Crystalloid solutions contain inorganic ions (e.g. sodium) as well as small organic substances (e.g. glucose). Examples of crystalloid solutions include 0.9% sodium chloride (normal saline) and Hartmann’s solution. Up to 80% of the volume of crystalloids ends up in the interstitial, making it an ideal solution for IVMT. The remaining 20% volume is considered “interstitial loss” and is influenced by colloids, acid base status, their tonicity, and their chloride load.
Large volumes of 0.9% sodium chloride may cause a metabolic acidosis. In addition, the high chloride load of 0.9% sodium chloride causes renal vasoconstriction, decreasing the glomerular filtration rate (GFR) and leading to acute kidney injury. Hence, IVMT should kept at 250ml to 500ml.