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
- establish precipitant and treat
- assess severity of metabolic derangement
- cautious fluid resuscitation with replacement of body H2O
- provision of insulin
- 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