Diabetic Ketoacidosis

PBL

CASE

An 18-year-old female was taken to the

emergency room in coma

Her parents noticed that she had polydipsia,

polyuria, and rapid weight loss which started

approximately 1 month ago and had worsened

in the last week

She had not been taking any medications and

the clinical history was otherwise unremarkable

On examination

breathing was deep and rapid (Kussmaul respiration),

pulse rate was 100 beats per minute, and

blood pressure 110/70 mmHg;

she also had signs of dehydration

CNS - She was drowsy and confused, no FND

CVS – S1 and S2 heard

RS – NVBS, No added sounds

INVESTIGATIONS

hematocrit 44%,

hemoglobin 13 g/dl

white blood cell count 12,000/ μl,

glucose 520 mg/dl

urea 50 mg/dl creatinine 1.0 mg/dl

Na+ 130 mEq/L K+ 4.6 mEq/L, PO4 2.0 mEq/L Cl− 112 mmol/L Mg 1.6

Arterial pH was 7.0, PO 98 mmHg, PCO 25 mmHg, HCO 12 mEq/L AG 16

O 2 sat 98%.

Serum Osmolality 306

What is your diagnosis?

Which additional biochemical tests are

required to confirm the diagnosis?

Precipitating events?

Inadequate insulin administration

Infection (pneumonia/UTI/gastroenteritis/sepsis)

Infarction (cerebral, coronary, mesenteric, peripheral)

Drugs (cocaine)

Pregnancy

Symptoms and signs

Polyuria, thirst

Weight loss

Weakness

Nausea, vomiting

Leg cramps

Blurred vision

Abdominal pain

Dehydration

Hypotension (postural or supine)

Cold extremities/peripheral cyanosis

Tachycardia

Air hunger (Kussmaul breathing)

Smell of acetone

Hypothermia

Confusion, drowsiness, coma (10%)

Management?

Fluids

Fluid replacement

Time: 0–60 mins

Commence 0.9% sodium chloride

If systolic BP > 90 mmHg, give 1 L over 60 mins

If systolic BP < 90 mmHg, give 500 mL over 10–15 mins,

then re-assess

60 mins to 12 hrs

IV infusion of 0.9% sodium chloride with 40 mmol/L potassium chloride

added as indicated below

1 L over 2 hrs

1 L over 4 hrs

1 L over 6 hrs

If plasma sodium is > 155 mmol/L, 0.45% sodium chloride maybe used

When hemodynamic stability and adequate urine output are achieved, IV

fluids should be switched to 0.45% saline at 250–500 mL/h

Insulin

If the initial serum potassium is <3.3 mmol/L, do not administer insulin until

the potassium is corrected.

0.1 units/kg bolus

intravenous insulin infusion of 0.1 U/kg body weight/hr is recommended

Continue with SC basal insulin analogue if usually taken by patient

glucose concentration should fall by approximately 55–110 mg/dL per hour

Failure of blood glucose to fall within 1 hour of commencing insulin infusion

should lead to a re-assessment of insulin dose

5% glucose and 0.45% saline at 150–250 mL/h when plasma glucose

reaches 200 mg/dL

Potassium

Plasma potassium Potassium replacement

> 5.5 Nil

3.5–5.5 40

< 3.5 additional potassium required

Cardiac rhythm should be monitored in severe DKA because of the risk of

electrolyte-induced cardiac arrhythmia.

Bicarbonate, Mg, Po4

Adequate fluid and insulin replacement should resolve the acidosis.

The use of intravenous bicarbonate therapy is currently not recommended

severe acidosis (arterial pH <6.9), the ADA advises bicarbonate

50 mmol/L of sodium bicarbonate in 200 mL of sterile water with 10 meq/L

KCl per hour for 2 h until the pH is >7.0

Hypomagnesemia may develop during DKA therapy and may also require

supplementation.

serum phosphate < 1 mg/dL, then phosphate supplement should be

considered and the serum calcium monitored

Monitoring

Hourly capillary blood glucose testing

Venous bicarbonate and potassium after 1 and 2 hrs, then

every 2 hrs

Plasma electrolytes every 4 hrs

Clinical monitoring of O2 saturation, pulse, BP, respiratory rate and urine

output every hour

If ketoacidosis has resolved and patient is able to eat and drink

Re-initiate SC insulin

Do not discontinue IV insulin until 30 mins after SC short-acting insulin

injection

Hyperglycaemic hyperosmolar state

severe hyperglycaemia >600 mg/dL

hyperosmolality serum osmolality > 320 mOsm/kg

Dehydration

in the absence of significant hyperketonaemia(< 3 mmol/L) or acidosis (pH

> 7.3, bicarbonate> 15 mmol/L).

hyperglycaemia usually develops over a longer period, causing more

profound hyperglycaemia and dehydration

fluid loss may be 10–22 litres in a person weighing 100 kg

typically occurs in the elderly

Common precipitating factors include

infection,

myocardial infarction,

cerebrovascular events

drug therapy (e.g. corticosteroids).

Give fluid replacement with 0.9% sodium chloride (IV)

Use 0.45% sodium chloride only if osmolality is increasing, despite positive

fluid balance

Target fall in plasma sodium is ≤ 10 mmol/L at 24 hrs

Aim for positive fluid balance of 3–6 L by 12 hrs

replacement of remaining estimated loss over next 12 hrs

Initiate insulin IV infusion (0.05 U/kg body weight/hr) only when blood

glucose is not falling with 0.9% sodium chloride

Reduce blood glucose by no more than 5 mmol/L/hr