Increased level of bronchial responsiveness in inactive children with asthma

We estimated the association between bronchial responsiveness and hours of exercise per week in children with and without asthma. A random sample of school children (n = 2188), 6-16 years old, was enrolled in a cross-sectional study of asthma in Oslo using the ISAAC questionnaire. Lung function and bronchial responsiveness (BR) using methacholine was measured in a random sample of 80 children with asthma, wheeze and no asthma/no wheeze. The relation between hours of exercise per week and BR [log (DRS)] was estimated by linear regression. Sex and age were included as covariates. Hours of exercise were categorized in: none, 30 min, 1 h, 2-3 h, 4-6 h and 7 h or more. The mean values of log (DRS) were different in the low and high exercise groups for children with asthma (P = 0.02), whereas there was no effect of exercise on BR for children without asthma. BR increased with decreasing hours of exercise per week in children with asthma. The bronchial responsiveness decreased with 0.11 (95% CI -0.20, -0.01) pr unit in scale. This pattern was not present in children without asthma. The results suggest that there is a relation between hours of exercise per week and bronchial responsiveness in children with asthma.

Can asthma treatment in sports be doping? The effect of the rapid onset, long-acting inhaled beta2-agonist formoterol upon endurance performance in healthy well-trained athletes

Inhaled beta2-agonists have been subject to restrictions in relationship to sports due to fear of possible improvement in endurance performance. According to the international doping regulations only inhaled salbutamol, terbutaline and salmeterol are allowed for use in sports. Formoterol is a recently introduced rapid onset-long-acting inhaled beta2-agonist. The main aim of the present randomized, double-blind placebo-controlled study was to investigate possible improvement in endurance performance of inhaled formoterol in 24 healthy well-trained competitive male athletes, 21-29 years old. Lung function (flow-volume loops) was measured before, 15 min after each inhaled study drug and before and repeatedly after exercise. On day 1, maximum oxygen uptake (VO2max), peak ventilation (VEpeak) and running time till exhaustion were measured and used to determine the exercise load on days 2 and 3. On days 2 and 3 the subjects inhaled the study drugs, rested for 1 h, then exercised, and VO2max, VEpeak and running time until exhaustion were determined. Inhaled formoterol did not improve any parameter of endurance performance. On the other hand a statistically significant, although not clinically significant (0.05 ml(-1) min kg(-1)), change was found in estimated difference of VO2max between formoterol and placebo in favour of placebo. Lung function increased significantly after inhaled formoterol, and after exercise also for placebo, but without differences between the beta2-agonist and placebo after exercise. In conclusion, inhaled formoterol did not improve endurance performance compared to placebo.

Lung function measurements in young children with spinal muscle atrophy; a cross sectional survey on the effect of position and bracing

BACKGROUND

Spinal muscular atrophy (SMA) affects respiratory muscles, which in addition to progressive scoliosis leads to respiratory impairment. Children with developing scoliosis are usually treated with spinal bracing to delay the progress.

AIMS

To assess the impact of body position and application of spinal bracing on lung function during tidal breathing in children with SMA.

METHODS

Lung function was determined by tidal flow volume loops and passive respiratory mechanics (single breath occlusion technique) in all eight children in southern Norway with SMA type I and II, in both the sitting and supine position. Additional measurements were performed with and without bracing in five children. Muscle strength was assessed by the Brooks scale.

RESULTS

Tidal expiratory volume (V(E)) and compliance of the respiratory system (CRS) tended to be higher in the sitting compared to the supine position, but this was not statistically significant. However, applying bracing in the sitting position significantly reduced V(E). The highest values of CRS and V(E) were found in the sitting position without bracing.

CONCLUSION

Impairment of tidal respiration must be considered when applying spinal bracing in very young children developing scoliosis with SMA.

Nebulized budesonide after hospitalization for recurrent bronchial obstruction in children younger than 18 months

A multi-center, double-blind, randomized dose-response study was performed to assess the effect of 3 months of treatment with two different doses of inhaled nebulized budesonide in children with acute recurrent bronchial obstruction (BO) causing hospitalization. Steroid-naive children younger than 18 months were included when admitted to hospital because of BO for at least the second time, and were followed-up monthly for 15 months. Forty-five of 49 subjects (43 boys, 2 girls) (mean age 9.3 months upon inclusion) completed the study. Twenty-four patients (20 boys, 4 girls) received nebulized budesonide 0.5 mg twice daily for 1 month followed by 0.25 mg daily for the next 2 months, whereas 25 children received 0.1 mg twice daily throughout the 3-month treatment period. Outcome (number of BO episodes, time to first BO after start of treatment, and use of rescue medication), as well as height/length and weight, were assessed at the start of treatment and monthly for the following 3 months, as well as for 12 months after cessation of treatment (15 months in total). There was an overall tendency towards better symptom control (fewer episodes of acute BO during treatment and follow-up, fewer hospital visits because of acute BO, lower clinical score during follow-up, and less use of rescue medication during follow-up) in the high-dose treatment group vs. the low-dose treatment group. However, the differences did not reach statistical significance for any of the outcomes. The only significant difference in effect between the groups was fewer children in the high-dose group treated openly with nebulized budesonide during follow-up. Length/height and weight gain did not differ significantly between the two treatment groups throughout the study. There was no significant dose-dependent beneficial effect of 3 months of treatment with nebulized budesonide in infants and toddlers with at least two hospitalizations for acute bronchial obstruction.

Effects of maternal and early tobacco exposure on the development of asthma and airway hyperreactivity

In 1999 a comprehensive review was published in Thorax that evaluated the role of exposure to tobacco smoke products (TSPs) in respiratory disease. The present review addresses papers published within the past 12 months on the effects of TSPs on childhood asthma and atopic disease, along with a few reports on possible mechanisms by which TSPs exert their adverse effects. Most of the observational studies published during the past year support the conclusion that both in-utero and, to some degree, passive (environmental) tobacco smoke (ETS) exposure adversely affect pulmonary function, and predispose to asthma symptoms and possibly bronchial hyperresponsiveness in childhood, but play little or no role in atopy development. However, in TSP-induced pulmonary disease, a mechanism of upregulation of pulmonary neuroendocrine cells has been hypothesized. An interventional study clearly demonstrated a need for a total (instead of partial) ban on indoor smoking in the homes of children with asthma in order to achieve significant reductions in levels of urinary cotinine. Because there is a large body of evidence for adverse effects of in-utero TSP as well as ETS exposure on respiratory health in children, we are in dire need of studies to elucidate when TSP exposure causes most damage, the mechanisms that underlie this damage, and how we can prevent unnecessary harm to the respiratory system in the vulnerable child.

[Asthma--a condition of our time, a condition in change?]

BACKGROUND

This article reviews causative factors for asthma and allergy during childhood and describes current trends in prevalence and hospitalisation for childhood asthma.

MATERIALS AND METHODS

A review of the prevalence of childhood asthma in Norway over the last 50 years together with recent trends in hospitalisation for childhood asthma, is given. Possible causative factors for childhood asthma are reviewed, and recent theories for the current increase in prevalence are discussed.

