title: Time-delay when updating infusion rates in the Graseby 3400 pump results in reduced drug delivery.
abstract: Infusion pumps are commonly used for infusion of drugs for physiologic control, and infusion rate has been demonstrated to affect the parameters of pharmacokinetic models. In attempting to develop a model that explained this behavior, we examined the behavior of the Graseby 3400 syringe pump under a range of flow conditions and with variations in syringe characteristics. Two issues were identified: start-up loss (the difference between actual and ideal delivery on initial infusion) and update loss (the difference between actual and ideal delivery when transmitting a command to change infusion rate). Under worst-case conditions, this may result in a 20-second period of zero delivery during start-up, and when updating infusion rates once per second, zero output. These effects are influenced by syringe characteristics and vary sufficiently as to make it impossible to isolate this effect from the pharmacokinetic process being controlled. The implications of this for previous published results and clinical application of target-controlled infusions are discussed.
authors.affiliation: From the Department of Anesthesiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Elie
authors.initials: E
authors.lastname: Sarraf
authors.forename: Jeff E
authors.initials: JE
authors.lastname: Mandel
mesh_terms: D016503:Drug Delivery Systems / Q000295:instrumentation* / Q000379:methods / Q000592:standards; D004867:Equipment Design / Q000295:instrumentation* / Q000592:standards; D007260:Infusion Pumps / Q000592:standards; D007262:Infusions, Intravenous; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D013997:Time Factors
chemical_list: D004364:Pharmaceutical Preparations