Progressive Care Nursing Certification (PCCN) Practice Exam

Which effect of cardiopulmonary bypass is the nurse likely to anticipate?

1. Decrease in vasopressin secretion

2. Decreased levels of RAAS

3. Increased immune response

4. Increased weight

The correct answer is: Increased weight

The correct choice highlights that cardiopulmonary bypass (CPB) can lead to increased weight, which is typically associated with fluid retention and edema resulting from the inflammatory response triggered by the bypass process. During CPB, the body undergoes various physiological changes, including alterations in blood flow and volume, which can contribute to a shift in fluid balance. As the body reacts to the CPB, fluid can accumulate in interstitial spaces, leading to increased body weight. This is a common observation in patients following cardiac surgeries that utilize CPB as the body manages the fluid status and responds to the stress of surgery. In contrast, the other options address different physiological changes that may not directly correlate with the anticipated effects of CPB. For instance, while vasopressin secretion may be influenced by changes in blood volume and pressure, the typical expectation is for it to increase due to the stress response rather than decrease. Similarly, though the renin-angiotensin-aldosterone system (RAAS) may be activated in response to hemodynamic alterations, the overall physiological environment during and after CPB often leads to a complex interaction that may not result in decreased levels. Lastly, the immune response can also be modified by CPB; however