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.

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.

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.

Indoor risk factors for asthma and wheezing among Seattle school children.

Indoor risk factors for physician-diagnosed asthma and wheezing in the past 12 months without previous asthma diagnosis were assessed in a survey of parents of 5-9-year-old Seattle primary school students. Among the 925 respondents, 106 (11%) reported a physician diagnosis of asthma, 66 (7%) had wheezing without diagnosis, and 753 (82%) were asymptomatic. After adjusting for age, sex, gender, ethnicity, medical history, socioeconomic status (SES) and parental asthma status, an increased risk of physician diagnosis of asthma was associated with household water damage, the presence of one or more household tobacco smokers, and at least occasional environmental tobacco smoke (ETS) exposure. Similarly, an increased risk of wheezing in the past 12 months among children without diagnosed asthma was associated with household water damage, presence of one or more household tobacco smokers, and occasional or more frequent ETS exposure. No increased risk of either condition was associated with gas, wood, or kerosene stove use, household mold, basement water, or wall/window dampness. Similarities in the indoor risk factors patterns between diagnosed asthma and wheezing without diagnosis suggested a similar etiology of these two conditions. The slightly higher association between ETS and asthma may indicate that parents of diagnosed asthmatics were more conscious of ETS, and were more likely to prohibit household smoking by resident smokers. Future research is needed to quantify which aspects of household water damage are related to respiratory illness.

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.

Factors associated with prolonged hospitalization of children with asthma.

OBJECTIVE: To identify clinical features of asthma present before arrival in the emergency department, at the time of emergency department treatment, and during hospitalization that differ between children with asthma hospitalized for a prolonged period and those hospitalized for an average duration. DESIGN: Retrospective chart review. PATIENTS AND SETTING: Hospital records of patients with asthma (International Classification of Diseases, Ninth Revision, code 493) admitted to Children's Hospital and Medical Center, Seattle, Wash, from October 1989 to September 1991. RESULTS: The medical records of 23 children hospitalized from October 1989 to September 1991 for more than 4 days with acute asthma were compared with those of 62 sex- and age-matched children hospitalized for 2 days. Patients in the long-stay and short-stay groups had similar histories of home medication use. The presence of asthma symptoms before arrival in the emergency department was prolonged in the long-stay group (P < .001). Only one of the 23 patients in the long-stay group had augmented asthma treatment within 24 hours before hospitalization, compared with 39 of the 62 patients with short stays (P < .001). During hospitalization, a greater proportion of children in the long-stay group than the short-stay group received supplemental oxygen (P < .01). More children in the long-stay group than the short-stay group had residual hypoxemia (arterial oxygen saturation, < 94%) in room air at discharge, suggesting that hospital stay was not prolonged to reach normal oxygen saturations. None of the children were readmitted within 1 month of their index admission. CONCLUSIONS: Early augmentation of home therapy for acute asthma is associated with a reduced duration of hospitalization for children admitted with asthma. In addition, hypoxemia in children with acute asthma on presentation and during hospitalization is associated with prolonged hospital stay.

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.

Passive smoke exposure impairs recovery after hospitalization for acute asthma.

OBJECTIVE: To determine if children with chronic asthma hospitalized for an acute exacerbation experienced prolonged clinical recovery after hospital discharge if they returned to a home environment in which they were exposed to environmental tobacco smoke. DESIGN: A prospective longitudinal study. SETTING: Children's Hospital and Medical Center, Seattle, Wash. PATIENTS: Patients admitted to the emergency department of the Children's Hospital and Medical Center with the single diagnosis of asthma (International Classification of Diseases, Ninth Revision [ICD-9] code 493). RESULTS: Twenty-two children with acute asthma were sequentially enrolled in the study and longitudinally observed between February and -June 1994. The tobacco-smoking group (n = 11) was defined as having at least 1 smoker in the home. The nonsmoking group (n = 11) had no environmental tobacco smoke exposure at home. The 2 groups were similar in age, sex, preadmission chronic asthma severity, and immediate predischarge asthma status. Discharge medication use was similar in the 2 groups During a 1 month follow-up period, the tobacco-smoking group had a significantly greater number of symptomatic days than the nonsmoking group (P < .05) Of the children in the nonsmoking group, 9 (82%) had less than 1 symptomatic day per week compared with 3 (27%) in the tobacco-smoking group. beta 2-Agonist bronchodilator use declined significantly (P < .001) during follow-up in the nonsmoking group but not in the tobacco-smoking group, despite similar anti-inflammatory drug therapy in both groups. CONCLUSIONS: Recovery by children after hospitalization for acute asthma is impaired by environmental tobacco smoke exposure when the period of recovery is characterized by persistent respiratory symptoms and use of asthma medication for symptomatic relief. These findings underscore the need to limit environmental tobacco smoke exposure in children with asthma and argue for closer physician follow-up of those children returning to a home environment in which smokers are present.

