Dexmedetomidine-esketamine Combination and Moderate-to-severe Pain After Spinal Surgery

Official title

Effect of Perioperative Use of Dexmedetomidine-esketamine Combination on Incidence of Moderate-to-severe Pain After Spinal Surgery: a Randomized Controlled Trial

Overview

Spinal surgery is generally followed by severe postoperative pain, and poor pain control may cause adverse outcomes such as cardiovascular events, neurocognitive disorders, and chronic postsurgical pain (CPSP). In previous studies, perioperative use of dexmedetomidine or esketamine is each associated with improved analgesia after surgery. Recent studies suggest that combined use of dexmedetomidine and esketamine may produce synergetic effects in improving analgesia. This trial is designed to test the hypothesis that perioperative combined use of dexmedetomidine and esketamine may improve analgesia and reduce moderate-to-severe pain in patients after spinal surgery.

Detailed description

Spinal surgery is genrally followed by severe pain due to extensive trauma. The reported rate of moderate-to-severe pain ranged from 30% to 63%. Uncontrolled postoperative pain is associated with worse outcomes including cardiovascular events, neurocognitive complications, and chronic postsurgical pain. Opioids are the main stay of analgesia after spinal surgery. However, high dose opioids provoke side effects such as nausea and vomiting, delirium, and even respiratory depression. Multimodel analgesia is suggested for these patients.

Dexmedetomidine is a highly selective alpha 2 adrenergic receptor agonist with sedative, analgesic, and anxiolytic effects. A meta-analysis suggest that, for patients undergoing spinal surgery, intraoperative dexmedetomidine improved early postoperative analgesia, but the effect did not persist beyond 6 hours. Ketamine is a noncompetitive N-Methyl-D-aspartic acid (NMDA) receptor antagonist and has been used as an anesthetic and analgesic for decades. Esketamine is the S-enantiomer of ketamine and has an analgesic potent of approximately 2 times of that of ketamine. Small sample size studies in patients undergoing spinal surgery showed that intra- or postoperative use of subanesthetic dose esketamine improved analgesia and reduced rescue analgesics.

The analgesic effects of dexmedetomidine and esketamine are dose-dependent. However, routine dose dexmedetomidine may increase bradycardia and hypotension, and even subanethetic dose esketamine may produce neuropsychiatric symptoms. Combined use of dexmedetomdine and esketamine may augment analgesic and sedative effects while decreasing side effects. In a previous study, using low-dose dexmedetomidine (1 ug/ml) and esketamine (0.25 mg/ml) as supplements to self-controlled sufentanil analgesia improved pain relief and sleep quality after spinal surgery, but the rate of moderate-to-severe pain remained high. In a recent study, when used as a supplement to sufentanil analgesia, increasing esketamine dose to 0.5 mg/ml did not significantly improve analgesia, whereas increasing esketamine dose to 0.75 mg/ml increased nausea and vomiting.

In available studies, use of dexmedetomidine and/or esketamine were mostly limited to either intra- or postoperative period. Introperative use of the combination only improve early postoperative analgesia. Whereas postoperative use of the combination did not have effects on peak intraoperative stress. It is reasonable to hypothesize that using dexmedetomidine-esketamine combination during both the intra- and postoperative periods may provide better analgesia in patients after spinal surgery.

Interventions

• Drug Combined dexmedetomidine-esketamine administration
  During anesthesia, a loading dose (0.2 ml/kg) of dexmedetomidine-esketamine (DEX-ESK) combination (DEX 2 ug/ml; ESK 1 mg/ml) will be infused after anesthesia induction (DEX 0.4 ug/kg; ESK 0.2 mg/kg), followed by a continuous infusion at 0.1 ml/kg/h (DEX 0.2 ug/kg/h; ESK 0.1 mg/kg/h) until 1 hour before the expected end of surgery. After surgery, patient-controlled intravenous analgesia will be established with dexmedetomidine (DEX 1.5 ug/ml), esketamine (ESK 0.5 mg/ml), and sufentanil (1.25 ug/
• Drug Placebo administration
  During anesthesia, a loading dose (0.2 ml/kg) of normal saline will be infused after anesthesia induction, followed by a continuous infusion at 0.1 ml/kg/h until 1 hour before the expected end of surgery. After surgery, patient-controlled intravenous analgesia will be established with sufentanil (1.25 ug/ml), programmed to deliver 2-ml boluses (sufentanil 2.5 ug) with a 8-10-minute lockout interval and a 1-ml/h (sufentanil 1.25 ug/h) background infusion, and used for up to 48 hours.

