Davies RG, Myles PS
Dept. of Anaesthesia & Pain Management, Alfred Hospital, Melbourne

Epidural analgesia is considered by many to be the best method of pain relief after major surgery. It is near-routine in many thoracic surgical centres. Although effective, side effects include hypotension, urinary retention, incomplete (or failed) block, and, in rare cases, paraplegia. Paravertebral block (PVB) is an alternative technique that may offer comparative analgesic effectiveness and yet a better side effect profile.

Method

We undertook a systematic review and meta-analysis of all relevant randomised trials comparing PVB with epidural analgesia, using Cochrane methodology. Data were abstracted and verified by both authors. Studies were tested for heterogeneity, and meta-analyses were done with random effects (if P>0.05) or fixed effects (if P<0.05) models. Weighted mean differences were estimated for numerical outcomes and odds ratios for dichotomous outcomes, both with 95% CI.

Result

We identified 9 trials that had enrolled 380 patients; most patients had undergone thoracic surgery. There was no significant difference between PVB and epidural groups for pain scores at 4-8, 24 or 48 h, WMD 0.35 [-0.5, 1.2], 0.06 [-0.8, 0.9], -0.20 [-0.6, 0.2], respectively. Rates of inadequate block were lower in the PVB group but were not significantly different, OR 0.49 [0.17, 1.37]. Respiratory function was improved at 48 h with PVB, +12 [2.3, 21]%. Urinary retention, PONV and hypotension were less common with PVB, 0.21 [0.09, 0.47], 0.33 [0.16, 0.70], 0.11 [0.03, 0.44], respectively. Pulmonary complications occurred less often with PVB, 0.30 [0.10, 0.89].

Conclusion

PVB and epidural analgesia provide equivalent analgesia after surgery, but PVB has a better side effect profile (less urinary retention, less PONV, less hypotension) and a reduction in pulmonary complications. PVB can be recommended for major thoracic and upper abdominal surgery.

Time of Presentation
Saturday 7 May 2005 - 1530-1700