Effects of hyperoxia on vasoconstriction and VA/Q matching in the neonatal lung.

Exposure of adult animals to 48-72 h of 100% O2 breathing is associated with a blunting of hypoxic pulmonary vasoconstriction (HPV) (Newman et al. J. Appl. Physiol. 54: 1379-1386, 1983). It is unknown whether HPV is also diminished in neonates after hyperoxic exposure and if so to what extent such suppression might interfere with pulmonary gas exchange during hypoxic gas breathing. We tested the possibility that hyperoxia would suppress HPV and interfere with ventilation-perfusion (VA/Q) matching and therefore gas exchange in neonatal piglets. Twelve 2- to 4-wk-old piglets were exposed for an average of 68 h to greater than 90% inspired O2. A control group of eight piglets was exposed to room air for a similar period of time. Immediately after exposure the animals were anesthetized and instrumented. Pulmonary hemodynamics and respiratory and inert gas exchange were assessed while the animals inspired an O2 fraction of 1.0, 0.21, and 0.12. After 20 min of hypoxic gas breathing, pulmonary arterial pressure rose to a lesser degree in the hyperoxia (H)-exposed animals than in the control (C) animals (P less than 0.02). The increase in pulmonary vascular resistance was similarly blunted. Venous admixture of the insoluble inert gas, sulfur hexafluoride, an index of extremely low VA/Q areas, was increased during hypoxic gas breathing compared with room air breathing in the H-preexposed animals (P less than 0.02). Standard deviation of pulmonary blood flow was increased (P less than 0.02), indicating an increase in mismatching of VA/Q during hypoxic breathing in the H-preexposed animals compared with the C animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Additivity in adaptation to optical tilt.

Tests of proprioceptive adaptation (head-hand), visual adaptation (eye-head), and both components (eye-hand) were made during 15-min exposure to 20 degrees tilt in two experiments. In both experiments, subjects alternated exposures in which they explored hallways (hall) or viewed their active hand (hand), but in Experiment 2 subjects received two exposures to each condition, while in Experiment 1 only one exposure was given. Hall exposure produced greater visual change, and hand exposure produced greater proprioceptive change; but in both conditions, when order of conditions was controlled, the sum of performance on visual and proprioceptive tests was not statistically different from performance on the common test. In Experiment 2, adaptive components appeared to be inversely related, both within and between exposure conditions, thus providing some evidence of a reciprocal relationship, but a reliable negative correlation between components was not found. Finally, adaptation increased over alternation-repetition of exposure tasks in the second experiment, even though adaptation appeared limited within any given exposure. Results are interpreted in terms of the linear model, and the possible role of attentional factors in processing sensory inconsistencies is discussed.

Effects of homogeneous and variable exposure on magnitude of adaptation to optical tilt.

Repeated exposure to hallway exploration, alternated with periods of either watching the active hand or exploring a different set of hallways, maintains increasing visual adaptation beyond the point in time at which previous studies using homogeneous exposure have found such visual shift (VS) to be asymptotic. Experiment 1 established that this alternation-repetition effect does not depend on an actual change in task (hall to hand) but also occurs when the task context alone is changed (hall to hall). Experiment 2 compared variable (hall-to-hall) exposure with homogeneous (hall) exposure, showing that variable exposure removes the usual limit on adaptation. In both experiments, proprioceptive shift (PS) and total negative aftereffect (NA) both tended to be less than VS, producing substantial overadditivity (i.e., VS + PS greater than NA). General requirements for an attentional explanation of the alternation-repetition effect are outlined, and possible explanations of overadditivity consistent with the linear model are discussed.

Adaptive spatial alignment and strategic perceptual-motor control.

When starting limb and target locations were simultaneously visible in a visuomotor task, performance during prism exposure was nearly perfect, but aftereffects were absent. When starting limb location was not visible, accurate exposure performance was slow to develop, but aftereffects were substantial. Adaptive spatial alignment of sensorimotor spaces and strategic perceptual-motor control to coordinate sensorimotor systems are distinct processes. However, realignment is dependent on whether the exposure task evokes control strategies that enable detection of misalignment. If the task can be performed solely by coding the visible difference between limb and target locations, misalignment detection is disabled. If movement is initiated by target location and then the limb is controlled by the visible difference between target and limb, the discordance between initialized and terminal locations enables misalignment detection and realignment.

Processing line location and orientation.

