Final answer:
The pressure often maintained at the initiation of bypass is the mean arterial pressure (MAP), targeted within the range of 70-110 mm Hg to ensure adequate circulation and avoid ischemia and hypoxia. This is crucial for protecting sensitive neurons from damage.
Step-by-step explanation:
The question relates to the pressure maintained at the initiation of bypass, presumably cardiopulmonary bypass, during cardiac surgery. At the initiation of bypass, the mean arterial pressure (MAP) is generally targeted to be within the range of 70-110 mm Hg to ensure adequate circulation and perfusion of the tissues. The provided reference from Figure 20.10 indicates a calculated MAP of approximately 93.33 mm Hg, which is derived from the equation that adds one-third of the difference between systolic and diastolic pressures (also known as pulse pressure) to the diastolic pressure. This pressure is crucial to avoid ischemia and hypoxia, conditions that result from insufficient blood flow and oxygenation of the tissues respectively. It is also noted that neurons are particularly sensitive to hypoxia and can be damaged without prompt restoration of adequate blood flow and oxygen supply.