Heat exchanger/temperature management in CPB serves what purpose?

• A. To oxygenate the blood
• B. To pump the blood
• C. To manage blood temperature and preserve organs
• D. To deliver cardioplegia

Answer: (C)

Managing blood temperature during cardiopulmonary bypass is used to protect organs by altering the body's metabolic demand. Cooling the blood lowers tissue metabolism, helping organs like the brain, heart, and kidneys tolerate the period of bypass and ischemia. As bypass proceeds, the heat exchanger can rewarm the blood to normothermia so that physiological function returns smoothly before weaning off bypass. This temperature control is distinct from oxygenation (handled by the oxygenator) and from pumping (done by the bypass pump). Delivering cardioplegia may be coordinated with temperature goals, but the exchanger’s primary role is adjusting temperature to preserve organ function.