title: Flow increases with an enlarging intravenous catheter.
abstract: OBJECTIVE
  To determine the increase in flow of a hydratable enlarging intravenous (IV) catheter in anesthetized patients.
  
  
  METHODS
  A randomized, nonblinded study, with standard Teflon IV catheters used as controls.
  
  
  METHODS
  Operating room at a university medical center.
  
  
  METHODS
  Thiry adult patients receiving general anesthesia for lower extremity surgery.
  
  
  METHODS
  An IV catheter was placed in the upper extremity, and flow measurements were made by measuring the time for infusion of 250 ml of normal saline within 1 minute after placement and at 1 hour after placement.
  
  
  RESULTS
  The enlarging catheters had a statistically significant average flow increase of 26% after 1 hour indwelling time. The standard Teflon catheters had no statistically significant change in flow after 1 hour. The percentage increase in flow for the enlarging catheters was not as great as previously seen in vitro.
  
  
  CONCLUSIONS
  Flow through enlarging IV catheters placed in anesthetized patients increases after 1 hour. The percentage increase in flow is not as great as previously seen in vitro and may be due to skin, vein, and subcutaneous tissues preventing complete expansion.
authors.affiliation: Department of Anesthesiology, School of Medicine, University of California, San Diego.
authors.forename: B R
authors.initials: BR
authors.lastname: Jones
authors.forename: M S
authors.initials: MS
authors.lastname: Scheller
mesh_terms: D000328:Adult; D000768:Anesthesia, General; D002406:Catheterization, Peripheral / Q000295:instrumentation*; D005440:Fluid Therapy / Q000295:instrumentation*; D006801:Humans