title: Influence of microcatheter length on flow rates of disposable infusion kits.
abstract: OBJECTIVE
  Continuous spinal analgesia (CSA) offers considerable pain relief, and has been used in various procedures such as for surgery and cancer pain control. In Japan, portable and disposable infusion kits are increasingly employed for continuous epidural analgesia and CSA. In CSA, the use of a microcatheter is expected to reduce the incidence of spinal headache previously encountered with larger catheters. However, the flow rate of disposable infusion kits is reduced when used in conjunction with a microcatheter.
  
  
  METHODS
  This study aimed to investigate the influence of catheter length on the flow rate of two different devices: 20- or 91-cm 28-G microcatheters connected to balloon- or syringe-type infusion pumps were examined (50 mL, 1 mL h(-1)). There were four groups each of 10 experiments: Group A: balloon-type infuser, 91 cm catheter; Group B: balloon-type infuser, 20 cm catheter; Group C: syringe-type infuser, 91 cm catheter; Group D: syringe-type infuser, 20 cm catheter.
  
  
  RESULTS
  The mean flow rate in Group A was significantly less than that in Group B and the mean flow rate in Group C was significantly less than Group D (P < 0.05).
  
  
  CONCLUSIONS
  These results indicated that the use of a shorter microcatheter achieves a better flow rate during CSA.
authors.affiliation: Department of Anaesthesiology, Kyoto Prefectural University of Medicine, Kyoto, Japan. kasai@koto.kpu-m.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Kasai
authors.forename: M
authors.initials: M
authors.lastname: Hirose
authors.forename: K
authors.initials: K
authors.lastname: Yaegashi
authors.forename: T
authors.initials: T
authors.lastname: Fujita
authors.forename: Y
authors.initials: Y
authors.lastname: Hirai
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D015360:Analgesia, Epidural / Q000295:instrumentation* / Q000592:standards; D000704:Analysis of Variance; D002404:Catheterization / Q000295:instrumentation*; D004209:Disposable Equipment / Q000592:standards*; D004867:Equipment Design / Q000379:methods; D006801:Humans; D007260:Infusion Pumps / Q000592:standards*; D013997:Time Factors