RESULTS AND INTERPRETATION

During the last 50 years, a steady increase in the prevalence of childhood asthma has been documented through published studies from 1948 and onwards. From 1980 and until 1990, an increase in hospital admissions due to acute asthma was observed; later, admissions have leveled off, particularly as regards readmissions. Smoking during pregnancy and childhood decreases lung function. Allergic sensitisation is related to asthma development and may occur already during pregnancy. Increased allergic sensitisation may occur due to reduced load of infections. However, respiratory virus infections, and especially RS virus and rhinovirus infections, are closely related to asthma development and symptoms during childhood. A reduction in readmissions for asthma may be related to increased use of antiinflammatory therapy for asthma.

Eosinophil cationic protein (ECP) in school children living in a mountainous area of Norway: a population-based study of ECP as a tool for diagnosing asthma in children with reference values

BACKGROUND

Most previous studies on eosinophil cationic protein (ECP) have been performed on carefully selected groups of asthmatic patients. Few studies based upon population cohorts have been reported. The primary objective of the present study was to assess the usefulness of serum eosinophil cationic protein (s-ECP) in the diagnosis of asthma in schoolchildren and determine reference values based on measurements in healthy children.

METHODS

The population consisted of 216 schoolchildren (aged 7-16 years) who in a previous questionnaire had reported asthma or asthma-like symptoms and a control group. The questionnaire study comprised the entire population of schoolchildren in Upper Hallingdal. After clinical assessment, blood samples, and skin prick tests, these subjects were then reclassified into four groups: atopic and nonatopic asthmatic and nonasthmatics. S-ECP was assessed in relation to atopy, asthma severity, allergen exposure, and sex.

RESULTS

The asthma group (n = 105) had significantly higher mean s-ECP level than the nonasthma group (n = 111) (13.3 vs 8.3 microg/l, P < 0.001), with no significant difference between atopic asthmatics and atopic nonasthmatics. Mean s-ECP levels in children with mild, moderate, or severe asthma were 12.1, 18.5, and 12.2 microg/l, respectively. The children with animal dander allergy demonstrated higher levels of s-ECP than children without this allergy (12.9 vs 9.1 microg/l, P = 0.001). The upper reference limit (determined as the 95th percentile in healthy children) of 19.1 microg/l, showed low sensitivity (24%) and high specificity (93%) for the diagnosis of asthma. The positive and negative likelihood ratios for the asthma diagnosis were found to be 3.2 and 0.83, respectively.

CONCLUSIONS

The highest s-ECP values were found among children with moderate asthma. Animal dander allergy resulted in elevated s-ECP. However, mean values were still below the reference value of 19.1 microg/l, and the sensitivity was low, suggesting that s-ECP is not a useful parameter for diagnosing asthma in population-based studies.

[Physical activity and respiratory tract diseases asthma and allergy]

BACKGROUND

This article presents a review of the relationship between physical training and airways diseases: the relationship between physical activity and the development of airways diseases, and the effect of physical training in rehabilitation after airways diseases.

MATERIAL AND METHODS

The article is a systematic review of exercise-induced asthma (EIA), the effect of physical training upon bronchial hyperresponsiveness and the development of asthma; how chronic lung diseases affect the ability to participate in physical activity; and the use of physical training in rehabilitation after airways diseases.

RESULTS AND INTERPRETATION

Physical training may provoke EIA in asthmatic patients. Furthermore, heavy regular training over long periods of time may contribute to the development of asthma. Mastering EIA is an important goal in the management of asthma, especially in children and adolescents, in order to foster normal physical and mental development. Physical training improves fitness and the mastering of asthma, but not of bronchial hyperresponsiveness and asthma activity. In other airways disorders like cystic fibrosis or chronic obstructive lung disease, a reduced lung function may limit the ability to participate in physical activity. Training is an important tool in the rehabilitation of patients with pulmonary disorders as it improves physical fitness and quality of life.

Asthma drug adherence in a long term clinical trial

AIM

To measure drug adherence in children with mild asthma receiving long term prophylactic treatment.

METHODS

Double blind randomised placebo controlled trial. Patients received inhaled budesonide 100 microg or 200 microg daily, or placebo for 27 months. All participants were asked to inhale medication or placebo from two different Turbuhalers (morning and evening) during the study. A total of 122 children (80 boys, 42 girls) aged 7-16 years with mild asthma (mean FEV(1) 103.7% of predicted) were included in the trial. Drug adherence was assessed by counting the number of remaining doses in the inhaler when study medication was returned at six month intervals.

RESULTS

A statistically significant and continuing decrease in measured drug adherence was found from three to nine months and then to 27 months, reaching mean values of 40.6% and 46. 9% for inhaled morning and evening medication respectively. Drug adherence declined more rapidly in the placebo group (compared to active treatment); this difference became significant after two years of treatment. Children aged 9 years or less had better drug adherence during the entire study period, but the difference was only significant for the first three months of the study. Measured drug adherence was significantly higher for evening medication compared to morning medication for all study intervals after nine months.

CONCLUSION

Measured drug adherence diminishes significantly when treating children with mild asthma in a long term trial. This emphasises the importance of monitoring compliance in clinical trials.

Low-dose inhaled budesonide once or twice daily for 27 months in children with mild asthma

This study is an extended follow-up for 24 months of a 12-week trial to study the long-term clinical efficacy of low-dose inhaled budesonide (BUD) once or twice daily in children with mild asthma. A total of 122 children (mean age 9.7 years, girls/boys; 42/80) with mild asthma (FEV1 103.7% of predicted, reversibility in FEV1 3.5%, and fall in FEV1 after exercise 12.2%), not previously treated with inhaled steroids, were included in a double-blind, randomized, parallel-group study. The children were treated with inhaled BUD 100 or 200 microg administered via Turbuhaler once daily in the morning, 100 microg twice daily, or placebo for 27 months. Exercise and methacholine challenges were performed at 3-month intervals the first year and at 6-month intervals the second year, in a total of seven visits. A significant dose-response effect favoring BUD 200 microg daily (vs 100 microg daily) was found when comparing changes in FEV1, FEF25%, and FEV50%; the fall in FEV1 after an exercise test; and the effect on blood eosinophils. Bronchial hyperreactivity to methacholine decreased significantly on three visits in patients treated with BUD 200 microg daily compared to placebo. Growth rate was not significantly affected except in children aged 7-11 years at baseline after 12 months of treatment. In conclusion, 100 or 200 microg daily of inhaled BUD for 27 months is safe and effective in protecting against exercise-induced asthma and achieving nearly normal lung function. Baseline lung function was not significantly affected in this group of children with mild asthma.

Exercise-induced bronchoconstriction depends on exercise load

Exercise-induced bronchoconstriction (EIB) is often used as a measure of bronchial hyperresponsiveness and employed in epidemiological studies. Different tests are used, including free running tests with poor standardization of exercise load. The present study aimed to assess the role of exercise load in relationship to level of EIB.

