CCRN - Review Gastrointestinal and Renal Care Questions and Answers 1 — Questions and Answers
Question 1: A patient with end-stage liver disease is admitted with worsening confusion, lethargy, and asterixis. The serum ammonia level is elevated. The nurse anticipates administering lactulose. What is the primary therapeutic mechanism of action for this medication?
- It binds directly with ammonia in the bloodstream for renal excretion.
- It lowers colonic pH, trapping ammonia in the gut and promoting its excretion. (Correct answer)
- It stimulates the liver to increase its metabolism of ammonia into urea.
- It acts as a sedative to decrease the neurological effects of ammonia.
Correct answer: It lowers colonic pH, trapping ammonia in the gut and promoting its excretion.
Lactulose is a non-absorbable disaccharide that is metabolized by bacteria in the colon. This process produces lactic acid and other organic acids, which lowers the pH of the colon. The acidic environment promotes the conversion of absorbable ammonia (NH3) to non-absorbable ammonium (NH4+), effectively trapping it in the gut to be excreted in the stool.
Question 2: A patient is receiving continuous veno-venous hemofiltration (CVVH). The nurse notes a high pre-filter pressure alarm and observes that the transmembrane pressure (TMP) is also rising. Which of the following is the MOST likely cause of these alarms?
- A kink in the return line after the filter.
- Disconnection of the access catheter.
- Clotting or clogging of the hemofilter. (Correct answer)
- Hypotension in the patient.
Correct answer: Clotting or clogging of the hemofilter.
A high pre-filter pressure, especially when accompanied by a rising transmembrane pressure (TMP), is a classic sign of increased resistance to blood flow through the hemofilter itself. This is most commonly caused by the accumulation of protein and cellular debris (clogging) or the formation of clots within the filter fibers.
Question 3: A critical care nurse is monitoring a patient at high risk for abdominal compartment syndrome (ACS) following massive fluid resuscitation for trauma. According to the World Society of the Abdominal Compartment Syndrome (WSACS), ACS is defined as a sustained intra-abdominal pressure (IAP) greater than what threshold, accompanied by new organ dysfunction?
- 12 mmHg
- 16 mmHg
- 20 mmHg (Correct answer)
- 25 mmHg
Correct answer: 20 mmHg
The World Society of the Abdominal Compartment Syndrome (WSACS) defines abdominal compartment syndrome (ACS) as a sustained intra-abdominal pressure (IAP) greater than 20 mmHg that is associated with new organ dysfunction or failure. Intra-abdominal hypertension (IAH) is defined as a sustained IAP of 12 mmHg or greater.
Question 4: A patient is admitted to the ICU with acute upper gastrointestinal bleeding from ruptured esophageal varices. In addition to endoscopic intervention, which medication should the nurse anticipate administering as a continuous infusion to reduce splanchnic blood flow and portal pressure?
- Norepinephrine
- Octreotide (Correct answer)
- Pantoprazole
- Vasopressin
Correct answer: Octreotide
Octreotide, a synthetic analog of somatostatin, is a primary vasoactive medication used for acute variceal bleeding. It works by causing selective splanchnic vasoconstriction, which reduces blood flow to the portal system and decreases portal pressure without the significant systemic side effects of vasopressin.
Question 5: A patient with severe acute pancreatitis develops sudden, severe flank pain and ecchymosis around the left flank. The nurse recognizes this finding as Grey Turner's sign. This sign is indicative of which life-threatening complication?
- Peripancreatic abscess formation
- Ruptured pancreatic pseudocyst
- Splenic vein thrombosis
- Retroperitoneal hemorrhage (Correct answer)
Correct answer: Retroperitoneal hemorrhage
Grey Turner's sign (flank ecchymosis) and Cullen's sign (periumbilical ecchymosis) are clinical signs of retroperitoneal hemorrhage. In severe acute pancreatitis, inflammatory and enzymatic processes can erode blood vessels, leading to significant bleeding into the retroperitoneal space.
Question 6: A critical care nurse is evaluating laboratory results to determine the cause of a patient's acute kidney injury (AKI). Which set of findings is most consistent with a prerenal cause, such as hypovolemia?
- Urine sodium > 40 mEq/L, FENa > 2%
- BUN:Creatinine ratio of 10:1, FENa > 2%
- Urine sodium < 20 mEq/L, BUN:Creatinine ratio > 20:1 (Correct answer)
- Presence of muddy brown casts in urine, urine sodium > 40 mEq/L
Correct answer: Urine sodium < 20 mEq/L, BUN:Creatinine ratio > 20:1
In prerenal AKI, the kidneys are responding to decreased perfusion by avidly conserving sodium and water. This results in a low urine sodium concentration (<20 mEq/L), a high BUN to creatinine ratio (>20:1) due to passive reabsorption of urea with water, and a fractional excretion of sodium (FENa) typically less than 1%.
CCRN - Review Gastrointestinal and Renal Care Questions and Answers 1
A patient with end-stage liver disease is admitted with worsening confusion, lethargy, and asterixis.
The serum ammonia level is elevated.
The nurse anticipates administering lactulose.
What is the primary therapeutic mechanism of action for this medication?