In patients undergoing thoracic surgery is paravertebral block as effective as epidural analgesia for pain management?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: in patients undergoing thoracic surgery is paravertebral block (PVB) as effective as epidural analgesia for pain management? Altogether >184 papers were found using the reported search, seven of which represented the best evidence to answer the clinical question. All studies agreed that PVB is at least as effective as epidural analgesia for pain control post-thoracotomy. In one paper, the visual analogue pain score (VAS) at rest and on cough was significantly lower in the paravertebral group (P=0.02 and 0.0001, respectively). Pulmonary function, as assessed by peak expiratory flow rate (PEFR), was significantly better preserved in the paravertebral group. The lowest PEFR as a fraction of preoperative control was 0.73 in the paravertebral group in contrast with 0.54 in the epidural group (P<0.004). Oximetric recordings were better in the paravertebral group (96%) compared to the epidural group (95%) (P=0.0001). Another article reported that statistically significant differences (forced vital capacity 46.8% for PVB and 39.3% for epidural group P<0.05; forced expiratory volume in 1 s (FEV(1)) 48.4% in PVB group and 35.9% in epidural group, P<0.05) were reached in day 2 and continued until day 3. Plasma concentrations of cortisol, as marker of postoperative stress, increased markedly in both groups, but the increment was statistically different in favour of the paravertebral group (P=0.003). Epidural block was associated with frequent side-effects [urinary retention (42%), nausea (22%), itching (22%) and hypotension (3%) and, rarely, respiratory depression (0.07%)]. Additionally, it prolonged operative time and was associated with technical failure or displacement (8%). Epidurals were also related to a higher complication rate (atelectasis/pneumonia) compared to the PVB (2 vs. 0). PVB was found to be of equal efficacy to epidural anaesthesia, but with a favourable side effect profile, and lower complication rate. The reduced rate of complication was most marked for pulmonary complications and is accompanied by quicker return to normal pulmonary function. We conclude intercostal analgesia, in the form of PVB, can be at least as effective as epidural analgesia.