A Prospective, Multi-center, Randomized Controlled Study of Muscle Relaxation Effect and Safety of Mivacurium Chloride in Pediatric Surgery Patients

Inclusion Criteria: * The parent/guardian must sign a parental permission consent document * American Society of Anesthesiologists (ASA) physical status class 1-3 * Elective surgery patients with tracheal intubation, and the operation duration is expected to be longer than 30 min but no longer than 120 min(cleft lip and palate, orthopedic, bilateral hernia, bilateral cryptorchidism, hypospadias crack, and other ear, nose and throat surgery, etc) * Age between 2 months to 14 Years Exclusion Criteria: * BMI\<18kg/m2 or BMI\>31kg/m2 * Patients with serious respiratory, cardiovascular disease, and liver and kidney dysfunction\[AST（glutamic oxalacetic transaminase）,ALT(glutamic-pyruvic transaminase)\>1.5 Normal;BUN(blood urea nitrogen)\>Normal)\] * Patients with asthma or airway hyperresponsiveness, neuromuscular patients disease or cachexia * Preoperative hemoglobin less than 10g/L * Hypoproteinemia TP（total protein) \<45g/L * Diabetic patients * Patients with difficulty airway * Patients with Known or suspected atypical plasma cholinesterase gene homozygous * Burn patients * Patients with serious acid-base imbalances, or severe electrolyte imbalance * Patients with neuromuscular relaxants in a week * Patients prohibited with muscle relaxants, or allergy to any component of mivacurium * Patients participated in any drug clinical trial with 30 days before the start of the study * Other situations not suitable for inclusion * Blood loss more than 10 ml/kg in surgery