Chem Path: Diabetes cases Flashcards
What does compensation mean in acid base?
Correcting the pH at the expense of pCO2
What happens in metabolic acidosis?
Due to excess of H+ ions, you try to compensate by hyperventilating to get rid of CO2 so pCO2 drops.
What is osmolality?
2 x (Na + K) + Urea + Glucose
What is anion gap?
Na + K - Cl - HCO3
When a patient comes in unconscious with acidosis, what do you do?
Look at anion gap. If anion gap is large, it means there is some other anion involved other than Cl and HCO3. If anion gap is normal, that means there is an excess of Cl
What is a normal anion gap?
18mM
What are some anions that can be raised?
Ketones
What are causes of metabolic acidosis?
DKA, lactic acidosis
What would the ABG look like for respiratory alkalosis?
High pH and low pCO2
Why is there tetany when pH is high?
When pH is high, there is more albumin-calcium binding and less ionised calcium, leading to tetany
What does tetany look like?
Carpal and pedal spasm
What is Hyperosmolar non ketotic coma (HONKC)/HHS?
Complication of long standing diabetes. So their osmolality will be high and they would be dehydrated.
How do you treat this?
0.9% normal saline. 500ml over an hour or 1L over an hour if very dehydrated.
When do you know they are euvoleamic?
When you can see their JVP.
What can happen when you give too much fluid too quickly in the elderly?
Cerebral and pulmonary oedema
When someone comes in with a T1DM crisis, how do you treat?
Insulin
When someone comes in with a T2DM crisis, how do you treat?
Fluids first, reassess, then give insulin. Otherwise there will be circulatory collapse, BP will fall.
What is the diagnosis when ketones are high and glucose is high?
DKA
What is the diagnosis when ketones are high and glucose is low?
Starvation
What is the diagnosis when ketones are low and glucose is high?
HONKC/HHS
What is the diagnosis when ketones are low and glucose is low?
Fatty acid oxidation defect (MCADD)
What parameters do you look at when deciding acid base balance?
pH, pCO2, bicarb, anion gap, osmolality
When there is metabolic acidosis and high anion gap, what is the next thing you look at?
Look at ketones to see if it is DKA.
Low ketones, what can the other causes be? What is the mnemonic?
KLUT
What does it stand for?
K - DKA, alcoholic, starvation
L - Lactic acidosis
U - Uraemia - Renal failure
T - Toxins -
What is the cori cylce?
Glucose metabolism in muscles creates lactate, which is transported to the liver, where it converted back to glucose
What does metformin do?
It stops the liver from converting lactate to glucose.
What happens in metformin overdose?
Lactic acidosis
What are the 2 tests for T2DM?
Fasting glucose > 7.0mM
Glucose tolerance test (75g glucose given at time 0) - Plasma glucose >11.1mM at 2 hours
What is impaired glucose tolerance
GTT - Plasma glucose 7.8-11.0 at 2 hours
What about HB1Ac levels for diabetes
42mM = Impaired glucose tolerance
> 48mM = Diabetes
Is COPD type 1 or 2 respiratory failure
Type 2
What is the pH level and pCOs level in COPD and explain why so?
You retain more CO2 and since this is long standing, the kidneys retain more HCO3 which leads to chronic resp acidosis. You will eventually compensate but pH will be normal and pCO2 will be HIGH. Patients will not feel breathless. If they get infections, they get hypoxic really quickly.
What happens when you take a lot of antacids?
Metabolic alkalosis
Explain blue boaters and pink puffers
Blue bloaters - Insensitive to CO2 - you are not breathless and co2 will rise
Pink puffers. - CO2 retention due to poor lung function
What happens in chronic aspirin use
Resp alkaalosis and metabolic acidosis
