The infusion of vasoactive drugs in preterm babies using syringe pumps can be complicated by important variations in the infusion rate.
Aims of the study: 1) to assess the time between pump start and the actual presence of a substance in the circulation, when using slow rates; 2) to evaluate the effects of changes in the main infusion rate on substance rates infused on the same line.
Methods: We used 10% glucose to mimic vasoactive drugs. The main infusion consisted of saline, and both were infused on the same line using syringe pumps. Glucose concentration was measured at the end of the line.
Results: The time between pump start and the actual infusion of glucose depended on syringe volume and on the adjustment of the syringe in the pump. There was a transient increase in glucose rate when the main rate increased, and a transient decrease when the main rate decreased.
Conclusion: To minimize the time before a substance is actually infused, one should use low volume syringes and correctly adjust the syringe in the pump. Moreover, when a steady infusion rate is necessary, one should avoid variations in the main infusion rate.