Preemptive Infiltration With Betamethasone and Ropivacaine for Postoperative Pain in Laminoplasty or Laminectomy

Laminoplasty and laminectomy have been used for decades for the treatment of intraspinal space occupying lesions, spinal stenosis, disc herniation, injuries, etc. After these procedures, patients often experience severe postoperative pain at the surgical site. However, current methods of pain control are mostly insufficient. At present, several pain controlling methods are available, to reduce postoperative pain after laminoplasty or laminectomy. Methods for systemic administration include: oral analgesics, intermittent intravenous, intramuscular injections, patient- controlled intravenous analgesia, etc. However, the aforementioned methods may have a lot of side effects, and are usually used after the occurrence of pain and the analgesic effects are sometimes inadequate. Topical administration options use a lower dose of drugs and therefore have less systemic side effects. Pre-emptive injection of local anesthetics can significantly reduce postoperative pain during rest and movement, however, the analgesic effect is maintained for a relatively short period of time. It is necessary to use more cases to explore the other compatibility of drugs with longer duration of action and stronger analgesic effect. Betamethasone as the stereoisomer of dexamethasone is a long-acting corticosteroid, which has long lasting anti-inflammatory properties. Whether betamethasone combined with local anesthetic for laminoplasty or laminectomy has better short-term and long-term effects than the local anesthetic alone has not been reported yet. Therefore, a prospective, randomized, controlled, blinded-endpoint study is needed to compare the postoperative analgesic efficacy of preemptive wound infilteration of ropivacaine alone and betamethasone plus ropivacaine for laminectomy or laminoplasty.


Eligibility Criteria:
Inclusion Criteria:

* Patients scheduled for surgery under general anaesthesia for laminectomy or laminoplasty;
* American Society of Anaesthesiologists (ASA) classification of I or II;
* Age 18 to 64 years;
* Participates with an anticipated full recovery within 2 hours postoperatively.

Exclusion Criteria:

* Patient refusal;
* Participants who cannot use a patient-controlled analgesia (PCA) device and cannot understand the instructions of a Visual Analogue Score (VAS);
* Previous history of spinal surgery;
* Allergy to opioids, betamethasone or ropivacaine;
* Peri-incisional infection;
* History of stroke or a major neurological deficit;
* Trauma, deformity;
* Psychological problems;
* Extreme body mass index (BMI) (\< 15 or \> 35);
* History of excessive alcohol or drug abuse, chronic opioid use (more than 2 weeks), or use of drugs with confirmed or suspected sedative or analgesic effects;
* Patients using systemic steroids;
* Pregnant or breastfeeding;
* Preoperative Glasgow Coma Scale \< 15;
* Participants who have received radiation therapy or chemotherapy preoperatively, or with a high probability to require a postoperative radiation therapy or chemotherapy according to the preoperative imaging.
* Not able to give written informed consent