.84) for DDA, OR = 4.66 (1.88-11.57) for DDHF]. CONCLUSIONS: These findings are contrary to the "hygiene hypothesis". Recent immunologic and epidemiologic studies refute the inverse association between allergy and TB and may be one explanation for the positive association in this study. The positive association with pig ownership and farming may be because of exposures on farms in a developing country that may be different from exposures in farms of developed countries.

Calibration and alignment are separable: evidence from prism adaptation.

In 2 prism adaptation experiments, the authors investigated the effects of limb starting position visibility (visible or not visible) and visual feedback availability (early or late in target pointing movements). Thirty-two students participated in Experiment 1 and 24 students participated in Experiment 2. Independent of visual feedback availability, constant error was larger and variable error was smaller for target pointing when limb starting position was visible during prism exposure. Independent of limb starting position visibility, aftereffects of prism exposure were determined by visual feedback availability. Those results support the hypothesis that calibration is determined by limb starting position visibility, whereas alignment is determined separately by visual feedback availability.

Differences in asthma prevalence between samples of American Indian and Alaska Native children.

OBJECTIVES: To better understand the prevalence of asthma among American Indian and Alaska Native (AI/AN) children and to explore the contribution of locale to asthma symptoms and diagnostic assignment, the authors surveyed AI/AN middle school students, comparing responses from metropolitan Tacoma, Washington (metro WA) and a non-metropolitan area of Alaska (non-metro AK). METHODS: Students in grades 6-9 completed an asthma screening survey. The authors compared self-reported rates of asthma symptoms, asthma diagnoses, and health care utilization for 147 children ages 11-16 self-reporting as AI/AN in metro WA and 365 in non-metro AK. RESULTS: The prevalences of self-reported asthma symptoms were similar for the metro WA and non-metro AK populations, but a significantly higher percentage of metro WA than of non-metro AK respondents reported having received a physician diagnosis of asthma (OR 2.33; 95% CI 1.23, 4.39). The percentages of respondents who reported having visited a medical provider for asthma-like symptoms in the previous year did not differ. CONCLUSIONS: The difference in rates of asthma diagnosis despite similar rates of asthma symptoms and respiratory-related medical visits may reflect differences in respiratory disease patterns, diagnostic labeling practices, or environmental factors. Future attempts to describe asthma prevalence should consider the potential contribution of non-biologic factors such as diagnostic practices.

Current concepts in adult respiratory distress syndrome in children.

Acute respiratory distress syndrome (ARDS) is an acute form of severe alveolar-capillary injury that evolves after a direct or indirect lung insult. It begins as noncardiogenic pulmonary edema and develops into a neutrophilic alveolitis, and, later, pulmonary fibrosis. Mortality remains high among children with ARDS, particularly when serious underlying conditions co-exist, sepsis occurs, and when there is multi-organ failure. Lung function improves with time among survivors, but pulmonary fibrosis may persist. Advances in the care of children with ARDS include the use of lung-protective ventilator strategies, permissive hypercapnia, inhaled nitric oxide, high-frequency ventilation, and extra-corporeal life support. These approaches reduce ventilator-associated lung injury and may improve survival when used in combination with one another. Interventions that reduce alveolar inflammation, enhance alveolar fluid removal, and reduce pulmonary fibrosis will further improve survival and recovery from ARDS in the future.

Prism exposure aftereffects and direct effects for different movement and feedback times.

The effects of movement time and time to visual feedback (feedback time) on prism exposure aftereffects and direct effects were studied. In Experiment 1, the participants' (N = 60) pointing limb became visible early in the movement (.2-s feedback time), and eye-head aftereffects increased with increasing movement time (.5 to 3.0 s), but larger hand-head aftereffects showed little change. Direct effects (terminal error during exposure) showed near-perfect compensation for the prismatic displacement (11.4 diopters) when movement time was short but decreasing compensation with longer movement times. In Experiment 2, participants' (N = 48) eye-head aftereffects increased and their larger hand-head aftereffects decreased with increasing movement time (2.0 and 3.0 s), especially when feedback time increased (.25 and 1.5 s). Direct effects showed increasing overcompensation for longer movement and feedback times. Those results suggest that aftereffects and direct effects measure distinct adaptive processes, namely, spatial realignment and strategic control, respectively. Differences in movement and feedback times evoke different eye-hand coordination strategies and consequent direct effects. Realignment aftereffects also depend upon the coordination strategy deployed, but not all strategies support realignment. Moreover, realignment is transparent to strategic control and, when added to strategic correction, may produce nonadaptive performance.

