I am not sure whether, by the term ‘acid’, you are meaning
the accumulation of organic and inorganic acids normally excreted by the kidneys but which, in lay-mans terms, ‘build up’ due to the failure of adequate clearance as kidney funtion declines, and which then leads to the chronic metabolic acidosis of CKD.
the occurrence of the ‘acid’ of indigestion … the ‘acid’ which accompanies gastro-oesphageal reflux (or GORD) - in the US you would probably spell that as esophageal and GERD …which so commonly troubles patients with CKD.
One of the functions of dialysis is to remove and/or ‘buffer’ (neutralise) with bicarbonate the acids which build up during the period between dialyses. Chronic metabolic acidosis can affect several body systems but, commonly, it affects bone metabolism. In CKD (before dialysis), this is commonly treated with ‘mother’s baking soda’ … or sodium bicarbonate … though this can lead to a significant sodium load and in turn, worsen blood pressure and the strain on the heart. Often treatment becomes a ‘trade off ‘or balance between the correction of the acidosis on the one hand vs the effect that treatment has on volume, blood pressure and the heart on the other.
As regards the ‘acid’ of heartburn, there is some data … the Japanese have published on this … which suggests that GORD is more common in CKD and dialysis patients than in others. There is a ‘sphincter’ – a muscular ‘ring’ - at the lower end of the oesophagus - you may find it referred to as the lower esophageal sphincter or LES or, in our literature, the cardiac sphincter - which is normally contracted and which thus prevents the regurgitation (reflux) of the normally acid content of the tummy back up into the lower end of the oesphagus. This sphincter appears to trend to relaxation or becomes ‘patullous’ (lax) in some patients with CKD/dialysis.
Why? ... I don’t know the answer ... but, what sphincter 'malfunction' does allow, however, is the trickle, trickle of acid content back up into the oesophagus – especially when lying flat at night. This irritates, inflames and ‘burns’ the lining of the lower end of the gullet (oesphagus) and causes symptoms of reflux or heartburn.
In addition, many of the pills we use can irritate the lining of the upper gastroinestinal tract and contribute to heartburn ‘acid’.
There are many treatments for the acid reflux of heartburn ... both medical, dietary and positional … and your doctor will discuss and manage these.
As for the removal and/or neutralising of the ‘acids of metabolism’ … this is one of the integral functions of dialysis. The bicarbonate level will fall between dialysis treatments and be restored during dialysis as ‘hydrogen ion’ is removed or buffered.
While there are some differences between conventional dialysis and longer hour and/or frequency dialysis in the efficiency and effectiveness of buffering – and the bicarbonate concentration achieved during dialysis – this is something your local team can help you with and they will make any necessary adjustments to your dialysis regime.