Revised Evaluation of Hemodilution Response in the Semi-Closed Loop Infusion System

摘要

A mini volume loading test (mVLT) method is used for decision making in our prototype semi-closed loop infusion system (SCLIS). The mVLT fluid protocol consists of hemodilution response-guided mini fluid challenges. Each mini fluid challenge (MFC) consists of a 2.5 ml kg(-1)-5 ml kg(-1) crystalloid bolus infused over 2 min-5 min and followed by a 5 min period with no fluids. Arterial plasma dilution efficacy (aPDE) of a MFC is calculated from invasively measured hemoglobin (aHb) before and after each MFC. Capillary plasma dilution efficacy (cPDE) is calculated from non-invasively measured hemoglobin (SpHb). The zero or negative arterio-capillary plasmadilution efficacy difference (acPED <= 0 p.d.u.) is an indication of hemodilution non-response and imminent edema. However, it requires both invasive and non-invasive hemoglobin measurements. A non-invasive assessment of hemodilution response within the mVLT method would increase its practical application and reduce costs further enhancing its applicability in the SCLIS. This possibility exists if the cPDE could reliably predict the acPED value or the hemodilution response (the presence of acPED within a range of > 0) or non-response (acPED <= 0).