Which solution is an example of a balanced crystalloid used for perfusion in surgery?

• A. Dextrose 5% in water
• B. Normal saline
• C. Normal saline and lactated Ringer's
• D. Colloids like albumin

Answer: (C)

A balanced crystalloid is a fluid Reformulated to resemble plasma in electrolytes and to provide a buffering effect, helping maintain perfusion and acid–base balance during fluid resuscitation. Lactated Ringer's fits this description well. It contains sodium, chloride, potassium, calcium, and lactate; the lactate is a buffer that the body can convert to bicarbonate, helping to keep the pH more stable during surgery. This makes it gentler on acid–base status compared with other crystalloids when large volumes are given.

Dextrose 5% in water provides calories but ultimately turns into free water with no sustained electrolyte support, so it’s not ideal for perfusion. Normal saline is isotonic but has a relatively high chloride load, which can lead to hyperchloremic acidosis and less favorable perfusion effects. Colloids like albumin are not crystalloids; they behave differently in the intravascular space and aren’t classified as balanced crystalloids.