Critical
Care volume 29, Article number: 148 (2025) Published: 11
April 2025
Background
The tip design and length of catheter impact catheter
function. Two types of catheters with different tips, side-hole catheters and
step-tip catheters, are commonly used during continuous renal replacement
therapy (CRRT). However, there is insufficient evidence comparing their
efficacy and safety in CRRT. In addition, whether the insertion of a longer
catheter could enhance catheter function remains poorly studied and
controversial.
Methods
In this open-label, three-arm, randomized trial, critically
ill patients receiving CRRT were randomized to three groups. Group A received
20 cm side-hole catheters (GDHK‐1120), group B received 20 cm step-tip catheters (GDHK‐1320) and group C received 25 cm step-tip catheters (GDHK‐1325). The primary outcomes were
the incidence of catheter dysfunction and catheter survival time.
Results
A total of 351 patients were enrolled, with 116 in group A,
117 in group B, and 118 in group C. The incidence of catheter dysfunction in
group A (35.7%, 51/143) was significantly higher than that in group B (17.7%,
22/124) (P = 0.001). However, there was no
difference between group B and group C (15.6%, 23/147) (P = 0.744).
The catheter survival time was comparable between group A (5.5 days, IQR 2.5–9.3) and group
B (5.0 days, IQR 3.0–10.0) (P = 0.626).
In contrast, group C (6.4 days, IQR 3.9–12.0) demonstrated a significantly longer catheter survival time
compared to group B (P = 0.019). Cox regression analysis
identified BMI (HR 1.052, 95% CI 1.003–1.103, P = 0.036) as an independent risk
factor for catheter dysfunction. Results were not consistent across BMI
tertiles, with similar results observed only in patients with a lower BMI (BMI < 24.2) (chi-square 13.65, P = 0.001).
There was also a trend that patients in group C have a longer filter lifespan
(36.5 h, IQR 16.9–68.1, P = 0.001) and a lower incidence of
catheter-related thrombosis (10.40 per 1000 catheter-days, 95% CI 5.93, 17.83, P = 0.019). Other secondary outcomes
were not significantly different among groups.
Conclusions
Step-tip catheters may be preferable for CRRT, particularly
for patients in the lower BMI tercile. Longer femoral vein catheterization
demonstrated enhanced benefits in CRRT, especially among obese patients.
Further high-quality, multicenter RCTs are essential to strengthen the evidence
guiding catheter selection during CRRT.