Practice of pediatric pulmonology: results of the Future of Pediatric Education Project (FOPE)

In 1996, the Future of Pediatric Education (FOPE) Project of the American Academy of Pediatrics (AAP) developed surveys to describe the nature of pediatric practices, recent trends in clinical practice, and anticipated workforce needs for both pediatric generalists and pediatric sub-specialists. A survey was specifically developed to describe the features of pediatric pulmonology as self-reported by pediatric pulmonologists. The survey was distributed to members of the AAP Pulmonology Section, the Pediatric Assembly of the American Thoracic Society, and certified pediatric pulmonologists recognized by the American Board of Pediatrics. Of the 535 respondents (67% of those invited to respond), the responses of 388 certified and 94 trained but not board-certified pulmonologists were included in the results. The characteristics of certified and non-certified respondents were the same for most survey questions. Clinical activities occupy 73 +/- 29% of professional time. Most pulmonologists work in urban, inner city, or suburban settings and 85% are affiliated with a medical school. One third are in private practice. As a group, research activities occupy less than 15% of their time. Most pediatric pulmonologists maintain a referral practice and use physician extenders to provide care. Patients with asthma and cystic fibrosis comprise 60-70% of patient volume. Both the volume and complexity of patients are increasing, as is competition for pediatric sub-specialty services. Pediatric pulmonary practices vary in size and in volume of patients that they manage in various settings. Forty percent of respondents identify allergists and other pediatric pulmonologists as sources of competition. Sixty-nine percent of respondents do not believe that there is a current need for additional pediatric pulmonologists in their respective communities. Only 15% of respondents plan to retire in the next decade.

Bronchiectasis in Alaska Native children: causes and clinical courses.

Although bronchiectasis has become a rare condition in U.S. children, it is still commonly diagnosed in Alaska Native children in the Yukon Kuskokwim Delta. The prevalence of bronchiectasis has not decreased in persons born during the 1980s as compared with those born in the 1940s. We reviewed case histories of 46 children with bronchiectasis. We observed that recurrent pneumonia was the major preceding medical condition in 85% of patients. There was an association between the lobes affected by pneumonia and the lobes affected by bronchiectasis. Eight (17%) patients had surgical resection of involved lobes. We conclude that the continued high prevalence of bronchiectasis appears to be related to extremely high rates of infant and childhood pneumonia. Pediatr Pulmonol. 2000;29:182-187. Published 2000 Wiley-Liss, Inc.

Impact of respiratory syncytial virus immune globulin in 1996-1997: a local controlled comparison.

BACKGROUND: Immune globulin containing high titers of neutralizing antibodies specific for respiratory syncytial virus (RSV) is clinically used to prevent hospitalizations for RSV-related respiratory infections among high-risk infants. However, recommendations regarding which patient populations should receive RSV immune globulin are inconsistent. OBJECTIVE: To compare hospitalization rates for prematurely born infants with and without chronic lung disease who received RSV immune globulin with similar infants whose parents refused such treatment during the 1996-1997 winter season. DESIGN: Inception cohort study. PARTICIPANTS: Infants born at less than 35 weeks' gestation and less than 6 months old without lung disease and children who had been born prematurely, had chronic respiratory disease, and were less than 2 years old at the onset of the RSV season. MAIN OUTCOME MEASURE: Hospitalization for an RSV-related respiratory illness. RESULTS: Seventy-six infants (66 [87%] with chronic lung disease and 10 [13%] born prematurely without lung disease) received RSV immune globulin; 65 infants (18 [28%] with chronic lung disease and 47 [72%] born prematurely without lung disease) did not. Three (4%) of the treated group and 2 (3%) of the untreated group were hospitalized for RSV infections. Of those with chronic lung disease, 5% (3/66) of those treated with RSV immune globulin were hospitalized, compared with 11% (2/18) of those untreated. Of those born prematurely without lung disease, no infant in the treated (0/10) or untreated (0/47) group was hospitalized. CONCLUSIONS: The risk of hospitalization of infants born prematurely who are younger than 6 months without lung disease is low. Current recommendations for preventing RSV illness in this group by using RSV immune globulin may require inclusion of more specific clinical characteristics rather than gestational age alone.

