Fluid Management Flashcards
(57 cards)
What are some important intracellular solutes?
Potassium
Magnesium
Phosphate
What are some important extracellular solutes?
Sodium
Chloride
Bicarbonate
How can plasma osmolality be calculated approximately?
2[NA] + Glucose + Urea
What solutions are isotonic with the plasma?
0.9% Saline
5% Glucose in water
How much sodium chloride is in a litre of 0.9% saline?
150mmol/L
What is Hartmann’s solution?
Sodium= 131mmol/L Chloride= 111mmol/L Lactate= 29mmol/L Potassium= 5mmol/L Calcium = 2mmol/L
What is the difference between colloids and crystalloids?
Colloids contain large molecular weight molecules which should stay within the intravascular space
Crystalloids contain ions which distribute around the body.
What should be used for resuscitation?
NICE recommend using crystalloids, and colloids have been found to have little extra benefit
Where is Hartmann’s solution commonly used?
Often in theatres
It has concentrations of ions which are more similar to physiological levels
What are some examples of colloids?
Albumin
Gelatin
Dextran
Often suspended in NaCl
Used in 1:1 ration for blood loss
What are some side effects of colloids?
Anaphylaxis to the molecules
Antithrombotic action
Deposit in the reticuloendothelial system to cause itching/pruritus
How should you examine to assess fluid status?
JVP Peripheral oedema Pulmonary oedema Mucous membranes CRT Blood pressure Urine output Skin turgor
What blood test results might you see in someone who is dehydrated?
Raised Hb (or if previously anemic may be normal)
Raised creatinine and urea if reduced renal perfusion
Raised sodium
What happens when you infuse fluid with sodium?
Sodium stays in the extracellular fluid and water stays with it so it can raise circulating volume (as the extracellular fluid is the fluid around cells (interstitial fluid) and the circulating volume.
What happens when you give someone 5% glucose solution?
Glucose is metabolised so this is effectively giving the person water. This will distribute in the bodies compartments so raises total body water.
When is dextrose solution indicated?
Dehydrated patients- as the glucose is metabolised and the water distributed around the bodies compartments, therefore raising total body water. It will not adequately increase circulating volume.
Where does 1L of 0.9% saline distribute to?
Sodium stays within the extracellular fluids and water stays with it.
This comprises of the interstitial fluid (around cells) and the circulating volume.
Distributes in a 2:1 ratio between interstitial fluid and circulating volume
Therefore giving 1 litre raises circulating volume by 333ml
Where does 0.9% saline distribute to?
Sodium stays in the extracellular fluid and water stays with it.
Therefore distributes to the interstitial fluid (around cells) and the circulating fluid (intr-vascular). This is in a 2:1 ration
A third of the volume of 0.9% NaCl therefore stays in the intravascular space
What ratio does 0.9% saline distribute between the interstitial fluid and the intravascular fluid?
2: 1
2 in interstitial fluid
1 in the intravascular fluid
Where does 5% dextrose distribute?
Everywhere so it increases the whole total body water.
It’s only indication is dehydration, and should never be used for resuscitation.
What should hypovolaemia be treated with?
Rapid infusion of isotonic (0.9% saline solution)
What should dehydration be treated with?
5% dextrose
NEVER FOR RESUS
If someone is NBM what maintenance fluids are required?
1.5mls/kg/hr
Otherwise they will become dehydrated
What are the sodium electrolyte requirements?
2mmol/kg/day
A litre of normal saline normally replaces this (contains 150mmol in 0.9%)