METHODS

20 asthmatic children, 9-17 years old with a history of EIB, underwent two treadmill test with 85% and 95% exercise load. The children ran with increasing speed for the first 2 min until reaching a heart rate of 85% or 95% of calculated maximum (220-age) and maintained this speed for the last 4 min. Lung function was measured before running, and 0, 3, 6, 10 and 15 min after the run. Borg scale for perceived exertion was employed for children's self-evaluation of exercise load.

RESULTS

Peak heart rate, mean Borg score during 85% exercise load was 178.7/13.6 and during 95% was 194.3/18.2 (P<0.001). Maximum fall in FEV1 after 85% exercise load was 8.84% vs. 25.11% after 95% (P<0.001). Nine subjects (40%) fell > or = 10% in FEV1 after 85% exercise load vs. 20 subjects (100%) after 95% exercise load. EIB from the 95% exercise load test had markedly higher correlation with serum ECP (r=0.77, P<0.001).

CONCLUSION

Exercise load is essential for the interpretation of EIB, and strict standardization of exercise tests should be undertaken. The EIB from the high exercise load tests seemed better correlated to inflammatory activity than the low exercise load test.

Inhaled nebulized adrenaline improves lung function in infants with acute bronchiolitis

Beta2-agonists have questionable symptomatic effect in infants with acute bronchiolitis, whereas inhaled, nebulized racemic adrenaline, commonly used in Norway, appears (clinically) to be effective. Limited lung function observations during acute bronchiolitis exists, and less for assessing possible effects inhaled adrenaline. In this preliminary study, tidal flow-volume loops were measured in 16 infants with acute bronchiolitis and seven healthy controls (mean age 7.9 and 4.4 months, respectively), with repeated measurements 15 min after inhaled nebulized racemic adrenaline (4 mg diluted in 2 ml saline) in nine bronchiolitis patients. The ratio of time to reach peak tidal expiratory flow to total expiratory time (tPTEF/tE) was significantly reduced in children with acute bronchiolitis (mean, 95% CI) (0.08, 0.05-0.10) compared to controls (0.31, 0.18-0.43), with significant improvement after inhaled racemic adrenaline 0.19 (0.13-0.25), parallel with significant clinical improvement. Lung function (tPTEF/tE) was reduced in infants with acute bronchiolitis and improved significantly after inhaled racemic adrenaline. Inhaled racemic adrenaline is potentially an important alternative for treating infants with acute bronchiolitis.

Low-dose budesonide improves exercise-induced bronchospasm in schoolchildren

The aim of this study was to compare the clinical efficacy of low-dose inhaled budesonide (once or twice daily) and placebo, administered via Turbuhaler, on exercise-induced bronchoconstriction (EIB) in children with mild asthma. Fifty-seven steroid-naive children (7-16 years old; 41 boys, 16 girls) with EIB participated in this sub-population study according to the following inclusion criterion: a maximum fall in forced expiratory volume in 1 s (FEV1) > or = 10% after a standardized treadmill test. Mean baseline FEV1 was 100.3% of predicted, and mean maximum fall in FEV1 after the standardized exercise test was 22%. The study was a double-blind, randomized, parallel-group design. After 2 weeks of run-in, the children received inhaled budesonide 100 microg or 200 microg once daily in the morning, 100 microg twice daily, or placebo, for 12 weeks. After 12 weeks of treatment, the fall in FEV1 after the exercise test was significantly less in all three budesonide groups (7.2-7.8%) vs. placebo (16.7%). Daytime symptom scores were significantly lower in all three budesonide groups compared with placebo (p <0.02). The three budesonide groups did not differ significantly, and no significant change in lung function was found in any group. Therefore children with mild asthma, but with significant EIB, improved their exercise tolerance and symptom control after 3 months of treatment with a low dose of inhaled budesonide given once or twice daily.

Trends in hospital admissions for childhood asthma in Oslo, Norway, 1980-95

BACKGROUND

The prevalence of asthma and quality of asthma care both influence hospital admission rates for childhood asthma. Therefore, we aimed to assess possible changes in the hospital admission rate for acute asthma in Oslo, Norway, from 1980 to 1995, as well as evaluate the possible effect of changes in asthma treatment upon hospitalization for acute asthma in this period.

METHODS

All pediatric patient records from the two municipal hospitals in Oslo from 1980 through 1995 with the discharge diagnoses (ICD-9) acute asthma, acute bronchitis/bronchiolitis, pneumonia, and/or atelectasis were thoroughly reviewed.

RESULTS

Of the 3,538 children admitted for acute asthma, 66% were boys and 75% were younger than 4 years, and the admittance rate increased significantly among children aged 0-3 years. First admissions increased throughout the study, whereas readmissions, as well as the mean duration of hospital stay, decreased significantly. Prophylactic treatment with inhaled steroids prior to admission increased over 1980-89, but stabilized thereafter. The use of a short course of systemic steroids during admission increased markedly from 1991.

CONCLUSIONS

The findings of increasing first admission rate as well as overall admission rate for acute asthma in children under 4 years of age, but decreasing readmissions as well as number of treatment days in hospital, probably reflect changes in the management of the disease, as well as an increasing prevalence of childhood asthma.

Asthma and allergy among schoolchildren in a mountainous, dry, non-polluted area in Norway

The aim of this study was to assess prevalence of asthma and allergy in the non-polluted mountain area of Upper Hallingdal, Norway. All schoolchildren (7-16 years) who in a previous questionnaire survey (n = 1177) reported 'sometime' asthma were enrolled in group I (n = 80), the 59 who reported asthma-like symptoms in the past 12 months formed group II, and 77 of the healthy controls were randomly selected as group III. All 216 children underwent clinical examination, skin prick test, spirometry, bronchial provocation (PD20 metacholine) and treadmill exercise test. Subsequently they were reclassified as (1) healthy, never had asthma or symptoms, (2) symptoms not confirmed as asthma, (3) previous asthma, now healthy, (4) current asthma. Lifetime asthma prevalence was 10.2%. Based upon clinical examination, the specificity and sensitivity of the questionnaire for asthma diagnosis were 88 and 74%, respectively. Forced vital capacity was significantly higher among the asthmatics (group 4 versus 1), whereas forced expiratory volume in one second (FEV1) and forced expiratory flow at 50% of vital capacity were similar in all groups. More than 10% reduction in FEV1 following treadmill-run was found in 20% of children. Children with current asthma compared to controls had significantly; lower mean values of PD20 (9.1 versus 16.5 micromol), higher eosinophil cationic protein (13.4 versus 7.7 micromol) and more frequent sensitization to animal dander (56% versus 10%). In conclusion, despite a favorable climate, little mite sensitization and low outdoor pollution, asthma prevalence was surprisingly high in Upper Hallingdal. Sensitization to animal dander was the most important contributing factor for current asthma.

