Diabetic Emergencies Flashcards
What is diabetic ketoacidosis (DKA)?
Disordered metabolic state that usually occurs in the context of an absolute or relative insulin deficiency accompanied by an increase in counter regulatory hormones
Who gets DKA?
Can occur in both type 1 and 2 diabetics, but more common in type 1
What causes ketoacidosis?
Increased lipolysis causes increased FFA to the liver, increases ketogenesis which causes acidosis
Glycosuria leads to electrolyte loss and dehydration, causing increased lactate and acidosis
What is needed for biochemical diagnosis of DKA?
Ketonaemia > 3mmol/L or significant ketonuria (>2++ on standard urine stick)
Blood glucose > 11.1 mol/L or known DM
Bicarbonate < 15 morning/L or venous pH < 7.3
What is the mortality rate in DKA?
2-5% in developed countries
6-24% in developing countries
What causes death from DKA?
Adults = hypokalaemia, aspiration pneumonia, ARDS, co morbidities Children = cerebral oedema
What are some precipitants to DKA?
Newly diagnosed, infection, illicit drug and alcohol use, non-adherence to insulin/poor self management (most common cause)
What are osmotic symptoms of DKA?
Thirst and polyuria
What are ketone body related symptoms of DKA?
Flushing, vomiting, abdominal pain and tenderness, breathless (Kussmaul’s respiration), smell of ketones on breath
What are some conditions associated with DKA?
Underlying sepsis, gastroenteritis, coma (rare), thrombo-embolism
What are the typical biochemistry results at diagnosis of DKA?
Glucose = median level 40 mmol/L, from 11- >100
Potassium = often raises above 5.5 mmol/L
Creating often raised, sodium low, raised lactate, amylase raised, median white cell count is 25
Ketones > 5, bicarbonate < 10 in severe cases
What can be lost in DKA?
Fluid = up to 12L Sodium = 500 mmol Potassium = 350-700 mmol Phosphate = 50-100 mmol
What are some complications of DKA?
Cardiac arrest secondary to hypokalaemia, ARDS, cerebral oedema, gastric dilation (risk of aspiration)
Where are patients with DKA managed?
In HDU
How are fluids managed in patients with DKA?
Initially with 0.9% NaCl, once glucose falls to 15 switch to dextrose
What are some other management requirements for patients with DKA?
Replace insulin and potassium (rarely phosphate and bicarbonate), possible nasogastric tube, monitor potassium, prescribe prophylactic LMWH
How are blood ketones measured?
Using optium meter = measures beta hydroxybutyrate, meter range is 0-8mmol/L, <0.6 mmol/L is normal
How are urine ketones measured?
Measure acetoacetate, indicates levels of ketones 2-4hrs previously
Does ketonuria resolve straight away in DKA?
No = persists after clinical improvement
How can recurrence of DKA be prevented?
Provide patient with ketone meter, arrange DSN follow up and inform GP
How is hyperglycaemic hyperosmolar syndrome (HHS) diagnosed by biochemistry l?
Hypovolaemia, hyperglycaemia > 30mmol/L, no/mild ketonaemia < 3mmol/L, bicarbonate > 15mmol/L, venous pH >7.3, osmolarity >320mosmol/kg
What can HHS overlap with to cause a mixed clinical picture?
DKA
What is the typical presentation of HHS?
Diabetes may be known at presentation (often not), older patients or young Afro Caribbean’s, high refined CHO intake pre-presentation
What are some complications and associations of HHS?
MI, stroke, sepsis
Associated medication = steroids, thiazide diuretics
Wha is the typical biochemistry of HHS?
Higher glucose than DKA = usually above 50mmol/L, significant renal impairment, sodium often raised, less ketogenic/acidotic than DOA, raised osmolarity
How is osmolarity calculated l?
2[Na] + urea + glucose
Normal is 275-295
How should HHS be treated?
Administer fluids more cautiously (risk of increased overload)
Administer insulin slowly or not at all
Sodium = <0.5mmol/L/hr, may need 0.45% saline
Why should HHS patients be screened for comorbidities?
More likely for comorbidities to occur = all patients get LMWH unless contraindicated
What are some features of alcoholic/starvation ketoacidosis?
History important, dehydration common and marked, ketonuria >3mmol/L or significant ketonuria (>2+), bicarbonate usually <15mmol/L or venous pH <7.3 in severe cases, glucose usually normal
What are some features of in-patient experience of diabetics?
Longer stay, higher in-patient mortality, higher risk of medical error, enhanced foot risk, poorer overall experience
What are some reasons that type 1 diabetics are admitted to hospital?
Unable tolerate oral fluids, persistent vomiting, persistent hyperglycaemia, abdominal pain/SOB, persistent positive/increasing levels of ketones
What is the target in-patient blood sugar?
6-10mmol/L, range of 4-12mmol/L is acceptable
What patients don’t require right control of their blood sugar?
End of life patients, those who may be severely disabled by significant hypoglycaemia
What are some features of elective surgical procedures?
Planned, preferably first on list, pre-assessment clinics
Anaesthetic risk = CV, autonomic dysfunction, foot risk, HbA1c at least <70m/m
What are some features of emergency surgery?
Increased risk as unplanned, anaesthetic risk in those with micro/macro vascular complications, care with potassium if glucose is high, post operative sepsis and foot care risks
Where does lactate originate from?
Red cells, skeletal muscle, brain and renal medulla = end product of anaerobic metabolism of glucose
What is required for lactate clearance?
Hepatic uptake and aerobic conversion to pyruvate then glucose
What can lactic acidosis be confused with?
Hyperlactaemia
What is the normal lactate range?
0.6-1.2mmol/L = generally lowest in fasted state, may rise to 10mmol/L in severe exercise
How is the ion gal calculated?
[Na + K] - [HCO3 + Cl]
Normal range is 10-18 mmol/L, useful for determining cause of acidosis
What is type A lactic acidosis?
Associated with tissue hypoxaemia = infarcted tissue, cardiogenic/hypovolaemic shock, sepsis, haemorrhage
What are some features of type B lactic acidosis?
May occur in liver disease or leukaemic states, associated with diabetes, consider rare inherited metabolic conditions if well and non-diabetic
How does type B lactic acidosis occur in diabetics?
10% of DKA associated with lactate > 5mmol/L, associated with metformin in severe illness states or renslnfailure
What are the clinical signs of lactic acidosis?
Hyperventilation, mental confusion, stupid or coma if severe
What are the lab findings for lactic acidosis?
Reduced bicarbonate, raised anion gap, raised phosphate, absence of ketonaemia, glucose variable (often raised)
How is lactic acidosis treated?
Treat underlying condition with fluids and antibiotics l, and withdraw offending medication
