Simulated haemodynamic parameters and different infusion set-up affect drug delivery during syringe pump change over: A bench-top study in a laboratory setting

Background: Infusion therapy is widely used in clinical settings, particularly in intensive care units. Aim: to explore the influence of simulated cardiac output on “bolus” or “backflow” events that can occur during syringe pump changeover, considering several factors that have been previously outlined in published research. Syringe infusion pumps are commonly used for precise continuous intravenous drug delivery. Syringe pump changeover can be a challenging procedure. Methods: Bench-top study in a laboratory setting. An extracorporeal circuit was used to simulate a cardiac output of 5 l/min. The following variables were used: three levels of vertical position of the syringe pump (−50 cm, 0, +50 cm), three levels of Central Venous Pressure (−5, 10, and 15 mmHg), presence/absence of carrier infusion (5 ml/h), and presence/absence of a needle-free connector between the syringe and extension line. Results: A total of 108 syringe pump changes were performed with different combinations of the investigated variables. The mean time for syringe pump changeover was equal to 9.48 ± 2.45 s and the overall fluid displacement was 8 ± 40 µL (microlitres) (range, −262–156 µL). The CVP level and vertical position of the pump always statistically affected the overall displacement during syringe pump changeover. When a second infusion with an equal velocity rate to that of a syringe pump infusion is present in the same lumen, the presence of a needle-free device reduces the overall volume of displacement. Conclusions: Syringe pump changeover can be a critical moment for patients when vasoactive drugs are administered. Implications for clinical practice: In a simulated environment with a cardiac output of 5 L/min, the CVP level and vertical position of the syringe pump generated bolus or backflow events during the syringe pump changeover. The application of carrier infusion appeared to intensify these phenomena. Employing a neutral, needle-free system can potentially aid in reducing the development of boluses or backflows.