Diabetic metabolic emergencies

Question 1

What is ketouria?

Answer 1

Detectable ketone levels in the urine.

Ketouria occurs in fasted non-diabetics.

Question 2

What is ketosis?

Answer 2

Elevated plasma ketone levels in the absence of acidosis.

Question 3

What is DKA?

Answer 3

A metabolic emergency in which hyperglycaemia is associated with metabolic acidosis.
Due to greatly raised (>5 mmol/L) ketone levels.
It is potentially fatal and requires prompt medical attention for successful treatment.
Characterised by absolute insulin deficiency and is the most common acute hyperglycaemic complication of T1DM

Question 4

What is a hyperosmolar hyperglycaemic state (HHS)?

Answer 4

Metabolic emergency in which uncontrolled hyperglycaemia induces a hyperosmolar state in the absence of significant ketosis.

Question 5

What is lactic acidosis?

Answer 5

A metabolic emergency in which elevated lactic acid induces a metabolic acidosis in diabetic patients.
It is rare and associated with biguanide (metformin) therapy.

Question 6

Triad of DKA

Answer 6

Hyperglycaemia
Ketonaemia
Lactic acidosis

Question 7

Aetiology of DKA

Answer 7

• Net reduction of circulating insulin
• Elevation of glucagon, catecholamines, cortisol and GH
• These alterations lead to the extreme manifestations of metabolic derangements that can occur in diabetes.
• Underlying medical conditions such as MI or stroke that can provoke the release of glucagon are also likely to result in DKA in patients with DM

Question 8

Differentials of DKA

Answer 8

HHS
Lactic acidosis 
Starvation ketosis 
Alcoholic ketoacidosis 
Salicylate poisoning
Uraemic acidosis

Question 9

Signs & symptoms of DKA

Answer 9

Physical signs include: 
Dry mucous membranes 
Poor skin turgor 
Tachycardia 
Hypotension 
In severe cases, shock 
Kussmaul respiration- deep, laboured breathing 
Acetone breath- smells like nail polish 
Symptoms: 
Nausea
Vomiting 
Occasionally abdominal pain
Symptoms of DKA usually develop rapidly over 1 day ore less.

Question 10

Management of DKA

Answer 10

Restoration of volume deficits- isotonic solution of 0.9% NaCl (careful IV fluids to prevent aspiration pneumonitis)
Resolution of hyperglycaemia and ketosis/acidosis- Insulin.
Don’t stop insulin transfusion in a DKA patient
Correction of electrolyte abnormalities before initiation of insulin therapy- potassium (prevent fatal arrhythmias), bicarbonate and phosphate therapy
Prophylactic LMWH in case of PE
Airway protection if comatose (GCS< 9)

Question 11

Investigations of DKA

Answer 11

Plasma glucose > 13.9 mmol/L with the presence of acidosis and ketonaemia.
Urinalysis is positive for glucose and ketones.
ABG shows metabolic acidosis which is essential for diagnosis.
pH varies from 7-7.3.
Capillary or serum ketones: acetone, acetoacetate and BOHB are the main ketones produced
Urea and creatinine increased due to volume depletion
Serum electrolytes

Question 12

How can steroids lead to HHS?

Answer 12

Steroids increase blood glucose as the liver produces more through gluconeogenesis.

Question 13

How does hyperglycaemia affect the immune response to infection?

Answer 13

The immune response is depressed during hyperglycaemia due to glycosylation of lymphocytes.

Question 14

Classification of DKA

Answer 14

Mild DKA: plasma glucose > 13.9 mmol/L
Arterial pH: 7.25-7.3
HCO3-: 15-18 mmol/L
Urine and serum ketones: Positive
Anion gap: >10 (>12 in moderate and sever)
Mental status is changed to drowsy in moderate DKA and changed to stupor/coma in severe DKA.