RESUMEN
OBJECTIVE: To compare the efficiency of a stopcock system and a newly designed device to titrate low-flow infusions to critically ill infants. DESIGN: In vitro study comparing fluid delivery through readily available and custom-built equipment. SETTING: Engineering laboratory of a university-affiliated hospital. PATIENTS/SUBJECTS: None. INTERVENTIONS: Two infusion pumps were used to deliver five 0.1-mL/hr infusions and an 8-mL/hr carrier through a conventional stopcock system. A diluted dye was used to quantize the amount of any given infusion reaching the patient. Samples were collected over a 90-min period and analyzed by spectophotometry. Thirty minutes into each trial, the red dye infusion rate was doubled. A multiple infusion connector was manufactured and tested in place of the stopcock system. Without a stopcock system or multiple infusion connector, both an infusion and a syringe pump were tested for accuracy of delivery of 0.1 mL/hr and 0.2 mL/hr of dye infusions. MEASUREMENTS AND MAIN RESULTS: The infusion pump was more accurate than a 60-mL syringe pump in generating infusion rates of both 0.1 mL/hr and 0.2 mL/hr. When delivering a 0.1-mL/hr dye infusion through the distal port of an array of six stopcocks, the actual delivery of a diluted red dye infusion took approximately 32 mins to double after being increased from 0.1 mL/hr to 0.2 mL/hr. When using the multiple infusion connector to connect the low-volume drips together, the same change in flow rate caused the actual delivery of dye to double in <8 mins (a result comparable to the data from the proximal port of a stopcock). This result was independent of which port was used for dye delivery. Streaming of the red dye within the stopcock system was observed. CONCLUSIONS: When using the conventional stopcock array to titrate low-rate infusions, significant delays were observed. A device designed specifically for infusions in infants may substantially improve this system.