Abstract
OBJECTIVE: To evaluate color flow Doppler flow ultrasound compared to standard clinical techniques, to detect the intravascular position of peripheral intravenous catheters in adult surgical patients. METHODS: A prospective study was conducted in adult (>18 years old) patients scheduled to undergo elective surgery. Peripheral intravenous catheter position was evaluated with standard clinical techniques (free flow of fluid from a hanging bag, easy saline injection, and aspiration of blood), and with color flow Doppler ultrasound proximal to the insertion site to identify intravascular catheter position. Comparative test performance was carried out. RESULTS: In total, 174 patients were enrolled. The venous catheter was deemed to be intravascular in 92.53% (n = 161) and 90.23% (n = 157) based on clinical evaluation and color flow Doppler, respectively (p = 0.206). Moderate to substantial agreement between the two approaches was found. Cohen's kappa was 0.64 (95% CI 0.43-0.83). Specificity of clinical judgment to detect catheter extravascular position was only 58.82%, when the color flow Doppler technique was set as the gold standard. Free flow from a hanging bag method showed the best agreement with color flow Doppler to determine intravascular position of a catheter (p = 0.3173, kappa = 0.68), with sensitivity of 98.09% and specificity of 64.71%. CONCLUSION: Color flow Doppler is a specific tool complementary to sensitive clinical indicators to detect peripheral venous catheter infiltration. The ability of color flow Doppler to accurately determine the position of a peripheral venous catheter depends on experience and familiarity with the tool by providers, who can master the technique with education and training.