OBJECTIVES: We evaluated the impact of sleep position on the effectiveness of shock wave lithotripsy (SWL) in renal calculi. PATIENTS AND METHODS: Patients (n = 120) with a single radiopaque renal stone who were candidates for SWL were enrolled. For studying patients' position during sleep, a novel sleep position recorder was designed. Group 1 (n = 60) consisted of patients who slept preferentially on the ipsilateral side of the stone; group 2 (n = 60) comprised patients who slept preferentially on the contralateral side. Treatment effectiveness was defined as the absence of residual stones >3 mm up to 3 months after SWL. RESULTS: The mean (range) percent of sleep on the ipsilateral side of the stone was 61.5% (51-78) and on the contralateral side it was 62.4% (51-81) in groups 1 and 2, respectively (p > 0.05). The overall success rate of SWL was 88.3% (77.4-95.2) and 70.0% (56.8-81.2) in groups 1 and 2, respectively (p = 0.01). Stone clearance increased with an increasing percent of total sleep time on the ipsilateral side of the kidney stone (p = 0.045). CONCLUSIONS: The percent of stone-free patients was higher in the group of patients who slept ipsilaterally relative to the kidney stone compared with patients who slept on the contralateral side.
OBJECTIVES: We evaluated the impact of sleep position on the effectiveness of shock wave lithotripsy (SWL) in renal calculi. PATIENTS AND METHODS: Patients (n = 120) with a single radiopaque renal stone who were candidates for SWL were enrolled. For studying patients' position during sleep, a novel sleep position recorder was designed. Group 1 (n = 60) consisted of patients who slept preferentially on the ipsilateral side of the stone; group 2 (n = 60) comprised patients who slept preferentially on the contralateral side. Treatment effectiveness was defined as the absence of residual stones >3 mm up to 3 months after SWL. RESULTS: The mean (range) percent of sleep on the ipsilateral side of the stone was 61.5% (51-78) and on the contralateral side it was 62.4% (51-81) in groups 1 and 2, respectively (p > 0.05). The overall success rate of SWL was 88.3% (77.4-95.2) and 70.0% (56.8-81.2) in groups 1 and 2, respectively (p = 0.01). Stone clearance increased with an increasing percent of total sleep time on the ipsilateral side of the kidney stone (p = 0.045). CONCLUSIONS: The percent of stone-free patients was higher in the group of patients who slept ipsilaterally relative to the kidney stone compared with patients who slept on the contralateral side.