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Information ⬇

Author(s): Vimal Venugopal , Vito Carone , Manohara Kenchaiah

Consider diabetic ketoacidosis (DKA) in any ill patient with diabetes, especially if nausea, vomiting or abdominal pain are prominent. DKA typically occurs in patients with type 1 diabetes, but may also be seen in those with type 2 diabetes (ketosis-prone type 2 diabetes).

Priorities ⬆ ⬇

  1. Is this DKA?
    • Clinical assessment and investigation of the patient with suspected DKA are summarized in Tables 83.1 and 83.2.
    • Examination typically shows signs of volume depletion (average deficit 6L) and tachypnoea from the metabolic acidosis. There may also be features of an associated disorder that has precipitated DKA.
    • DKA is confirmed by a blood glucose >11 mmol/L, serum ketones >3 mmol/L and venous blood pH <7.3 or bicarbonate<15 mmol/L.
    • Venous blood gases are preferred to arterial blood gases as venous sampling is easier and less painful for the patient. The differences in venous and arterial pH and bicarbonate levels are not significant enough to affect management. Capillary blood glucose and capillary blood ketones are sufficiently accurate for monitoring.
  2. If DKA is confirmed, start treatment immediately
    • The treatment of DKA (Tables 83.3, 83.4, 83.5) involves fluid replacement to restore the circulating volume, replacement of lost potassium and the use of fixed-rate intravenous insulin infusion to correct the ketonaemia and acidosis.
    • If the patient is taking a long-acting insulin, this should be continued, as this allows earlier weaning from the infusion.
    • If the patient has a continuous subcutaneous insulin infusion pump, this should be disconnected unless you are instructed not to do so by a specialist diabetes team.
  3. Identify and treat the precipitant of DKA
    • Infection is a common precipitant (∼30% cases) and complication of DKA and may not cause fever. Check carefully for a focus of infection, including examination of the feet and perineum.
    • Seek a surgical opinion if abdominal pain or abnormal signs do not resolve with correction of acidosis.
    • Other causes of DKA are an inappropriate reduction in, or poor compliance with, insulin therapy (∼20% cases), errors in insulin prescription or administration, surgery, acute coronary syndrome, alcohol or substance use and emotional stress (∼25% cases).
    • DKA may also be the first presentation of type 1 (and, less commonly, type 2) diabetes (∼25% cases).
  4. Consider admission to ICU/HDU if the patient
    • Is aged 18–25 years (as higher risk of cerebral oedema) or >70 years (as higher risk of fluid overload)
    • Has a reduced conscious level or hypotension which is not corrected by fluid replacement
    • Has cardiac or renal failure
    • Is pregnant
    • At presentation has one or more of the following features:
      • Plasma ketones >6.0 mmol/L
      • Venous bicarbonate <5 mmol/L
      • Venous pH <7.0
      • Plasma potassium <3.5 mmol/L
      • Anion gap >16mOsmol/kg (calculated as [(plasma sodium+potassium)-(plasma chloride+bicarbonate)]

Further Management ⬆ ⬇

Supportive Care

  • Place a nasogastric tube if the patient is too drowsy to answer questions or there is a gastric succussion splash. Aspirate the stomach and leave on continuous drainage. Inhalation of vomit is a potentially fatal complication of DKA.
  • Use graduated compression stockings and prophylactic low-molecular-weight heparin to reduce the risk of deep vein thrombosis.

Monitoring

  • Continuous display of ECG and oxygen saturation
  • Check hourly:
    • Conscious level (e.g. by AVPU or Glasgow Coma Scale score) until fully conscious
    • Respiratory rate until stable and then 4-hourly
    • Blood pressure until stable and then 4-hourly
    • Fluid balance
    • Capillary blood glucose and plasma ketones
    • Venous blood glucose by laboratory measurement until capillary blood glucose is <20 mmol/L
  • Check venous pH, bicarbonate and potassium on admission, at 60 min, 120 min and then 2-hourly on a blood gas analyser
  • Put in a bladder catheter if no urine has been passed after 1h, or if the patient is incontinent, but not otherwise

Insulin Infusion

  • The blood glucose should fall with the administration of IV insulin. However, as long as ketoacidosis persists, the fixed rate insulin infusion must be continued even if the blood glucose enters the normal range. When blood glucose is <14 mmol/L, start an infusion of 10% glucose to prevent hypoglycaemia (the commonest complication of treatment of DKA)
  • Once the exit criteria for DKA are met, and the patient is eating and drinking, the IV insulin infusion can be weaned off (Table 83.6).

Further Reading ⬆

Joint British Diabetes Societies Inpatient Care Group (2013) The management of diabetic ketoacidosis in adults, 2nd edition. https://www.diabetes.org.uk/Documents/About%20Us/What%20we%20say/Management-of-DKA-241013.pdf