Ultrasound-guided multilevel paravertebral block versus local anesthesia for medical thoracoscopy

BACKGROUND: Local anesthetic infiltration for medical thoracoscopy has an analgesic properties for short duration. Single injection thoracic paravertebral block (PVB) provides limited analgesia. PURPOSE: Comparison between thoracic PVB performed at two or three levels with local infiltration for anesthetic adequacy in adult medical thoracoscopy as a primary outcome and postthoracoscopic analgesia and pulmonary function as secondary outcomes for adult medical thoracoscopy. PATIENTS AND METHODS: Prospective randomized control study included 63 adult patients with exudative pleural effusion randomly divided into three groups of 21 patients: 3-level PVB, 2-level PVB group, and local infiltration group. Patients with contraindications to regional anesthesia or uncontrolled comorbidities were excluded from the study. Pain visual analog scale and spirometry were used for comparison as anesthetic adequacy in adult medical thoracoscopy as a primary outcome besides prolonged analgesia and improved pulmonary function as secondary outcomes. RESULTS: The anesthetic adequacy was 95.3% in 3-level PVB group, 81% in 2-level PVB group, and 71.5% in local infiltration group. The mean sensory level was 1 ± 0.8 and 1 ± 0.6 segment above and 0.8 ± 0.6 and 0.7 ± 0.7 segment below the injected level in 3-level PVB group and 2-level PVB, respectively. VAS was statistically significant higher in local infiltration compared to the other two groups immediately postthoracoscopic and 1 h after. Two-hour postthoracoscopy, significant increase in forced vital capacity values in the three groups compared to their basal values whereas forced expiratory volume at 1 s (FEV1) only in both PVB groups. CONCLUSION: Unilateral 3-level TPVB was superior to 2-level TPVB and LA infiltration for anesthetic adequacy for patients undergoing medical thoracoscopy. Moreover, US-guided TPVB was followed by higher FEV1 values and lower pain scores during the next 12 h postthoracoscopy in comparison to local infiltration, so 3-level TPVB is an effective and relatively safe anesthetic technique for adult patients undergoing medical thoracoscopy which may replace local anesthesia.