Acidosis, Renal Tubular




Risk





  • Incidence in USA: Unknown



  • Present in a variety of disease states, from mild to severe systemic illness





Perioperative Risks





  • Hemodynamic instability (related to arteriolar vasodilation, acidosis, and decreased cardiac output)



  • Hyperkalemia



  • Insulin resistance and hyperglycemia



  • Acute respiratory failure





Perioperative Risks





  • Hemodynamic instability (related to arteriolar vasodilation, acidosis, and decreased cardiac output)



  • Hyperkalemia



  • Insulin resistance and hyperglycemia



  • Acute respiratory failure





Worry About





  • Decreased responsiveness to vasopressors and inotropes



  • Decreased activity of local anesthetic agents



  • Arrhythmias





Overview





  • RTA is a type of metabolic acidosis that is due to either abnormal bicarbonate loss or acid excretion by the kidneys in presence of a normal or near normal glomerular filtration rate.



  • Results in non-anion gap metabolic acidosis.



  • Metabolic acidosis not due to gastrointestinal bicarbonate loss or acute/chronic renal insufficiency.



  • Related to either proximal tubule dysfunction of bicarbonate reabsorption, failure of distal tubule excretion of acid, or mineralocorticoid deficiency.



  • Other findings may include recurrent nephrocalcinosis, growth retardation, and osteomalacia/rickets in children.



  • Can be either inherited, transient, or acquired.





Etiology





  • Distal RTA (type 1) is due to defective distal tubular H + secretion.




    • Clinical features include impairment of growth, polyuria, hypercalciuria, lithiasis, nephrocalcinosis, and K + depletion.



    • Acquired forms related to hypergammaglobulinemia, autoimmune disorders such as SLE or Sjögren syndrome, and pts with chronic liver disease.



    • Can be associated with sensorineural hearing loss.




  • Proximal RTA (type 2) is due to defective proximal tubule reabsorption of bicarbonate.




    • Manifests as stunted growth in children.



    • Can be associated with Fanconi syndrome, and if so, can manifest with osteomalacia and rickets.



    • Other causes include medications and toxins such as acetazolamide, aminoglycoside antibiotics, expired tetracyclines, lead, cadmium, and mercury.




  • Type 3 RTA is a combination of types 1 and 2.




    • Can be transient in pediatric pts with type 1 RTA.



    • Carbonic anhydrase II deficiency is an AutoR syndrome associated with osteoporosis, RTA, cerebral calcification, and mental retardation.




  • Hyperkalemic RTA (type 4): Due to either mineralocorticoid deficiency or hormone resistance




    • Most frequently observed in children with hypo- or pseudohypoaldosteronism



    • Also found to be related with diabetic nephropathy, SLE, and AIDS nephropathy



    • Drug induced causes include COX inhibitors, ACE-I’s, heparin, K retaining diuretics, trimethoprim, and others



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Sep 1, 2018 | Posted by in ANESTHESIA | Comments Off on Acidosis, Renal Tubular

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