Patient compliance in a clinical trial with inhaled budesonide in children with mild asthma

Children's use of inhalation devices can give valuable information about their adherence to asthma therapy. The aim of this study was to examine treatment adherence of low dose inhaled budesonide or placebo administered via Turbuhaler twice daily in children with mild asthma participating in an asthma trial, by comparing diary registration with the number of doses remaining in the inhaler. A total of 163 children (age 7-16 yrs, 56 females, 107 males) with mild asthma (mean baseline forced expiratory volume in one second (FEV1) was 103% of predicted), were included into a double blind, randomized study. After a two-week run-in period, the children received inhaled budesonide, either 100 microg or 200 microg daily, and/or placebo for 12 weeks. All patients used daily diary cards throughout the study. Results from 161 patients were analysed. Mean compliance according to the diary was 93%, whereas estimated mean compliance when counting remaining doses in the Turbuhaler was 77%. Overuse of medication was found in 7% of the children. There was no significant difference in compliance between sex in the study group, whereas children aged < or =9 yrs had significantly better drug adherence than older children. No significant relationship was found between symptom score and compliance. In conclusion, even with optimal patient follow-up in a clinical trial, adherence to prophylactic asthma treatment is considerably lower than the patients own reports from the use of daily diary cards.

Perinatal risk factors for recurrent wheeze in early life

The possible value of tidal flow volume (TFV) loops measured at birth in relation to the risk of developing recurrent or persistent bronchial obstruction within two years of life was assessed. TFV loops were measured at a mean age of 2.7 days in 802 neonates enrolled in the 'Environment and Childhood Asthma' (ECA) study in Oslo. Of these, 77 children developed recurrent or persistent bronchial obstruction (cases) and were included in a nested case-control study within the ECA study; 88 controls (the child born closest in time to the case), with no history of bronchial obstruction in the first two years of life, were also included. Information on socio-economic factors, parental atopic diseases and parental smoking habits during the pregnancy was collected from a questionnaire completed by the parents in the maternity ward, and cord blood IgE (CB-IgE) was determined as part of routine sampling in the delivery ward. Mean tPTEF/tE (time to reach peak flow to total expiratory time) was slightly lower in cases (0.31; 95% CI 0.28-0.34) than in controls (0.33; 0.31-0.35) (difference not significant), whereas geometric mean CB-IgE was significantly higher among cases (0.39; 0.30-0.52) than controls (0.27; 0.23-0.33). No significant differences between cases and controls were found for respiratory rate, peak tidal expiratory flow or expiratory volume. However, the odds ratio for developing recurrent or persistent bronchial obstruction was 3.5 (1.1-11.6) if tPTEF/tE was < 0.20 and 4.1 (1.1-14.5) with maternal daily smoking during the pregnancy, after adjusting for age, weight, sex, CB-IgE, parental atopy, maternal education and family income. The TFV parameter tpTEF/tE < 0.20 measured within the first week of life as well as maternal daily smoking during pregnancy are significant, independent risk factors for developing recurrent or persistent bronchial obstruction within the first two years of life.

Wheezing in school children is not always asthma

Our objective was to study whether children with reported asthma differed from children with wheeze but without asthma, and from children with neither asthma nor wheeze, regarding lung function, bronchial hyper-responsiveness (BHR) using methacholine inhalation, exercise-induced bronchoconstriction (EIB), and skin prick test (SPT) reactivity. School children (n=2188), enrolled in a survey of asthma, were classified into three mutually exclusive groups by parental report of: asthma, wheeze, and no asthma/no wheeze. A random sample of 80 children in each group was tested (n=240). Among asthmatics, 68% (95% confidence interval (CI), 57-79) had a BHR (measured as PD20 forced expiratory volume in 1 s (FEV1) < or = 8.16 micromol using methacholine) compared to 31% (CI 20-42%) and 30% (CI 19-40%) in the wheeze and no asthma/no wheeze groups. The dose-response slope (DRS) confirmed the PD20 data and distinguished equally between groups. EIB (> or =10% fall in FEV1) was more frequent (40%, CI 29-52%) among asthmatics than among children with wheeze (12%, CI 4-19%) and no asthma/no wheeze (7%, CI 1-13%). The prevalence of at least one positive SPT was twice as high in the asthma group (58%, CI 47-69%) than in the wheeze (27%, CI 16-37%) and the no asthma/no wheeze (25%, CI 15-35%) groups. These results indicate that children with asthma differ from children with wheeze and children with no asthma/no wheeze regarding lung function, BHR, EIB, and SPT reactivity. Children with wheeze are more similar to children with no asthma/no wheeze with respect to these parameters.

Recurrent respiratory tract infections during the first 3 years of life and atopy at school age

BACKGROUND

The hypothesis that infections reduce the risk of atopy was investigated by estimating the association between recurrent respiratory tract infections during the first 3 years of life and atopy at school age.

METHODS

According to surveys in three different areas of Norway, children were classified into three groups: asthma, wheeze without asthma (wheeze), and no asthma/no wheeze. The skin prick test (SPT) was conducted on a stratified random sample of children (n = 502). The outcome was at least one positive SPT. The exposure variable was retrospective parental report of respiratory tract infections during the first 3 years of life.

RESULTS

Infections were negatively associated with atopy, crude odds ratio (cOR) = 0.3, 95% confidence interval (95% CI) 0.1-0.7, in the asthma group. A similar association was present in children with wheeze cOR = 0.4 (95% CI 0.1-1.2). The number of siblings was not associated with atopy in any group. Infections remained negatively associated with atopy in children with asthma, aOR = 0.3 (95% CI 0.1-0.7), in a logistic regression model adjusting for confounding factors. A similar pattern was present in the wheeze group.

CONCLUSIONS

Recurrent respiratory tract infections during the first 3 years of life are negatively associated with atopy at school age in children with asthma.

Exposure to nitrogen dioxide and the occurrence of bronchial obstruction in children below 2 years

BACKGROUND

The objective of the investigation was to test the hypothesis that exposure to nitrogen dioxide (NO2) has a causal influence on the occurrence of bronchial obstruction in children below 2 years of age.

METHODS

A nested case-control study with 153 one-to-one matched pairs was conducted within a cohort of 3754 children born in Oslo in 1992/93. Cases were children who developed > or = 2 episodes of bronchial obstruction or one episode lasting >4 weeks. Controls were matched for date of birth. Exposure measurements were performed in the same 14-day period within matched pairs. The NO2 exposure was measured with personal samplers carried close to each child and by stationary samplers outdoors and indoors.

RESULTS

Few children (4.6%) were exposed to levels of NO2 > or = 30 microg/m3 (average concentration during a 14-day period). In the 153 matched pairs, the mean level of NO2 was 15.65 microg/m3 (+/-0.60, SE) among cases and 15.37 (+/-0.54) among controls (paired t = 0.38, P = 0.71).

CONCLUSIONS

The results suggest that NO2 exposure at levels observed in this study has no detectable effect on the risk of developing bronchial obstruction in children below 2 years of age.

