Question

Mr. W., a 26-year-old man, entered the emergency department with complaints of fever, severe abdominal pain, and nausea. He denied any health problems but disclosed a daily intake of four to six beers per day. An abdominal computed tomography (CT) scan performed on admission revealed pancreatic inflammation and intraabdominal ascites. He was admitted to the step-down unit for the management of acute pancreatitis. His treatment plan included intravenous antibiotics, pain control, and management of alcohol withdrawal. Within 48 hours of admission to the hospital, Mr. W. developed tachycardia (heart rate 120 beats per minute), hypotension (blood pressure 88/46 mm Hg), and tachypnea (respiratory rate 30 breaths per minute) and a temperature of 38.5° C. Arterial blood gases results were pH 7.20; partial pressure of arterial oxygen (PaO2) 78 mm Hg; partial pressure of arterial carbon dioxide (PaCO2) 28 mm Hg; and bicarbonate 18 mEq/L. He was intubated for acute respiratory distress syndrome (ARDS) and transferred to the critical care unit. Prone positioning and pressure control ventilation were initiated for the management of hypoxemia. Mr. W. required repeated fluid boluses and the titration of vasoactive infusions to achieve hemodynamic stability. A second CT scan of the abdomen revealed extensive edema and necrosis of the pancreas. Intraabdominal pressure was measured at 17 mm Hg. During the first 48 hours of admission to the critical care unit, urine output ranged from 10 to 20 mL per hour or greater than 0.5 mL/kg/hr. His serum potassium level was 6.3 mEq/L, and his creatinine level had risen to 3.8 mg/dL (admission creatinine level was 0.9 mg/dL). The renal medical service was consulted for management of acute kidney injury. Continuous venovenous hemofiltration was initiated and continued for 5 days. The patient was extubated on day 14 and transferred to the step-down unit on day 20.

1. What are the factors that predispose Mr. W. to acute kidney injury?

2. Acute kidney injury can be classified as prerenal, intrarenal, or postrenal. Select the classification that best describes Mr. W.’s acute kidney injury, and provide rationale for your selection.

3. The physician requested intraabdominal pressure measurements. Why is this measurement important in the evaluation of acute kidney injury?

4. Discuss the benefits of continuous venovenous hemofiltration (CVVH) in the management of Mr. W.’s acute kidney injury.

5. On hospital day 20, a third CT scan of the abdomen was requested by the treatment team. What precautions need to be considered to prevent or minimize further kidney injury?

Answer 1

1. ANS: The daily intake of 4 to 6 cans of beers, having an inflamed pancreas and abdominal ascites, and possibly being septic.

2. ANS: Prerenal due to the fluid shifting into the abdominal area because of the inflamed pancreas and ascites.

3. ANS: The combination of elevated abdominal pressure and the adverse physiological effects that develop is known as abdominal compartment syndrome (ACS). This condition can occur because of the patient's sepsis, pancretitis, and ascites. ACS can cause reduction in cardiac output, impaired ventilation and with a continued increase can lead to organ failure and death.

4. ANS: CVVH is a renal replacement therapy that is used to treat acute kidney injury (AKI). During hemofiltration a patientt blood is passed through a set of tubing via a machine to a semipermeable membrane, or filter. where waste products and water are removed by convection. Replacement fluid is added and the blood a returned to the patient.

5. ANS: The kidneys must be protected from the IV contrast. It is recommended that patient's with impaired kidney function received IV fluids 3 to 12 hours prior to the scan and or at least 6 hours after with hourly I/0's. Labs such as BUN. Creatinine and GFR should also be done prior to the CT to evaluate the patient's current kidney function.

Reference:

Sole ML, Klein DG, Moseley MJ: Introduction to critical care nursing, ed 5, St Louis Saunders.