Figure 5. The individual minute ventilation determinations as a function of blood remifentanil concentration in the subjects with liver disease (A) and the control subjects (B). Each dashed line represents the data from one subject, and the heavy lines represent the minute ventilation versus remifentanil curve predicted by the model. The subjects with liver disease had an EC50value of 1.56 ng/ml (95% confidence interval 1.37-1.76 ng/ml). The control subjects had an EC50value of 2.52 ng/ml (95% confidence interval 2.07-2.97 ng/ml).