title: Over-the-wire catheter exchanges: reduction of the risk of air emboli.
abstract: OBJECTIVE
  This study evaluated the aerostatic properties of the catheter clamp during over-the-wire catheter exchanges and determined if protective devices reduce volumes of air emboli (AE).
  
  
  METHODS
  A cuffed catheter was placed in an AE model in physiologic conditions and the volume of AE was recorded during 60 seconds (n = 10). Similarly, the volume of AE entering the model during 30 seconds was recorded with the catheter clamp open (n = 10) or closed over the wire (n = 10), and with the sliding clamp in the open position (n = 10). The volume of AE during 60 seconds was recorded with the sliding clamp closed over the wire (n = 10) and with the aerostatic valve with (n = 10) and without (n = 10) a wire in place.
  
  
  RESULTS
  Without a wire, no AE occurred with the catheter clamp closed (60 seconds, n = 10). There was no statistically significant difference between the volumes of AE with the catheter clamp open or closed over the wire during 30 seconds (43 mL +/- 4 and 32 mL +/- 11, respectively). With the protective devices in place and the wire unchanged in position, no AE occurred during 60 seconds. A positive control (sliding clamp and catheter clamp open, n = 10) yielded AE volumes of 44 mL +/- 5 in 30 seconds.
  
  
  CONCLUSIONS
  AE can occur with the catheter clamp closed over a wire. Protective devices reduce the volume of AE under simulated physiologic conditions and are recommended with over-the-wire catheter exchanges.
authors.affiliation: Dotter Interventional Institute, Oregon Health and Science University, L605, 3181 Southwest Sam Jackson Park Road, Portland, OR 97239, USA. kolbeckk@ohsu.edu
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Kolbeck
authors.forename: S William
authors.initials: SW
authors.lastname: Stavropoulos
authors.forename: Scott O
authors.initials: SO
authors.lastname: Trerotola
mesh_terms: D002405:Catheterization, Central Venous / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods*; D020878:Device Removal / Q000009:adverse effects* / Q000379:methods; D004618:Embolism, Air / Q000209:etiology* / Q000517:prevention & control*; D019544:Equipment Failure Analysis; D006801:Humans; D011474:Prosthesis Design; D011475:Prosthesis Failure; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D040242:Risk Reduction Behavior