Monitorización de la respuesta al tratamiento de hemodiálisis mediante el análisis bioquímico de la saliva y la determinación de amonio en el aire exhalado

Abstract

Renal failure is a process that expresses a loss of functional capacity of the nephrons, independently of its aetiology. Although acute renal failure is reversible in the majority of cases, chronic renal failure (CRF) presents a progressive course towards terminal renal failure, even if the cause of the initial nephropathy disappears. Chronic Kidney Disease (CKD) has received increasing attention since publication of the National Kidney Foundation¿s chronic kidney disease guidelines in 2002. This document described a 5-stage CKD classification system, using microalbuminuria and estimated glomerular filtration rate (GRF) to define the level of kidney damage. When the GFR is < 15 ml/min (terminal renal failure), it is necessary to start renal replacement therapy to avoid the serious medical complications which can lead even to the death of the patient. Hemodialysis is the most widely used renal replacement technique. Chronic renal failure can give rise to a wide spectrum of oral manifestations affecting the hard and/or soft tissues of the mouth. There is no consensus in the literature regarding the predisposition of these patients to dental caries. Most studies demonstrated that hemodialysis patients have lower prevalence of caries while other investigations show higher dental caries rates. Several studies showed that oral hygiene care is reduced in end stage renal disease patients compared with controls. Most studies have reported high levels of dental plaque and calculus, increased number of teeth with clinical attachment loss, more missing teeth and gingival inflammation in the terminal renal failure population than in healthy control subjects. Dialysis leads to systemic dysfunctions as well as alterations in the salivary flow and the biochemical composition of the saliva. Salivary function including lubrication, buffering action, maintenance of tooth integrity, antibacterial activity, and taste and digestion, may by disturbed by saliva flow and biochemical alterations. The distinctive odor of the breath of patients with renal failure, usually termed the ¿uremic fetor¿ is frequently described as ammoniacal and its potency is generally believed to reflect the uremic state. It has been suggested that the analysis of ammonia in exhaled air has the potential to be an effective substitute for Blood Urea Nitrogen (BUN) for monitoring the effectiveness of hemodialysis. The main aims of this study are: to determine the ammonia levels in exhaled air in terminal renal failure patients before and after a hemodialysis session, by applying a new colorimetric test; to analyze if any relationship exists between the organoleptic mouth-odor ratings and the ammonia levels in exhaled air; and to investigate if there is any correlation between the ammonia concentrations in exhaled air, blood and/or saliva.