Correlation of preoperative pain threshold and pain tolerance threshold with the intensity of stress reaction induced by endotracheal intubation and skin incision

Abstract

Objective To investigate the correlation of preoperative pain threshold and pain tolerance threshold with the intensity of stress reaction induced by endotracheal intubation and skin incision. Methods Fifty ASA Ⅰ or Ⅱ women, aged 20-55 yr, undergoing elective abdominal surgery requiring at least a 10-cm-long skin incision under general anesthesia, were studied. The electricity dolorimeter was used to measure the patients＇ pain sensitivity, including pain threshold and pain tolerance, and a State Trait Anxiety Inventory （STAI） was also used to examine the mental state the day before surgery. Total intravenous anesthesia was performed in all the patients.Anesthesia was induced with TCI of propofol 4 μg/ml （effect-site concentration）. After patients lost consciousness,fentanyl 3 μg/kg and vecuronium 0.1 mg/kg were injected intravenously. Tracheal intubation was performed 3 min later and the patients were mechanically ventilated. MAP and HR were recorded and arterial blood samples were taken for determinvress reaction induced by endotracheal intubation and skin incision, but there is no correlation between pain threshold and the intensity of stress reaction. Key words: Pain threshold; Stress; Intubation,intratracheal