title: Vasovagal rates in flouroscopically guided interventional procedures: a study of over 8,000 injections.
abstract: OBJECTIVE
  To determine the rate of vasovagal (vv) complications in fluoroscopically guided interventional procedures.
  
  
  METHODS
  Retrospective case series analysis of prospectively collected data from March 8, 2004 to January 30, 2009.
  
  
  METHODS
  A single academic medical center.
  
  
  METHODS
  Four thousand one hundred eighty-three subjects undergoing 8,010 consecutive injections.
  
  
  METHODS
  Pearson's chi-square test was used to determine the relationship between categorical variables.
  
  
  RESULTS
  A total of 8,010 injections, including epidural steroid injections, radiofrequency nerve ablations, medial branch blocks, hip injections, knee injections, and glenohumeral injections were performed. Overall vv reaction rate was 2.6%, with 0.8% of procedures resulting in early terminated due to vv reaction. Peripheral joint injections had a vv rate of 0.2%, all occurring in hip injections. Transforaminal epidural steroid injections had a vv rate of 3.5%. Diagnostic blocks of the medial branches had the highest rate of vv (5.1%). Other predictors of vv reactions were identified including preprocedure pain score visual analog scale <5 (P = 0.004), male gender (P < 0.001), and age less than 65 years old (P < 0.001).
  
  
  CONCLUSIONS
  vv reactions have an overall low occurrence rate (2.6%) in interventional procedures ranging from 0% in peripheral knee and shoulder injections to 5.1% in medial branch blocks. Conservative treatment of vv reaction and willingness to terminate procedures resulted in no serious adverse events related to vv reaction in 8,010 procedures.
authors.affiliation: Department of Orthopaedics, Stanford University, Redwood City, California, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Kennedy
authors.forename: Byron
authors.initials: B
authors.lastname: Schneider
authors.forename: Ellen
authors.initials: E
authors.lastname: Casey
authors.forename: Joshua
authors.initials: J
authors.lastname: Rittenberg
authors.forename: Bryan
authors.initials: B
authors.lastname: Conrad
authors.forename: Matthew
authors.initials: M
authors.lastname: Smuck
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Plastaras
mesh_terms: D000368:Aged; D005260:Female; D005471:Fluoroscopy / Q000379:methods; D006801:Humans; D007270:Injections, Intra-Articular / Q000009:adverse effects*; D007278:Injections, Spinal / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects*; D015642:Radiology, Interventional / Q000379:methods; D012189:Retrospective Studies; D012307:Risk Factors; D019462:Syncope, Vasovagal / Q000453:epidemiology* / Q000209:etiology
keywords: Facet Joint; Fluoroscopy; Interventional; Medial Branch; Physician Performance; Sacroiliac Joint; Zygoapophyseal Joint