Clinical efficacy of low-dose inhaled budesonide once or twice daily in children with mild asthma not previously treated with steroids

The aim of the present study was to examine the efficacy of low-dose inhaled budesonide (BUD) administered via Turbuhaler once or twice daily on symptoms, lung function and bronchial hyperreactivity in children with mild asthma. One hundred and sixty-three children (mean age 9.9 yrs, 56 females/107 males) with mild asthma (forced expiratory volume in one second (FEV1) 103% of predicted, morning peak expiratory flow (PEF) 87% pred, reversibility in FEV1 3%, fall in FEV1 after exercise 10.4% from pre-exercise value) and not previously treated with inhaled steroids, were included in a double-blind, randomized, parallel-group study. After a two-week run-in period, the children received inhaled BUD 100 microg or 200 microg once daily in the morning, 100 microg twice daily or placebo for 12 weeks. Exercise and methacholine challenges were performed before and at the end of treatment. After 12 weeks of therapy, the fall in FEV1 after an exercise test was significantly less in all three BUD groups (43-5.1%) than in the placebo group (8.6%). Bronchial hyperreactivity to methacholine with the provocative dose causing a 20% fall in FEV1 decreased significantly in the BUD 100 microg twice-daily group compared with placebo (ratio at the end of treatment 156%). Changes in baseline lung function (FEV1 and PEF) were less marked than changes in bronchial responsiveness. In conclusion, low doses of inhaled budesonide, given once or twice daily, provided protection against exercise-induced bronchoconstriction in children with mild asthma and near normal lung function.

Serum inflammatory markers and effects of age and tobacco smoke exposure in young non-asthmatic children

Serum eosinophil cationic protein (ECP), but not serum myeloperoxidase (MPO), has been found to reflect disease activity of asthma and eczema, but no reference values exist for young children. Thus, we aimed to provide values of serum-ECP and serum-MPO in young children without obstructive airways disease (OAD), and determine possible influencing factors. Parental interview was performed and serum was collected from a total of 245 children (207 children aged 24-41 months and 76 children aged 0-23 months) with no history of lower respiratory disease. Repeated serum samples were obtained in 38 subjects. Ten percent of the children had active eczema at examination. All children were controls in the "Environment and Childhood Asthma" study in Oslo. Geometric means (GM +/- 1.96 SD) for serum ECP were 11.8 microg/l (2.5-56.0) and 7.9 microg/l (2.0-30.4), respectively, in the 0-23 and 24-41-month-old children, with the corresponding values for serum MPO 453 microg/l (153-1349) and 347 microg/l (142-859), respectively. Age was inversely associated with serum-ECP and serum-MPO, most pronounced in the youngest children. Active eczema and maternal daily smoking adversely affected serum-ECP, but not serum-MPO. Gender and parental atopy did not influence the results. We conclude that serum-ECP in very young children is influenced by age and active eczema and is related to maternal smoking in a dose-dependent fashion. These factors should be considered when assessing inflammatory markers in very young children.

Cold air inhalation and exercise-induced bronchoconstriction in relationship to metacholine bronchial responsiveness: different patterns in asthmatic children and children with other chronic lung diseases

Cold air inhalation and exercise-induced bronchoconstriction (EIB) have both been used as measures of bronchial responsiveness. Both stimuli are often combined in the Nordic climate. The main objective of the present study was to investigate the climatic influence of cold temperatures upon exercise-induced asthma. The secondary aims were: (a) to assess metacholine bronchial hyper-responsiveness and EIB in children with bronchial asthma (n = 32; mean age 10.8 years) compared to children with other chronic lung diseases (CLD) (n = 26, mean age 10.1 years); and (b) to assess the influence of cold air inhalation upon EIB in the two groups of children. Methods used were: (a) the metacholine concentration causing a reduction in FEV1 of 20% (PC20-M), (b) maximum FEV1 fall (delta FEV1) after submaximal treadmill run (EIB test); and (c) delta FEV1 after submaximal treadmill run while inhaling cold (-20 degrees C) dry air (CA-EIB test). Geometric mean PC20-M did not differ significantly between the asthma children (1.28 mg ml-1) and the CLD children (2.90 mg ml-1). In the asthma children, mean delta FEV1 after EIB test was 12.8% vs 21.8% after adding cold air (P < 0.0001), compared to 5.2 and 7.4%, respectively (P = 0.03), in the CLD group. Maximum sensitivity and specificity for the EIB test were 69.8% at a fall in FEV1 of 6.8%; for the CA-EIB test, 72% at a fall in FEV1 of 10.2%; and for metacholine provocation, 56% at a PC20-M of 1.5 mg ml-1. In conclusion, children with bronchial asthma are substantially more sensitive to cold air than children with CLD, and EIB is markedly increased by cold air inhalation in asthmatic children, maintaining the specificity of the EIB test and increasing the sensitivity. The low sensitivity of the EIB test is probably influenced by the use of inhaled steroids. Metacholine inhalation test has less specificity and sensitivity in discriminating asthma from other chronic lung diseases.

Determinants of tidal flow volume loop indices in neonates and children with and without asthma

The tidal flow volume (TFV) loop ratios of (1) time to peak flow (tPTEF) to total expiratory time (tE) [tPTEF/tE] and (2) volume to peak flow (VPTEF) to expired volume (VE) [VPTEF/VE] are reported to decrease with age in early life, and to decrease in subjects with obstructive airways disease (OAD). However, the mechanisms behind these changes are not well known. Thus, we reanalyzed data from 24 healthy neonates (mean birthweight: 3.49 kg +/- 0.42 kg (SD)), 26 presently asymptomatic asthmatic children (age: 33 +/- 21 months), and 26 controls (age: 34 +/- 19 months) to elucidate what is responsible for the changes in these ratios in health and disease. Lung function was measured by TFV loops (SensorMedics 2600) at 1 hour of life and on the following day in the neonates, and before and after inhaled nebulized salbutamol (0.05 mg/kg) in the asthmatics and their controls. The observed decreases in mean tPTEF/tE and VPTEF/VE from 1 hour to 1 day of life (neonates) were entirely due to increased tE and VE, respectively secondary to a decrease in respiratory rate (P = 0.03). In asthmatics (young children), the decreased baseline tPTEF/tE and VPTEF/VE were due to lower tPTEF and VPTEF, with no significant differences in tE and VE in asthmatics and controls. The improved ratios in asthmatic children following inhalation of a bronchodilator were mainly due to increased tPTEF and VPTEF. Our observations point out the importance of evaluating both tPTEF and either tPTEF/tE or VPTEF/VE when attempting to differentiate between changes in ratios that are related to age versus changes that reflect underlying obstructive airways disease.

