Critical parameters in drug delivery by intravenous infusion

Introduction: Intravenous infusion is commonly used to deliver medications and fluids to patients. The duration of an infusion is short (hours) in the operating room where intravenous agents are infused to anesthetize patients and to manage circulation. Critically ill patients often receive infusions for days. Infusion technology has become increasingly sophisticated and complex. The technical advances broaden the clinical application of intravenous infusion methodology and provide safety features. Areas covered: This article provides an historical overview of intravenous infusion and discusses components of infusion systems. A section describes configuration of components to meet clinical needs. The article describes physical properties of infusion systems, emphasizing how critical parameters of resistance to flow, infusion pump performance and interactions between fluid flows and the dead volume influence medication and fluid delivery. The authors emphasize the use of infusions in the intensive care and operating room environments, although the general principles apply to other clinical settings. Expert opinion: Intravenous infusion systems contribute significantly to clinical care, but in a deceptively simple way. Several critical parameters combine to influence the performance of an infusion system, with a number of pitfalls potentially confounding utility of the technology. Safe and effective clinical application of intravenous infusion technology depends on an appreciation of this complexity which impacts the performance of infusion systems.