A breath ammonia analyser for monitoring patients with end-stage renal disease on haemodialysis.

OBJECTIVE: Breath ammonia measurement has attracted increasing interest for clinical diagnosis and metabolic status monitoring. This pilot study aims to evaluate a simple detection method to measure breath ammonia levels in haemodialysis patients. MATERIALS AND METHODS: The study group comprised 44 adults undergoing haemodialysis and a control group of 44 age- and sex-matched individuals with a glomerular filtration rate >90 mL/min. To measure breath ammonia concentration, we designed a device based on that used to monitor atmospheric air, which uses a specific colorimetric tube. A single operator took two readings from each haemodialysis patient (one predialysis and one postdialysis) and one reading from each control. The results were compared with the urea concentrations in blood and saliva. RESULTS: Breath ammonia concentration correlated significantly with blood urea both predialysis (P < 0.001; R2 = 0.55) and postdialysis (P = 0.009; R2 = 0.25), as well as with predialysis saliva urea concentration (P < 0.001; R2 = 0.24). Ammonia was not detectable in breath of any of the control group. CONCLUSIONS: The collection of breath samples in polyvinyl fluoride bags and their subsequent analysis using colorimetric tubes is a simple, noninvasive method that enables variations in breath ammonia concentration to be measured rapidly in haemodialysis patients. Using this method, we found that the breath ammonia concentration correlated significantly with the blood urea concentration before and after haemodialysis.

Early tooth loss in end-stage renal disease patients on haemodialysis.

OBJECTIVE: This article sets out to evaluate the prevalence and aetiopathogenesis of edentulism in patients on haemodialysis. SUBJECTS AND METHODS: The study group comprised 44 adult patients with end-stage renal disease (ESRD) on haemodialysis. A control group was formed of 44 individuals matched for age and sex and with a glomerular filtration rate >90 ml min(-1) . All participants underwent intra-oral examination, gathering information on dental and periodontal status, and a saliva sample was taken to determine saliva debit and its biochemical composition. RESULTS: The average number of missing teeth was higher in ESRD patients than in controls (P = 0.018). Six (13.6%) fully edentulous individuals were detected in the study group and 1 (2.2%) in the control group. Some of the clinical and biochemical variables with statistically significant differences between the study group and the control group showed a significant relationship with the number of missing teeth, but the depth of the periodontal pockets presented the highest coefficient of determination (OR = 3511.1; 95%CI = 82.2-6834.3; P < 0.001; R(2)  = 0.827). CONCLUSIONS: Premature tooth loss is common in haemodialysis patients. Although the aetiology and pathogenesis of this finding has still not been fully clarified, it appears that severe periodontal disease may play a relevant role.