Epidural analgesia versus paravertebral block in video-assisted thoracoscopic surgery

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: In patients undergoing video-assisted thoracoscopic surgery, is paravertebral block (PVB) superior to epidural analgesia (EP) in terms of pain control and its postoperative complication rates? Altogether, 153 papers were found using the reporting search, of which 4 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. At present, there are a limited number of studies directly comparing pain control and postoperative outcomes between PVB and EP, and no large-scale randomized trials have been reported. Three of the 4 papers are small prospective randomized trials, with a small cohort study featuring as the final piece of literature. There is no conclusive body of evidence to recommend either route as more efficacious from a pain control perspective; one study demonstrated significantly lower levels of pain with EP (P = 0.01), with a second study demonstrating significantly better pain control with PVB (P < 0.01) and a third failing to demonstrate any significant difference (P = 0.899). The frequency of requiring supplemental analgesia was similar between the PVB and EP cohorts (56% vs 48%, P = 0.26). PVB is associated with lower rates of postoperative complications compared to EP, specifically urinary retention (64% vs 34.6%, P = 0.0036) and hypotension (32% vs 7%, P = 0.0031; 21% vs 3%, P = 0.02). In summary, PVBs appear to offer an equivalent level of analgesic effect following video-assisted thoracoscopic surgery, with a more favourable side-effect profile, compared to EP. This does need to be contextualized in light of the scarcity of published material, with the available studies each containing a small number of participants.