An in vitro evaluation of infusion methods using a syringe pump to improve noradrenaline administration

International guidelines recommend noradrenaline (NA) as the vasopressor of choice to treat septic shock. The aim of this study was to determine the best way to infuse patients with NA.

The in vitro study was designed to measure NA concentration at the end of each studied assembly line. Three infusion systems used the double pump method and three single pumps, which differed as regards NA concentrations (0,2 - 0,5 - 1 mg/h), dead space volume of the devices and the use of saline. Infusion systems were compared according to the time necessary to reach an NA mass flow rate steady-state plateau after the onset of infusion or after a flow change.

Times were significantly different between the six methods for infusing NA. The system using the double syringe method with a standard extension set was the longest to reach the steady state after the onset of infusion [40.00 min (19.57 - 49.22)]. The steady-state plateau was obtained most rapidly with the double-syringe pump systems using very low dead-space volume extension sets and single-syringe pump systems containing diluted noradrenaline at the beginning of NA infusion.

A combination of a low dead-space volume extension set and a double pump method with a constant saline flow rate at 5 ml/h might be the solution to provide the most reliable NA infusion delivery.