PRINCIPLES OF HHS THERAPY

Measure or calculate osmolality (2Na+ + glucose + urea) frequently to monitor the response to treatment.

• Use intravenous (IV) 0.9% sodium chloride solution as the principle fluid to restore circulating volume and reverse dehydration. Only switch to 0.45% sodium chloride solution if the osmolality is not declining despite adequate positive fluid balance. An initial rise in sodium is expected and is not itself an indication

for hypotonic fluids. The rate of fall of plasma sodium should not exceed 10 mmol/L in 24 hours.

• The fall in blood glucose should be no more than 5 mmol/L/hr. Low dose IV insulin (0.05 units/kg/hr) should only be commenced once the blood glucose is no longer falling with IV fluids alone OR immediately if there is significant ketonaemia (3â-hydroxy butyrate greater than 1 mmol/L or urine ketones greater than 2+).

• IV fluid replacement aims to achieve a positive balance of 3-6 litres by 12 hours and the remaining replacement of estimated fluid losses within next 12 hours though complete normalisation of biochemistry may take up to 72 hours.

• The patient should be encouraged to drink as soon as it is saf

e to do so and an accurate fluid balance chart should be maintained until IV fluids are no longer required.

• Assessment for complications of treatment e.g. fluid overload, cerebral oedema or central pontine myelinosis (as indicated by a deteriorating conscious level) must be undertaken frequently (every 1-2 hours).

• Underlying precipitants must be identified and treated.

• Prophylactic anticoagulation is required in most patients.