Diabetic emergencies and high glucose states Flashcards
What is DKA?
A disordered metabolic state that usually occurs in the context of an absolute or relative insulin deficiency accomapined by an increase in the counter-regulatory hormones such as glucagon, adrenaline, cortisol and GH
How does increased lipolysis lead to acidosis?
Increased lipolysis, increased free fatty acids at liver
Increased ketogenesis leading to acidosis
How does hyperglycaemia lead to ketosis?
Osmotic diuresis leads to glycosuria, electrolyte loss and dehydration which leads to increased lactate and decreased renal function
What is needed for the biochemical diagnosis of DKA?
Ketonaemia > 3mmol/L or significant ketonuria (2+ on urine stick)
Blood glucose > 11.0 mmol/L or known diabetes
Bicarbonate < 15 mmol/L or venous pH < 7.3
What are some common precipitants of DKA?
Infection
Ilicit drugs and alcohol
Non-adherence with treatement
Newly diagnosed diabetes
What are the osmotic related symptoms of DKA?
Thirst and polyrua
Dehydration
What are the ketone body related symptoms of DKA?
Flushed
Vomiting
Abdominal pain and tenderness
Kaussmauls respiration
What are the associated conditions of DKA?
Underlying sepsis
Gastroenteritis
What is the classic biochemistry of DKA at presentation?
Glucose - around 40 mmol/L Potassium - raised above 5.5mmol/L Creatinine: often raised Sodium; often raised Raised lactate Blood ketones over 5 Bicarb below 10 in the most severe cases Amylase raised White cell count around 25
What are the main causes of mortality in DKA?
Hypokalaemia
Aspiration pneumonia
ARDS
Co-morbidities
What are the main causes of mortality in children who present with DKA?
Cerebral oedema
What are the management principles in DKA?
Replace losses: fluid (0.9% sodium chloride, glucose falls to 15, switch to dextrose)
Insulin
Potassium
Phosphate and bicarb very rarely replaced
Address risks; NG tube, monitor K+, prescribe prophylactic LMWH, source sepsis (CXR, blood cultures, MSSU +/- viral ttitres)
What does a blood ketone measure test?
Beta-hydroxybutryate
Meter range 0-8 mmol/L
<0.6 mmol/L normal
What does urine ketone testing measure?
Acetoacetate
Indicated levels of ketones 2-4 hours previously
Ketonuria persists after clinical improvement due to mobilisation of ketones from fat tissue
When should type 1 diabetics be admitted to hospital?
Unable to tolerate oral fluids Persistent vomiting Persistent hyperglycaemia Persistent positive/ increasing levels of ketones Abdominal pain Breathlessness
What are the typical features of HHS?
Hypovolaemia
Hyperglycaemia (BG >30mmol/L) without significant acidosis or ketonaemia
Hyperosmolar (osmolality > 320 mosmol/kg)
What is the typical biochemistry in HHS?
Median glucose around 60 mmol/L Significant renal impairement Sodium raised Significant eleation of osmolality (around 400) i.e. significant dehydration Less ketonaemic/ acidotic
How is osmolality calculated?
Osmolality = (2x (Na+K)) + urea + glucose)
What is the normal range for osmolality?
275 to 295
Compare DKA to HHS?
DKA in younger patients
Diabetes in type 1, HHS in type 2
DKA caused by insulin deficiency, HHS caused by dieuretics/ steroids/ fizzy drinks
DKA precipitated by insulin omission, HHS precipitated by a new diagnosis or infection
DKA treatment is insulin, HHS treatment is diet/ OHA/ insulin
Where does lactate originate from?
Red cells, skeletal muscle, brain and renal medulla
End product of anaerobic metabolism of glucose
Clearance requires hepatic uptake and aerboic conversion to pyruvate then glucose
What is type A lactic acidosis?
Associated with tissue hypoxaemia - infarcted tissue (ischaemic bowel), cardiogenic shock, hypovomaemic shock (sepsis, haemorrhage)
What it type B lactic acidosis?
May occur in liver disease
May occur in leukaemic states
Associated with diabetes (10% of DKA associated with lactate >5 mmol/L, with metformin in severe illness states or renal failure)
Also consider rare inherited metabolic conditions if well and non-diabetic
What are the clinical features of lactic acidosis?
Hyperventilation
Mental confusion
Stupor or coma if severe
What are the lab findings of lactic acidosis?
Reduced bicarb Raised anion gap (Na+ + K+) - (HCO3 + Cl-) Glucose variable Absence of ketonaemia Raised phosphate
What can cause a raised anion gap?
Lactic acidosis DKA Starvation Uraemia Alcohol Ethylene glycol Methanol Salicylate or paraldehyde poisoning
What is the normal anion gap?
10-18 mmol/L
How is lactic acidosis treated?
Underlying condition: fluids, antibiotics
Withdraw offending medication
How is alchol induced ketoacidosis treated?
Pabrinex IV fluids - dextrose Insulin may be required IV anti-emetics Address alcohol dependency
What should be assessed in an acute patient who has diabetes?
What type of diabetes Medication Insulin regimen Blood sugar and keton level Renal function Evidence of peripheral or autonomic neuropathy
What should the glycaemic control be in diabetics pre-operatively?
HbA1c at least less than 75 mmol/mol
What is the target level for glucose in inpatients?
6-10 mmol/L but 4-12 is accepted
Who is likely to get HHS?
Diabetics
Elderly or young afro-carribean
High refined CHO intake pre-presentation
What carries a risk association and complication factor with HHS?
Cardiovascular disease (MI/ stroke)
Sepsis
Medication: steroids/ thiazie diuretics
How does the treatment of HHS differ fom DKA?
More cautious with fluids due to increased risk of fluid overload
Insulin delivered more slowly
Avoid rapid fluctuations in sodium - consider 0.45% saline
Co-morbidities more common
Screen for a vascular event (silent MI), sepsis
LMWH unless CI
How are elective surgical procedures carried out in diabetics?
Planned
Pre-assessment clinics
Anaesthetic risk: cardiac, autonomic dsfunction, foot risk
Glycaemic control: HbA1c at least <70 mmol/mol
First on surgical list
How are diabetics managed in emergency surgery?
Increased risk
Recognise anaesthetic risk in those with micro and macrovascular complications
Care with potassium esp. if glucose high
Post-op sepsis risk if poor control
What is the anion gap?
(Na+ + K+) - (HCO3- + Cl-)
What are the clinical findings of lactic acidosis?
Hyperventilation
Mental confusion
Stupor or coma if severe
