Abstract
Sequential blood gas tensions and pH have been measured in 84 children selected from 486 admitted to hospital during a 15-month period with acute lower respiratory tract infections. Of those selected 73 were treated conservatively and 11 by intermittent positive-pressure ventilation; one infant in the latter group died. Respiratory syncytial virus (R.S.V.) was isolated from 24 out of 62 patients studied and the main pathogen in the most severely affected infants. Statistical analysis showed that age and R.S.V. infection were independent determinants of severity, as reflected by a peak Pco(2) measurement at the height of the illness (age, P < 0.01; R.S.V. 0.05 > P > 0.01).