Extraction of the plasticizers diethylhexylphthalate and polyadipate from polyvinylchloride nasogastric tubes through gastric juice and feeding solution

Objectives: Except for polyadipate, which is used as an alternative in polyvinylchloride (PVC) feeding tubes, diethylhexylphthalate (DEHP) is the plasticizer used almost exclusively in PVC medical products. A clear response to the chronic intake of DEHP has been shown in several organ systems from different species. In the present study, we compared the extraction of DEHP and polyadipate from PVC gastric tubes. Methods: An in vivo setting was simulated. We used 5 cm of PVC nasogastric tubes containing DEHP or polyadipate, which were incubated with gastric juice for I week and a feeding solution for 4 weeks. The leakage of these plasticizers was measured daily in the gastric juice group and weekly in the feeding solution group. The amount of plasticizer extracted was compared between groups and days. Results: In the feeding solution group, the extraction of DEHP ranged from 200 to 542 mu g after I week and from 660 to 1700 mu g after 4 weeks. The extraction of polyadipate was 10 times lower than that of DEHP. In the gastric juice group, extracted DEHP ranged from 635 to 1043 mu g, whereas the extraction of polyadipate was 100 times lower. Conclusions: Within I week, the extraction of DEHP from a 5-cm PVC tube reaches up to I mg. Extrapolated, this represents an in vivo load of up to 4 mg. The load accumulated by a newborn in an intensive care unit can therefore easily reach several milligrams of DEHP per day. Polyadipate nasogastric tubes may therefore be an alternative and help to reduce the daily load of DEHP.