Choosing between colloids and crystalloids for IV infusion

Hypovolaemia resulting from illness or trauma can precipitate imbalances in homoeostasis due to the loss of circulating fluid volume. By addressing hypovolaemia, homoeostasis can be restored, preventing hypoperfusion and subsequent organ dysfunction. Administering intravenous fluids can replace any lost circulating volume. The National Institute for Health and Care Excellence outlines five ‘Rs’ of fluid therapy: resuscitation, routine maintenance, replacement, redistribution and reassessment. This article provides an overview of fluid therapy, covering the NICE guidance and clarifying the differences between crystalloids and colloids, and when to use them.