経内視鏡的ポリープ摘除術における消化管内ガスの防爆対策に関する研究

The recent improvements on both technic and instrument have made endoscopic polypectomy easier and safer. The endoscopic polypectomy has become popular, but complications such as bleeding, perforation, electric short circuit and intestinal gas explosion have still been reported on occasions. One hundred and fifty six samples of intestinal gas from 117 cases are collected in three ways such as during colonoscopy, surgical operation and autopsy. Through the analysis of three groups, it was comfirmed that inflammable gas; hydrogen was the highest in surgical operation group, followed by autopsy group. On the contrary methane was the highest in autopsy group. Therefore inflammable gas was found to be explosive in surgical operation and autopsy group. It is surprising that the highest score of hydrogen was 48.03 vol% in surgical operation group. Both hydrogen and methane were noted at the lowest concentration in colonoscopy group. The anesthetic gas; dinitrogen oxide appeared only in surgical operation group, due to a dead space effect caused by GOF inhalation. It may be contributed to replacement as incombustible gas for prevention of intestinal gas explosion. Ordinarily we use a modified Brown's preparation. Using magnesium citrate and low fat and no residue diet, it was cofirmed that hydrogen concentration is definitely lower than inadequate preparation. A direct method of preventing intestinal gas explosion is effective when the incombustible calbon dioxide gas is insufflated before endoscopic polypectomy. It is necessary to insufflate carbon dioxibe for more than 150 sec, using suction and insufflation repeatebly. If the two channel fiberscope is used for polypectomy, suction and insufflation can be manuplated conveniently at the same time through the empty channel. Recent models install the insufflation channel and button for carbon dioxide. The premixed gas (N₂O+O₂) inhalation is useful to prevent intestinal gas explosion utilizing the dead space effect during endoscopic polypectomy.