Hemoglobin in arteries (invasive, aHb) and capillaries (non-invasive, SpHb) are used to calculate the arterial and capillary plasma dilution efficacies (aPDE and cPDE, respectively) and arteriocapillary plasmadilution efficacy difference (acPED) , .
The secondary objective was to investigate the feasibility of a statistical optimization method (SOM) in predicting the acPED using the measured cPDE.
The cPDE and acPED were obtained in 48 subjects who had two mVLT sessions--before the induction of anesthesia (preoperative session) and again 24 hours later (post-operative).
Thus, there were 480 paired values of cPDE and acPED from 96 mVLT sessions.
3) was created to assess the discriminative power of cPDE to predict the presence of the acPED value within a range of hemodilution non-response (acPED [less than or equal to] 0).
We used the SOM as an alternative method for predicting hemodilution response by calculating the predicted acPED.
Statistical Optimization Method (SOM) The SOM was based on the inverse relationship between cPDE and acPED in individual patient's records (Fig.
The SOM was applied to calculate the predicted acPED value ([acPEDs.sub.om]) from the non-invasively measured (actual) cPDE by using two approaches:
The proportion of hemodilution response patterns was compared between the actual (based on the measured acPED) and the predicted (based on the calculated acPEDsom and [acPED.sub.of]) hemodilution responses.
We analyzed cPDE and acPED records, 480 values of each.
The actual acPED [less than or equal to] 0 (p.d.u.) was found in 296 (61.7 %) of the mini fluid challenges defined as non-responders.
There was no difference between the proportions of response patterns in pre- and post-operative mVLT sessions: there were 82 pre-operative MFCs with acPED [less than or equal to] 0 and 158 with acPED > 0 while there were 102 post-operative MFCs with acPED [less than or equal to] 0 and 138 with acPED > 0 (P = 0.074).