Levobupivacaine versus Levobupivacaine–Dexmedetomidine in Thoracic Paravertebral Block for Laparoscopic Sympathectomy

BACKGROUND: Thoracic paravertebral block (TPVB) is a high-quality analgesic technique used for many types of surgery, trauma, and chronic pain. AIM: The aim of this study is to assess safety and efficacy of adding dexmedetomidine to levobupivacaine in TPVB for postoperative analgesia after unilateral laparoscopic thoracic sympathectomy. PATIENTS AND METHODS: Sixty adult patients of the American Society of Anesthesiologists physical status classes I and II, aged 20–45 years, of either sex, submitted for unilateral laparoscopic thoracic sympathectomy under general anesthesia at Mansoura University Hospital. Patients were classified into two groups such as levobupivacaine (G(L)): patients received isobaric 0.5% levobupivacaine 1 mg/kg in 20-ml volume for TPVB and levobupivacaine–dexmedetomidine (G(LD)): patients received isobaric 0.5% levobupivacaine 1 mg/kg and 10-μg dexmedetomidine in 20 ml volume for TPVB. STATISTICAL ANALYSIS: Data were first tested for normality by Kolmogorov–Smirnov test. Normally distributed continuous data were analyzed using unpaired Student's t-test. Nonnormally distributed continuous and ordinal data were analyzed using Mann–Whitney U-test. Categorical data were analyzed by Chi-square test or Fisher's exact test as appropriate. RESULTS: A faster onset and longer duration of sensory blockade was significantly higher in group G(LD) with mean ± standard deviation (SD) (8.57 ± 7.22 min and 11.98 ± 1.42 h) than in group G(L) (15.21 ± 4.35 min and 9.75 ± 3.29 h). Sensory block regression time was significantly longer in group G(LD) with mean ± SD (10.8 ± 2.31 h) compared to group G(L) (8.82 ± 1.71 h). Furthermore, a significant reduction in visual analog scale occurred in group G(LD) compared with the G(L) group up to 24 h postoperatively (P < 0.05). No significant difference in Ramsay Sedation Scale (RSS) between both groups. The number of patients asked for postoperative analgesia was significantly fewer in group G(LD) compared with group G(L) (14 compared to 21)*. The time (hours) of first request for analgesia was significantly longer in group G(LD) compared with G(L) group (7.8 ± 3.22 compared to 9.7 ± 2.51*). The total postoperative fentanyl requirements in 24 h (in micrograms) was significantly less in G(LD) group compared to G(L) group (320 ± 110 compared to 190 ± 120*). CONCLUSION: The addition of dexmedetomidine as adjuvant to levobupivacaine in TPVB for elective unilateral laparoscopic thoracic sympathectomy can markedly improve the postoperative analgesia with lower pain scores and a marked reduction of the postoperative analgesic requirements and low side effect profile.