What is the initial fluid volume recommended in the moderate/severe anaphylaxis protocol for vascular access?

• A. 250 mL
• B. 500 mL
• C. 750 mL
• D. 1000 mL

Answer: (B)

In moderate to severe anaphylaxis, systemic vasodilation and increased vascular permeability can reduce effective circulating volume and compromise perfusion. The goal of fluid resuscitation is to quickly restore preload and support blood pressure. The protocol specifies giving an IV bolus of 500 mL of isotonic crystalloid (such as normal saline) as the initial fluid volume. After this initial bolus, reassess perfusion and blood pressure and repeat if needed based on the patient’s response. Smaller amounts, like 250 mL, may not adequately improve perfusion in shock, while larger initial boluses (750 or 1000 mL) are not the standard initial dose and can risk fluid overload before reassessment.