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6606564 
Journal Article 
Single Use Tracheal Tube Made of a Non-PVC Material 
Ohmura, A; Yahagi, N; Ogushi, M; Inai, K; Shibatani, K 
2002 
2002 
A-509 
BCI:BCI200300108531 
Introduction: Tracheal tubes made of flexible polyvinyl chloride (PVC) have been widely used because of the excellent mechanical properties and bio-compatibility of the material. Flexible PVC, however, has the problems of the elution of phthalate plasticizer during use and the generation of dioxins when incinerated at improper conditions after disposal. To solve these problems, cuffed Murphy-type tracheal tubes have been developed utilizing a new material, which contains neither of chloride and plasticizer. Tracheal tube manufacturing: The material used for extrusion and blow molding was basically the blend of hydrogenated styrene-isoprene-styrene thermoplastic elastomer (product by Kuraray, Japan. styrene content; 20 wt %, molecular weight; 113,000, degree of hydrogenation; 88 mole %, isoprene 1,4 bond; 55 %) and polypropylene (blend ratio 70/30 and 75/25). The material was found to have similar properties to flexible PVC. Through modification of the technology used to produce PVC components and assemblies, tracheal tubes were manufactured (Bates Industries, New York) to the similar configuration to the current products made of flexible PVC. Test Methods and Results: The performance of the tubes was tested according to the protocols of ISO 5361:1999(E). Every single tube tested (N = 10) passed all the specifications of the protocols including tube collapse, cuff symmetry and herniation. The nitrous oxide permeability coefficients of cuff materials measured at 25 degreeC using Gas Permeability Rate Analyzer (GTR-10, GTR TEC, Japan ) were 3.4x10-9 cm3cntdotcm/cm2cntdotscntdotcmHg for this new material and 9.1x10-9 cm3cntdotcm/cm2cntdotscntdotcmHg for the flexible PVC, respectively. The cuff pressure increase on exposure to nitrous oxide was measured using a test apparatus similar to that shown in the ASTM F1242-96 FIG. X2.1 without seal as one side of the cuff exposed to nitrous oxide-oxygen mixture and the other side to air. The pressure increase was significantly less with this material as compared to the flexible PVC as shown in Fig.1. Veterinarians who carried out intubations in pigs described their impressions of the new tubes comparable to the tubes made of flexible PVC. Discussion and Conclusions: We have developed a tracheal tube made of an entirely different material, which contains neither of chloride and phthalate. The tube showed comparable performance to the conventional tube made of flexible PVC and less permeability to nitrous oxide. It will not produce dioxins during incineration. The results suggest this new tracheal tube may have significant clinical and environmental implications.