A nurse is reviewing the history of a client who has developed metabolic alkalosis. Which of the following findings is the most likely cause?

A.Daily antihypertensive use manages systemic vascular resistance and cardiac output but does not inherently suppress the immune system or impair the primary phases of wound healing. While uncontrolled hypertension can affect overall surgical outcomes, it is not a direct independent risk factor for the colonization of pathogens at the incision site. The nurse should monitor blood pressure stability rather than increased infectious risk.

B.A history of deep vein thrombosis increases the client's risk for venous thromboembolism during the perioperative period due to venous stasis and hypercoagulability. However, the presence of a previous clot does not compromise the skin barrier or the cellular response required to prevent a surgical site infection. Prophylaxis for this client would focus on anticoagulation and mechanical compression rather than antimicrobial stewardship.

C.Age over 65 years old is associated with physiological changes such as decreased tissue perfusion, thinning of the dermal layer, and a naturally declining immune response known as immunosenescence. These factors collectively hinder the body's ability to clear pathogens and synthesize collagen efficiently at the surgical site. The nurse must recognize that older adults have a statistically higher incidence of postoperative infections compared to younger populations.

D.A body mass index of 23 falls within the healthy reference range of 18.5 to 24.9, indicating an appropriate nutritional status and a normal distribution of adipose tissue. Unlike obesity, which impairs blood flow to subcutaneous tissue, or malnutrition, which prevents protein synthesis, a BMI of 23 supports optimal wound healing. This finding actually suggests a lower risk for complications related to surgical site integrity.

A.A fully compensated state would require the pH to return to within the normal physiological range of 7.35 to 7.45 while both the PaCO2 and HCO3 remain abnormal. Since the client's pH is 7.47, the body has not yet achieved total homeostatic balance. The presence of a pH outside the normal limits clearly excludes full compensation as a valid interpretation of these specific laboratory findings.

B.An uncompensated state occurs when the pH is abnormal and only one of the metabolic or respiratory components is abnormal, while the other remains within its reference range. In this sample, both the PaCO2 at 47 mmHg and the HCO3 at 31 mEq/L are outside their normal limits. This indicates that the secondary system has already begun to respond to the primary imbalance, thus ruling out an uncompensated interpretation.

C.These results indicate a partially compensated metabolic alkalosis because the pH is alkaline, the primary bicarbonate (HCO3) is elevated, and the respiratory system is attempting to compensate. The PaCO2 is elevated at 47 mmHg as the lungs retain carbon dioxide to lower the pH. Because the pH remains above 7.45, the compensation is active but not yet successful in returning the blood to a normal acid-base state.