Thoracic paravertebral block for video-assisted thoracoscopic surgery: Single injection versus multiple injections

Abstract

Objective: Thoracic paravertebral blocks (PVBs) have been shown to be effective for analgesia after video-assisted thoracoscopic surgery (VATS) with single- and multiple-injection techniques. The efficacy of single-injection PVB was compared with multiple-injection PVB on postoperative analgesia in VATS was studied. Design: Prospective, randomized study. Setting: Single university hospital. Participants: Fifty patients undergoing VATS. Interventions: A nerve stimulator-guided PVB was performed in the sitting position before surgery using a solution of 20 mL 0.5% bupivacaine with 1:200,000 epinephrine by a single injection at T6 (group S, n = 25) or by 5 injections of 4 mL each at T4 to T8 (group M, n = 25). Measurements and Main Results: A successful PVB was achieved in all patients. The times to perform the blocks were 6.8 +/- 1.9 minutes in the S group and 17.9 +/- 3.0 minutes in the M group (p < 0.001). The times to block onset were 8.3 +/- 1.8 minutes in the S group and 7.2 +/- 0.9 minutes in the M group (p = 0.014). The numbers of anesthetized dermatomes were 5.8 +/- 0.8 for the S group and 6.6 +/- 1.1 for the M group (p = 0.009). The postoperative pain scores and morphine consumption with patient-controlled analgesia were comparable in the two groups. There were no significant differences in times to the first mobilization and hospital discharge for two groups. Patient satisfaction with the analgesic procedure was greater in the S group (p < 0.05). No complications were attributed to the blocks. Conclusions: The two techniques provided comparable postoperative analgesia. However, single-injection PVB may represent an advantage over multiple-injection PVB in patients undergoing VATS, with greater patient satisfaction associated with a shorter procedure and the likelihood of decreased complications.