- •Net acid production (NEAP) in individuals with normal kidney function and CKD results from metabolism of ingested animal protein (H+) and fruits and vegetables (base) and is similar, approximately 1 mEq/kg/d.
- •Reduction in renal acid excretion with CKD is primarily due to reduction in ammonium excretion which can fall below acid production, with the decrease in ammonium excretion being primarily caused by a reduction in ammonium production and possibly alterations in ammonium transport.
- •With mild reductions in GFR (60 to 80 mL/min), net acid excretion may fall below net endogenous acid production levels resulting in acid retention which is initially sequestered in the interstitial compartments in kidney, bone, and muscle resulting in no apparent systemic acid-base disturbance (eubicarbonatemic metabolic acidosis), while with greater reductions in GFR (<60 mL/min), the greater quantities of acid retained spillover systemically resulting in low blood pH (overt metabolic acidosis).
- •Evaluation of acid-base balance in patients with a decrease in GFR should include measurement of serum blood gases and, in some instances, urinary citrate and urinary ammonium levels.
The Net Endogenous Acid Production
Kidney Bicarbonate Reclamation in CKD
- Buerkert J.
- Martin D.
- Trigg D.
- et al.
Titratable Acid Excretion in CKD
Ammonia Production and Transport with Normal Kidney Function
Ammonia Production and Transport in CKD
- Buerkert J.
- Martin D.
- Trigg D.
- et al.
- Buerkert J.
- Martin D.
- Trigg D.
- et al.
Stages of Acid Retention in CKD
Acid-Base Parameters and Electrolyte Profile in CKD
Evaluation of Acid-Base Balance in Chronic Kidney Disease
Other Measures of Acid-Base Balance in CKD
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Financial Disclosure: The authors declare that they have no relevant financial interests.
Support: See Acknowledgments on page 341.