title: Rapid infusion pump overestimates delivered flow during rapid vascular filling: a bench study.
abstract: OBJECTIVE
  Despite now being rarely used in the prehospital and emergency department arena because of their excessive length and low inner diameter, narrow-bore central venous catheters (CVC) are sometime used to perform fluid resuscitation using a rapid infusion pump to enhance delivered flow. In this bench study, we tested the hypothesis that the delivered flow rate downstream from the catheter connected to a rapid infusion pump would be significantly lower than the preset flow rate, and this difference would be affected by the catheter size.
  
  
  METHODS
  Eight units of each type of catheter [two 15 and 20 cm narrow-bore CVC and three 14, 16 and 18 G peripheral venous catheters (PVC)] were connected to a rapid infusion device and were tested with physiological saline. Measurements were repeated using glycerol solution with a viscosity similar to that of packed red blood cells. Infusion pump flow rates were preset to 100, 200, 300 and 400 ml/min. Flow rates were measured downstream from catheters, each connected to a rapid infusion device.
  
  
  RESULTS
  The downstream flow rate remained lower than the preset flow rate except with the 14 and the 16 G PVC at 100 ml/min (P<0.001). The type of catheter significantly impacted the flow rates measured with physiological saline (F4,105=1008.83, P<0.001) and glycerol solution (F4,105=1843.46, P<0.001).
  
  
  CONCLUSIONS
  Using a rapid infusion device, the delivered flow rate was lower than the preset flow rate. Even PVCs are better than narrow-bore CVC, neither is the most suitable cannula for patients requiring massive resuscitation.
authors.affiliation: Departments of aAnaesthesiology and Critical Care bEmergency Medicine and Surgery, Pitié Salpêtrière University Hospital cFaculty of Medicine, Pierre et Marie Curie University dVygon, Paris, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Le Noel
authors.forename: Martine
authors.initials: M
authors.lastname: Goffrais
authors.forename: Agnès
authors.initials: A
authors.lastname: Almayrac
authors.forename: Bruno
authors.initials: B
authors.lastname: Riou
authors.forename: Olivier
authors.initials: O
authors.lastname: Langeron
authors.forename: Mathieu
authors.initials: M
authors.lastname: Raux
mesh_terms: D002405:Catheterization, Central Venous / Q000295:instrumentation* / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data; D002406:Catheterization, Peripheral / Q000295:instrumentation* / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data; D006801:Humans; D007260:Infusion Pumps / Q000592:standards / Q000706:statistics & numerical data; D007262:Infusions, Intravenous / Q000295:instrumentation / Q000379:methods; D011312:Pressure; D014783:Viscosity