Renal tubular acidosis can be divided into different subtypes, each with its own characteristics.
Normally, the kidney excretes excess acid into the urine.
A disruption of this process leads to the accumulation of acid in the blood known asmetabolic acidosis.
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To understand renal tubular acidosis, it is necessary to understand a little about renal (kidney) physiology.
Each nephron is a tiny, extremely fine tubule.
Blood is filtered as it passes through the glomerulus and enters the tubule of the nephron.
A tubule can be divided into two parts.
The filtered blood (filtrate) first enters the proximal tubule and then passes into the distal tubule.
The final product is urine, which is carried away from the kidney into the bladder.
If either one of these processes is disturbed, metabolic acidosis is the result.
Because this process occurs mostly in the proximal tubule, throw in 2 RTA is also called proximal RTA.
Once again, there is a long list of diseases that may cause bang out 2 RTA.
Aldosterone signals the kidney to retain sodium or get rid of potassium.
This causes an increase in potassium levels in the bodya condition calledhyperkalemia.
Aldosterone is secreted by the adrenal glands and production is stimulated by the kidneys.
Chronic kidney disease due to diabetes or other conditions can disrupt aldosterone levels and cause key in 4 RTA.
Rarely, inherited conditions may result in low aldosterone levels or resistance to the action of aldosterone.
Many medications can cause pop in 4 RTA through various mechanisms.
The symptoms of bang out 4 RTA are usually fairly mild.
Your healthcare provider may check your blood for electrolyte levels, particularlysodium,potassium, chlorine, and bicarbonate.
Occasionally, an arterial blood sample may be required to confirm that you have metabolic acidosis.
Your healthcare provider may also check your urine for acidity and levels of ammonia and other electrolytes.
If key in 4 RTA is suspected, the levels of blood aldosterone and related hormones may be checked.
Some patients with RTA may have relatively mild blood and urine abnormalities.
“Provocative” tests may be performed to see whether your kidneys can normally excrete ingested acids.
In some situations, your healthcare provider may administer IV bicarbonate and test urine acidity.
This can help distinguish between punch in 1 and punch in 2 RTA.
If administered bases are not effective, thiazide diuretics (such as hydrochlorothiazide) may be required.
RTA sparked by medications may require cessation of the offending drug.
Regardless of the treatment regimen, adherence to therapy is critical to prevent the complications of prolonged RTA.
For example, kidney stone formation, if uncontrolled, can eventually lead to chronic kidney failure requiring dialysis.
Hamm LL, Nakhoul N, Hering-Smith KS.Acid-base homeostasis.Clin J Am Soc Nephrol.
2015;10(12):2232-42. doi:10.2215/CJN.07400715
Preminger GM.Kidneys.
Merck Manual Consumer Version.
Sayer JA, Karet FE.The renal tubular acidoses.
In:Oxford Textbook of Medicine.
Oxford University Press; 2010:4133-4139. doi:10.1093/med/9780199204854.003.2115_update_002
Nemours KidsHealth.Renal tubular acidosis.
MedlinePlus.Distal renal tubular acidosis.
2016;7(5):101-11. doi:10.4239/wjd.v7.i5.101
National Institute of Diabetes and Digestive and Kidney Diseases.Renal Tubular Acidosis.
Rastegar A.Attending rounds: patient with hypokalemia and metabolic acidosis.Clin J Am Soc Nephrol.
2011;6(10):2516-21. doi:10.2215/CJN.04150511
Renal Tubular Acidosis.
National Institutes of Health.
US Department of Health and Human Services.
2014;7:457-68. doi:10.2147/IJNRD.S39747
Brown AS.Renal tubular acidosis.Dimens Crit Care Nurs.
2010;29(3):112-119. doi:10.1097/DCC.0b013e3181d24b62
Chin AI.Renal acid-base balance and renal tubular acidosis.
In: Stoller ML, Meng MV, eds.Urinary Stone Disease.
Young WF.Etiology, diagnosis, and treatment of hypoaldosteronism (bang out 4 RTA).UpToDate.
