What happens if you cool a patient too quickly?

• A. Intravascular aggregation
• B. Hypothermia
• C. Vasoconstriction
• D. Arrhythmia

Answer: (A)

Rapid cooling can provoke intravascular aggregation because the abrupt drop in temperature promotes clumping of blood components inside vessels. Platelets become more prone to activation and form microthrombi, and coagulation factors can aggregate as well, leading to obstructions within the microcirculation. This intravascular plugging can impair tissue perfusion and contribute to perfusion-related injury during cooling and subsequent rewarming.

Vasoconstriction is a general response to cold and can occur, but it’s a broad hemodynamic effect rather than the specific intravascular clumping phenomenon described by rapid cooling. Arrhythmias can occur with hypothermia, but the mechanism most directly tied to cooling rate in this context is the tendency for blood elements to aggregate within vessels. Hypothermia is the state you approach, not the immediate consequence of cooling too quickly.