Evaluation of the Effect of Different Types of Extended Infusion Lines on Pulse Contour-based Measurements Based on the Arterial Pressure Signal

Brief Summary

Detailed Description

Hemodynamic continuous monitoring of critically-ill patients is increasingly performed with minimally-invasive methods, such as the proAQT sensor (PULSION Medical Systems SE, Munich, Germany). The proAQT sensor calculates hemodynamic variables such as the cardiac output, stroke volume (variation), pulse-pressure variation and systemic vascular resistance by pulse contour analysis of the arterial pressure waveform using an arterial radial or femoral catheter. This minimal invasive technique, also permits continuous beat-to-beat assessment. In patients in who an arterial catheter is placed for clinical reasons, the hemodynamic variables are continuously recorded. An extension line is coupled to a 3-way stopcock, connected to the proAQT sensor. In a neutral position of the 3-way stopcock, the pressure wave travels from the pressure sensor through the standard line. By turning the handle of the stopcock the standard line is bypassed and the pressure wave travels through the extended line. The hemodynamic registration will be as follows: * two minutes in the neutral position; * two minutes with one type of extension line * two minutes in the neutral position * two minutes with a second type of extension line * two minutes in neutral position The arterial pressure curve and all calculated hemodynamic variables are electronically registered. The influence of two types of extension lines on the accuracy of the calculated hemodynamic variables will be evaluated by comparing the variables measured in neutral position and variables measured with the extended pressure lines. The changes in the calculated variables will be correlated to possible arterial pressure waveform modifications and used to evaluate different algorithms, which might be used to reconstruct the primary pressure wave.

Primary Outcomes

Secondary Outcomes

• change in Area Under the Curve (AUC) of the arterial pressure wave form after placement of extension lines.(one minute of measurement after changing the length of the extension line.)
• relative change in ProAQT-calculated SVR after placement of extension lines.(one minute of measurement after changing the length of the extension line.)
• relative change in ProAQT-calculated diastolic blood pressure after placement of extension lines.(one minute of measurement after changing the length of the extension line.)
• relative change in ProAQT-calculated systolic blood pressure after placement of extension lines.(one minute of measurement after changing the length of the extension line.)
• relative change in ProAQT-calculated stroke volume variation after placement of extension lines.(one minute of measurement after changing the length of the extension line.)
• relative change in ProAQT-calculated pulse pressure variation after placement of extension lines.(one minute of measurement after changing the length of the extension line.)