William S. Jordan

Ten-year experience with IPPB in the treatment of acute laryngotracheobronchitis.

ARYNGOTRACHEOBRONCHITIS, or infectiL ous croup, is an acute infection of the upper respiratory tract. Several viral agents can now be identified as the pathogens, the most common being parainfluenza 2 (CA) .I** The condition is generally seen in children, ages 6 months through 3 years, but may occur up to 14 years.3 Croup is manifest by signs and symptoms of laryngeal and sublaryngeal edema. This idammatory swelling results in respiratory distress of varying degree: hoarseness with barking cough; stridorous, noisy, labored breathing; intercostal, sternal, and suprasternal retractions. As in other forms of respiratory obstruction, restlessness and the extreme anxiety of hypoxia may occur before cyanosis is evident. This picture is identical to the postintubation croup msionally seen in children after endotracheal anesthesia.

Infectious and allergic aspects of bronchiolitis

A clinical and etiologic study was conducted among children who wheezed during acute respiratory infections. The results suggest that the clinical response of many children who first wheeze with respiratory infections not due to respiratory syncytial virus may represent the initial bout of asthmatic bronchitis. In contrast, children who wheeze with an attack of bronchiolitis due to RS virus probably do not have an increased likelihood of developing bronchial asthma.

Stability Characteristics of Coe Virus.

Summary Coe virus dissociates from infected cells, but 25% to 50% of virus is still intracellular at time of maximum cytopathic effect. The virus was relatively stable when exposed to repeated freezing and thawing, and to storage at −70°C, 4°C, and room temperature. At 37°C, 90% of the virus was inactivated within 3 days, and less than 1% of particles were infectious after 20 days. Coe virus is rapidly inactivated at 50°C, but a few particles survive 30 minutes at this temperature. Coe virus is ether resistant and resistant to inactivation at pH 6 to 9. The excellent technical assistance of Eleanor Sturgill is gratefully acknowledged.