Evaluation of Impulse-Oscillometric Extravasation Prevention

Infusion liquid extravasation occurs in up to 6% of all intensive care patients and up to 78% for neonates. Currently, emerging extravasation cannot be detected. An impulse-oscillometric method to detect the onset of extravasation is tested and evaluated in vitro. A pinch valve compresses the infusion line, an impulse is formed, and the pressure response is recorded at the peripheral vein catheter. The response of this catheter-sensor-system is analysed by measuring the transient-step response (n = 10) for an opened and closed pinch valve. Trials utilising porcine shanks (n = 15) are performed with venous and extravasational catheter placement. The fundamental frequency, maximum amplitude, damping and decay constant of the pressure response are tested for differences between venous and extravasational placement. The response of the catheter-sensor-system shows no significant differences between an opened or closed pinch valve. The maximum amplitude, frequency, damping and decay constant of the pressure response differ highly significant for venous and extravasational catheter placement (p < .001). The parameters also differ depending on the presence of infusion liquid flow (p < .001). The method enables the detection of the onset of extravasation. Further tests are performed to investigate the relationships between impulse response and hydraulic impedance.