title: Impact of sleep position on stone clearance after shock wave lithotripsy in renal calculi.
abstract: OBJECTIVE
  We evaluated the impact of sleep position on the effectiveness of shock wave lithotripsy (SWL) in renal calculi.
  
  
  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.
authors.affiliation: Shahid Labbafinejad Medical Center, Shahid Beheshti University, M.C. (SBMU), Tehran, Iran.
authors.forename: Seyed Amir Mohsen
authors.initials: SA
authors.lastname: Ziaee
authors.forename: Seyed Reza
authors.initials: SR
authors.lastname: Hosseini
authors.forename: Amir H
authors.initials: AH
authors.lastname: Kashi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Samzadeh
mesh_terms: D000328:Adult; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D007492:Iran; D007669:Kidney Calculi / Q000000981:diagnostic imaging / Q000628:therapy*; D008096:Lithotripsy; D008297:Male; D011187:Posture; D011859:Radiography; D012890:Sleep; D013997:Time Factors; D016896:Treatment Outcome