DIABETIC KETOACIDOSIS

Recognition

Diagnosis (LTHT Diabetic Ketoacidosis in Adults 2014 guidelines)

• Raised blood glucose > 11 mmol/L (or known diabetes)
• Capillary ketones > 3 mmol/L (or ketones ≥ 2⁺ in urine)
• Venous pH < 7.3 or venous bicarbonate < 15 mmol/L

History

If possible, ascertain if patient has:

• Been diagnosed with diabetes previously
• Had previous admissions with DKA
• Been taking medication for diabetes
• Any allergies

General symptoms

• Blurred vision
• Excess Thirst
• Excess urine production
• Infective symptoms
• Nausea and vomiting

General Signs

• Tachypnoeic
• Acetone smell on breath
• Delayed capillary refill time
• Reduced skin turgor
• Dry mucous membranes
• Hypotensive
• Tachycardic
• Tender abdomen
• Confused
• Reduced Glasgow Coma Scale (GCS)

Severity

• One or more of the following may indicate severe DKA (Joint British Diabetes Societies Inpatient Care Group- The management of Diabetic Ketoacidosis in Adults March 2010).
  • Blood ketones > 6 mmol/L
  • Bicarbonate level < 5 mmol/L
  • Venous/arterial pH < 7.0
  • Hypokalaemia on admission (under 3.5 mmol/L)
  • GCS < 12 or abnormal ACVPU scale
  • Oxygen saturation < 92% on room air (RA). This is assuming normal baseline respiratory function
  • Systolic Blood Pressure < 90 mmHg
  • Pulse > 100 or < 60 bpm
  • Anion gap > 16
• If a patient has any of these criteria, they should have an senior review and be considered for transfer to High Dependency Unit (HDU)

Initial Assessment and Investigations

• ABCDE assessment
• Sit patient up if able to tolerate
• Assess patient’s airway
• Monitor oxygen saturations and respiratory rate
  • If patient is hypoxic give Oxygen (O₂) to achieve target saturations. Initially give 15 L/min via a reservoir mask if the patient is acutely unwell
• Target saturations:
  • 94 - 98% for patients not at risk of hypercapnic respiratory failure
  • 88 - 92% for patients at risk of hypercapnic respiratory failure due to conditions such as Chronic Obstructive Pulmonary Disease (COPD)
• Examine patient’s chest
• Arterial blood gas (ABG) if concerned about patient’s ventilation
• Chest X-ray should be requested. If the patient is unwell request a portable X-ray
• Obtain intravenous access by placing 2 large bore cannulae in the antecubital fossa. Take blood to check Full Blood Count (FBC), Urea and Electrolytes (U&Es), Glucose, Venous Blood Gas (VBG), C-Reactive Protein (CRP), Pregnancy Test and Blood Ketones if available
• Check Capillary Refill Time (CRT) - hold for five seconds and refilling should occur in 3 seconds
• Assess pulse rate, rhythm and character
• Monitor heart rate and blood pressure
• Listen to patient’s heart sounds
• Electrocardiogram (ECG) if patient tachycardic or abnormal rhythm palpated
• Check urine output and consider catheterisation
• Intravenous fluids as described in “management”
• Consider sepsis six if sepsis suspected. For further information see “Sepsis” Section in “Medical Emergencies” Chapter
• Check capillary blood glucose
  • Following this result a diagnosis of DKA should be able to be made and management started as below
• Call for senior help
• Check pupils are equal and reactive
• Assess GCS or ACVPU using the NEWS2 chart
• Check patient’s temperature
• Examine patient’s abdomen and legs
• Dip urine and send for microscopy and culture
• Consider venous thromboembolism prophylaxis

Response

Management

Immediate pharmacological management

• Fixed rate Insulin (0.1 units/kg/hour)
  • Continue long acting insulin in all cases
• Intravenous (IV) fluids. These patients are severely hypovolaemic and require a large volume of fluid replacement. Follow local trust guidelines for regimes. See below for an example of a fluid replacement regime:
  • If blood pressure > 90mmHg:
    • 1 L 0.9% Sodium Chloride over 1 hr, then
    • 1 L 0.9% Sodium Chloride over 2 hrs, then
    • 1 L 0.9% Sodium Chloride over 2 hrs, then
    • 1 L 0.9% Sodium Chloride over 4 hrs
    • Then continue as required to restore circulating volume
  • If blood pressure < 90 mmHg:
    • Fast bolus 500 ml 0.9% Sodium Chloride over 10 – 15 mins
• Potassium addition to IV fluids dependent on blood potassium results
  • < 3.5        Patient requires senior review
  • 3.5 – 5.5  40 mmol Potassium Chloride per Litre 0.9% Sodium Chloride
  • ≥ 5.5        None
• Potassium cannot be given at a rate faster than 20 mmol/hour
• Treatment targets:
  • Blood Glucose fall of > 3 mmol/L/hour until <14 mmol/L
  • Capillary Ketones fall > 0.5 mmol/L/hour until <0.6 mmol/L
  • Venous Bicarbonate rise of > 3 mmol/L/hour until > 15 mmol/L

Non-pharmacological management

• Monitoring
  • Patients initially require hourly vital signs and check of blood Glucose, Potassium Bicarbonate and Ketones

Referrals

• Discuss with senior member of the team
• Contact critical care outreach team
• Referral to Medical team
• Consider referral to Intensive Care Unit (ICU) if:
  • Failure to respond to medical management
  • Patient requires ventilator support
  • Patient requires blood pressure support
  • Deterioration of blood gas following medical management

Future management

• If the patient is a newly diagnosed diabetic then refer to the diabetes team for them to initiate subcutaneous insulin
• Ensure patient has outpatient follow-up with diabetes team prior to discharge