Vilar DG et al, 2012: Topical EMLA for pain control during extracorporeal shock wave lithotripsy: prospective, comparative, randomized, double-blind study
Vilar DG, Fadrique GG, Sacoto CD, Persiva JB, Mestre MP, De Francia JA, Martin IP, Aguado JM, Perelló CG, Verdu LS, Gomez JG
Hospital General de Castellón, Castellon de la plana, Castellón, Spain
Patient collaboration in external shock wave lithotripsy (ESWL) is critical for its correct application, making proper analgesic selection indispensable. The aim of this study was to evaluate the efficacy of combined application of EMLA and intravenous (i.v.) pethidine compared with pethidine plus placebo cream in patients undergoing ESWL for ureteral and/or renal lithiasis. Prospective, controlled, randomized, double-blind study was conducted in patients receiving ESWL for renal and/or ureterolithiasis. The patients were randomly assigned to receive i.v. pethidine plus either EMLA cream (group A) or placebo hydrating cream (group B). Evaluated were type, location, and size of lithiasis, patient's sex, age, body mass index, comorbidity, Visual Analogue Scale (VAS) score of pain, and degree of lithiasis fragmentation. EMLA cream provided significantly better pain relief and lithiasis fragmentation and more completed ESWL treatment. Topical application of EMLA cream combined with i.v. pethidine improved VAS scores and lithiasis fragmentation and decreased the rate of withdrawal from ESWL procedure versus i.v. pethidine plus placebo therapy.
Urol Res. 2012 Oct;40(5):575-9. doi: 10.1007/s00240-012-0468-0. Epub 2012 May 4
PMID: 22555869 [PubMed - as supplied by publisher]
The authors show in this report that by applying EMLA-cream on the skin at the entrance of the shockwave a better pain relief was obtained than with placebo cream. In addition a standard dose of pethidine and metoclopramide was given intravenously. It is surprising that as many as 12 and 31 of the patients in Groups A and B, respectively, did not complete the treatment because of pain. Moreover, incomplete treatment in as many as 30 and 58 patients, respectively, indicates that the patients generally were given insufficient analgesics and sedatives during the procedure. It is difficult to know which role the larger number of shockwaves and the higher total energy in Group B played.
My personal experience of EMLA together with meperidine and diazepam for patients treated with ESWL in the unmodified HM3-lithotripter (Journal of Urology 1993; 149: 8-11) showed that the doses of analgesics/sedatives given intermittently during the procedure could be reduced in the presence of EMLA. In that clinical setting the effect of EMLA was most evident at low energy levels. It is also my own experience that with appropriate shockwave power it is the visceral and skeletal pain that is most important and not the pain experience at the skin level.