Comparison of a beta-lactam alone versus beta-lactam and an aminoglycoside for pulmonary exacerbation in cystic fibrosis.

UNLABELLED: We determined whether a beta-lactam and an aminoglycoside have efficacy greater than a beta-lactam alone in the management of a pulmonary exacerbation in patients with cystic fibrosis. STUDY DESIGN: Azlocillin and placebo or azlocillin and tobramycin were administered to 76 patients with a pulmonary exacerbation caused by Pseudomonas aeruginosa in a randomized double-blind, third-party monitored protocol. Improvement was assessed by standardized clinical evaluation, pulmonary function testing, sputum bacterial density, sputum DNA content, and time to the next pulmonary exacerbation requiring hospitalization. RESULTS: No significant difference was seen between the 2 treatment groups in clinical evaluation, sputum DNA concentration, forced vital capacity, forced expiratory volume in second 1, or peak expiratory flow rate at the end of treatment (33 receiving azlocillin alone and 43 both antibiotics); adverse reactions were equivalent in each group. Sputum P. aeruginosa density decreased more with combination therapy (P =.034). On follow-up evaluation, an average of 26 days after the end of treatment, all outcome indicators had worsened in both groups. Time to readmission for a new pulmonary exacerbation was significantly longer in the group receiving azlocillin plus tobramycin (P <.001). Treatment-emergent tobramycin resistance occurred in both groups and was more frequent with combination therapy. CONCLUSION: We conclude that the combination of a beta-lactam and an aminoglycoside produces a longer clinical remission than a beta-lactam alone and slightly better initial improvement.

The impact of asthma and asthma-like illness in Seattle school children.

The impact of asthma and asthma-like illness was measured in a population of 5-9-year-old Seattle public school children. Child health information was obtained from a survey of 1665 parents of first and second grade students to assess medical services use and impaired physical functioning among diagnosed asthmatics and those with current wheezing, defined as wheezing in the past 12 months without a diagnosis of asthma, relative to an asymptomatic population with neither condition. Relative to the asymptomatic population, the prevalence of respiratory-related activity limitation, and perception of poorer child health was larger among diagnosed asthmatics than children with current wheezing. However, the prevalence of sleep disturbances, school absences, medical services use, and parental concern over their child's health was similar for both the asthmatic and wheezing groups relative to the asymptomatic group. Also, in both symptomatic groups, a history of moderate or severe wheezing was associated with an increased prevalence of respiratory-related sleep disturbances and activity limitation. The similarity between the impact of diagnosed asthma and undiagnosed asthma-like illness suggests that the overall social and economic burden of asthma may be higher than previously estimated.

The Asthma Outreach Project: a promising approach to comprehensive asthma management.

We describe a pilot system of coordinated asthma care emphasizing home visits by a community-based lay worker collaborating with a pediatrician, pharmacist, and public health nurse. Study participants included 23 low-income children with moderate to severe asthma and their families at an inner-city pediatric clinic. This system was successfully implemented, and client satisfaction was extremely high. Utilization review showed a reduction in hospitalizations, emergency department visits, and unscheduled clinic visits, and an increase in follow-up clinic visits. This model of care may reduce unscheduled service use and deserves further study as an alternative for asthma management among similar patient populations.

Phenomenal versus process explanations of prism aftereffects.

The phenomenal hypothesis that prism aftereffects depend upon sight of the limb was tested in a ball-throwing task during prism exposure; the participant's (N = 28) limb was either visible or not visible, but feedback from the moving ball was available during the exposure. Aftereffects were clearly demonstrated in both the visible- and nonvisible-limb conditions, and total aftereffect was larger for participants in the nonvisible-limb condition. Proprioceptive aftereffects were greater than visual aftereffects in the visible-limb group; however, the reverse was true for the nonvisible-limb group. Those results support a processing hypothesis in which sensory feedback, not phenomenal experience, is necessary.