For stimulus dimensions of line location and orientation with both card-sorting and discrete reaction-time trials, facilitation occurred when dimensions were positively correlated, and interference appeared when dimensions varied orthogonally. Interference could not be attributed to differential sensory accrual arising from positional uncertainty or to a repetition-effects advantage for control over orthogonal conditions. Facilitation tended to disappear when the same response was not required for the two dimensions, and when competing responses were required, interference appeared with redundant dimensions (negatively correlated stimulus sets). These data seem consistent with a model that calls for automatic and parallel extraction of features and their locations, with facilitation-interference effects having their locus in postperceptual response processing.

Mechanisms for precuing superiority in visual recognition.

Superior recognition, when similar alternatives are studied prior to brief target pictures of common objects, is usually attributed to selective feature analysis, which is beneficial only when the target is not readily discriminable in the alternatives. The present study found equal precuing superiority, however, for similar and dissimilar alternatives with abstract geometric stimuli, and with pictures of common objects, precuing superiority occurred only when each alternative represented the same semantic category. Precuing effects did not appear when different categories were represented in the alternatives, and performance was similar to other conditions in which only a categorical match between target and alternatives was possible. These results suggest that selective feature analysis and precuing superiority only occur when the target cannot be identified by its semantic category. With dissimilar alternatives activation of the target's category can be used to select a response, and there is no benefit from precuing.

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.

Safety of aerosol tobramycin administration for 3 months to patients with cystic fibrosis.

To determine the potential toxicity of prolonged aerosol tobramycin administration, 22 patients with cystic fibrosis were monitored while receiving inhaled tobramycin three times a day for 12 weeks. Prior to, four times during administration and approximately 6 weeks after discontinuation of treatment, we assessed pulmonary function, weight, height, body temperature, eighth cranial nerve function, serum creatinine, blood urea nitrogen, urinary creatinine clearance, plasma iothalamate clearance, urinary beta-2 microglobulin concentration, and Pseudomonas aeruginosa density in sputum. There was no detectable laboratory evidence of nephrotoxicity. Neither a decrease in auditory acuity (range 250-20,000 Hz) nor vestibular dysfunction was detected. Pulmonary function tests significantly improved during the first month in all subjects (P less than 0.05) but returned to enrollment values by the end of the 12th week of administration of tobramycin aerosol. Sputum P. aeruginosa density initially decreased from a mean of 10(7) cfu/gm to a mean of 10(4) cfu/gm after 2 weeks of aerosol tobramycin administration and remained significantly below the enrollment value throughout. Coincident with the reduced bacterial density, a reduction in cough frequency and sputum production, as well as a weight gain was observed. Seventy-three percent of the patients with sputum P. aeruginosa isolates susceptible to tobramycin on enrollment yielded resistant organisms during aerosol administration. However, 1 year later all sputum P. aeruginosa isolates obtained from patients were susceptible to tobramycin. We conclude that thrice daily aerosol tobramycin administration for 3 months is not associated with detectable eighth cranial nerve or renal toxicity. Transient emergence of tobramycin resistant P. aeruginosa may occur.

Effect of amrinone during group B Streptococcus-induced pulmonary hypertension in piglets.

Intravenous infusion of group B Streptococcus (GBS) into neonatal animals produces pulmonary hypertension, ventilation/perfusion (VA/Q) mismatch, and an increase in serum levels of thromboxane B2 (TxB2) and tumor necrosis factor (TNF) alpha. The vasodilator amrinone (amr) is a cGMP-inhibited phosphodiesterase inhibitor and is reported to inhibit thromboxane A2 and TNF production. We hypothesized that infusion of amr would cause pulmonary vasodilation and reduce serum TxB2 and TNF levels in piglets with late phase GBS-induced pulmonary hypertension. The effect of amr on gas exchange was also determined. A continuous infusion of GBS was administered for 5 hr to 4 groups of anesthetized, mechanically ventilated neonatal piglets. An amr bolus of 8 mg/kg was given at 4 hr followed by a 1 hr continuous infusion of either 10 or 20 micrograms/kg/min of amr (amr 10 and amr 20, respectively). Control piglets received a bolus and 1 hr infusion of amr carrier. The infusion of amr, but not of carrier reversed late phase GBS-induced pulmonary hypertension. Piglets infused with amr 20 showed transient selective pulmonary vasodilation, based on a reduced ratio of pulmonary to systemic vascular resistance (PVR/SVR ratio) value at 30 min but not at 1 hr, compared to pre-amr treatment values. The PVR/SVR ratio values for amr 10 and control group did not change after treatment with either amr or carrier. Treatment with amr 10 or 20 did not decrease serum TxB2 or TNF levels or increase VA/Q mismatch.(ABSTRACT TRUNCATED AT 250 WORDS)

Atelectasis in childhood.

The clinician who identifies atelectasis in a child must determine the mechanism by which atelectasis developed, the functional significance of the collapsed lung, and the etiology responsible for its presence. This article provides a framework to help physicians address these issues and thereby elect the most rational diagnostic and therapeutic interventions at the most appropriate time.