Crystalloids (ASAN002/7) Flashcards
What are Crystalloids? (1)
Water–based solutions that contain small particles (ions & molecules).
What are the common constituents of Crystalloids? (3)
- Electrolytes
- Glucose or Dextrose
- Buffers
What are common Electrolytes found in Crystalloids? (5)
- Sodium
- Potassium
- Calcium
- Magnesium
- Chloride
What is the main purpose of Electrolytes in Crystalloids? (2)
- to replace or maintain plasma levels
- to correct electrolyte imbalances
What is the purpose of Glucose or Dextrose in Crystalloids? (1)
To provide energy to the patient
What is the purpose of Buffers in Crystalloids? (1)
To correct or maintain the normal acid–base balance of plasma.
What are the main characteristics of Crystalloids? (2)
- The small particles readily pass through membranes and into all body compartments.
- The fluid is rapidly redistributed through the body.
Do Crystalloids stay in the intravascular space?
No
What % of crystalloid fluids given will leave the intravascular space within 30 mins of administration?
75%
IMAGE – Crystalloids passing through membrane
What types of Tonicity can Crystalloid solutions be? (3)
- Isotonic
- Hypotonic
- Hypertonic
What are the two types of fluids that Crystalloids are divided into? (2)
- Replacement fluids
- Maintenance fluids
What is the aim of Replacement fluids? (2)
Replace patient deficits of water & electrolytes.
What are Replacement fluids used to correct? (2)
- Dehydration
- Hypovolaemia
What are the main characteristics of Replacement fluids? (3)
- Similar composition to plasma
- Isotonic
- Can be given rapidly in large volumes without causing electrolyte shifts.
What are the two most common Replacement fluids? (2)
- Hartmann’s (Lactated Ringers Solution)
- 0.9% NaCl (Normal saline)
What is the other name for Hartmann’s? (2)
Lactated Ringers Solution or LRS
What are the main characteristics of Hartmann’s? (6)
- Crystalloid solution
- Isotonic
- Similar concentration of electrolytes as extracellular fluid
- High concentrations of Sodium & Chloride
- Small amounts of Potassium & Calcium
- Lactate as a buffer
Why must a patient’s liver function be adequate if administering Hartmann’s? (1)
Has a negative ion that requires hepatic metabolism
What is 0.9% NaCl commonly called?
Normal Saline
What are the main characteristics of 0.9% NaCl? (4)
- Isotonic
- High concentrations of Sodium & Chloride
- No Potassium
- Can be used with other fluids / medications
Why would a type of fluid be classed as a Maintenance Fluid? (1)
When used to ‘maintain’ fluid balance.
Why are Maintenence fluids used? (2)
To meet patient’s ongoing sensible & insensible fluid losses
When is it appropriate to use Maintenance fluids? (1)
Once hydration has been restored.