2 - diabetic emergencies Flashcards
what is diabetic ketoacidosis?
disordered metabolic state usually in context of absolute or relative insulin deficiency accompanied by increase in counter-regulatory hormones e.g. glucagon, adrenaline, cortisol, growth hormone
what are causes of DKA?
- increased insulin deficiency e.g. missed dose, new diagnosis, high carbs
- increased in insulin demand, 5 I’s:
- infections = pneumonia
- inflammatory = pancreatitis
- intoxication = alcohol, drugs
- infarction = MI, stroke
- iatrogenic = steroids, surgery
what is the triad of pathophysiology causing DKA?
triad = hyperglycaemia, ketosis, acidosis
insulin usually inhibits lipolysis (reducing risk of ketone body overload)
= problem is missed insulin as high glucose remains high but insulin not there to help glucose get into cells to be used for energy so body resorts to breakdown of fats & amino acids = means ketones and overload of sugars in blood
what is difference with starvation ketoacidosis? (just to note)
when glucose not available body uses lipolysis and free fatty acids to provide energy - means ketones made as by product
how does DKA lead to significant dehydration?
lots of glucose excreted via PCT (proximal convoluted tubules) = glycosuria, osmotic diuresis follows as water & electrolytes leave with glucose = dehydration
what are symptoms & signs of diabetic ketoacidosis?
- osmotic related = polyuria & dehydration & thirst
- ketone related = flushed, vomiting, increased HR, sweet smell, abdo pain, kussmaul breathing (deep, rapid)
how do ketone bodies cause
a) nausea & vomiting
b) kussmaul breathing
c) arrhythmias
a) ketones trigger chemotrigger zone in medulla
b) ketone bodies release H+ making acidotic blood, act on peripheral chemoreceptors to increase resp rate to breathe off CO2 & acetone (sweet smell)
c) as H+ ions made, K+ pushed out to maintain balance and then once try to fix with insulin K+ can’t get back in so arrhythmias, palpitations & IBS
what are biochemical results for diabetic ketoacidosis?
- hyperglycaemia (above 11 mmol)
- ketonaemia (above 3 mmol)
- acidotic, low bicarb low pH
*also could dp FBCs, U&Es, LFTs (amylase)
what are complications of DKA?
- hypo or hyperkalemia = arrhythmias
- cerebral oedema
- pulmonary infiltrates (ARDS)
- gastric bubble (from hypocalcemia)
- aspiration pneumonia (from vomiting symptom)
- DVT or PE since hypercoagulable blood (like fizzy drink on stable is sugar in blood)
what is management of DKA?
= close monitoring
- correct dehydration (fluids to dilute excess sugar) - should be 3L within hour 4
- correct hyperglycemia with insulin
- electrolyte imbalance (fluids will lower K+ so give K+ if needed)
- identify complications
what is values of ketones?
T1DM patients have ketone monitors
- less than 0.6 is good
- between 0.6 and 3 suggests starting to develop
- above 3 is significant ketosis
what is hyperglycaemic hyperosmolar state (HHS)?
severe hyperglycemia & hyperosmolarity (normal ketone levels)
- usually in T2DM when still some production of insulin so enough insulin to prevent lipolysis & ketogenesis but not enough for glucose utilization
what are main causes of HHS?
- consumption of glucose rich fluids
- trauma or something leading to compromised water intake
- non compliance with diabetic medications
- newly diagnosed diabetes
what is presentation of HHS?
- dehydration (due to osmotic imbalance + polyuria)
- polydipsia (excessive thirst)
- nausea & vomiting
- impaired consciousness (depending on osmolarity level)
what is in biochemical diagnosis for HHS?
- hypovolaemia (low fluid)
- hyperglycaemia (above 30 mmol)
- normal ketones (below 3)
- bicarb normal, normal pH
- osmolality high
