Please assess the completion status of the following clinical trial:

Trial Title: Low-dose S-ketamine and Dexmedetomidine in Combination With Opioids for Postoperative Analgesia

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

Eligibility Criteria:
Inclusion Criteria:~* Age ≥ 18 years old, body weight ≥ 40 kg;~* Scheduled to undergo scoliosis correction with pedicle screw fixation;~* Planned to use patient-controlled intravenous analgesia after surgery.~Exclusion Criteria:~* Refused to participate in the study;~* Preoperative sick sinus syndrome, severe sinus bradycardia (heart rate \< 50 beats/min), atrioventricular block grade II or above without pacemaker; or comorbid with congenital heart disease, arrhythmia, or other serious cardiovascular diseases with a cardiac function grade ≥ III;~* Patients with obstructive sleep apnea syndrome, or a STOP-Bang score ≥ 3 in combination with a serum HCO3- level ≥ 28 mmol/L;~* History of hyperthyroidism and pheochromocytoma;~* History of schizophrenia, epilepsy, myasthenia gravis, or delirium;~* Severe liver dysfunction (child Pugh grade C), severe renal dysfunction (preoperative dialysis), or American Society of Anesthesiologists grade ≥ IV;~* Barrier in communication;~* Other conditions that are considered unsuitable for study participation.

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Combined analgesia group (Type: EXPERIMENTAL): Patient-controlled analgesia is established with S-ketamine 50 mg, dexmedetomidine 200 microgram, and sufentanil 4 microgram/kg (maximum 250 microgram), diluted with normal saline to 200 ml, and programmed to administer 2-ml boluses with a lock-out interval of 8 minutes and a background infusion rate at 1 ml/h.
- Control group (Type: PLACEBO_COMPARATOR): Patient-controlled analgesia is established with sufentanil 4 microgram/kg (maximum 250 microgram), diluted with normal saline to 200 ml, and programmed to administer 2-ml boluses with a lock-out interval of 8 minutes and a background infusion rate at 1 ml/h.

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