The Cerebrospinal Fluid in Diabetic Ketoacidosis

Cerebrospinal fluid and blood were studied in six patients with ketoacidosis before and four to nine hours after treatment, when neurologic improvement began. Alkali was excluded from the treatment regimen. Initial spinal-fluid pH was normal or elevated in all patients and fell with therapy in four patients. Osmolality was significantly higher in cerebrospinal fluid than in blood before treatment; lactate was increased initially and did not change with therapy. The concentrations of keto acids and glucose were initially lower in cerebrospinal fluid than in blood and fell with treatment at a less rapid rate consistent with a slow equilibration with blood. It is speculated that bicarbonate therapy would aggravate the spinal-fluid acidosis and could interfere with clinical improvement. Also, the increased osmolality before therapy is viewed as reason for caution against the excessively rapid correction of blood hyperosmolality.