Acidosis and coma in adult diabetic maintenance dialysis patients with extreme hyperglycemia.

BACKGROUND: Extreme hyperglycemia (serum glucose ≥ 800 mg/dL or 44.4 mmol/L) is infrequently associated with impaired consciousness in patients on maintenance dialysis. The purpose of this study was to determine features of extreme hyperglycemia that bring about coma in dialysis patients who do not have any of the potential conditions, other than hyperglycemia, that can affect the sensorium. METHODS: We analyzed 24 episodes of extreme dialysis-associated hyperglycemia in men who did not have neurological disease or sepsis. We compared serum parameters related to hyperglycemia between a group of 12 patients (8 on peritoneal dialysis, 4 on hemodialysis) who were alert and oriented (group A) and another group of 12 patients (5 on peritoneal dialysis, 7 on hemodialysis) who displayed varying degrees of impairment of sensorium, ranging from drowsiness to coma (group B). RESULTS: Group B had, in the serum, lower total carbon dioxide (TCO2, 8 ± 4 vs. 20 ± 3 mmol/L, P < 0.01) and higher anion gap (AG, 32 ± 8 vs. 15 ± 4 mEq/L, P < 0.01) and potassium (6.3 ± 1.5 vs. 4.6 ± 1.0 mEq/L, P < 0.05) than group A. Serum levels of glucose, chloride, urea nitrogen, calculated osmolarity and tonicity did not differ between the two groups. The test for serum ketone bodies was positive only in group B (all patients). Stepwise multiple linear regression identified serum TCO2 and AG as the only predictors of impaired sensorium (r (2) = 0.74. P < 0.01). CONCLUSION: There is a strong statistical association between the severity of diabetic ketoacidosis (DKA) and the level of impairment of consciousness in patients on dialysis with extreme hyperglycemia and no neurological or infectious disease. This association suggests that the presence or absence of DKA is usually the primary etiologic factor in the development of impaired sensorium in these patients.