Hyperglycaemic crises are discussed together followed by a separate section on lactic acidosis.
DIABETIC KETOACIDOSIS (DKA) AND HYPERGLYCAEMIC HYPEROSMOLAR STATE (HHS) Definitions DKA has no universally agreed definition. Alberti proposed the working definition of ‘‘severe uncontrolled diabetes requiring emergency treatment with insulin and intravenous fluids and with a blood ketone body concentration of .5 mmol/l’’.1 Given the limited availability of blood ketone body assays, a more pragmatic definition comprising a metabolic acidosis (pH ,7.3), plasma bicarbonate ,15 mmol/l, plasma glucose .13.9 mmol/l, and urine ketostix reaction ++ or plasma ketostix > + may be more workable in clinical practice.2 Classifying the severity of diabetic ketoacidosis is desirable, since it may assist in determining the management and monitoring of the patient. Such a classification is based on the severity of acidosis (table 1). A caveat to this approach is that the presence of an intercurrent illness, that may not necessarily affect the level of acidosis, may markedly affect outcome: a recent study showed that the two most important factors predicting mortality in DKA were severe intercurrent illness and pH ,7.0.3