Emergency x-ray examinations in paediatric practice.

DIFFICULTY IN SWALLOWING This may, inter alia, be due to (a) oesophageal atresia, (b) pharyngo-oesophageal inco-ordination of swallowing or (c) retro-pharyngeal abscess. In oesophageal atresia early diagnosis is essential if the child's life is to be saved. The history is one of excessive salivation, with attacks of choking and coughing if feeding is attempted. Aspiration pneumonia follows feeding, especially affecting the right upper lobe. The greater the lung involvement the poorer is the prognosis. It is usually sufficient to pass a soft rubber catheter into the oesophagus from the mouth, with or without fluoroscopic control, and take films with this in situ. Some surgeons do not approve of the instillation of a positive contrast medium but if this is employed, all the contrast medium should be sucked out before the catheter is removed. The two main types of oesophageal atresia are (a) those with a distal oesophageo-tracheal fistula, showing air in the gastro-intestinal tract, and (b) those without a fistula. The latter have the more serious prognosis as the gap between the segments is usually greater. In the rarer types there may be a fistula between the upper sac and the trachea, or fistulae between both sacs and the trachea or bronchi. Tracheo-oesophageal fistula without atresia rarely presents as an emergency problem and calls for specialised investigational techniques. Recently MacEwan, Dunbar and Murphy (1960) have successfully used cinefluorography to demonstrate high tracheo-oesophageal fistulae. Children with birth injury to the basal cerebral ganglia may present with difficulty in swallowing and often regurgitation of the feed through the nose, with excess of mucus. The symptoms may mimic those of oesophageal atresia but this can be excluded by the passage of a rubber catheter into the stomach. If the baby is fit enough for the examination to be continued, a Dionosil swallow can be carried out; the baby will usually suck Dionosil through a rubber teat attached to a warmed bottle of the substance. The opaque medium tends to be held up in the mouth and pharynx, and whilst a little will pass into the oesophagus and stomach, some will be returned to the mouth, pass into the nasal cavity and spill over into the trachea (Fig. 1). Severe oral and oesophageal thrush infection will give a similar picture. Oxygen and suction apparatus should be at hand during the X-ray examination. A retropharyngeal abscess may not be very obvious clinically but will cause difficulty in swallowing and the child is acutely ill. A lateral teleradiograph of the neck with the head extended will provide the diagnosis. The film must be taken in full inspiration as the prevertebral tissues in infants are normally redundant and widen during expiration so that they may give a deceptive appearance. An abscess will show as a curved prevertebral swelling, displacing anteriorly the larynx, trachea and sometimes the upper oesophagus. It is important that the trachea should show as a straight airfilled structure on the film; buckling of the trachea shows that the radiograph was taken in expiration. A cervical neuroganglioma may also cause a prevertebral swelling but this condition is rare and the child is not acutely ill.