Connecting multiple low-flow intravenous infusions in the newborn: problems and possible solutions.

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.