Eight randomised trials were included in the review (n=510). On the Jadad scale three studies scored 3, three studies scored 2 and two studies scored 1. None of the trials were blinded. Sample sizes ranged from 45 to 108.
There were no statistically significant differences in pain scores between PNB and epidural during 0-12 hours and 12-24 hours after surgery, although there was significant heterogeneity (0-12 hours I2=87% and 12-24 hours I2=93%). The authors reported that significantly lower pain scores were found for 24-48 hours in the epidural group, WMD -0.35 (95% CI: -0.64 (forest plot -0.69), -0.02, p=0.04), with no heterogeneity detected (although a random-effects model was still used). This result was not deemed to be clinically significant. However, the associated forest plot indicated that lower pain scores actually occurred in the PNB group.
Hypotension was significantly more prevalent in the epidural group, OR 0.19 (95% CI: 0.08, 0.45, p=0.0001, I2=18.7%). There was no difference in rates of nausea and vomiting, nor in morphine consumption. Further results were reported.