Primary outcome measures

• Incidence of moderate-to-severe pain within 72 hours after surgery [Time frame: Up to 72 hours after surgery]

Secondary outcome measures (2)

• Incidence of delayed neurocognitive recovery at postoperative day 5 [Time frame: Up to 5 days after surgery]
• Incidence of cardiovascular events within 30 days after surgery [Time frame: Up to 30 days after surgery]

Eligibility criteria

Inclusion criteria

• Aged >= 40 years but < 80 years;
• Scheduled to undergo elective posterior cervical, thoracic, or lumbar spine surgery with an expected duration >= 2 hours under general anesthesia;
• Required patient-controlled intravenous analgesia (PCIA) after surgery.

Exclusion criteria

• Uncontrolled preoperative hypertension (ward systolic blood pressure > 180 mmHg or diastolic blood pressure > 110 mmHg);
• Severe bradycardia (heart rate <= 50 bpm), sick sinus syndrome, atrioventricular block of grade II or higher without pacemaker implantation, a history of myocardial infarction within one year, or presence of rapid ventricular arrhythmia;
• History of schizophrenia, epilepsy, Parkinson's disease, or myasthenia gravis, or prresence of intracranial hypertension;
• Uncontrolled hyperthyroidism or pheochromocytoma;
• Inability to communicate due to coma, severe dementia, or language barrier;
• Severe cardiac insufficiency (preoperative left ventricular ejection fraction < 30% or New York Heart Association Functional classification IV), severe hepatic dysfunction (Child-Pugh class C), severe renal dysfunction (preoperative dialysis), or American Society of Anesthesiologists physical status >= IV;
• Other conditions that are considered unsuitable for study participation.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Quadruple blind

Primary purpose

Prevention

Study locations

China · 1 center

• Peking University First Hospital — Beijing

Publications

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• Rodrigues NB, McIntyre RS, Lipsitz O, Lee Y, Cha DS, Shekotikhina M, Vinberg M, Gill H, Subramaniapillai M, Kratiuk K, Lin K, Ho R, Mansur RB, Rosenblat JD. A simplified 6-Item clinician administered dissociative symptom scale (CADSS-6) for monitoring dissociative effects of sub-anesthetic ketamine infusions. J Affect Disord. 2021 Mar 1;282:160-164. doi: 10.1016/j.jad.2020.12.119. Epub 2020 Dec 29 PMID 33418362
• Busse JW, Bartlett SJ, Dougados M, Johnston BC, Guyatt GH, Kirwan JR, Kwoh K, Maxwell LJ, Moore A, Singh JA, Stevens R, Strand V, Suarez-Almazor ME, Tugwell P, Wells GA. Optimal Strategies for Reporting Pain in Clinical Trials and Systematic Reviews: Recommendations from an OMERACT 12 Workshop. J Rheumatol. 2015 Oct;42(10):1962-1970. doi: 10.3899/jrheum.141440. Epub 2015 May 15. PMID 25979719
• Zhang Y, Cui F, Ma JH, Wang DX. Mini-dose esketamine-dexmedetomidine combination to supplement analgesia for patients after scoliosis correction surgery: a double-blind randomised trial. Br J Anaesth. 2023 Aug;131(2):385-396. doi: 10.1016/j.bja.2023.05.001. Epub 2023 Jun 9. PMID 37302963
• Junior AB Jr, Bendazzoli PS, Ferreira Melo FW Jr, Porto Franco RM, de Sousa Rocha EM, Matos Lima RD, Brondi EB. Efficacy and Safety of the Ketamine-Dexmedetomidine Combination in Adult Sedation and Anesthesia: A Systematic Review and Single-Arm Meta-Analysis of Randomized Controlled Trials. Cureus. 2025 Nov 21;17(11):e97432. doi: 10.7759/cureus.97432. eCollection 2025 Nov. PMID 41431543

Identifiers

NCT: NCT07523321 · 2026-0136

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