Israel Medical Association Journal

Background: Bronchiolitis caused by respiratory syncytial virus is one of the major causes of hospitalization in young children, especially during the winter.  Recent evidence has shown that pharmacological treatment, especially nebulized epinephrine, in addition to the traditional supportive treatment, can alleviate symptoms and shorten hospitalization, but this approach is not yet widespread.

Objectives: To determine whether the management of bronchiolitis in Israel is moving toward a stronger emphasis on pharmacological care.

Methods: A questionnaire on the diagnosis and management of bronchiolitis was completed by 27 heads of pediatric departments throughout Israel.  The questionnaire dealt with the frequency of usage of diagnostic and selected therapeutic procedures.

Results: Chest X-ray and arterial blood gases are commonly used as a diagnostic aid in more than 75% of the departments, and antibiotics are prescribed routinely in 24%.  Corticosteroids are still in use: 48% use systemic steroids, and 19% nebulized steroids.  Nebulized epinephrine is used in 22% of the departments, while nebulized beta-agonists are used frequently in two-thirds of the departments.

Conclusions: Despite convincing data that beta-agonists and steroids have no positive effect on the outcome of bronchiolitis on the one hand, and that nebulized epinephrine has advantages in children on the other, we found significant use of the former two agents and sparse use of the latter.  Greater awareness is needed among pediatricians, and measures should be introduced to incorporate the new recommendations, with further study of the effect of the old and new drugs on bronchiolitis.

 

Background: The growth plate increases its activity in response to exercise. Likewise, decreased physical activity exerts a negative effect on bone growth and development, leading to rarefaction of the subepiphyseal bone. Limb immobilization inhibits the growth plate’s activity, indirectly shown by a recorded arrest in longitudinal growth of the long bones. However, there is no direct evidence concerning the growth plate itself.

Objective: To determine whether the growth plate exhibits measurable microstructural changes in response to decreased levels of physical activity.

Methods: Histomorphometric analysis was used to qualitatively and quantitatively assess the changes in the epiphyseal plate in response to single hind limb immobilization in the rat. In 16 of 25 Sprague-Dawley male rats the left hind limb was immobilized for 3 weeks; the remaining 9 rats served as controls. The left proximal tibia of each animal was examined by computerized image analysis.

Results: There was a decrease in epiphyseal height, cell column density and subepiphyseal trabecular area - all indices of growth plate activity. Metaphyseal cortical thickness was also depressed, thereby confirming the efficacy of the immobilization method applied.

Conclusions: Limb immobilization in the rat induces inhibitory histological changes in the epiphyseal growth plate, which are in contrast to the excitatory microscopic changes seen with exercise. These changes can be assessed quantitatively. Their potential for reversibility remains to be determined by future experiments.

Objectives: To suggest a simple outpatient technique for evaluating the response of arterial oxygen saturation to exercise for use as a marker of disease severity.

Patients and methods: Ninety-six patients with various degrees of COPD¹ were divided into three groups: mild (forced expiratory volume in 1 sec >65%), moderate (FEV1² between 50 and 65%), and severe (FEV1 <50%). Using continuous oximeter recording we measured oxygen saturation during 15 steps of climbing, and quantified  oxygen desaturation by measuring the “desaturation area”, defined as the area under the curve of oxygen saturation from the beginning of exercise through the lowest desaturarion point and until after recovery to the baseline level of oxygen percent saturation. Desaturation was correlated to spirometry, lung gas volumes, blood gas analysis, and 6 min walking distance.

Results A good correlation was found between severity of COPD and baseline SaO2³, lowest SaO2, recovery time, and desaturation area.  A negative correlation was found between desaturation area and FEV1 (r=-0.65), FEV1/forced vital capacity (r=-0.58), residual volume to total lung capacity (r=0.52), and diffusing lung capacity for carbon monoxide (r=-0.52). In stepwise multiple regression analysis only FEV1 correlated significantly to desaturation area.  A good correlation was noted between 6 min walking distance and desaturation area with the 15 steps technique (r=0.56).

Conclusions: In patients with severe COPD, arterial hypoxemia during exercise can be assessed by simple 15 steps oximetry. This method can serve both as a marker for disease severity and to determine the need for oxygen supplementation.

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COPD = chronic obstructive pulmonary disease

FEV1 = forced expiratory volume in 1 sec

SaO2 = arterial oxygen saturation