Pneumomediastinum in childhood asthma

The objective of this study was to examine the presentation and clinical course of patients with asthma and pneumomediastinum (PNMD). A retrospective chart review was performed from a computer-generated list of all patients discharged from an urban children's hospital between 1981 and 1991 with the diagnoses of asthma and PNMD. Thirty cases and 30 controls with asthma, matched for age and sex, were identified. The incidence of PNMD and asthma was 0.3%. Mean age was 11.8 years with a male:female ratio of 1.15:1. Chest pain was reported in 27% of patients and 13% of controls (P = 0.17). There was no difference in presenting respiratory rate, heart rate, or systolic blood pressure between cases and controls, nor was there a difference in respiratory distress by modified Wood-Downes scale. Fifty percent of patients had room air oxygen saturation measured at presentation. There was a significant difference in mean oxygen saturation between those with PNMD and those without (90.4 vs 94.1 %; P = 0.03). Subcutaneous emphysema was detected in 73% of cases versus none in controls (P < 0.001; positive predictive value (PPV) = 100%). Sixty-seven percent of patients with PNMD had repeat radiographs during hospitalization. Of these x-rays, 85% showed no change in, improvement, or complete resolution of the PNMD. Three patients (15%) developed a small increase in the PNMD. No patient developed pneumothorax, pneumopericardium, or deterioration in cardiovascular status. PNMD is a rare complication of asthma. Subcutaneous emphysema was the most useful predictor of PNMD in asthma. Chest pain and diminished oxygen saturation should heighten suspicion. Further complications of PNMD were exceedingly rare, and all patients recovered uneventfully, suggesting that attention to excellent treatment for the acute exacerbation may be sufficient in most instances of PNMD.