Markers of airway inflammation in preschool wheezers

Airways inflammation markers may help in predicting prognosis, in diagnosis and in monitoring respiratory diseases. Inflammation markers specific for certain cells may indicate the nature of the inflammatory processes, whilst others indicate stage and intensity. Intercellular adhesion molecule 1 (ICAM-1) helps to establish contact between the antigen-presenting cell and T-lymphocytes. Soluble serum ICAM-1 is increased in developing chronic lung disease of the newborn and atopic bronchial asthma. ICAM-1 is also the major human rhinovirus receptor. Interleukin 4 and interferon-gamma regulate the immunoglobulin E response, are difficult to measure in serum, and most groups employ stimulated cell cultures. These early inflammation markers may have predictive value. The leukotrienes are released from mast cells and eosinophils. Leukotriene (LT) B4 may be analysed in serum, whereas the cysteinyl leukotrienes, LTC4, LTD4, LTE4, may be assessed in urine. Serum LTB4 and urinary LTE4 have been found to be elevated during acute wheezy exacerbations. Tryptase is released from mast cells and is elevated in serum during acute anaphylaxis. However, tryptase has not been found to be related to inflammatory activity under other conditions. Myeloperoxidase is released from neutrophils, and serum levels are elevated in asthma, respiratory infections and other chronic lung diseases. The eosinophil markers eosinophil cationic protein (ECP) and eosinophil protein X (EPX) reflect eosinophil activation. ECP in serum and EPX in urine are elevated in asthma, atopic eczema and other conditions with eosinophil activation. They are related to symptom activity in asthma and atopic eczema and are influenced by anti-inflammatory therapy. In early wheezing, serum ECP may have predictive value. Serum ECP is dependent upon sampling procedures. Nitrogen oxide in exhaled air reflects inflammatory activity in asthma, and is influenced by anti-inflammatory therapy. However, in young children there are sampling difficulties.

In utero exposure to cigarette smoking influences lung function at birth

To avoid the possible confounding effects of postnatal exposure to tobacco smoke, we investigated possible effects of uterine tobacco smoke (UTS) exposure upon infant lung function shortly after birth. Infants with no major disease, in one maternity ward in Oslo, Norway, participating in a cohort study established in 1992/1993, were included in the present study (n=803). Exposure information, assessed as maternal active and passive smoking during pregnancy and other personal and environmental factors, was obtained by questionnaire. Tidal flow-volume (TFV) loops (n=802) and compliance (Crs) and resistance (Rrs) of the respiratory system (n=663) were measured at a mean age of 2.7 days. In girls, the TFV ratio (time to reach peak expiratory flow to total expiratory time (tPEF/tE)), and Crs were significantly lower with active as well as passive maternal smoking compared to nonexposure to UTS. Respiratory rate and Rrs were not significantly influenced by UTS exposure. However, in linear regression analysis adjusted for confounding factors (including respiratory rate), tPEF/tE and Crs, but not Rrs, were related to maternal active but not passive daily smoking. One daily cigarette corresponded to a change in tPEF/tE of -0.0021 (95% confidence interval (95% CI) -0.0040 to -0.0002) and a change in Crs of -0.026 mL x cmH2O (95% CI -0.045 to -0.007 mL x cmH2O). The decrease was 0.023 and 0.29, respectively, in infants of an average smoker. Maternal smoking during pregnancy adversely affected tidal flow-volume ratios in healthy newborn babies, as well as the compliance of the respiratory system in girls, independently of the reduced body size also resulting from maternal smoking.

Inflammation markers and symptom activity in children with bronchial asthma. Influence of atopy and eczema

BACKGROUND

Eosinophil cationic protein (ECP) has been reported to reflect the eosinophil inflammatory activity in asthma. However, the relative impact of asthma symptoms and atopic eczema upon serum (s)-ECP in asthmatic children has not been established.

OBJECTIVES

To examine s-ECP levels and s-myeloperoxidase (MPO) in relation to asthma symptoms and atopic eczema in asthmatic children.

METHODS

S-ECP and s-MPO were assessed in relation to symptom activity, lung function, exercise-induced bronchoconstriction and bronchial responsiveness in 101 children; median age 9 years, range 1-16 years; with moderate to severe asthma, admitted to Voksentoppen Center.

RESULTS

S-ECP was significantly higher in children with persistent compared to episodic or no asthma symptoms in the past four weeks. S-ECP was also higher in children with atopic compared to non-atopic asthma, as well as in those with active compared to past history or no history of atopic eczema. S-MPO was higher in children with persistent asthma symptoms, but did not differ in relation to atopy or eczema state. Persistent asthma symptoms had the greatest impact upon s-ECP levels, followed by atopy and active eczema.

CONCLUSION

S-ECP may be used in assessing symptom activity in asthmatic children, but with the realisation that active eczema and the presence of atopy may also influence levels.

The effect of inhaled salbutamol and salmeterol on lung function and endurance performance in healthy well-trained athletes

The present randomized, double-blind placebo-controlled study aimed at investigating the possible improvement in endurance performance caused by inhaled salmeterol (long-acting beta 2-agonist) and salbutamol (short-acting) compared to placebo in 18 healthy well-trained athletes, aged 17-30 years old. Lung function (flow-volume loops) was measured before and after each inhaled study drug and after run to exhaustion. After inhalation of study drug and 10 min warm-up, anaerobic threshold was measured; thereafter maximum oxygen uptake, peak ventilation and running time until exhaustion during a brief graded exercise were measured. No significant differences were found for ventilation, oxygen uptake or heart rate at anaerobic threshold or at maximum performance between placebo and the beta 2-agonists. Lung function increased significantly after exercise, but without differences between the beta 2-agonists and placebo. Running time till exhaustion was significantly reduced after both the long- and the short-acting beta 2-agonist compared to the placebo.

Changing prevalence of asthma in school children: evidence for diagnostic changes in asthma in two surveys 13 yrs apart

It is still unclear whether the reported increase in the prevalence of asthma is real or due to changes in diagnostic criteria. The objectives of this study were to compare the prevalence of diagnosed asthma with the prevalence of respiratory symptoms, and to compare the association between asthma and other atopic diseases in 1981 and 1994. The study populations comprised randomly selected school classes in Oslo in 1981 (n=1,772) and 1994 (n=2,577). The main outcomes in these comparable cross-sectional studies of children, 6-16 yrs of age, were parent-reported prevalence of diagnosed asthma, respiratory symptoms, eczema and hay fever. The questionnaire was identical in 1981 and 1994. The response rates were 94% (1,674 out of 1,772) in 1981 and 85% (2,188 out of 2,577) in 1994. The lifetime prevalence of asthma increased from 3.4% in 1981 to 9.3% in 1994; odds ratio (OR) 2.9 (95% confidence interval (95% CI) 2.1-4.0) comparing 1994 to 1981. The prevalence of occasional wheezing increased from 9.0 to 10.8%; OR 1.2 (95% CI 1.0-1.5), and attacks of wheezing from 3.7 to 6.8%; OR 1.8 (95% CI 1.3-2.5). Survival analyses for 3 year birth cohorts showed that asthma was more readily diagnosed in the latest birth cohort (1985-1988). The association between asthma and other atopic diseases decreased during the period under study. The increase in diagnosed asthma and respiratory symptoms supports a true increase in asthma. However, the larger increase in diagnosed asthma than wheezing and a reduced association between asthma and other atopic diseases suggest that the increase in asthma may be explained, in part, by changes in diagnostic criteria.

