A Review of the Restrictive Flow Infusion Devices Available for Parenteral Drug Therapy

Abstract

Restrictive flow devices use a restriction to control the outflow of pressurised fluid. The two most common types of restrictive flow device available are elastomer and spring powered. The former includes the Homepump, lnfusor and Intermate and they consist of a highly elastic, pressure‐distendable bladder that functions as a reservoir and pressurises the drug solution within. A spring is used in the Springfusor to apply force to the piston of a syringe, and in the Paragon and SideKick to pressurise an infusion bag. These devices offer a portable, self‐powered, cost‐effective alternative to electronic pumps for many applications. The major limitations are their dose inflexibility and accuracy. Users should be aware of the operating conditions that affect flow rate, and since flow rate is described by Poiseuille's law, these include temperature, drug concentration, hydrostatic pressure and the addition of narrow lumen catheters. Aust J Hosp Pharm 1997; 27: 115–24.