The Efficacy and the Safety of Dexmedetomidine Sedation on the Pediatric Intensive Unit(PICU) Patients.

The Efficacy and the Safety of Dexmedetomidine Sedation on the PICU Patients-A Randomized, Controlled Study.

To observe the efficacy and safety of dexmedetomidine sedation on the patients admitted to the pediatric intensive care unit after surgery.

Inclusion Criteria:

1. written informed consent；
2. pediatric patients admitted to intensive care unit after general anesthesia;
3. expected mechanical ventilation time >6 hours; （4）1 months to 16 years old; -

Exclusion Criteria:

1. congenital heart disease, arrhythmias and heart failure;
2. Alanine transaminase（ALT） and (or) Aspartate aminotransferase（AST） level is more than twice the upper limit of normal;
3. Creatinine and (or) Blood urea nitrogen（BUN） is more than the upper limit of normal;
4. central nervous system disease;
5. spinal analgesia or muscle relaxants is used during PICU;
6. the drug that affects the nerve conduction is used in one month;
7. allergy to the test drug or having other contraindications;
8. participated in other studies 30 days prior to admission of PICU; -