What is the approach for a patient with suspected ischemic Acute Tubular Necrosis (ATN), newly diagnosed hepatocellular carcinoma, and possible chronic Gastrointestinal (GI) bleed, presenting with oliguric Acute Kidney Injury (AKI) and impaired renal function, where abdominal imaging is suggested but contrast study is contraindicated due to elevated creatinine levels?

From the Guidelines

Perform a non-contrast abdominal MRI to evaluate the hepatocellular carcinoma and potential GI bleed source while avoiding further kidney injury.

Specific Steps:

• Order a non-contrast MRI of the abdomen and pelvis.
• Ensure proper hydration before and after the MRI procedure.
• Monitor urine output closely, aiming for >0.5 mL/kg/hour.
• Check serum creatinine daily to track kidney function.

Additional Information:

• Avoid nephrotoxic medications, including NSAIDs and certain antibiotics.
• Consider consulting nephrology for management of the acute kidney injury.
• If MRI is not available, a non-contrast CT could be an alternative, though less ideal for soft tissue evaluation.

Justification:

Non-contrast MRI provides detailed imaging of abdominal organs without the risk of contrast-induced nephropathy, as highlighted in the ACR Appropriateness Criteria for renal failure 1. This approach allows for evaluation of the hepatocellular carcinoma and potential GI bleed sources while protecting the already compromised kidneys. MRI offers better soft tissue contrast than non-contrast CT, making it more suitable for assessing liver lesions and potential sources of GI bleeding. The combination of ischemic acute tubular necrosis (ATN) and oliguric acute kidney injury (AKI) necessitates avoiding further insults to the kidneys, such as iodinated contrast, which could worsen renal function. The AGA clinical practice update on the evaluation and management of acute kidney injury in patients with cirrhosis also supports the use of non-contrast imaging to avoid further kidney injury 1.

From the Research

Approach to Patient Care

The patient presents with suspected ischemic Acute Tubular Necrosis (ATN), newly diagnosed hepatocellular carcinoma, and possible chronic Gastrointestinal (GI) bleed, along with oliguric Acute Kidney Injury (AKI) and impaired renal function. Given the contraindication of contrast studies due to elevated creatinine levels, the approach to care should focus on alternative diagnostic methods and management strategies.

Diagnostic Considerations

• Abdominal imaging without contrast can be considered to evaluate the patient's condition, taking into account the newly diagnosed hepatocellular carcinoma and possible chronic GI bleed.
• The use of non-contrast computed tomography (CT) or magnetic resonance imaging (MRI) may provide valuable information without the risk of contrast-associated acute kidney injury (CA-AKI) 2.
• Ultrasound can also be a useful diagnostic tool in this scenario, especially for evaluating the liver and detecting any potential obstructions.

Management Strategies

• The patient's oliguric AKI and impaired renal function require careful management, with a focus on optimizing fluid balance and avoiding nephrotoxic agents.
• The 'ABCDE' checklist (Address drugs, Boost blood pressure, Calculate fluid balance, Dip urine, Exclude obstruction) can be a useful tool in guiding the management of AKI 3.
• Multidisciplinary education and teamwork are essential in recognizing and managing AKI, as demonstrated by improved outcomes in studies where these approaches were implemented 3.

Risk Factor Assessment

• The patient's risk factors for CA-AKI, such as elevated creatinine levels and possible chronic kidney disease, should be carefully assessed and managed.
• The use of risk factor scores and preventive measures, such as adequate hydration and avoiding nephrotoxic drugs, can help minimize the risk of CA-AKI 2.
• The patient's overall clinical condition, including the presence of hepatocellular carcinoma and possible chronic GI bleed, should be taken into account when assessing risk factors and developing a management plan.

Monitoring and Follow-up

• Close monitoring of the patient's renal function, urine output, and overall clinical condition is essential in managing AKI and preventing further complications.
• Regular follow-up and reassessment of the patient's condition can help guide adjustments to the management plan and ensure optimal outcomes.