BACKGROUND: Video-assisted thoracic surgery (VATS) is widely used as a less invasive procedure for thoracic surgery. However, there is still significant postoperative pain, although less severe than with conventional thoracic surgery. The aim of this study was to assess the efficacy of an interpleural block and a paravertebral block for postoperative pain control and the recovery of the pulmonary function.

METHODS: Fifty-one patients with similar demographic and preoperative physiologic parameters were divided randomly into interpleural or thoracic paravertebral block groups. The visual analogue pain score (VAS) was assessed at 30 min, and 2, 6, 12, and 24 hours after surgery and the forced vital capacity was tested preoperatively, the pulmonary function was evaluated at 30 min, and 2, 6, 12, and 24 hours.

RESULTS: The pain scores were significantly lower in the paravertebral block group at 30 min, 2, 6 and 12 hours after surgery during rest (6.4 ± 1.8, 5.1 ± 1.1, 4.2 ± 1.5, 2.8 ± 0.8 vs 2.9 ± 1.8, 2.5 ± 1.6, 2.1 ± 1.6, 1.9 ± 1.7, P < 0.05), and only within 2 hours after operation for coughing (7.8 ± 1.0, 6.4 ± 0.8 vs 4.7 ± 2.2, 4.2 ± 2.1, P < 0.05) than in the interpleural block group. There was significant recovery of the pulmonary function 30 min, 2, and 6 hours after surgery (32%, 43%, 56%, 67%, 75% vs 59%, 59%, 71%, 75%, 84%, P < 0.05) in the paravertebral block group.

CONCLUSIONS: A thoracic paravertebral block is more effective in decreasing the level of post-VATS pain, and allows earlier recovery of the forced vital capacity compared with an interpleural block.