Please assess the completion status of the following clinical trial:

Trial Title: Effect of Dexmedetomidine on Parturient Undergoing Elective Cesarean Section.

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: PREVENTION
- Time Perspective: None
- Masking: TRIPLE
- Phase: PHASE4
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~1. ASA class I or II~2. BMI≦35kg/m2~3. Greater than 37 weeks gestation~4. Expressed a desire to breastfeed for a least 3 months postpartum~5. Elective cesarean section~Exclusion Criteria:~1. Intraspinal anesthesia contraindication~2. Twin or fetal Intrauterine distress~3. Preoperative history of application of analgesia or sedative drug~4. Severe cardiac and pulmonary dysfunction~5. History of neurological and psychiatric diseases

- Gender: FEMALE
- Minimum Age: 20 Years
- Maximum Age: 40 Years
- Healthy Volunteers: f

Study Arms:
- dexmedetomidine group (Type: EXPERIMENTAL): After umbilical cord was cut, a loading dose of dexmedetomidine was pumped at 0.5ug/kg within 10min, followed by a further infusion of dexmedetomidine at 0.5ug /kg/h until the end of the surgery.Then connected with patient-controlled intravenous analgesia pump (dexmedetomidine 2ug/kg + sufentanil 1.5ug/kg + dolasetron 25mg/100ml saline).
- control group (Type: PLACEBO_COMPARATOR): Continuous infusion of saline after the umbilical cord was cut until the end of the operation.Then connected with patient-controlled intravenous analgesia pump (sufentanil 1.5ug/kg + dolasetron 25mg/100ml saline).

Based on this trial design, predict the completion outcome and termination type (if applicable).