From the Guidelines
I would recommend proceeding with the contrast-enhanced CT scan for this 88-year-old male patient without repeating labs first, as the benefits of prompt diagnosis and treatment may outweigh the risks of contrast-induced acute kidney injury (CI-AKI) 1. The lab results from two weeks ago show a creatinine of 1.16 mg/dL, elevated BUN of 55 mg/dL, and a GFR of 60.6 mL/min/1.73m², which indicates borderline renal function. However, recent studies have shown that the risk of CI-AKI may be lower than previously thought, especially with the use of low-osmolal contrast agents and proper hydration 1. Some key points to consider:
- The patient's age and renal function do not necessarily preclude the use of contrast-enhanced CT scans 1.
- The use of contrast media can be beneficial in diagnosing and treating conditions such as diverticulitis, which is common in elderly patients 1.
- Proper hydration and the use of low-osmolal contrast agents can minimize the risk of CI-AKI 1.
- Non-contrast CT or alternative imaging modalities such as ultrasound or MRI may not provide the same level of diagnostic accuracy as contrast-enhanced CT scans 1. It is essential to weigh the potential benefits and risks of contrast-enhanced CT scans in this patient and to take steps to minimize the risk of CI-AKI, such as ensuring proper hydration and using the minimum necessary contrast dose.
From the Research
Patient's Current Condition
- The patient is an 88-year-old male with a BMI of 22.3.
- Lab results from two weeks ago: Cr 1.16, BUN 55, GFR 60.6.
Risk of Contrast-Induced Nephropathy (CIN)
- According to 2, the incidence of CIN has been reported to range from 0% to 24%, and it is usually transient.
- A study by 3 found that the overall incidence of CIN in patients with renal insufficiency was 6.1%, with no significant difference in the incidence of CIN compared to patients who did not receive contrast medium.
- Another study by 4 reported a CIN incidence of 5.1% in patients with renal dysfunction, and found that cardiac dysfunction and ICU admission were associated with an increased risk of CIN.
Considerations for CT with Contrast
- 5 suggests that minimizing the amount of contrast administered and providing adequate hydration are key to preventing CIN.
- 6 notes that the true risk of CIN after intravenous contrast media administration is debatable, and that new studies have challenged the paradigm that CIN is a common occurrence with dire consequences.
Decision to Repeat Labs or Proceed with CT with Contrast
- Given the patient's current GFR of 60.6, which is considered mild renal insufficiency, the risk of CIN may be relatively low, as suggested by 3.
- However, the patient's age and potential comorbidities should be taken into consideration when deciding whether to repeat labs or proceed with the CT with contrast, as recommended by 2 and 5.