Diabetic Emergencies Flashcards
(38 cards)
What are the 3 life-threatening diabetic emergencies?
Diabetic ketoacidosis (DKA)
Hyperosmolar hyperglycaemic state (HHS)
Hypoglycaemia
Which type of hyperglycaemic emergency is most common in type 1 and type 2 diabetes? Why is there are difference?
Type 1= DKA
Type 2= HHS
Difference due to type 1 having ABSOLUTE insulin deficiency whereas type 2 only has relative insulin deficiency
I.e. even small amount of insulin can act to inhibit ketogenic processes
What are the 4 biochemical consequences of insulin deficiency and how are they related to the symptoms of hyperglycaemic emergency?
- Increased glycogenolysis + gluconeogenesis
- increased serum glucose leads to osmotic diuresis and consequent dehydration and loss of electrolytes (Na+ and K+) - Increased proteolysis
- increased serum AA= glucogenic and ketogenic - Lipolysis
-increased glycerol and FA= ketogenic and glucogenic
I.e. alternative energy source due to lack of glucose uptake into cells - Increased ketogenesis
- induces metabolic acidemia i.e. ketone bodies lead to acidosis
What is the triad of DKA?
Hyperglycaemia
Ketonaemia
Metabolic acidosis
What are the 2 basic causes underlying the pathophysiology of DKA and why do they lead to DKA?
- Insulin deficiency
- Increased counter-regulatory hormones (can be released in response to stress causes by illness)
Consequences:
-increased hepatic gluconeogenesis and glycogenolysis which leads to HYPERGLYCAEMIA
-induces lipolysis which increases the concentration of free FA which induces KETOGENESIS AND KETOACIDOSIS
What complications of DKA can result in death?
Hypovolemic shock due to acidosis inducing collapse of vessels
MI
CVA
Mesenteric arterial occlusion
Acute pancreatitis
Infection i.e. pneumonia
Cerebral oedema
ARDS (pulmonary oedema)
What are possible precipitating factors of DKA?
Infection i.e. UTI or pneumonia
Treatment errors i.e. missing insulin or insufficient dose
New diagnosis of T1DM
Stress
Alcohol
Pregnancy
MI
What is important advice/steps that T1DM patients need to be given to help prevent DKA?
Sick day rules= more insulin required when unwell
Monitor blood glucose and ketones when ill
Check that pen/pump working
Don’t miss a dose (even if not eating due to illness)
Stay hydrated
Avoid strenuous activity
Keep same diet
What are the clinical features of DKA?
Hyperglycaemia: Excessive thirst Polyuria Weight loss Abdominal pain Nausea Blurred vision
Ketonaemia: Rapid breath (Acidotic respiration) Headache Confusion Acetone breath (pear drops) Hot dry skin (inappropriate vasodilation) Hypothermic (“”) Circulatory collapse (“”) = tachycardia + hypotension Drowsiness Coma
Why does vasodilation occur in DKA patients and what are the clinical signs of this?
Acidosis induces vasodilation
Signs:
- hot dry skin
- hypothermic
- circulatory collapse = hypotension and tachycardia
What are the 3 diagnostic criteria for DKA?
Glucose:
>11mmol/L or known diabetic
Lab glucose
Ketones:
Capillary blood showing ketonaemia i.e. >=3 mmol/L
Urinary test showing ketonuria i.e. >2+ on dip stick
pH:
<7.3 (venous)
HCO3 <15mmol/L
What other tests are important outside the diagnostic criteria and why is this?
Other tests can be used to assess for any precipitating factors which can them help to guide treatment
Eg:
- U+E ie assess renal impairment to indicate level of dehydration
- FBC and cultures= infection markers
- ECG= evidence of MI
- ABG to assess acid-base status= can see if acidosis has been compensated for i.e. decreased CO2
What happens to ureas and sodium and potassium levels in DKA and why?
Raised Urea= due to dehydration
Low sodium= electrolyte i.e. increased Na loss in hyperglycaemia
Low potassium= osmotic diuresis
What 2 forms of management should be done immediately in DKA and why?
Fluid replacement
- replace circulatory volume + correct hypotension
- clear ketones
- correct electrolyte imbalance
Insulin = fixed rate IVII (0.1 units/kg/h) -suppression of ketogenesis -reduction of blood glucose -correct electrolyte imbalance NOTE: continue normal insulin
What are the different things which need to be monitored in a DKA patient?
Blood glucose
Ketones
Blood gas for pH and HCO3
Potassium
What are possible complications which can arise whilst managing DKA?
Hypoglycaemia
Potassium derrangment
Fluid overload
What is rebound ketosis and why does it occur? What can be done to avoid this in DKA?
Ketosis induced by allowing glucose levels to reach hypoglycaemic range and therefore inducing counter-regulatory hormones which induced ketosis
Give 10% glucose infusion when blood glucose falls <14mmol/L
Why do potassium levels need to be monitored once DKA treatment has begun? When and how can it be replaced if necessary?
Insulin can induce fall in potassium due to activating Na+/K pump which promotes movement of K+ into cells
If fall <5.5mmol/L= 0.9% NaCl solution with potassium 40mmol/L
How can fluid overload by managed in DKA?
Manage fluid balance i.e. monitor how much IV fluid going in vs how much fluid going out
Catheterise to monitor urine output
Why might thromboprophylaxis be given in DKA? What type is given?
Increased risk of thromboembolism in DKA
LMWH
What is the criteria for DKA to be classified as resolved? What are the measures taken after DKA resolution? How does this differ depending on whether px eating and drinking?
Blood ketone <0.3 mmol/L
Venous pH >7.3
If E+D:
- convert to SC insulin
- stop IVI
If not E+D:
- move to variable rate IV insulin infusion
- continue IVI
What is the pathophysiology relating to HHS?
Hyperglycaemia causes osmotic diuresis
Osmotic diuresis causes excess water and electrolyte loss
Water moves out of intracellular compartment== cellular dehydration
Why don’t HHS patients become ketoacidotic?
Insulin NOT completely absent- some present to suppress lipolysis and ketogenesis
Hyperosmolarity also inhibits lipolysis
Decreased FFA which leads to decreased induction of ketogenesis
What are the characteristic features of patient presenting with HHS?
Hypovolaemia
Hyperglycaemia (>30mmol/L)
Lack of significant kyperketonaemia and acidosis
Osmolality >320 mosmol/Kg
Dehydration= 10-15% weight water deficit
Altered mental state= associated with >330mosmol/kg
Thrombotic complications
