IV Fluids Flashcards
What different mechanisms of movement between fluid compartments exist?
Electrochemical gradients, hydrostatic pressure, osmotic forces, oncotic pressure, primary and secondary AT
What is the equation for calculating oxygen delivery to tissues?
CO x Hb conc x 1.34(mls O2/g Hb) x O2 sats % (0-1.00)
What is the unit of DO2 (oxygen delivery to tissues)?
mls O2/min
What is the unit for Hb?
g/litre
What makes a solution hypotonic and hypertonic?
Amount of Sodium present
Hypotonic is when there is little sodium
Hypertonic is when there is too much sodium
Why is it dangerous to give fluid that is hypotonic?
hypotonic hyponatraemia causing intracerebral osmotic shift and cerebral oedema
How many grams of glucose do you require every day?
50-100g
What is the breakdown of fluid in the body?
2/3 is intracellular
1/3 is extracellular broken down into interstitial and intravascular
Comparing intracellular and extracellular compartments, which has higher sodium? potassium? calcium? magnesium? chloride? phosphate?
sodium - higher extracellularly potassium - high intracellularly calcium - higher extracellularly Magnesium - high intracellularly Chloride - high extracellularly Phosphate - higher intracellularly
What are the 3 layers of blood vessels called and made of?
Tunica intima - endothelium single cell lining supported by basement membrane and CT
Tunica media - muscular layer
Tunica adventitia - CT
Which layer of the blood vessels differs depending on the blood vessel type?
Tunica media as muscular layer only present in bigger vessels and not present in capillaries
What is the pathophysiology of oedema occuring?
Causes leakage through the blood barrier (tunica intima) as well as larger molecules and cells leaking
Is serum sodium and potassium a good indicator of total body?
Serum Na is good indicator but serum K is not
Difference between crystalloids and colloids?
Crystalloids have smaller particles and can therefore pass through semipermeable membranes whereas colloids have larger particles and therefore largely remain within the intravascular system
What can an excess of NaCl fluid cause?
Hyperchloraemic acidosis
What should you never add to Hartmanns solution
Any additional electrolytes
What happens to solute concentration when osmolality decreases?
Decreased conc making it more watery
What happens when glucose 5% is administered
It is metabolised very quickly by the body leaving water which can distribute across all departement
What situation would you administer colloid instead of crystalloids?
When you want a higher sodium concentration administration
Name the principle natural colloid that can be given IV? potential risk?
Human albumin infusion wither 4.5% or 20%
Risk of transmitting infection
What are the indications for administration of human albumin?
Low serum albumin in haemodynamically unstable patient Large volume paracentesis for ascites Spontaneous bacterial peritonitis Hepatorenal syndrome Therapeutic plasma exchange
2 artificial colloids that can be administered and their associated side effects?
Gelatin - anaphylaxis, coagulation effects
Dextrans - highly branched polysaccharide, coagnulation defects, anaphylaxis, coats RBC so can cause interference to cross matching, precipitate an AKI
What 2 reasons is Dextrans primarily used for?
Microsurgery
VTE prophylaxis
What is the definition of hyponatraemia and what are the categories of causes?
An Na less than 135 mmol/l
Can be hypotonic hyponatraemia, isotonic hyponatraemia, hypertonic hyponatraemia