American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the preferred catheter type to use for continuous renal replacement therapy (CRRT)?

1. Single-lumen catheter

2. Double-lumen catheter

3. Triple-lumen catheter

4. Peripherally inserted central catheter (PICC)

The correct answer is: Double-lumen catheter

The preferred catheter type for continuous renal replacement therapy (CRRT) is a double-lumen catheter. This type of catheter is designed specifically to facilitate concurrent blood inflow and outflow, which is essential in CRRT to ensure effective blood purification. In CRRT, one lumen is used for the withdrawal of blood from the patient, while the other lumen allows for the return of treated blood back into the circulation. This dual-lumen design not only maximizes blood flow rates, which are critical for the efficacy of the therapy, but also minimizes the risk of recirculation of the filtered blood, ensuring that the treatment remains effective. While single-lumen and triple-lumen catheters are available, they are not as effective as double-lumen catheters for this specific application. A single-lumen catheter would be inadequate for the simultaneous withdrawal and return of blood, making it unsuitable for continuously running therapies like CRRT. A triple-lumen catheter, although it allows for multiple access points, does not inherently provide the same efficiency in blood flow for the specific needs of CRRT. Additionally, a peripherally inserted central catheter (PICC) may have its uses in various medical applications, but its design does not optimize the flow rates for