Lung function measurements in awake compared to sleeping newborn infants

Tidal breathing flow-volume loops were recorded in 19 healthy newborn infants when awake and asleep. This preceded and followed measurements of passive lung mechanics (by single breath occlusion). Our aim was to evaluate possible differences in lung function due to state of arousal or any influence of the occlusion technique. Expiratory volumes and flow rates were larger in awake than in sleeping infants before, but not after occlusion measurements. In sleeping, but not in awake infants, expiratory volumes and flow rates were higher after occlusion than before. Respiratory system compliance was significantly larger in sleeping than awake infants, while differences in respiratory system resistance and airway plateau pressure did not reach a significant level. Our results show that lung function can be measured in awake as well as sleeping infants, but differs significantly according to their arousal state, and whether tidal expiratory flow measurements are performed before or after airway occlusion measurements. Separate reference values for awake and sleeping infants may, therefore, be required. Marked intrasubject variability was found in the occlusion measurements, and criteria for acceptable measurements need to be defined.

[Asthma and mountain air]

Geilomo hospital for children with asthma and allergy is situated 800 m above sea level in a non-polluted area in the central part of Norway. 31 children who were admitted to this hospital from different parts of Norway (mostly from the main cities) were studied for six weeks. They underwent physical training and daily measurements were taken of lung function and the effect of bronchodilators. The bronchial responsiveness of the children improved significantly from week 1 to week 6, as measured by reduction in lung function after sub-maximal running on a treadmill. There was significant improvement in daily symptom score, and in degree of obstruction as shown by physical examination. The children's improvement was probably the result of a stay in a mountainous area with very little air pollution or allergens, combined with regular planned physical activity, and regular medication and surveillance.

[Morbidity and mortality from obstructive lung disease among Norwegian children]

From 1980 through 1986 hospitalization of children because of obstructive airways disease has increased in the ten Norwegian counties studied. Most of the increase related to acute bronchiolitis and bronchitis among children under five years of age. The hospitalization rate is greater in urban than in rural areas, and greatest in Oslo, the capital of Norway. From 1980 through 1988, the national sale of inhaled beta 2-agonists has increased two-fold, and of local steroids for inhalation ten-fold. Mortality from obstructive airways disease has decreased from 1960 through 1987, mostly in children below five years of age. Mortality from bronchial asthma in children below 15 years has remained unchanged.

[Bronchial asthma. Immunologic and biochemical aspects]

Bronchial asthma is a multifactorial condition, both as regards causes of illness and pathogenetic mechanisms. The pathogenetic mechanisms are discussed, starting with the type 1 allergic reaction as an inductor of mediator release from leukocytes in the bronchial mucosa. The article describes the interaction between bronchial smooth muscle contraction, vasodilatation, mucosal edema and increased mucosal secretions, with particular emphasis upon inflammatory changes and epithelial damage. It delineates the role of the nervous system, especially the parasympathetical nervous system, and the non-adrenergic non-cholinergic nervous system in the lung. The possibility of an interaction between mediator release and the parasympathetical nervous system is also discussed.

Nebulised beclomethasone dipropionate in recurrent obstructive episodes after acute bronchiolitis

Forty four children with recurrent obstructive episodes after acute bronchiolitis in infancy were treated with nebulised beclomethasone dipropionate or placebo for eight weeks in a randomised double-blind study. They were seen monthly for a year afterwards, and also if they had acute respiratory illnesses with or without bronchopulmonary obstruction. The two treatment groups were well matched. The children receiving active treatment had significantly fewer symptomatic respiratory illnesses and fewer episodes of bronchopulmonary obstruction during the follow up period. The children given placebo had significantly higher obstructive scores during the study period, and they were treated with inhaled beta 2 agonists and theophylline for longer periods of time during the follow up period. The results suggest that nebulised beclomethasone dipropionate may have prolonged effects on subsequent asthmatic symptoms after termination of treatment in children with recurrent obstructive episodes after acute bronchiolitis.

Acute bronchiolitis: predisposing factors and characterization of infants at risk

Fifty-one infants hospitalized because of acute bronchiolitis and 24 control children were prospectively followed until 2 years of age. Respiratory syncytial virus was detected initially in 31 index children, parainfluenza virus in two, and rhinovirus in one. More index children were born during the months April through September, and six index children had neonatal respiratory complications. The index children were breast-fed for shorter periods, lived in more crowded homes, and had more siblings. No significant differences were found for atopic background and atopic illness at 2 years of age. The index children had more respiratory infections and episodes of bronchopulmonary obstruction during the follow-up period (60% with three or more episodes). To characterize the hospitalized children, a discriminant analysis was performed. A discriminant function classified 47 of 51 index children as belonging to the index group and 21 of 24 control children to the control group.

Acute bronchiolitis in infancy. The relationship to later recurrent obstructive airways disease

Fifty-one infants admitted to hospital because of acute bronchiolitis were followed until 2 years of age. Sixty per cent had three or more attacks of bronchopulmonary obstruction, and the remainder two or less attacks. The children with three or more attacks also had more respiratory infections. They had younger parents and their close relatives more often had respiratory atopic illness. The children with three or more attacks wheezed for a longer time after the bronchiolitis. No difference was found for breast-feeding, neonatal respiratory complications, crowded homes, parental smoking and other social factors. To detect children at risk of recurrent obstructive airways disease after bronchiolitis, a discriminant analysis was performed. The discriminant function classified 28 of the 31 children with recurrent obstructive episodes as belonging to the risk group, and 18 of the 20 children with two or less episodes to the non-risk group.

