The influence of cardiac output on propofol and fentanyl pharmacokinetics and pharmacodynamics in patients undergoing abdominal aortic surgery

Figures

• 

  Fig. 1. The proposed PK/PD model of propofol, fentanyl, CO and BIS

• 

  Fig. 2. The individual propofol PK, fentanyl PK, BIS and CO time profiles. The dots represent raw measurements. They are connected with straight lines

• 

  Fig. 3. Goodness-of-fit plots for the final PK/PD model: the observed versus the population predicted responses, the observed versus the individual predicted responses, the conditional weighted residuals (CWRES) versus the individual predicted responses, and the CWRES versus time

• 

  Fig. 4. The prediction-corrected VPC plots for the final PK/PD. The VPC plots show the simulation-based 90% confidence intervals around the 10th, 50th, and 90th percentiles of the PK data in the form of blue (50th) and gray (10th and 90th) areas. The corresponding percentiles from the prediction corrected observed data are plotted in black color

• 

  Fig. 5. Relationship between the rate of CO output changes versus age and study number for all patients included in the study

• 

  Fig. 6. Context-sensitive effect-site decrement times (CSDT) for propofol-fentanyl infusions showing the time for decreasing the effect-site concentrations of a given percentage (20–80%) from the maintained effect-site concentration after propofol/fentanyl infusion cessations for subjects of different age. The solid and dashed lines corresponds to study I and study II predictions. The propofol and fentanyl biophase concentrations were kept at 3.0 mg/l and 1.5 ng/ml respectively for 200 min, which corresponds to the BIS values of about 35. CSDT of 80%, 70%, …, 20% corresponds to achieving a BIS values of 77, 68, 61, 55, 50, 46, 43