Diabetes Emergencies Flashcards
what is DKA?
diabetic ketoacidosis
disordered metabolic state usually occurring in context of an absolute or relative insulin deficiency accompanied by an increase in the counter-regulatory hormones (i.e glucagon, adrenaline, cortisol and growth hormone)
which diabetes does DKA occur in?
can occur in both
a bit more common in type 1
3 consequences of absolute/relative insulin deficiency?
hyperglycaemia
acidosis
hyperosmolarity
pathophysiology of DKA?
absolute or relative insulin deficiency leads to activation of stress hormones
causes increase in lipolysis, proteolysis and glycogenolysis and a decrease in glucose utilization
results in hyperglycaemia, acidosis and hypersmolality
biochemical features of DKA?
ketonaemia >3 or significant ketonuria >2
blood glucose >11 or known DM
bicarbonate <15 or venous pH <7.3
what can affect DKA risk?
higher HbA1c = higher risk
lower socioeconomic group = higher risk
describe mortality rates in DKA?
fairly low (2-5%) but higher in developing countires
what generally causes death in DKA?
adults - hypokalaemia - aspiration - pneumonia - ARDS - co-morbidities children - cerebral oedema
what can precipitate DKA?
new diagnosis
infection
drug and alcohol use
poor glycaemic control = biggest cause
what are the typical symptoms and signs of DKA?
thirst and polyuria dehydration flushed vomiting abdo pain/tenderness breathless (kussmauls) can sometimes smell ketones on breath underlying sepsis gastroenteritis
what is considered high glucose on glucose meter?
> 28
management principles of DKA?
replace losses
- NaCl then dextrose when glucose hits 15, insulin and potassium
address risks
what risks must be addressed in DKA?
is NG tube needed?
monitor potassium
prescribe prophylactic LMWH
source sepsis - CXR, blood culture, MSSU +/- viral titres
how can you monitor ketones?
blood ketone testing
<6 = normal
urine ketone testing
- indicates levels 2-4 hrs previously
what are the 2 predominant features in HHS?
hyperglycaemia
hyperosmolority
slight acidosis
biochemical features of HHS?
hypovolaemia hyperglycaemia (more than DKA, >50) No/mild ketonaemia (<3 mmol/L) Bicarbonate >15 mmol/L or venous pH >7.3 Osmolality >320 mosmol/kg sodium high normal/raised significant renal impairment
risk factors for HHS?
older patients type 2 diabetes afro-caribbean CV disease sepsis medication - steroids, thiazides high refined carbohydrate intake pre-presentation
how do you calculate osmolality?
2x[Na] + urea + glucose
normal osmolality range?
275-295
DKA vs HHS
HHS usually seen in older patients and type 2 rather than type 1
HHS has a higher mortality
DKA treatment vs HHS treatment?
DKA = insulin HHS = diet/OHA/insulin (sometimes)
how is alcohol induced ketoacidosis managed?
IV pabrinex IV fluids IV anti-emetics insulin may be needed on occasion address alcohol dependency
biochemical features of alcoholic/starvation ketoacidosis?
dehydration
ketonaemia >3 or significant ketonuria >2
bicarbonate <15 or venous pH <7.3
normal glucose
3 main characteristics of alcohol-induced ketoacidosis?
acetate
acetoacetate
beta-OHB
targets for in patient blood sugar?
6-10
4-12 is accepted
considerations in surgery if patient is diabetic?
anaesthetic risk due to autonomic neuropathy
foot risk
glycaemic control
what is lactate and how is it cleared from the body?
end product of anaerobic metabolism of glucose
originates from red cells, skeletal muscle, brain and renal medulla
clearance requires hepatic uptake and aerobic conversion to pyruvate then glucose
what is the normal level of lactate?
0.6-1.2 mmol/L
can rise to 10mmol/L in high exercise
what is the ion gap?
concentration of positively charged proteins - concentration of negatively charged proteins
useful in determining the cause of an acidosis
what is the normal range of ion gap?
10-18 mmol/L
high = acidosis
low = alkalosis
what is Type A lactic acidosis?
associated with tissue hypoxaemia
- infarction
- cardiogenic shock
- hypovolaemic shock
- sepsis
- haemorrhage
what is type B lactic acidosis?
may occur in liver disease, leukaemic states, diabetes
what are the clinical features of lactic acidosis?
hyperventilation
mental confusion
stupor or coma if severe
what are the lab findings in lactic acidosis?
reduced bicarbonate raised anion gap variable glucose - often raised no ketonaemia raised phosphate
how is lactic acidosis managed?
treat underlying condition
- fluids and antibiotics
withdraw causative medication (metformin)
what causes HHS and what can precipitate it?
diuretics and/or steroids
fizzy drinks
can be precipitated by new diagnosis or infection
how is HHS treated specifically?
fluids
insulin - slowly delivered (sometimes)
sodium
Consider likely co-morbidities (vascular event)
- LMWH given for all unless contraindicated
how is DKA diagnosed?
biochemistry
- ketonaemia >3 or ketonuria >2
- Blood glucose >11 (median = 40)
- bicarbonate <15 or venous pH <7.3
what are the typical biochemistry findings in DKA?
ketonaemia hyperglycaemia low bicarbonate/low pH low/low normal sodium low potassium high lactate high WCC high creatinine amylase often raised
