The Hyperglycaemic Patient

Question 1

You are the FY1 on call for acute medicine. You are asked to review a 28 year old patient who has been admitted with D+V. He is a type 1 diabetic and also has well-controlled asthma. His last CBG (capillary blood glucose) was done 3 hours ago - it was 13.2.
He has not eaten or drank and currently have no IV fluids running.
The nurse is worried as he ‘just don’t look right’. His observations are as follows:
HR 95, BP 107/63, RR 24, sats 95% on air, Temp 36.6.
He is drowsy and confused; he doesn’t really know where he is.

a) What are the most important initial tests to do in this patient?

Answer 1

a)

Question 2

What are the biochemical criteria for DKA?

Answer 2

1. Diabetic - glucose* > 11 (or known diabetes)
2. Keto - ketonaemia* (3 mmol/L) or ketonuria (2+ on urine dip)
3. Acidosis - bicarb < 15, or pH < 7.3
   * For initial glucose and ketones, use capillary blood test

Question 3

Initial A-E management of DKA.

Answer 3

Airway.

• are they protecting their airway? Aspiration risk?
• consider NG tube/ suctioning
• consider airway support

Breathing.

• are they hypoxic? Do they have a precipitating chest infection? Kussmaul breathing?
• Chest examination - lungs and heart
• Ix: SpO2 continuous monitoring
• Rx: consider oxygen 15L/min via NRB

Circulation.

• how dehydrated are they? (CRT, pulse, BP, RR, mucous membranes, urine output, etc.), what fluids do they need and how quickly?
• Cardiac examination (if not done in breathing)
• Ix: IV access, bloods (glucose, VBG, U+Es, FBC), consider cultures, ECG, consider continuous cardiac monitoring, take HR/BP, consider catheter
• Rx: 0.9% NaCl 500ml STAT

Disability.

• glucose, ketones
• pupils, GCS

Exposure.

• temperature
• abdominal exam
• calves - PE risk - consider VTE and TED stockings

Question 4

DKA: fluids and definitive treatment

Answer 4

Fluid replacement.

• If SBP < 90, give fluid replacement with 500 ml bolus of NaCl 0.9% STAT. Repeat if necessary and escalate
• When SBP > 90, give IV infusion NaCl 0.9% at rate that replaces fluid deficit
• Add KCl to each bag unless anuria is present

Glucose management.

• Glucose should come down with fluid replacement
• Add insulin to bag of NaCl
• Infuse at a rate of 0.1 units/kg/hr
• Once glucose < 14, add separate dextrose 10% infusion via a large cannula into a large vein at rate of 125 ml/hr
• Continue insulin infusion until ketones < 0.3 mmol/L, pH > 7.3 and the patient is able to eat and drink
• Give fast-acting SC insulin, a meal and stop insulin infusion 1 hour later

Question 5

DKA: monitoring and treatment targets

Answer 5

Monitoring.

• Manage in HDU or ITU
• Hourly blood glucose and ketones
• U+Es and venous bicarbonate checked at least every 1-2 hours for first 2-4 hours and then 2- to 4-hourly

Treatment targets.

• Reduce blood ketones by 0.5 mmol/L/hour
• Reduce capillary blood glucose by 3.0 mmol/L/hour
• Increase venous bicarbonate by 3.0 mmol/L/hour
• Maintain K+ between 4.0 and 5.5 mmol/L

Question 6

HHS: criteria

Answer 6

Hyperosmolar.
- Raised osmolality: usually 320 mosmol/kg or more

Hyperglycaemic.

• Marked hyperglycaemia (30 mmol/L or more)
• WITHOUT significant hyperketonaemia (<3 mmol/L) or acidosis (pH >7.3, bicarbonate >15 mmol/L).

State.
- hypovolaemic state