The pneumographic and medical investigation of infants suffering apparent life threatening episodes.

Investigation of 340 babies who suffered from apparent life threatening episodes (ALTE) was performed using pneumographic studies and a variety of medical investigations. A number of medical abnormalities were demonstrated by history or investigation, including gastro-oesophageal reflux (211), airways pathology (17), evidence of fits (25), brain-stem tumour (2), hypoglycaemia (2), respiratory syncytial virus (8) and possible Munchausen by proxy (5). Pneumographic abnormalities were detected in 27 of the 340 infants. Home monitors were used for 135 infants. Future central apnoeas occurred in 20 of the 26 infants on home monitors that had had an abnormal pneumogram, compared with one of the 109 infants on home monitors after a normal pneumogram. Thus pneumograms have a sensitivity and specificity of 95% for predicting central apnoeas in babies who have already suffered an ALTE. The effect of eyeball pressure on the heart rate was measured in 65 babies and was found to cause a brisk drop in heart rate in 32 babies. Twenty-two of the 32 babies had future white apnoeas (usually associated with gastro-oesophageal reflux), compared with five of the 33 babies who had no drop in heart rate in response to eyeball pressure. Thus this test has a sensitivity of 81% and a specificity of 74% at predicting white apnoeas in babies who have already suffered an ALTE.