USMLE Step 2 Clinical Knowledge (CK) Practice Exam

The complication most commonly associated with prolonged hypotension during surgery is acute kidney injury. During surgical procedures, especially those requiring significant fluid shifts or lengthy times of low blood pressure, renal perfusion can be compromised. The kidneys are highly sensitive to changes in blood flow; thus, inadequate perfusion due to hypotension can lead to acute tubular necrosis and subsequent acute kidney injury.

In the context of surgery, maintaining adequate blood pressure is crucial to ensure the kidneys receive enough blood flow to function properly. If blood pressure drops significantly and for an extended period, this can result in ischemic injury to the renal tissue, ultimately leading to a rise in serum creatinine levels and a decline in glomerular filtration rate.

The other options represent complications that may arise in a surgical setting, but they are less directly associated with the immediate effects of prolonged hypotension. The risk of infection and deep vein thrombosis are significantly influenced by multiple factors such as the type of surgery performed, patient mobility, and surgical site rather than directly linked to blood pressure levels. Similarly, postoperative cholestasis is not a primary concern related to the hemodynamic changes associated with hypotension. Hence, acute kidney injury stands out as the most directly correlated complication in this scenario.