At what rate should cooling be performed for deep hypothermic circulatory arrest (DHCA)?

In the context of deep hypothermic circulatory arrest (DHCA), cooling rates are critical because they influence neuroprotective effects and the overall outcome of the procedure. For optimal results, it is recommended to achieve a cooling rate of approximately 1 degree Celsius per minute. This rate facilitates rapid temperature reduction while maintaining physiological stability, ensuring a sufficient level of hypothermia to protect the brain and other vital organs during periods of circulatory arrest.

Cooling at this rate effectively lowers the metabolic rate of tissues, helping to preserve cellular integrity and function. A more gradual cooling rate, such as those specified in other choices, may be insufficient for achieving the desired depth of hypothermia within a clinically relevant timeframe, which can compromise the efficacy of the procedure. Thus, a cooling rate of 1 degree Celsius per minute is ideal for achieving the necessary thermal protection during DHCA.