Overnight protection by inhaled salmeterol on exercise-induced asthma in children

The main aim of the present study was to evaluate whether inhaled salmeterol given in the evening protected against exercise-induced asthma the next morning. Twenty three children (12 males and 11 females) with a mean age of 11 yrs and with exercise-induced asthma participated in a double-blind, randomized, placebo-controlled study. The children inhaled salmeterol 25 micrograms, salmeterol 50 micrograms and placebo by Diskhaler at 10 p.m. on 3 separate days. Next morning, half of the children ran on a motor-driven treadmill for 6 min at submaximal load at 8 a.m. and the remainder at 10 a.m. Lung function was measured by maximal expiratory flow-volume loops before running, immediately after, and 3, 6, 10 and 15 min after running. The mean maximum reduction in forced expiratory volume in one second (FEV1) after treadmill run was 34% before inclusion in the study. Mean maximum fall in FEV1 was significantly greater after placebo: 30% (23-36) 95% confidence interval) than after salmeterol 25 micrograms: 19% (12-23) or salmeterol 50 micrograms: 18% (12-25). In addition to the reduced postexercise bronchoconstriction, pre-exercise lung function (FEV1) was significantly higher both after salmeterol 25 micrograms: 2.4 L.s-1 (2.1-2.7) and salmeterol 50 micrograms: 2.5 L.s-1 (2.2-2.8) than after placebo: 2.2 L.s-1 (1.9-2.5). No significant differences in pre- and postexercise lung function were found between children tested at 8 or 10 a.m., or in relation to salmeterol dosage. Thus, inhaled salmeterol 25 and 50 micrograms offered similar overnight protection against exercise-induced asthma and improved baseline lung function in the morning as compared to placebo.

Eosinophil cationic protein and tidal flow volume loops in children 0-2 years of age

Many children with recurrent wheezing in early childhood develop asthma. Objective parameters to describe different groups of wheezers are limited, but tidal flow volume (TFV) response to inhaled salbutamol has demonstrated differences between children with and without asthma. Also, eosinophil cationic protein (ECP) has been associated with declining lung function in older children. We therefore investigated whether lung function and serum ECP (s-ECP) could differentiate between groups of wheezy young children. TFV loops were measured in 79 awake children (mean age 14 months). Minimum two wheezy episodes (mean 3.2) or minimum 4 weeks persistent wheeze were reported in 41 children (cases), whereas the 38 controls had no history of wheeze. Airways responsiveness (change in ratio of time until peak expiratory flow to total expiratory time (tPEF/tE) after inhaled nebulized salbutamol) was measured in 26 cases and 24 controls. Serum ECP and serum myeloperoxidase (s-MPO) were measured in all children. Cases had significantly lower mean tPEF/tE (0.21) than controls (0.33), and higher mean s-ECP (21.9 micrograms.L-1) than controls (14.0 micrograms.L-1). Serum ECP (but not s-MPO) correlated significantly with the percentage change in tPEF/tE from baseline (r = 0.7), but not with initial tPEF/tE. Serum ECP increased significantly with increasing immunoglobulin E (IgE), airways responsiveness and eosinophil count, but decreased with increasing age. TFV responsiveness to salbutamol and s-ECP levels correlate strongly, both probably reflecting airways inflammation, and may possibly be valuable prognostic tools in recurrent wheezy infants and toddlers.

Tidal flow volume loops and inflammatory indicators in small children

Serum eosinophilic cationic protein (sECP) serum myeloperoxidase (sMPO) and tidal flow volume loops were measured in 41 awake children with at least two episodes of bronchopulmonary obstruction, at least 3 weeks after an acute episode, and in 38 control children, all below 2 years of age. Reversibility to salbutamol was assessed in 26 cases and 24 controls. The baseline ratio of time to peak flow to total expiratory time (Tpef/Te) was significantly lower in cases (0.21) than in controls (0.33). sECP was significantly higher in cases (21.9 micrograms/l) than in controls (14.0 micrograms/l), and correlated significantly (r = 0.70) with the percentage change in Tpef/Te from before to after salbutamol. sMPO did not differ significantly between the two groups.

Respiratory tract infection and bronchial responsiveness in elite athletes and sedentary control subjects

To assess the effect of physical exercise during an acute respiratory tract infection (RTI) on bronchial responsiveness, methacholine bronchial challenge tests were performed prospectively in 19 nonasthmatic male cross-country skiers and 22 healthy control subjects with minimal physical activity. Twelve skiers and 10 controls contracted RTI and were studied before and 1, 3 and 6 weeks after the onset of symptoms. The skiers were given no restrictions in their training routines during the period of illness. The geometric mean provocation concentration of methacholine causing a 10% fall in the forced expiratory volume in the first second (PC10), was lower 1 week after onset of infection than at the initial test in the skiers. From the level at 1 week, PC10 increased to levels at 3 and 6 weeks after infection. The PC10 values at 3 and 6 weeks were not significantly different from the initial test. No significant changes in PC10 occurred after infection in the control group. No significant changes in pulmonary function tests were found during the study period in either of the two groups. In conclusion, RTI was associated with a transient increase in bronchial responsiveness in athletes performing physical training during the symptomatic period of respiratory illness but not in nonactive control subjects.

Tidal breathing analysis and response to salbutamol in awake young children with and without asthma

The purpose of the present study was to investigate: 1) whether tidal flow patterns can be used to discriminate between children with asthma and those without respiratory illness; and 2) whether reversibility to salbutamol in young children can be detected by tidal breathing analysis? Lung function was measured by tidal flow-volume loops (SensorMedics 2600) in 26 awake young children (13 males) with asthma (aged 7-85 months; mean age 33 months), and 26 (13 males) (aged 3-72 months; mean age 34 months) without respiratory illness, before and 15 min after inhalation of nebulized salbutamol, 0.05 mg.kg-1. The ratios of the time and volume until peak expiratory flow to the total expiratory time and volume, respectively, (TPEF/TE and VPEF/VE), and the ratio of tidal expiratory flow at 25% remaining expiration to peak expiratory flow, TEF25/PEF, were significantly lower in asthmatic children than in controls, and increased significantly after salbutamol inhalation in the former. Conversely, TPEF/TE and VPEF/VE, but not TEF25/PEF decreased significantly in the controls after salbutamol inhalation. Respiratory rate and expiratory volume.kg-1 body weight did not differ significantly between the two groups before and after salbutamol inhalation. We conclude that tidal breathing analysis can discriminate young children with asthma from children without respiratory illness, both regarding baseline lung function and reversibility to salbutamol.

