Lack of evidence of cerebral oedema in adults treated for diabetic ketoacidosis with fluids of different tonicity.

Each of ten adult patients consecutively admitted in DKA (diabetic ketoacidosis) was infused with either 0.15 or 0.12 mol/l saline as part of the treatment regimen. Computerized tomography (CT) scans of the brain were performed before treatment, and at 6-12 and 24 h together with a number of blood variables. The CT scans of a group of ten patients with no history of diabetes were studied as controls. The CT scans of all diabetic patients in DKA showed a definite increase in brain tissue density when compared with those of non-diabetic subjects (mean 36.2 vs. 28.9 Hounsfield units (HU), P<0.001). This did not change with either fluid regimen over the first 24 h. There was a statistically significant difference in brain tissue density between the CT scans of patients in DKA compared with CT scans taken >6 months after the last episode of DKA (32.6 vs. 25.4 HU, P<0.001). The CT scans taken >6 months after the last episode of DKA showed normal brain tissue density with no statistically significant differences from those of control scans. The density of diabetic brains on CT scanning during ketoacidosis is increased; this may be due to cerebral dehydration. This paper does not provide any evidence of cerebral oedema in adults during the treatment of ketoacidosis with isotonic and hypotonic fluids.