Lecture 9 - Fluid Replacement Therapy Flashcards Preview

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Flashcards in Lecture 9 - Fluid Replacement Therapy Deck (12)
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1
Q

In a standard 70kg male, what % of total body water is distributed into each compartment?

A
  • 60% water (42L)
  • 2/3 in ICF (28L)
  • 1/3 in ECF (14L) split into interstitial fluid (10.5L) and plasma (3.5L)
2
Q

What is the total body water % of a newborn baby, a female and an elderly person and why is this the case?

A

Babies = 73% because they have a high SA:body ratio and a very high metabolic rate

Elderly = 45% because muscle holds more water than fat and muscle mass decreases with age.

Female = 50% because they have less muscle and more fat

3
Q

What occurs to the cells during hypernatraemia and hyponatreamia?

A

Hypernatraemia = Increased Na+ in plasma (osmolality increases) so water moves out of cells causing cell shrinkage, confusion & seizures

Hyponatreamia = Decreased Na+ in plasma (osmolality decreases) so water moves out of blood into cells causing cell swelling, cerebral oedema, headaches & seizures

4
Q

How does a bag of 1L 5% dextrose (50g glucose) distribute across compartments?

A
  • 1L of water distributes evenly across compartments (2/3 to ICF, 1/3 to ECF)
  • Glucose is taken up into cells and goes entirely into ICF
  • Hyperglycaemia will occur if infusion rate fast than uptake and metabolism of glucose
5
Q

How does 1L 0.9& saline (NaCl) and 1L Hartmann’s distribute across fluid compartments?

A
  • Na+ remains entirely within ECF compartment (3/4 in IF, 1/4 in plasma)
  • Hartmann’s similar, almost entirely stays within ECF
6
Q

How will a bag of 1L of 4% dextrose and 0.18% saline distribute across fluid compartments

A
  • 800mL of H2O will distribute evenly across fluid compartments (2/3 ICF, 1/3 ECF)
  • 200mL of 0.9% saline will remain in the ECF only
7
Q

What patients require administration of I.V fluids?

A
  • Nil by mouth patients (having surgery)
  • Malfunctioning G.I.T (had a stoke/cant swallow)
  • Dehydration
  • Fluid losses
  • Abnormal electrolytes
8
Q

What patients require administration of I.V fluids?

A
  • Nil by mouth patients (having surgery)
  • Malfunctioning G.I.T (had a stoke/cant swallow)
  • Dehydration
  • Fluid losses
  • Abnormal electrolytes
9
Q

What hormonal changes do hospitalised patients normally undergo?

A
  • Metabolically stressed so activate RAAS, aldosterone causes secretion of ADH
  • This causes reduced water excretion leading to hyponatremia and increased water retention leading to volume overload.
10
Q

How is an individuals maintenance daily requirements (for fluids and electrolytes) calculated?

A

1) 25-30mL/kg/day water
2) 1mmol/kg/day of Na, K and Cl-
3) 50-100g glucose per day

11
Q

What is the protocol for giving fluid resuscitation to a hypovolaemic patient

A

1) Find cause of fluid deficit
2) Give 500mL bolus of crystalloids (either Hartmann’s or saline)
3) Replace fluids that are lost (check electrolyte crib sheet) and ongoing maintenance

12
Q

The electrolyte constitution of different body fluids are different, why is this important?

A
  • The reason for fluid loss will determine what type of fluids are used to replace. E.g.: vomiting will result in different loss of electrolytes than diarrhoea.
  • I believe this table below needs to be learned?