Diabetic Ketoacidosis Flashcards
Define Diabetic Ketoacidosis
Acute metabolic complication of diabetes characterised by:
Hyperglycaemia
Ketonaemia
Acidosis
with rapid onset of symptoms
Aetiology of Diabetic Ketoacidosis
Starvation - alternative metabolic pathway to glucose metabolism -> acetone production
Diabetes - lack of insulin - excess glucose cannot be absorbed in cells -> severe acidosis and hyperglycaemia
Associated with T1DM (inadequate insulin therapy or infection)
Also caused by MI, stroke, drugs (steroids, thiazides, pentamide)
Risk factors for Diabetic Ketoacidosis
Inadequate/inappropriate insulin therapy MI Infection Pancreatitis Stroke Acromegaly Hyperthyroidism Drugs (steroids, thiazides, pentamide) Cushing's
Presenting symptoms of Diabetic Ketoacidosis
Abdominal pain and vomiting Dehydration Gradual drowsiness Polyuria, polydipsia Polyphagia Lethargy Anorexia Severe: coma, deep breathing
Signs of Diabetic Ketoacidosis
Tachycardia and hypotension Ketotic/acetone breath Dehydration: poor skin turgor, prolonged capillary refill Kussmaul respiration (deep and rapid) Hypothermia
Criteria for Diabetic Ketoacidosis diagnosis
Acidaemia (venous pH <7.3 or bicarb <15)
Hyperglycaemia (glucose >11/known DM)
Ketonaemia (>3mmol/L) OR significant ketonuria (>++)
Investigations for Diabetic Ketoacidosis
VBG/ABG: metabolic acidosis (ABG used if hypoxia present)
Plasma glucose: hyperglcuaemia
Capillary/serum/urine ketones: elevated
Look for precipitating factor e.g. CXR for infection, ECG for electrolyte imbalances or MI
Criteria for severe Diabetic Ketoacidosis
pH <7.0 Ketonaemia >6mmol/L Bicarb <5 Potassium <3.5 GCS <12 Sats <92 Brady/Tachycardia Anion gap <16 Systolic BP <90
Management for Diabetic Ketoacidosis
- 1L 0.9% saline over 1 hour (add 500mL boluses over 15mins if BP <90)
- Send blood tests for ketoacidosis
(If HYPOKALAEMIC - give POTASSIUM before insulin)
- Insulin, 50 units to 50ml 0.9% saline and infuse + continue long-acting insulin
- Consider catheter or NG tube (vomiting or drowsy) and catheter if no urine output
- When glucose <14 mmol/L -> start 10% glucose
- Continue fix rate insulin until ketones < 0.6 mmol/L
- Treat cause
Complications of Diabetic Ketoacidosis
Cerebral oedema
Aspiration pneumonia
Hypokalaemia/magnesaemia/phosphataemia
Thromboembolism
Prognosis Diabetic Ketoacidosis
Mortality rate 5% in experienced centres
Death often caused by the underlying illness
Prognosis worsened at extremes of age and with coma or hypotension