Abstract: Objective To observe the respiratory depression of sufentanil with target-controlled infusion under propofol sedation or not.Methods40 patients, ASAⅠ or Ⅱ, scheduled for selective neurosurgery were randomly divided into the sufentanil group (group S) and the combined group (group SP) with 20 cases in each group. In the group SP, sedation was maintained with target-controlled infusion of propofol by plasmas concentration of 2 μg/ml. Target-controlled infusion of sufentanil was performed at the initial plasma concentration (Cp) of 0.2 ng/ml, and increased in a increment of 0.2 ng/ml at 3 minutes interval; while in the group S, only the infusion of sufentanil was performed. The respiratory rate (RR), minute ventilation (MV), partial pressure of end-tidal carbondioxide (PETCO₂), pulse oxygen saturation (SpO₂), mean arterial pressure (MAP), heart rate (HR), Observer's Assessment of Alertness/Sedation (OAA/S) were measured and respiratory depression was defined as one of the following end points were achieved: muscle rigidity, RR<6 bpm, MV<3 L/min, PETCO₂>55 mmHg, SpO₂<90% or apnea>15 s.ResultsThe RR, MV of patients in two groups decreased and PETCO₂ increased significantly as increase of Ce ( P<0.05). The calculated effect site concentration (Ce) of sufentanil for respiratory depression was (0.46±0.14)ng/ml in the group S and (0.23±0.06)ng/ml in the group SP having a significant difference between two groups ( P<0.01).ConclusionSufentanil can dose-dependently suppress spontaneous respiration.

Key words: sufentanil, propofol, target-controlled infusion, respiratory depression