Purpose: We conducted a comparative study to evaluate analgesic efficacy between paravertebral block via the surgical field (PVB-sf), in which the catheter was inserted into the ventral side of the sympathetic trunk in the paravertebral space by a thoracic surgeon under thoracoscopic visualization, and epidural block (Epi) using ropivacaine for post-thoracotomy pain relief.
Methods: Lung cancer patients scheduled for lobectomy via thoracotomy were randomly allocated to receive either PVB-sf or Epi (n = 36 per group). Before thoracotomy closure, 0.375% ropivacaine was administered as a bolus (PVB-sf, 20 mL; Epi, 5 mL), followed by a 300-mL continuous infusion of 0.2% ropivacaine at 5 mL/h. Postoperative pain was assessed using a visual analog scale (VAS) score at various time points, including the primary endpoint of 2 h after ropivacaine bolus injection. Sensory block area, vital signs, serum ropivacaine concentrations, and side effects were also evaluated.
Results: The Epi group showed significantly lower VAS scores and blood pressure and a wider sensory block area than the PVB-sf group at all evaluation time points. While the mean serum ropivacaine concentration in the PVB-sf group was significantly higher than that in the Epi group until 1 h after injection of the ropivacaine bolus, there was no significant difference at any subsequent assessment point. The incidence of side effects was similar between the groups.
Conclusion: The Epi was superior to PVB-sf for the management of post-thoracotomy pain in this patient cohort. The number of dermatomes anaesthetized by Epi was greater than that anaesthetized by PVB-sf. No difference in complication rates was observed between the two groups.
Keywords: Epidural block; Paravertebral block via the surgical field; Ropivacaine; Thoracotomy; Visual analog scale.