Intracerebroventricular Application of Dexmedetomidine Produces Antinociception and Does not Cause Neurotoxicity in Rats

Thoracic Paravertebral Nerve Block with Ropivacaine and Adjuvant Dexmedetomidine Produced Longer Analgesia in Patients Undergoing Video-Assisted Thoracoscopic Lobectomy: A Randomized Trial

Purpose

This study evaluated the postoperative analgesic effect of ultrasound-guided single-point thoracic paravertebral nerve block (TPVB) combined with dexmedetomidine (DEX) in patients undergoing video-assisted thoracoscopic lobectomy.

Methods

Sixty adult patients of the American Society of Anesthesiologists (ASA) I-III were randomly assigned into three groups (n = 20 each). G group: patients received routine general anesthesia; PR group: patients received 0.5% ropivacaine; and PRD group: patients received 0.5% ropivacaine with 1 μg/kg DEX. TPVB was performed in the T5 space before surgery, and then, general anesthesia induction and video-assisted thoracoscopic lobectomy were performed. Analgesics were administered through the patient-controlled analgesia (PCA) device intravenously. The background infusion of each PCA device was set to administer 0.02 μg/kg/h sufentanil, with a lockout time of 15 min, and a total allowable volume is 100 ml.

Results

Compared to PR and G groups, the total sufentanil consumption after operation, the times of analgesic pump pressing, the pain score, and the incidence of postoperative nausea or vomiting in the PRD group were significantly reduced (p < 0.05). Also, the duration of first time of usage of the patient-controlled analgesia (PCA) was longer. The heart rate (HR) and mean arterial pressure (MAP) during operation were lower in the PRD group as compared with the other two groups in most of the time. However, hypotension and arrhythmia occurred in three groups with no statistically significant difference.

Conclusions

A small volume of TPVB with ropivacaine and DEX by single injection produced longer analgesia in patients undergoing video-assisted thoracoscopic lobectomy, reduced postoperative opioids consumption, and the incidence of side effects.

Efficacy of dexmedetomidine as an adjuvant in paravertebral block in breast cancer surgery

PURPOSE

This study evaluated the analgesic efficacy of dexmedetomidine in combination with bupivacaine for single-shot paravertebral block (PVB) in patients undergoing major breast cancer surgery.

METHODS

This prospective, randomized double blind study was conducted in 45 ASA I/II/III females, aged ≥18 years, undergoing modified radical mastectomy or breast conservation surgery with axillary lymph node dissection. Patients in group PB (paravertebral-bupivacaine) received PVB with 0.5 % bupivacaine 0.3 ml/kg with 1 ml normal saline; group PBD (paravertebral-bupivacaine-dexmedetomidine) received PVB with 0.5 % bupivacaine 0.3 ml/kg and dexmedetomidine 1 μg/kg in a volume of 1 ml; and group C (control) patients were given a sham block (a subcutaneous injection with 2 ml normal saline) before receiving general anesthesia (GA). All patients received analgesia by fentanyl intraoperatively and morphine patient-controlled analgesia postoperatively.

RESULTS

The control group patients required more intraoperative fentanyl than the other two groups. Patients receiving dexmedetomidine had lower morphine consumption (p < 0.001), pain scores and incidence of postoperative nausea/vomiting (p = 0.011); longer time to first analgesic request; earlier time to mobilize; and better satisfaction scores. Heart rate and blood pressure values during the intraoperative period were also lower at many time points in this group. However, the incidence of hypotension and bradycardia were statistically similar in all groups.

CONCLUSIONS

PVB using dexmedetomidine 1 µg/kg added to 0.5 % bupivacaine in patients undergoing major breast cancer surgery under GA provides analgesia of longer duration with decreased postoperative opioid consumption and lower incidence of nausea/vomiting compared to PVB with bupivacaine alone or no PVB.