Introduction: Preliminary data have suggested that delaying voltage escalation for SWL might both improve fragmentation and minimize renal injury. No concensus has been reached regarding the optimal treatment protocols for SWL.

Objective: To investigate a randomized trial of ESWL efficacy by immediate vs delayed voltage escalation during shockwave lithotripsy (SWL) consist the consumption level of the electrode, and the rate of shock wave administration.

Methods: A total of 119 patients with urinary calculi were randomized to undergo immediate vs delayed voltage escalation SWL. Success was defined as an asymptomatic patient who was stone free of had adequate fragmentation (sand of fragments ≤ 4 mm) at 4 weeks after treatment.

Results: Of the 119 patients, 59 were treated with immediate voltage escalation SWL and 60 patients with delayed escalation. The groups were similar in sex, stone area, and stone location. The overall success rate at 4 weeks was 50.8% for immediate vs 58.3% for delayed SWL (P = .412). No differences were seen in the complications between the 2 treatments.

Conclusions: A trend was also seen for delayed voltage escalation to be less energy in the treatment of urinary calculi compared with calculi with immediate voltage escalation (~ 10%, when Patients had been delivered to 6,000 shocks). We suggest that the patients in delayed group had more total shocks and less total energy should implied less kidney injury.