Value of Music and Nitrous Oxide for Pain Control during Extracorporeal Shock Wave Lithotripsy (ESWL)

OBJECTIVES: To compare the efficacy of 4 different analgesic regimens that include music and nitrous oxide during the treatment of renal lithiasis with ambulatory extracorporeal shock wave lithotripsy (ESWL). MATERIALS AND METHODS: A single-centre, longitudinal, prospective, randomized, open and parallel group study was conducted. Patients with renal lithiasis were included and were randomized to Group A (basal analgesia: midazolam (1 mg), fentanyl (0.05 mg) and dexketoprofen (50 mg)), Group B (basal analgesia and nitrous oxide), Group C (basal analgesia and music) and Group D (basal analgesia, nitrous oxide and music). For the measurement of pain, a visual analogue scale ranging from 0 (no pain) to 100 (maximum pain imaginable) was used. Patient satisfaction was assessed using a Likert questionnaire. The epidemiological data of the patients in terms of lithiasis, previous clinical and ESWL sessions, and pain measured with the VAS before, during (maximum) at the end of the session and at discharge were recorded. Data on complications were also collected, as was the patients\u27 subjective evaluation of the treatment and their satisfaction. The ESWL procedure was performed with a Storz Modulith SLX-F2® lithotripter. A maximum of 4000 waves were applied at a frequency of 1.5 Hz. RESULTS: Eighty patients were included (20 per group). None of the analgesia guidelines proved to be superior to the others for pain control during the ESWL session. Patients younger than 50 years had significantly higher values for the maximum VAS. Only 13.75% of patients required rescue analgesia. A total of 77.5% described their experience as good, very good or excellent, regardless of the assigned group. CONCLUSIONS: The addition of nitrous oxide and/or music did not result in a statistically significant improvement over the basal analgesia regimen of midazolam, fentanyl and dexketoprofen; however, the degree of patient satisfaction was very high