Figure 1.

Response surface for inhibiting the haemodynamic response to endotracheal intubation. The raw data, model predictions and an assessment of model error were demonstrated. The circles represent the observed responses of patients. The circle at the bottom of the response surface represents the response to endotracheal intubation, and the circle at the top indicates no response. Prediction accuracy was defined as < .5 deviations from the true patient response. The red circle indicates the accurate prediction and the blue one indicates the inaccurate prediction. The size of the circle reflects the number of patients. There are 5 different sizes of circles, which represent the number of patients from 1 to 5. Abbreviations: Dex, dexmedetomidine. Suf, sufentanil.