Fluid Therapy Flashcards
What fraction of body fluid is ICF?
2/3
Extracellular Fluid is 1/3rd body fluid and comprises what structures?
Interstitial and Intravascular
Intracellular fluid has low/high Na+ and low/high K+
low Na+, high K+
Intravascular fluid when compared with interstitial fluid has high/low protein
high
What is the normal range for urinary losses
1500ml-2000ml per day
0.5-1.0mls/kg/hr
What is the normal Potassium requirement per day
0.5-1.0 mEq/kg/day
What is the normal Sodium requirements per day
1-2 mEq/kg/day
In 1L of N/S how many mEq of Na+ is there
154mEq, and 77mEq in a 500ml (the more commonly used bag at UHWI)
How much N/S and Potassium should be added for every litre of NG aspirate
1L N/S
10-20mEq K+
Do you administer supplementary potassium in the first 48 hrs post op ?
No
1) Hypovolemia causes aldosterone secretion and slat retention by kidney
2) potassium is released by damaged tissues
3) Potassium levels can also increase post blood transfusion
(Do not give K+ until the patient is passing adequate urine)
What is the maximum amount of potassium that can be safely administered in 500ml of N/S
20mEq
Q1-
In a 70 kg patient with normal U/Es and a daily urine output of 1500ml who also has NG losses of 2L what should the fluid replacement regime be?
Total vol. replaced: 4.5L
3L N/S, 1.5L D5W
60mEq of KCl
How much crystalloids should be given as replacement for every ml of blood lost, and why
3ml
This is because at least 2ml will move into the interstitial tissue and 1ml will remain intravascular
What is the formula for total fluid requiremnt?
Maintenance fluid + deficit + ongoing losses
List 4 types of ongoing losses
GI, Tubes/Drains, Third Spacing, Blood loss
Define crystalloids
These are solutions of crystalline solids in water
Why do you need to administer 3-4x the deficit when N/S is used to resuscitate a patient?
Because only 30% of the N/S administered actually remains in the intravascular component
Large volumes of N/S can lead to what metabolic complication
Hyperchloremic acidosis, since N/S has a higher concentration of Cl- ions than plasma
How can you avoid hyperchloremic metabolic acidosis when large volumes are required ?
Use balanced fluids such as Ringer’s LActate
What is the value, in mmol/L, of Na+ in Hartmann’s?
131
What is the value, in mmol/L, of Na+ in N/S
154
What is the value, in mmol/L, of Cl- in Hartmann’s
112
What is the value, in mmol/L, of K+ in Hartmann’s
5
What is the value, in mmol/L, of K+ in N/S
0
