Which intravenous fluid would most likely be used for a patient in shock?

Normal saline is the most appropriate intravenous fluid for a patient in shock due to its balanced electrolyte composition and volume-expanding properties. When a patient is in shock, they often exhibit significant dehydration and a decreased blood volume, which can impair circulation and oxygen delivery to vital organs. Normal saline, which is a sterile solution of sodium chloride in water, helps to restore intravascular volume and improve blood pressure, making it essential in the initial management of shock.

Additionally, normal saline is isotonic, meaning it maintains osmotic balance with blood, which helps avoid further cellular dehydration. This is critical, especially in situations like hypovolemic shock, where rapid rehydration and volume restoration are key to stabilizing the patient.

Other fluids listed, such as dextrose 5% in water, may not be suitable for immediate resuscitation in shock because they contain low electrolyte levels and primarily serve as a source of carbohydrates. Half-normal saline would dilute serum sodium levels further, and calcium gluconate is primarily used for specific electrolyte imbalances rather than fluid resuscitation. Thus, normal saline is the preferred choice in managing shock effectively.