Sabharwal S et al, 2017: A prospective randomised double-blind placebo-controlled trial to assess the effect of diuretics on shockwave lithotripsy of calculi.
Sabharwal S, Jeyaseelan L, Panda A, Gnanaraj L, Kekre NS, Devasia A.
Department of Urology, Christian Medical College, Vellore, Tamil Nadu, India.
2Department of Biostatistics, Christian Medical College, Vellore, Tamil Nadu, India.
Objective: To assess the effect of diuretics with shockwave lithotripsy (SWL) on the treatment of renal and upper ureteric calculi.
Patients and methods: Adult patients with a solitary non-obstructive radio-opaque renal or upper ureteric calculus with normal renal function were included. They were prospectively randomised to receive either SWL with placebo or SWL with diuretics (40 mg parenteral furosemide) in a double-blind manner with a sample size of 48 patients in each arm. The primary outcomes were the SWL success and failure rates. The secondary outcomes were the number of shocks and sessions.
Results: Complete fragmentation was achieved in 89.6% of the patients in the furosemide arm as compared to 81.3% in the placebo arm. Clearance was achieved in 77.1% of the patients in the furosemide arm as compared to 70.8% in the placebo arm. The number of shocks and the number of sessions were higher in the placebo arm. These differences were not statistically significant. Conclusion: The use of diuretics along with SWL treatment of renal and upper ureteric calculi does not show a statistically significant improvement in fragmentation or clearance.
Arab J Urol. 2017 Jul 8;15(4):289-293. doi: 10.1016/j.aju.2017.04.003. eCollection 2017 Dec. FREE ARTICLE
A proper, well done study with a small number of cases based on the presumption that the difference between the two groups would be 20%. But the results only showed a difference of 8% for fragmentation and 6% for clearance.
The conclusion in the abstract is less optimistic than in the text: “Despite statistically non-significant results, these findings suggest that furosemide might be beneficial. Conclusion: The use of diuretics with SWL in the treatment of renal and upper ureteric calculi improved fragmentation and clearance, although the difference was not statistically significant. The number of shocks and the number of sessions were also lower in the group that received diuretics.”
Taken together with the results reported in the referenced literature it is probably worth to further study the concept on subgroups.