IV crystalloid solutions come in two forms within the SJA, a 1000ml soft plastic bag, and a 10 ml plastic vial (primarily used a flush).

Both forms contain normal saline (NaCl 0.9%) which is essentially a sterile isotonic crystalloid solution of water and sodium chloride (more commonly known as table salt) at a percentage of 0.9%.

There is 9g of salt, in 1lt of saline which is a close approximation to the osmolality of NaCl in blood.

Uses within SJA

• Fluid replacement (volume expansion) for the treatment of shock, fluid loss, and cardiac arrest

• ‘Flush’ medication through a cannula into the circulatory system

• Rehydration

• Irrigation of wounds or eyes

• Cooling and irrigation of burns



When given as fluid replacement, onset is immediate; though effects will of course be directly proportional to the speed of infusion (larger bore cannula will potentially see a more rapid rise in BP)


Normal saline is an isotonic solution designed to have the correct tonicity to stay within the extracellular compartment (i.e. the circulatory system/vessels).

Normal saline will also replenish sodium and chloride losses, treat diabetic ketoacidosis, and replenish fluids in the early treatment of burns.


Throughout the circulatory system


Salt and water are not metabolised as such. The cells are in constant contact with the circulating fluids and the abundance of sodium in the fluids, means that the taking up of salts by the cells is an active or "selective" process, via osmosis.


Your body removes unwanted fluid by filtering your blood through your kidney, via osmosis, to draw excess water out of your blood. This requires a balance of sodium and potassium to pull the water across the wall from the bloodstream into a collecting channel in the kidney


Desired Effects

  • Increase in blood pressure
  • Increase in hydration

Side Effects

Circulatory overload

Duration of Action

Will vary depending on multiple factors including injury, medical conditions, hydration, kidney function etc

Other Drug Interactions

Not applicable

Did you know?

In the hospital environment various forms of crystalloid are available, including hypotonic and hypertonic solutions, with use dependent on patient’s sodium levels.

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