The risk and outcome of cerebral oedema developing during diabetic ketoacidosis

Background-Cerebral oedema is a major cause of morbidity and mortality in c hildren with insulin dependent diabetes. Aims-To determine the risk and outcome of cerebral oedema complicating diab etic ketoacidosis (DKA). Methods-All cases of cerebral oedema in England, Scotland, and Wales were r eported through the British Paediatric Surveillance Unit between October 19 95 and September 1998. Ah episodes of DKA were reported by 225 paediatricia ns identified as involved in the care of children with diabetes through a s eparate reporting system between March 1996 and February 1998. Further info rmation about presentation, management, and outcome was requested about the cases of cerebral oedema. The risk of cerebral oedema was investigated in relation to age, sex, seasonality, and whether diabetes was newly or previo usly diagnosed. Results-A total of 34 cases of cerebral oedema and 2940 episodes of DKA wer e identified. The calculated risk of developing cerebral oedema was 6.8 per 1000 episodes of DKA. This was higher in new (11.9 per 1000 episodes) as o pposed to established (3.8 per 1000) diabetes. There was no sex or age diff erence. Cerebral oedema was associated with a significant mortality (24%) a nd morbidity (35% of survivors). Conclusions-This first large population based study of cerebral oedema comp licating DKA has produced risk estimates which are more reliable and less s usceptible to bias than those from previous studies. Our study indicates th at cerebral oedema remains an important complication of DKA during childhoo d and is associated with significant morbidity and mortality. Little is kno wn of the aetiology of cerebral oedema in this condition and we are current ly undertaking a case control study to address this issue.