pneumomediastinum /no̅o̅′mōmē′dē·əstī″nəm/ [Gk, pneuma, air, mediastinus, midway] , the presence of air or gas in the mediastinal tissues. In infants it may lead to pneumothorax or pneumopericardium, especially in those with respiratory distress syndrome or aspiration pneumonitis. In older children the condition may result from bronchitis, acute asthma, pertussis, cystic fibrosis, or bronchial rupture from cough or trauma. Also called Hamman’s disease.