Lung function by tidal breathing in awake healthy newborn infants

The increasing availability of appliances for measuring lung function in infants may allow clinical and epidemiological applications. The aim of the present study was to establish reference values for tidal breathing lung function in awake newborn infants and to investigate potential sources of variability. Tidal flow-volume loops were measured in 803 awake, healthy infants (427 males and 376 females) and passive respiratory mechanics (single-breath occlusion technique) in 664. Mean postnatal age was 2.7 +/- 0.9 (sd) days, gestational age 39.8 +/- 1.4 weeks and birthweight 3.59 +/- 0.49 kg. Tidal expiratory volume (Vt), peak tidal expiratory flow (PEF), and mid-expiratory flow increased significantly with increasing birthweight. Flow ratios: ratio of time to PEF to total expiratory time (Tpef/Te), ratio of volume to PEF to total expiratory volume (Vpef/Ve); and ratio of tidal flow at 25% remaining expiration to PEF (TEF25/PEF), were highest in 1 day old infants (medians 0.39, 0.46 and 0.81 respectively), decreasing to a minimum in 4-5 day old infants, but were not influenced by birthweight. Tidal flows and flow ratios were higher in males versus females, even after weight adjustment. Respiratory rates correlated significantly with tidal flows (r = 0.66), inversely with Vt (r = 0.40), but not with flow ratios. Mean compliance of the respiratory system was 1.18 ml.cmH2O-1.kg birthweight (95% confidence interval (95% CI) 1.15-1.21) and mean resistance 0.051 cmH2O.ml-1.s (95% CI 0.049-0.054). These results demonstrate that lung function in awake healthy infants varies according to weight, gender and postnatal age.(ABSTRACT TRUNCATED AT 250 WORDS)

Nebulised racemic adrenaline in the treatment of acute bronchiolitis in infants and toddlers

The effect of inhaled nebulised racemic adrenaline upon symptoms of acute bronchiolitis was investigated in 29 infants and toddlers aged 2-17.5 months by transcutaneous oxygen tension (TcPO2), oxygen saturation, transcutaneous carbon dioxide tension (TcPCO2), and clinical evaluation in a double blind placebo controlled study. Clinical score and TcPO2 improved significantly at 30, 45, and 60 minutes after inhalation of racemic adrenaline, with an increase in TcPO2 > or = 0.5 kPa in 72% of the children < 1 year of age. No significant improvement was observed after inhalation of placebo. No significant changes in heart rate or TcPCO2 were observed from before to after inhalation, but a small increase in mean systolic blood pressure was observed immediately and 45 minutes after racemic adrenaline inhalation. This study demonstrates that treatment with nebulised racemic adrenaline improved oxygenation and clinical signs in hospitalised children aged less than 18 months with bronchiolitis.

Lung function in awake healthy infants: the first five days of life

Our main aim was to determine an appropriate time for lung function measurements in infants, prior to environmental influences upon their respiratory tract. Tidal flow-volume loops, respiratory system compliance (Crs) and resistance (Rrs) (single breath passive occlusion technique) were measured in 24 healthy, awake awake infants, at one hour and on the following four days of life to investigate variability and reproducibility over time. Possible differences in lung function were sought between the 12 vaginally-delivered and 12 Caesarean section-delivered infants. Tidal volumes increased each day, but significantly so only from Day 0 to Day 1. The expiratory flow-time ratios (time to reach peak expiratory flow to total expiratory time (Tme/Te) and tidal expiratory flow at 75% to peak flow (TEF25/PTEF)) and expiratory flow-volume ratio (volume to reach peak expiratory flow to total expiratory volume (Vme/Ve)) were significantly smaller on Day 1 than Day 0, but did not change significantly thereafter. Crs and Rrs were lower on Day 0 than later. Intra-individual variation remained stable for tidal flow-volume parameters throughout the study, but was significantly higher during Day 0 and Day 1 for Crs and Rrs. There were no significant differences related to mode of delivery of the infant. We conclude that, for epidemiological purposes, tidal lung function parameters may be measured from Day 2 to Day 4, and that they are not influenced by mode of delivery of the infant.

Lung function in awake healthy infants: the first five days of life

Our main aim was to determine an appropriate time for lung function measurements in infants, prior to environmental influences upon their respiratory tract. Tidal flow-volume loops, respiratory system compliance (Crs) and resistance (Rrs) (single breath passive occlusion technique) were measured in 24 healthy, awake awake infants, at one hour and on the following four days of life to investigate variability and reproducibility over time. Possible differences in lung function were sought between the 12 vaginally-delivered and 12 Caesarean section-delivered infants. Tidal volumes increased each day, but significantly so only from Day 0 to Day 1. The expiratory flow-time ratios (time to reach peak expiratory flow to total expiratory time (Tme/Te) and tidal expiratory flow at 75% to peak flow (TEF25/PTEF)) and expiratory flow-volume ratio (volume to reach peak expiratory flow to total expiratory volume (Vme/Ve)) were significantly smaller on Day 1 than Day 0, but did not change significantly thereafter. Crs and Rrs were lower on Day 0 than later. Intra-individual variation remained stable for tidal flow-volume parameters throughout the study, but was significantly higher during Day 0 and Day 1 for Crs and Rrs. There were no significant differences related to mode of delivery of the infant. We conclude that, for epidemiological purposes, tidal lung function parameters may be measured from Day 2 to Day 4, and that they are not influenced by mode of delivery of the infant.

Loratadine and terfenadine in perennial allergic rhinitis. Treatment of nonresponders to the one drug with the other drug

The efficacy of loratadine and terfenadine in perennial allergic rhinitis was evaluated in a double-blind, selected cross-over study consisting of two phases. During the first phase, 76 patients with perennial allergic rhinitis, 8-67 years old, were included in the study. Of these, 41 patients received loratadine 10 mg daily, and 35 patients received terfenadine 60 mg twice daily, for 2 weeks. According to symptoms and side-effects, 32 patients were classified as responders to loratadine, and 28 patients as responders to terfenadine. All observed symptoms were significantly reduced in both treatment groups, but with no significant differences between the two groups. Side-effects were few and mild. In patients with normal IgE, loratadine was significantly superior to terfenadine in relieving nasal secretion, whereas terfenadine was significantly superior to loratadine in relieving nasal congestion. In patients with increased IgE, patients treated with loratadine showed significantly greater reduction in sneezing than patients treated with terfenadine. A positive correlation between total IgE and reduction in overall symptoms was found for patients treated with loratadine, whereas a negative correlation was found for patients treated with terfenadine. During the second study phase, the nonresponders received the other drug for 2 weeks. All seven nonresponders to terfenadine responded to loratadine after crossing over, whereas four of nine nonresponders to loratadine responded to terfenadine. Nonresponders to one drug may respond to the other drug. Thus, more than one antihistamine drug should be tried in perennial allergic rhinitis if the first fails.

[Acute asthma in children--anaphylaxis]

Acute asthma is a manifestation of chronic inflammation of airways, and may be due to inadequate control. Assessment of acute asthma is based upon respiratory rate and pattern, thoracic respiratory recessions, auscultatory rales and rhonchi, skin colour (cyanosis/pallor) and heart rate. Acute asthma in children is best treated with inhaled nebulised drugs, especially beta 2-agonists and adrenaline. Acute severe asthma should be treated with systemic steroids (by injection or orally), and it is important that this treatment is not started too late. Symptomatic treatment with intravenous theophyllamine may also be relevant. Anaphylactic shock occurs most often after injection of drugs or after bites by a wasp or a bee. Food allergy may be the cause in some patients. Speed is necessary in the treatment of anaphylactic shock, and intramuscular injection of adrenaline is the treatment of choice. Systemic steroids or antihistaminics may be used to stabilize the state of the patient.