Blood and breath profiles of volatile organic compounds in patients with end-stage renal disease

Abstract

BackgroundMonitoring of volatile organic compounds (VOCs) in exhaled breath shows great potential as a non-invasive method for assessing hemodialysis efficiency. In this work we aim at identifying and quantifying of a wide range of VOCs characterizing uremic breath and blood, with a particular focus on species responding to the dialysis treatment.MethodsGas chromatography with mass spectrometric detection coupled with solid-phase microextraction as pre-concentration method.ResultsA total of 60 VOCs were reliably identified and quantified in blood and breath of CKD patients. Excluding contaminants, six compounds (isoprene, dimethyl sulfide, methyl propyl sulfide, allyl methyl sulfide, thiophene and benzene) changed their blood and breath levels during the hemodialysis treatment.ConclusionsUremic breath and blood patterns were found to be notably affected by the contaminants from the extracorporeal circuits and hospital room air. Consequently, patient exposure to a wide spectrum of volatile species (hydrocarbons, aldehydes, ketones, aromatics, heterocyclic compounds) is expected during hemodialysis. Whereas highly volatile pollutants were relatively quickly removed from blood by exhalation, more soluble ones were retained and contributed to the uremic syndrome. At least two of the species observed (cyclohexanone and 2-propenal) are uremic toxins. Perhaps other volatile substances reported within this study may be toxic and have negative impact on human body functions. Further studies are required to investigate if VOCs responding to HD treatment could be used as markers for monitoring hemodialysis efficiency.

A Compendium of Volatile Organic Compounds (VOCs) Released By Human Cell Lines

“…Breath volatiles mainly would be derived from living cells of the body and eventually also from the presence of infectious agents, while feces will contain a small fraction of cells derived from the gut lining and a substantial fraction of bacteria. A particular focus of VOC research has been on their possible use as bio-markers for various diseases [19-22], most promi-nently cancer [4, 21-33], but also liver [34-37], or renal diseases [38-41]. However, the problem with selection of breath biomarkers for cancer is very complex and advanced quantitative statistical tests need to be applied as those compounds are typically present not only in cancer patients but also in healthy controls, hence the clinical relevance could not be demonstrated for any of the so far reported candidate VOCs.…”

Exhaled volatile substances mirror clinical conditions in pediatric chronic kidney disease

“…Since then, several studies on the breath profile of volatile organic compounds (VOCs) have been performed with adults on hemodialysis [2–7] and evidence was obtained that the breath profile is already affected as renal function is only mildly impaired [5]. …”

The Measurement of Ammonia in Human Breath and its Potential in Clinical Diagnostics

“…Breath ammonia levels have been used to study uraemia breath during haemodialysis, which has also been found to correlate with BUN (Mochalski et al, 2014;Romero-Gomez et al, 2001). However, anomalies still remain over the use of breath ammonia as a surrogate for BUN, as some have shown that there is no correlation between blood ammonia and blood nitrogen levels (Imran et al, 2012).…”