Hyperglycaemic Hyperosmolar State (HHS)

• hypovolaemia
• osmolality usually greater than 320 mOsm/kg
• marked hyperglycaemia (usually greater than 30 mmol/L)

If significant ketosis (capillary greater than 3 mmol/L, urine greater than 2+) or acidosis (H+ more than 45 mmol/L; HCO3- less than 15 mmol/L) present treat as per the diabetic ketoacidosis (DKA) protocol.

An initial assessment form and monitoring chart (admission to 24 hours) is available to record required information. 

• repeated clinical and biochemical assessment is essential
• the patient’s ability to tolerate shifts in fluid balance if co-existing cardiac or renal disease must be taken into consideration
• assess if any markers of severity present (see section 'markers of severity')
• inform the on-call diabetes team.The BGH diabetes team are available in working hours. Contact diabetes/endocrinology via diabetes liaison nurse email inbox or, if urgent review required, via bleep to consultant covering ward referrals - diabetes secretaries have this rota.

• osmolality reducing by 3-8 mOsm/kg per hour
• plasma glucose reducing by 1-5 mmol/L per hour aiming for a target range of 10-15 mmol/L
• fluid replacement aims:
  • achieve positive fluid balance of 2-3L by 6 hours
  • achieve positive fluid balance of 50% of the estimated fluid loss within 12-24 hours and 100% estimated fluid loss by 24-48 hrs
  • always adapt fluid replacement to clinical assessment and presence of co-morbidities

Hour 1: assessment and treatment

Assessment:

• perform clinical assessment and necessary investigations as determined by the clinical picture eg ECG/sepsis screen/foot examination
• measure capillary glucose, capillary or urinary ketones, U&Es, venous blood gas, lactate, calculated osmolality
• consider catheterisation to allow accurate fluid balance measurement

Treatment:

• commence IV 0.9% sodium chloride – 1L over 1 hour
• commence insulin (Actrapid 0.05 units/kg/hour intravenously) only if significant ketonaemia (plasma ketones more than 1 mmol/L or urinary ketones more than 2+)
• commence prophylactic LMWH unless contraindicated (patients are at high risk of thromboembolic disease)
• treat any identified precipitant – eg infection, stroke, acute coronary syndrome

Hours 1-6 of treatment

Aim for a gradual decline in osmolality (3-8 mOsmol/kg/hour) and achieve positive fluid balance 2-3L by 6 hours.

• measure glucose, U&Es and calculate osmolality as per timings on flow sheet (page 3)
• monitor urine output
• adjust fluid administration based on clinical assessment and measurement of osmolality
• potassium replacement (see section 'potassium replacement')

If by 6 hours:

• osmolality falling less than desired rate (3-8 mOsmol/kg/hour)
  • if dehydrated clinically increase the IV fluid rate per hour
  • if patient in positive balance of more than 3L, commence IV insulin (Actrapid) at 0.05 units/kg/hour
• glucose falling less than desired rate (1-5 mmol/litre per hours) - commence insulin (Actrapid) - aim to keep glucose between 10-15 mmol/L
• Glucose falls below 14 mmol/L - commence 10% dextrose at 125ml/hr in addition to current fluids (ensure that this additional fluid is taken into consideration for other infusion rates)

Aim to achieve positive fluid balance of 50% estimated fluid loss within 12-24 hours and 100% estimated fluid loss by 24-48 hrs.

Continuing care

• consider and treat precipitating cause e.g. sepsis, stroke, myocardial infarction, limb ischaemia
• monitor for cerebral oedema
• assess for arterial venous thrombosis/pressure ulcers/ foot ulceration
• continue regular biochemical and clinical evaluation of hydration status

If 2 or more present discuss with senior medical staff and if appropriate consider discussion with critical care:

• osmolality more than 350 mOsmol/kg
• H+ more than 80mmol/L
• GCS less than 12
• systolic BP less than 90 mmHg
• urine output less than 0.5 ml/kg/hr
• hypothermia
• sodium more than 160 mmol/L
• potassium less than 3.5 mmol/L or 6.0mmol/L
• oxygen saturations less than 92% (if normal at baseline)
• creatinine more than 200 micromol/L
• macrovascular or other serious co-morbidity

• If K+ above 5.5 mmol/L - no additional KCL
• If K+ between 3.5 and 5.5 mmol/L – prescribe 40 mmol KCL per litre of infusion fluid
• If K+ below 3.5 mmol/L - seek senior advice as additional potassium is required

Ensure that the hourly rate of potassium administration is considered with rapid infusion rates.