Neutralizing activity in human milk fractions against respiratory syncytial virus

Neutralizing activity against respiratory syncytial virus (RSV) was measured in milk samples from 17 healthy women whose infants had an acute infection with respiratory syncytial virus (RSV) and from 27 women with healthy infants. All milk samples were obtained 2-8 months post partum. Neutralizing activity was detected in 36 samples. No major difference in neutralizing titers was observed between the two groups, and the titers were low. RSV-specific IgA was found in two samples, and RSV-specific IgG in one sample. RSV-specific IgM was not detected. In gel filtration studies, the neutralizing activity was eluted with an apparent molecular weight above 400,000. The neutralizing activity remained after removal of IgA by affinity chromatography. These findings suggest that both immunoglobulin and non-immunoglobulin components in human milk can neutralize RSV.

Radiological findings in children with respiratory syncytial virus infection: relationship to clinical and bacteriological findings

Respiratory syncytial virus (RSV) is a frequent cause of bronchiolitis leading to acute admission to hospital in the winter months. A wide range of findings accompanies this disease and the appearances are seldom completely diagnostic. Associated bacterial co-infections are common and we have shown an association with atelectasis among patients with pathogenic bacteria in the nasopharynx.

Respiratory virus infections and aeroallergens in acute bronchial asthma

Two hundred and fifty six attacks of acute bronchial asthma occurring in 169 children aged over 2 years were studied during a two year period. More attacks occurred during spring and autumn than at other times of the year. In 73 patients (29%) a respiratory virus infection was diagnosed, with the same seasonal variation as the asthmatic attacks. Most of the virus infections were caused by rhinovirus (45%) and respiratory syncytial virus (19%). There was no significant correlation between asthmatic attacks in patients with birch pollen, grass pollen, or Cladosporium herbarum allergy and counts of the respective pollen or spores in the air. More seasonal attacks occurred in patients with cladosporium allergy than in patients without cladosporium allergy but there was no seasonal variation among birch or grass pollen allergic patients. Information about exposure to animals was obtained in only 12% of attacks occurring in 121 patients with allergy to animal dander. The single precipitating factor most frequently associated with acute asthma was respiratory virus infection.

Bronchopulmonary obstruction in children with respiratory virus infections

Among 873 children hospitalized with confirmed respiratory viral infections, 492 suffered from bronchopulmonary obstruction. Respiratory syncytial virus infections were dominant among the patients with bronchopulmonary obstruction (80%). The majority of patients with rhinovirus infections suffered from bronchopulmonary obstruction (57%). Two main groups of children at risk from developing bronchopulmonary obstruction during respiratory virus infections were found: 1) infants, suffering from bronchiolitis, mainly due to respiratory syncytial virus, and 2) children of all ages with bronchial asthma, among whom acute attacks were precipitated by virus infections, mainly rhinovirus and respiratory syncytial virus infections. The pathogenesis of bronchopulmonary obstruction during respiratory virus infections is discussed.

Viral infections of the respiratory tract in hospitalized children. A study from Oslo during a 90 months' period

A diagnosis of 979 respiratory viral infections was made in hospitalized children. Respiratory syncytial virus greatly out-numbered the other viruses: it caused 58% of the total virus infections and occurred in winter epidemics. Influenza A and B virus occurred during late winter and spring, rhinovirus had a seasonal distribution towards spring and autumn, whereas adenovirus types 1, 2 and 5 had no distinct seasonal distribution. Whereas respiratory syncytial virus were mainly associated with bronchiolitis and adenovirus type 7 with pneumonia, rhinovirus infections were most often found in children with episodes of acute bronchial asthma. The influenza A and B and adenovirus types 1, 2 and 5 infections often occurred with extrarespiratory symptoms, especially febrile convulsions.

Respiratory syncytial virus infections in Oslo 1972--1978. II. Clinical and laboratory studies

Patient records from 422 children admitted to hospital during 6 winter outbreaks of RSV infection were examined retrospectively. Bronchiolitis (255 patients) and pneumonia (98 patients) were the most common diagnoses. Otitis media (76 patients) occurred as a complication to these conditions. Children at risk for contracting severe illness caused by RSV were infants below the age of one year, more often boys than girls. Of the children older than two years, 32% had already been diagnosed as asthmatics. Children with otitis media had more often positive bacteriological findings from nasopharyngeal swabs than children with bronchiolitis only. No such significant difference was found between patients with bronchiolitis and pneumonia. Rapid virus diagnosis by immunofluorescence led to a decreasing utilisation of antibiotics in patients with bronchiolitis and to a shorter stay in hospital. The value of antibiotics in these infections is discussed.

Respiratory syncytial virus infections in Oslo 1972--1978. I. Virological and epidemiological studies

Respiratory syncytial virus (RSV) infection was diagnosed in 464 children admitted to hospital with acute respiratory disease from autumn 1972 to spring 1978. The virological surveillance was approximately 70%. As a rule, RSV infections occurred in distinct outbreaks in late autumn and winter together with a marked increase in the number of children admitted to hospital with acute lower respiratory tract disease. The incidence in children less than 1 year of age was about 10/1000 children/year. Spread of the infection from one end of the city to the other was discernible in 2 outbreaks. More children than expected with siblings were admitted to hospital because of RSV infection, but no correlation could be observed with some other socioeconomic factors. A negative correlation was observed between RSV disease and mean air temperature and hours of sunshine per month. Rapid immunofluorescence diagnosis of RSV on cells from nasopharyngeal secretions was adopted and became comparable to cell culture technique. The rapid method has become an important adjunct to the clinical management of these patients and the method will form the basis for further epidemiological studies.