Endocrinology 17 - Ketoacidosis Tutorial

Question 1

How is diabetic ketoacidosis investigated?

Answer 1

• Capillary glucose
• Plasma glucose
• Creatinine, K+ and Na+
• FBC
• Arterial blood gases (oxygen levels - venous blood gas tells you bicarbonate)
• Amylase (triglyceride)
• ECG
• CXR
• Septic screen (urine dipstic/culture, sputum, stool samples)

Question 2

How is diabetic ketoacidosis treated?

Answer 2

• Fluids (saline 3-8 litres)
• Insulin (IV levels determined by capillary glucose)
• Potassium (insulin drives potassium into the cells, so levels need to be monitored with administration - given large amount in central line if less than 3mmol/L)
• Bicarbonate (not used clinically, dehydration is corrected instead)
• Other (cardiac monitor, catheterise, antibiotics, heparin, arterial line, NG tube in gastroparesis)

Question 3

List the risk-benifts for bicarbonate

Answer 3

DANGERS of ACIDAEMIA

• Negative ionotropism
• Peripheral vasodilation
• Hypotension
• Cerebral inhibition

DANGERS OF BICARBONATE

• Hypokalaemia
• Hypernatraemia
• Rebound alkalosis
• CSF acidosis
• Impaired oxyHb dissociation

Question 4

What is done in second phase ketoacidosis?

Answer 4

• Glucose < 10mmol/litre
• Change to 5% dextrose
• Continue insulin and potassium
• May need more saline

Question 5

How is diabetic ketoacidosis prevented?

Answer 5

• Education
• Don’t stop insulin
• Check glucose and modify insulin if ill
• Admit if vomiting

Question 6

List the precipitants for ketoacidosis

Answer 6

• New diagnosis of T1DM
• Not taking enough insulin/fasting
• Ischaemic event/infection causing stress

Question 7

What causes dehydration in T1DM patients?

Answer 7

• Insulin deficiency and stress hormones cause hyperglycaemia and ketosis
• Osmotic diuresis occurs
• When the patient can’t drink enough or is vomiting they will become dehydrated
• Fever also worsens dehydration
• Keotacidosis causes acidosis, resulting in vomiting and hyperventilation, contributing to dehydration.
• Acidosis worsens due to impaired renal perfusion and hydrogen excretion

Question 8

Where are ketones produced?

Answer 8

Liver

Question 9

What is seen in diabetic ketoacidosis?

Answer 9

• pH of blood low
• Bicarbonate low (impaired production and increased H+ buffering)
• CO2 will be low (due to excess breathing

Question 10

Describe electrolyte disturbance seen in diabetic ketoacidosis

Answer 10

• Water lost in urine
• Sodium lost in urine
• Potassium lost in urine (total body potassium is low, but high potassium in the blood)

Question 11

List the clinical features of DKA

Answer 11

• Dehydration
• Insulin deficient
• Total body potassium deficiency (high in blood)
• Acidosis
• Risk of arrhythmia
• Polyuria and polydipsia
• Dehydration
• Hyperventlation
• Abdominal pain, vomiting
• Coma
• Glycosuria and ketonuria