The nurse is caring for a client with intestinal obstruction who presents with severe, colicky abdominal pain, nausea, vomiting, and abdominal distention. Which pathophysiologic mechanism supports the client's clinical presentation?

The client's symptoms, along with the elevated serum amylase and lipase levels, suggest the development of acute pancreatitis as a postoperative complication. Here's a detailed explanation for why option A is the correct choice:

A) Acute pancreatitis:

Correct. Acute pancreatitis is characterized by inflammation of the pancreas, which can be triggered by various factors, including gallstones, alcohol consumption, and certain medications. In this case, the client's recent cholecystectomy for cholelithiasis (gallstones) may have led to the development of acute pancreatitis. The persistent upper abdominal pain radiating to the back, along with vomiting and fever, are classic symptoms of acute pancreatitis. Elevated serum amylase and lipase levels are common laboratory findings in acute pancreatitis due to pancreatic cell injury and leakage of these enzymes into the bloodstream.

B) Surgical site infection:

While surgical site infections are potential complications of cholecystectomy, the client's symptoms, including upper abdominal pain, vomiting, and fever, are more indicative of a systemic inflammatory process rather than localized infection at the surgical site.

C) Hepatorenal failure:

Hepatorenal failure, also known as hepatorenal syndrome, refers to kidney dysfunction that occurs as a complication of advanced liver disease. The client's symptoms and laboratory findings are not consistent with hepatorenal failure, as there are no signs of significant liver dysfunction or advanced liver disease.

D) Biliary duct obstruction:

While biliary duct obstruction can lead to symptoms similar to those of acute pancreatitis, such as upper abdominal pain and vomiting, the presence of elevated serum amylase and lipase levels strongly suggests pancreatic involvement rather than isolated biliary duct obstruction.

The loop of Henle, a critical structure within the nephron of the kidney, plays a key role in the concentration of urine through the process of countercurrent multiplication. Here's why option D is the correct choice:

A) Calyx:

The calyx is a structure in the kidney that collects urine from the renal papillae and channels it into the renal pelvis. It does not directly participate in the concentration of urine.

B) Proximal convoluted tubule:

The proximal convoluted tubule primarily reabsorbs water, electrolytes, and nutrients from the glomerular filtrate, but it does not contribute significantly to the concentration of urine.

C) Renal pelvis:

The renal pelvis is a funnel-shaped structure that collects urine from the calyces and funnels it into the ureter. It is not directly involved in the concentration of urine.

D) The loop of Henle:

Correct. The loop of Henle is the nephron segment responsible for generating a hypertonic medullary interstitium, which creates the osmotic gradient necessary for urine concentration. The loop of Henle achieves this through countercurrent multiplication, where the descending limb allows passive reabsorption of water, while the ascending limb actively pumps out sodium and chloride ions. This creates an osmotic gradient that allows for further water reabsorption in the collecting ducts, leading to concentrated urine.