What is an expected complication in the case of a patient post-cardiac surgery with abdominal pain and elevated lactic acid?

Mesenteric ischemia is a serious condition that can occur post-operatively, particularly in patients who have undergone cardiac surgery. This complication arises due to a reduction in blood flow to the intestines, which may result from postoperative factors such as low cardiac output, embolism, or thrombosis of mesenteric vessels.

In the context of abdominal pain and elevated lactic acid in a postoperative patient, mesenteric ischemia is indicated. Lactic acid levels typically rise in response to tissue hypoxia, which can occur when the intestines are not receiving adequate blood supply. The classic presentation includes severe abdominal pain, often disproportionate to physical examination findings, along with other symptoms such as nausea or vomiting.

The other options are less likely to be the primary cause of abdominal pain accompanied by elevated lactic acid in a post-cardiac surgery patient. Gastroenteritis generally presents with diarrhea and is not typically associated with significant increases in lactic acid levels. Pneumonia, while a common complication after surgery, usually presents with respiratory symptoms rather than isolated abdominal pain and does not directly cause elevated lactic acid derived from ischemia. Acute kidney injury may develop post-surgery as a result of various factors, but it typically doesn't present with abdominal symptoms