食道内pHモニタリング(pH検査)は,現在,胃食道逆流症(GER)の評価法として最も信頼度が高いが,乳児では哺乳による影響で胃内pHが高い傾向にあり,GERの評価に影響を及ぼすといわれている.我々はGER症状を有する乳児81例について,日常生活と同じ授乳法でpH検査を施行しGERも評価しているが,その際の胃内pHの影響について検討した.これらの症例には消化管造影,内圧検査も施行した.[結果](1)胃内pH<4の時間率は,乳児期の月齢に従って上昇する.(2)日常生活と同じ授乳法で行ったpH検査のGERの評価は,胃内pHに影響されなかった.(3)胃排出能遅延は,81例中15例に認められたが,胃内pHとの関連は認められなかった.(4)pH検査にてGER陰性であった36例中20例は消化管造影によるGERは陽性,内圧検査にて下部食道括約筋(LES)圧の異常値は24例,食道蠕動異常は18例に認めた.これらの症例には,当科のGERの治療プロトコールに従って治療を行い,全例,症状は軽快した.[結論]乳児では,哺乳により胃内pHは変動するものの,日常生活と同じ授乳法によるpH検査は,そのGERの評価が,胃内pH<4の時間率に関係することなく,乳児におけるGERの評価に有用であった.しかしGERの病態を把握するためには,pH検査のみでなく,内圧検査や放射線学的検査も行い,胃食道機能の全体的な評価をすることが必要であると思われた.Prolonged intraesophageal pH monitoring has become the preferred test to quantify acid gastroesophageal reflux (GER). We have performed this procedure concurrent with a regular feeding schedule as patients experienced symptoms in a similar environment. Hence, milk feedings tended to buffer gastric acidity, we attempted to investigate the influence of gastric pH on the evaluation of esophageal pH monitoring. Gastric and esophageal pH were simultaneously recorded by two separate pH electrodes for more than 20 hours in 81 infants (0～11 months) with GER symptoms. Radiological evaluations of GER and gastric emptying with barium and manometric studies were also performed in these infants. The results of this study indicate that: 1) Percentage of time with gastric pH < 4 increases with age in infancy. 2) Gastric pH is statistically not related to the evaluation of GER on esophageal pH monitoring. 3) Significantly delayed gastric emptying occurred in 15 out of the cases studied, however, gastric pH is not related to the delay. 4) In 36 cases that GER was negative on pH monitoring, GER was documented during radiological study in 20 cases, the abnormalities of lower esophageal sphincter (LES) pressure showed in 24 cases, and esophageal dysmotilities occurred in 18 cases on manometric study. These cases with abnormal findings were successfully treated followed by our treatment protocol for GER. In conclusion, prolonged esophageal pH monitoring with regular feeding is independent of the gastric acidity in infancy, and the method is useful to evaluate pathological GER. However, radiological and manometric studies, in addition to pH monitoring, should be required to evaluate the total gastresophageal function.東京女子医科大学附属第二病院小児科開局30周年記念論文
