Our review revealed a great heterogeneity in definition , format , and values of what is considered a clinical ly relevant difference in pain in RCTs of analgesics , and st and ardizations are advisable
OBJECTIVE To describe the  pain decrease considered as clinical ly relevant when design ing a trial and reporting its results .
Four Percent Intrauterine Lidocaine Infusion for Pain Management in First-Trimester Abortions
OBJECTIVE : To study the effects of a 4 % intrauterine lidocaine infusion on perceived patient pain in first-trimester abortions . METHODS : A r and omized , double-blind , placebo-controlled trial of 80 women receiving either a 5-mL 4 % lidocaine ( n = 40 ) or saline ( n = 40 ) intrauterine infusion and a st and ard paracervical block before first-trimester abortion . Women completed a series of 100-mm visual analog scales ( anchors : 0 = none , 100 mm = worst imaginable ) to measure their perceived pain ( anticipated pain , after speculum insertion , after intrauterine infusion , after cervical dilation , after suction aspiration , and 30 minutes postprocedure ) . Eight women volunteered for serum lidocaine levels after the lidocaine infusion . RESULTS : Groups were similar in respect to age , parity , prior abortion , ethnicity , gestational age , and level of dysmenorrhea .  Pain scores demonstrated a significant difference between groups during cervical dilation ( saline 55 mm ± 26 , lidocaine 35 mm ± 30 , P < .01 ) and during aspiration ( saline 71 mm ± 20 , lidocaine 43 mm ± 30 , P < .01 ) . The lidocaine group reported significantly more symptoms ( ie , oral numbness and tingling ) than the saline group ( saline 0/39 , lidocaine 16/38 , 42 % , P < .01 ) . The highest serum lidocaine level recorded was 4.0 & mgr;g/mL ( lidocaine group ) . There was no difference in overall satisfaction between the 2 groups . CONCLUSION : Compared with paracervical block alone , the addition of a 4 % intrauterine lidocaine infusion result ed in a significant reduction in patient perception of pain during first-trimester abortion . Although subjective symptoms of systemic lidocaine effect were common , no subjects demonstrated serum levels consistent with lidocaine toxicity . However , further studies to determine safety are needed . LEVEL OF EVIDENCE :
Our review revealed a great heterogeneity in definition , format , and values of what is considered a clinical ly relevant difference in pain in RCTs of analgesics , and st and ardizations are advisable
OBJECTIVE To describe the  pain decrease considered as clinical ly relevant when design ing a trial and reporting its results .