Intravenous fluid therapy An average adult patient in DKA will have a deficit of 5–7 litres of water, 500–700 mmol of sodium, 200–350 mmol of potassium, 350–500 mmol of phosphate, and 200– 350 mmol of chloride.5 26 Intravenous fluid therapy should aim to correct these water and electrolyte deficits over the first 24–48 hours, expanding the intravascular and extravascular volume and restoring renal perfusion. The speed of replacement will depend on the patient’s haemodynamic and cardiovascular status. This is assessed using clinical evaluation of jugular venous pressure and postural changes in blood pressure and heart rate. These changes, however, are difficult to interpret in the presence of suspected autonomic neuropathy (which is common in poorly controlled diabetes) or when the patient is using cardioactive or vasoactive medication (a common scenario in older diabetic subjects). This means that in most adults with moderate or severe DKA it is appropriate to assume a deficit of approximately five litres (three litres in mild DKA) and to be guided by the response to therapy. If the patient has significant cardiac disease, then central venous pressure monitoring is required in moderate/ severe DKA.