Diabetes Keto-acidosis (DKA)

Exam Cram

• DKA: diabetic keto-acidosis

• Pathophysiology: hypo-insulinaemia -> starvation ketosis -> acidosis

• Definition: (3/3) bicarbonate < 15, ketonaemia 2+, hyperglycaemia > 20mmol

• Management: (DKA protocol): IVF ++, fixed rate insulin, HDU, monitor K+

Outline

Background 

• DKA is caused by starvation hypo-insulinaemia. 

• Can develop dehydration deficits of 5-7 litres. 

• Causes: infective, poor insulin compliance, first episode of T1DM

Assessment

History:

• Abdominal pain +/- vomiting

• Infective symptoms: fevers, anorexia, cough, dysuria

• Acute general decline

Examination:

• Profound dehydration- dry mucous membranes, oliguria

• Abdominal tenderness (soft)

Investigations:

• VBG: 

  • BSL > 20

  • pH < 7.30, bicarb < 15

  • Raised lactate

  • K+ usually normal

• FBC, EUC, CRP- baseline 

• Blood cultures, CXR, urine dip ?infection

Diagnosis

Diagnosis: (3/3) bicarbonate < 15 or pH < 7.3, ketonaemia 2+, hyperglycaemia > 12mmol

Differentials: sepsis, ischaemic bowel: abdo pain + hyperlactaemia

Classification: bicarbonate and ketones are good markers of severity

Management

1. IVF Na Cl (6L)- 1L/ 1 hour and reassess

2. Fixed rate insulin infusion: IV insulin (0.1U/kg/hr)

3. Monitor K+, bicarbonate, pH, blood sugar

Admission Cycle

Acute Assessment Work up 

PC: ?DKA

1. Investigations: 

   • VBG- pH & blood sugar, blood ketones

   • Baseline: FBC, urea & electrolytes, LFTs

   • Septic screen: blood & urine cultures, CXR, viral PCR +- CRP/ procalcitonin

2. DKA Protocol (as per trust)

   • IVF Na Cl (6L)- 1L/ 1 hour and reassess

   • Fixed rate insulin infusion: IV insulin (0.1U/kg/hr)

   • Monitor K+: replace if K+ < 4.0

   • Monitor blood sugar: 5% dextrose < 12 mmol

   • Monitor ketones & pH- escalated if these are deterioating (concerning)

3. Disposition: HDU if bicarbonate < 15

4. Housekeeping: 

   • Continue basal insulin, stop SGL2- inhibitor; 

   •  VTE prophylaxis as normal, Escalation status

Markers of poor severity

• Blood ketones > 6

• Bicarb < 5, pH < 7.1

• K+ 3.5 on admission

• GCS < 12

• Sats < 92% RA

• SBP < 90, HR > 100 or < 60

• Anion gap > 16

The key issue is the acidosis from blood ketones. If this is deteriorating despite treatment, this is highly concerning. 

Complications

• Death

• Hypokalaemia- very common, due to large volume of insulin given

• Fluid overload +- cerebral oedema from IVF

• AKI

• Arrhythmias from K+ shifts

• VTE

These patients would die if left in the community but usually have a good response to medical treatment. 

Inpatient Management

1. IVF Regime

2. Insulin: 

   1. Convert fixed rate to variable rate

   2. Stop variable rate/ fixed; begin basal bolus insulin regime

3. Discharge planning

IVF Regime

Obviously so much fluid would require at least hourly fluid reviews and these regimes are trust dependent. 

• IVF: 2L/ 2hrs, 2L/4hrs, 2L /8hrs

• Start glucose 5% once blood sugar < 14mmol

• Start K+ replacement once K+ < 4.0

Indications to stop DKA protocol

• Eating and drinking

• Bicarbonate > 18 or pH > 7.3

• Ketones < 0.5

Discharge planning

These patients are often very unwell upon arrival but quickly recover, discharging on day 2-5 of admission. 

For discharge plan

• Diabetes educator 

• Endocrine review

• HbA1c

• Follow up: endocrine/ diabetes community team

Med Reg Notes

Euglycaemic non-acidotic DKA

Classically with SGL2 inhibitors. These patients still have starvation hypoinsulinaemia however the SGLT-2 inhibitors facilitate urinary losses of glucose to present euglycemia. 

If the patient has severe vomiting with DKA, very rarely they can lose enough HCL stomach acid to neutralise their acid base. 

DKA in T2DM

DKA can rarely occur in type 2 diabetes. Essentially DKA is from hypoinsulinaemia, therefore if the patient uses insulin for their diabetes and they are under dosing then they will achieve hypoinsulinaemia and DKA. Similarly, the patient could be on oral control but hypoinsulinaemic and require insulin, but not currently receiving it. The typical patient has a long history of T2DM and of chronic hypo-insulinaemia: weight loss & hyperglycaemia. 

References and Resources

Page written in 2024.