title: Ultrasonography for the prediction of urological surgical intervention in patients with renal colic.
abstract: BACKGROUND
  There are no clear indicators of which ultrasound findings in an emergency department (ED) renal colic population are predictive of urological surgical intervention.
  
  
  OBJECTIVE
  To determine the sonographic findings of renal colic that predict surgical intervention.
  
  
  METHODS
  We conducted a retrospective cohort study of 500 consecutive ED patients with a diagnosis of renal colic that had ultrasonography (performed by radiology) during their ED visit. Our main outcome was urological surgical intervention. This was defined as extracorporeal shock wave lithotripsy, percutaneous nephrostomy or ureteroscopy performed within 16 weeks of the initial ED presentation.
  
  
  RESULTS
  Of the 500 identified patients, 483 met our eligibility criteria. Of this group, 67 (13.9%) received a surgical intervention. Ultrasound (US) findings were 97% (95% CI 88.7% to 99.5%) sensitive and 28.1% (23.9% to 32.8%) specific in 'diagnosing' the requirement for surgery when the ultrasound (US) showed either at least a stone present or showed moderate to severe hydronephrosis. The presence of stone and moderate to severe hydronephrosis had a + likelihood ratio (LR) 3.86 (2.46 to 6.07) and a -LR 0.72 (0.60 to 0.86). Having a stone ≥6 mm had a sensitivity of 77.6% (65.5% to 86.5%), a specificity of 73.6% (69.0% to 77.7%), a +LR of 2.94 (2.39 to 3.6) and a -LR 0.30 (0.19 to 0.48).
  
  
  CONCLUSIONS
  Radiology performed ultrasonography is a valuable tool for identifying renal colic that will go on to receive a surgical intervention in the 16 weeks following an ED visit. Further studies are needed to confirm the utility of ultrasound findings of stone visualisation, stone size and moderate to severe hydronephrosis in determining which patients need outpatient urology follow-up.
authors.affiliation: Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Taylor
authors.affiliation: Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada Department of Radiology, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Michael Y
authors.initials: MY
authors.lastname: Woo
authors.affiliation: Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Pageau
authors.affiliation: Department of Radiology, University of Ottawa, Ottawa, Ontario, Canada Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, Ontario, Canada.
authors.forename: Matthew D F
authors.initials: MD
authors.lastname: McInnes
authors.affiliation: Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, Ontario, Canada Division of Urology, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: James
authors.initials: J
authors.lastname: Watterson
authors.affiliation: Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Jesse
authors.initials: J
authors.lastname: Thompson
authors.affiliation: Department of Emergency Medicine, University of Ottawa, Ottawa, Ontario, Canada Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, Ontario, Canada Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Perry
mesh_terms: D000328:Adult; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D056844:Renal Colic / Q000000981:diagnostic imaging* / Q000601:surgery*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014463:Ultrasonography; D013520:Urologic Surgical Procedures
keywords: emergency department; ultrasound