Final answer:
Controlled hypothermia is used during cardiopulmonary bypass weaning to increase the speed of shell warming. It involves cooling the patient's body temperature and stopping the heart while an external heart-lung pump maintains circulation. This method reduces the risk of damage to the brain, heart, and other organs.
Step-by-step explanation:
During cardiopulmonary bypass weaning, the speed of shell warming can be increased by using controlled hypothermia. Controlled hypothermia is often used during open-heart surgery to decrease the metabolic needs of the brain, heart, and other organs, reducing the risk of damage to them. The patient is cooled to a temperature of 25-32°C (79-89°F), the heart is stopped, and an external heart-lung pump maintains circulation to the patient's body. This very cold temperature helps the heart muscle tolerate its lack of blood supply during the surgery.