Background: For infusion therapy, polyvinylchloride (PVC)-infusion lines are commonly used. In this study, we examined the temperature dependency and the dynamics of extraction in the time course of infusion.
Methods: PVC-infusion lines used on the newborn ICU were perfused with a typical 24-hour fat infusion. We collected the perfused solution and measured the concentration of DEHP. This procedure was carried out at 27 degrees C and 33 degrees C. In another experiment, we examined the extraction rate in the time course of a 24-hour infusion. The infusion was collected every 4 hours.
Results: We discovered that extraction of DEHP depends highly on the surrounding temperature. Whereas at 27 degrees C, the extraction of DEHP was 422.78 microg/mL, the leaching reached 540.78 microg/mL at 33 degrees C under otherwise identical conditions. This is important because the temperature on a newborn ICU is between 31 and 37 degrees C in an incubator. In the other experiment, we found out that the extraction rate rose from 25.44 microg/mL in the first 4 hours to 478.1 microg/mL after 24 hours.
Conclusions: The result of this study is that the actual daily load of DEHP for a 2-kg newborn is 30% higher than measured before. The rate of extraction is dependent on the time of contact between solution and tubing. If PVC-infusion systems are used, solutions should be as cold as possible, and infusion time should be as short as possible.