To Explore the Optimal Dose of Dexmedetomidine for Skull Pin Fixation in Intracranial Surgery

The first patient was started on dexmedetomidine Cp 0.4 ng/ml, 2 minutes before the procedure, and the up and down method was used, with the Cp of dexmedetomidine adjusted to 0.05 ng/ml each time. The analgesia nociception index (ANI) during skull pin fixation is lower than (\<) 30 and the heart rate (HR) and arterial blood pressure (ABP) exceed (\>) 20% of the baseline (or the HR is \>100 bpm and the ABP is \>180/100 mmHg), indicating insufficient analgesia or hemodynamics (failure). If the patient is failure for the procedure, increase the Cp by 0.05 ng/ml for the next patient; the ANI is higher than or equal to (≥30) and the HR and ABP do not exceed 20% of the baseline or the HR is ≤100 bpm and the ABP is ≤180 /100 mmHg) indicates that the analgesia and hemodynamic stability are acceptable (success), and the next patient will be adjusted downward by 0.05 ng/ml.