Usefulness of breath ammonia measurement in hemodialysis patients

The relationship between the levels of breath ammonia, blood urea nitrogen (BUN), and blood ammonia was examined by using a gas detector tube (No. 3La, Gastec Co., Tokyo) in 25 hemodialysis patients, and the usefulness of this method was evaluated. The subjects consisted of 16 males and 9 females. Their mean age was 57 years, and the mean hemodialysis period was 74 months. As complications, 8 of the subjects had hepatic diseases, and another 6 had diabetes mellitus. As controls, 92 patients who did not have severe hepatic or renal diseases were examined. The breath ammonia level (mean±SD) before hemodialysis was 23.8±25.6ppm in the hemodialysis patients, which was significantly higher than the 2.7±1.7ppm level of the controls. Before hemodialysis, breath ammonia levels in patients were related to BUN levels, but not to blood ammonia levels. After hemodialysis, the breath ammonia level decreased to 8.2±9.6ppm, but it was not related to either the BUN or the blood ammonia level. In hemodialysis patients, increases in breath ammonia were related to the BUN level. Measurement of the breath ammonia level by using this simple method is useful for determining the physical condition of hemodialysis patients.