Table 2: Power analysis of the studies.

StudyVAS (2 h)VAS (4 h)VAS (8 h)VAS (24 h)PONV (24 h)Urine retention (24 h)

Bessa et al., 2010 [4]70%37%NA5%64%8%
Bessa et al., 2012 [1]100%100%32%NANANA
Kalaivani et al., 2014 [12]100%100%99%33%15%21%
Tzovaras et al., 2008 [11]NA100%95%97%8%27%
Ellakany, 2013 [13]NA67%91%98%NANA
Tiwari et al., 2013 [10]NANANA100%82%19%
Imbelloni et al., 2010 [14]NANANANA18%NA

NA: not available.