Nobuyuki Uchida, Michiaki Kudo, Yutaka Suzuki, Hirohito Muramatsu, Tomoyuki Ohta, Mikako Takahashi, Yukitsugu Arimoto, Chikou Kimura, Yasuto Itano, Toshiroh Kura, Yorihiro Nishiyama, Kazuhiko Ishida, Takao Endo, Masato Nakahori, Akihiko Itoh, Masashi Ijima, Tsuyoshi Iwase, Shingo Fukasawa, Toshiro Kusakabe, Satoshi Goshi, Hideki Yoshida, Akihiro Mizuhara, Mitsuyoshi Urashima, Koji Onishi, Akihiko Taira, Masami Matsumoto, Takao Iiri, Shinichi Takei, Shigeo Sakamoto, Satoyoshi Yamashita, Tetsushi Ogawa, Izumi Ishizuka, Makoto Kobayashi, Yutaka Tamamori, Yukio Nishiguchi, Toshiya Kobuke, Shinji Nishiwaki, Nobuaki Kajitani, Shin Imazato, and Makoto Shimazaki
Background During tube exchange for percutaneous endoscopic gastrostomy (PEG), a misplaced tube can cause peritonitis and death. Thus, endoscopic or radiologic observation is required at tube exchange to make sure the tube is placed correctly. However, these procedures cost extensive time and money to perform in all patients at the time of tube exchange. Therefore, we developed the "sky blue method" as a screening test to detect misplacement of the PEG tube during tube exchange. Methods First, sky blue solution consisting of indigocarmine diluted with saline was injected into the gastric space via the old PEG tube just before the tube exchange. Next, the tube was exchanged using a standard method. Then, we checked whether the sky blue solution could be collected through the new tube or not. Finally, we confirmed correct placement of the tube by endoscopic or radiologic observation for all patients. Results A total of 961 patients were enrolled. Each tube exchange took 1 to 3 minutes, and there were no adverse effects. Four patients experienced a misplaced tube, all of which were detectable with the sky blue method. Diagnostic parameters of the sky blue method were as follows: sensitivity, 94% (95%CI: 92-95%); specificity, 100% (95%CI: 40-100%); positive predictive value, 100% (95%CI: 100-100%); negative predictive value, 6% (95%CI: 2-16%). Conclusion These results suggest that the number of endoscopic or radiologic observations to confirm correct replacement of the PEG tube may be reduced to one fifteenth using the sky blue method.