Lidocaine, an amide local anesthetic, has advantages of low price and easily obtaining. Intravenous lidocaine (IVL)initially has been used in the treatment of arrhythmia. It was demonstrated that IVL had analgesic effect, especially in colorectal surgery, but remained controversy in other types of surgeries. Other beneficial effects, such as prevention of hyperalgesia and propofol-induced injection pain, reduction of incidence of postoperative ileus and nausea and vomiting and anti-inflammatory also were proposed.

The most frequent drugs for procedural sedation and analgesia are propofol, benzodiazepines and opioids. However, these drugs may cause respiratory depression and circulatory instability. Combination will increase the risk of hypoxia and apnea.

In China, most anesthesia for hysteroscopy and gastroenteroscopy is procedural sedation and analgesia(PAS) provided by anesthetists. Foester et,al. have been tested that IVL could significantly reduce propofol requirements 、postoperative pain and fatigue scores in colonoscopy. Chen,et,al. find the same effect of IVL in elderly. However, there is no research reporting IVL used in hysteroscopy and diagnostic curettage. So, our main objective is to evaluate the effect of intravenous lidocaine on propofol requirements in patients undergoing hysteroscopy and diagnostic curettage.

Inclusion Criteria:

• Patients who underwent hysteroscopy and diagnostic curettage, American Society of Anesthesiologist' physical status 1-2, BMI 18.5-24.9 kg/m2,

Exclusion Criteria:

• Patients with known allergy to lidocaine or other local anesthetics, taken sedatives and analgesics within 1 week before surgery, mental and neurological diseases, hearing impairment, unwilling to sign informed consent or participate in the study, serious arrhythmia and organic heart disease.

Only female could undergo hysteroscopy and diagnostic curettage