title: Intravenous fluid resuscitation: was Poiseuille right?
abstract: OBJECTIVE
  To compare the flow rates of readily available intravenous infusion devices and to compare the effect of the addition of pressure or a needle-free intravenous connector device.
  
  
  METHODS
  Several intravenous devices with different characteristics had their flow rates determined under a standard set of conditions. The flow rates were then measured with the addition of a pressure bag to the system and then with a needle-free intravenous connector device. The flow rates and change in flow rates were then analysed.
  
  
  RESULTS
  The results showed a general agreement with Poiseuille's law. The needle-free connector slowed the rate of flow by up to 41.4% with the greatest effect on short, wide-bore devices. The addition of pressure had a greater effect on longer devices.
  
  
  CONCLUSIONS
  Short, wide cannulae should be used when rapid fluid resuscitation is required. Needle-free devices should not be used when rapid fluid resuscitation is needed.
authors.affiliation: Emergency Department, Ninewells Hospital, Dundee DD1 9SY, UK. andrew.reddick@nhs.net
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Reddick
authors.forename: Julie
authors.initials: J
authors.lastname: Ronald
authors.forename: William G
authors.initials: WG
authors.lastname: Morrison
mesh_terms: D002405:Catheterization, Central Venous / Q000295:instrumentation*; D057785:Catheters; D004867:Equipment Design; D005440:Fluid Therapy / Q000295:instrumentation*; D006801:Humans; D057446:Hydrodynamics; D007262:Infusions, Intravenous / Q000295:instrumentation*; D013997:Time Factors