Diabetic Ketoacidosis

OVERVIEW

Diabetic Ketoacidosis (DKA) potentially life-threatening complication of diabetes mellitus resulting from the consequences of insulin deficiency

Diagnostic criteria

• pH < 7.3
• ketosis (ketonemia or ketonuria)
• HCO3 <15 mmol/L due to high anion gap metabolic acidosis (HAGMA)
• hyperglycemia (may be mild; euglycemic DKA can occur)

PATHOGENESIS

• increased glucagon, cortisol, catecholamines, GH
• decreased insulin
  -> hyperglycaemia
  -> hyperosmolality + glycosuria
  -> electrolyte loss
  -> ketone production from metabolism of TG
  -> acidosis

HISTORY

• dry, abdominal pain, polyuria, weight loss, coma
• risk factors: non-compliance, illness, newly diagnosed
• ROS to rule find out possible precipitant (infection, MI, pneumonia, GI illness)
• normal insulin regime
• diabetic control
• previous DKA / admissions
• previous ICU admissions

EXAMINATION

• volume assessment
• signs of cause e.g. (infection)
• GCS
• work of breathing

INVESTIGATIONS

• ABG
• electrolytes
• osmolality
• urinalysis: ketones
• pregnancy test
• standard investigations to rule out cause: FBC, ECG, CXR

MANAGEMENT

Goals

(1) establish precipitant and treat
(2) assess severity of metabolic derangement
(3) cautious fluid resuscitation with replacement of body H2O
(4) provision of insulin
(5) replacement of electrolytes

Resuscitate

• intubation for airway protection if required
• O2 as required
• IV access
• fluid boluses (20mL/kg boluses of NS/HMN)
• urinary catheter

Acid-base and Electrolyte abnormalities

• will have a severe metabolic acidosis with probable incomplete respiratory compensation
• K+ may be normal but patient will have a whole body K+ deficiency -> needs to be replaced once < 5mmol/L -> use KH2PO4
• Na+ may be deranged
• acidaemia rarely requires HCO3- therapy and will respond to other treatments

Specific therapy

• start insulin infusion (avoid bolus) 0.1u/kg/hr
• aim to lower glucose by 1-2mmol/L/hr
• balanced salt solution fluid resuscitation
• once glucose < 15mmol/L -> provide dextrose (5%) 100mL/hr
• monitor urinary ketones or BE clearance
• correct osmolality by 3mosmol/kg/hr

Underlying cause

• treat infection
• review compliance
• ischaemia (ACS, CVA, PVD, mesenteric ischaemia)
• pregnancy

COMPLICATIONS

• hypoglycaemia
• hyponatraemia
• hyperchloraemic acidosis
• cerebral oedema
• arrhythmias
• venous thrombosis
• infection
• hyperchloraemia

References and Links

LITFL

• CCC — Sodium Bicarbonate and Diabetic Ketoacidosis

Journal articles

• Beck LH. Should the actual or the corrected serum sodium be used to calculate the anion gap in diabetic ketoacidosis? Cleve Clin J Med. 2001 Aug;68(8):673-4. PMID: 11510523.
• Chua HR, Schneider A, Bellomo R. Bicarbonate in diabetic ketoacidosis – a systematic review. Ann Intensive Care. 2011 Jul 6;1(1):23. dPMC3224469.
• Chua HR, Venkatesh B, Stachowski E, Schneider AG, Perkins K, Ladanyi S, Kruger P, Bellomo R. Plasma-Lyte 148 vs 0.9% saline for fluid resuscitation in diabetic ketoacidosis. J Crit Care. 2012 Apr;27(2):138-45. PMID: 22440386.
• Kelly AM. The case for venous rather than arterial blood gases in diabetic ketoacidosis. Emerg Med Australas. 2006 Feb;18(1):64-7. PMID: 16454777.
• Rosenbloom AL. The management of diabetic ketoacidosis in children. Diabetes Ther. 2010 Dec;1(2):103-20. PMC3138479.
• Savage MW. Management of diabetic ketoacidosis. Clin Med. 2011 Apr;11(2):154-6. PMID: 21526698.