Injection rate threshold of triple-lumen central venous catheters: an in vitro study

Computed tomographic angiography (CTA) requires the rapid injection of contrast media ideally through an 18-gauge intravenous line in the antecubital fossa. Patients with CVCs undergoing CTA, however, are typically injected at low rates for two reasons: the potential for catheter failure and because of the lack of manufacturer recommendations for high injection rates typically used during CTA. The purpose of the study is to measure the injection rate thresholds of CVC. The results suggest that CVC can be used at high injection rates that are now typically used with peripheral intravenous catheters during CTA.

We used 16-cm-long catheters and 20-cm-long catheters in six groups (n = 5 for each catheter length). After the catheters were placed into a water bath, each group was injected at 5, 10, 15, 20, 25, and 30 ml/sec. New contrast, pressure tubing, and catheters were used for each test.

No catheter ruptures were encountered during the experiment, but there was one episode of power injector tubing rupture during the injection of a 16-cm catheter at an injection rate of 30 ml/sec.

No catheter failures were demonstrated in this study using injection rates well above those used in conventional CTA. Power injector tubing failure was demonstrated at an injection rate of 30 ml/sec, which generated mean pressures in the 16-cm catheters of 920 psi (tubing rating per manufacturer is 300 psi). This study demonstrated no catheter or injector tubing failure at injection rates of 5 to 25 ml/sec.