Di-(2-ethylhexyl)phthalate leakage and color changes in endotracheal tubes after application in high-risk newborns.
BACKGROUND
Polyvinylchloride (PVC) is often adopted for making medical devices.


OBJECTIVE
Testing the hypothesis that materials degradation occurs in PVC endotracheal tubes during infant ventilation, thus releasing the known toxic plasticizer di-(2-ethylhexyl)phthalate (DEHP).


METHODS
Endotracheal tubes degradation was assessed by: (1) analysis of color and spectral changes in endotracheal tubes after use in the 400- to 700-nm range and compared to virgin samples. Color changes were expressed as euclidean distances in the Commission International de l'Eclairage Laboratory and Lightness-Chroma-Hue (Munsell's) color spaces (i.e., Delta E, Delta L, Delta a, Delta b, Delta C, and Delta H units); (2) DEHP leakage was assessed by thermal characterization by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Data from used tubes were compared with those from either virgin devices or submitted to artificial aging, including O(2)-induced oxidation, washing, UV photodegradation and exposition to acid solutions.


RESULTS
Significant color differences of 13.33 +/- 0.85 Delta E were evidenced in used endotracheal tubes, as compared to virgin samples (p < 0.0001). Chromatic changes were independent from intubation duration. DSC and TGA analyses showed a loss of DEHP from used tubes, as indicated by increase of the glass transition temperature (Tg) and DEHP weight loss. In vivo application of tubes was associated with an aging process whose effects on the optical and spectral properties were similar to those observed following artificial aging processes.


CONCLUSIONS
Our findings indicate that significant spectrocolorimetric, DSC and TGA changes occur in endotracheal tubes after application, thus demonstrating for the first time the occurrence of in vivo materials degradation and DEHP leakage from medical devices worldwide used for neonatal ventilation.
Latini
Giuseppe
G
Division of Neonatology, A. Perrino Hospital, Brindisi, Italy. gilatini@tin.it
De Felice
Claudio
C
Del Vecchio
Antonio
A
Barducci
Alessandro
A
Ferri
Marcella
M
Chiellini
Federica
F
D002152:Calorimetry, Differential Scanning; D003116:Color; D003124:Colorimetry; D004051:Diethylhexyl Phthalate; D004055:Differential Thermal Analysis; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007442:Intubation, Intratracheal / Q000295:instrumentation*; D008297:Male; D008422:Materials Testing / Q000379:methods*; D010968:Plasticizers; D011143:Polyvinyl Chloride; D012122:Ventilators, Mechanical
D010968:Plasticizers; D011143:Polyvinyl Chloride; D004051:Diethylhexyl Phthalate