Optimizing Ultrasound Methods for Determining Central Venous Catheter Tip Position.

Abstract

Background: In clinical practice, physicians hope to find better techniques for rapidly determining central venous catheter positions.

Objectives: This study aimed to investigate the advantages and disadvantages of using various ultrasound techniques to judge the tip positions of central venous catheters and to explore the specific application conditions of various ultrasound techniques.

Methods: We selected 194 patients with central venous catheterization admitted to our hospital. Vascular and cardiac ultrasound (CVUS), contrast-enhanced ultrasonography (CEUS), and the "flush the line and ultrasound the heart" (FLUSH) test were used to determine the central venous catheter tip position. We analyzed the ultrasound techniques' diagnostic accuracy and advantages.

Results: When locating the central venous catheter tip, chest radiography (CXR) took 72.1 ± 32.3 min whereas CVUS, CEUS, and the FLUSH test took 3.7 ± 0.9 min, 6.7 ± 2.3 min, and 6.0 ± 1.8 min, respectively. The time required for ultrasound examinations differed significantly from that for CXR (p < 0.01). Using CXR as the gold standard, CVUS had a sensitivity of 100% (95% confidence interval [CI]: 97.3%-100%) and a specificity of 68.4% (95% CI: 43.5%-86.4%). CEUS and the FLUSH test yielded consistent results (sensitivity: 100% [95% CI: 97.3%-100%]; specificity: 84.2% [95% CI: 59.5%-95.8%]).

Conclusion: The FLUSH test, which does not require contrast medium injection, offered higher result accuracies, making it promising for clinical practice. CEUS is recommended more for determining catheter position when the patient is not a good candidate for repeated fluid pushing or when the ultrasound image is not clear.