Metabolic acidosis: Difference between revisions

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*Compensatory respiratory tachypnea
*Compensatory respiratory tachypnea


== Differential Diagnosis==
==Differential Diagnosis==
{{Anion gap metabolic acidosis}}
{{Anion gap metabolic acidosis}}


=== Non-gap ===
===Non-gap===
*[[Hyperkalemia]]
{{Non anion gap acidosis}}
**Resolving [[DKA]]
**Early uremic acidosis
**Early obstructive uropathy
**[[RTA Type IV]]
**Hypoaldosteronism
**K-sparing diuretics
*[[Hypokalemia]]
**[[RTA Type I]]
**[[RTA Type II]]
**[[Acetazolamide]]
**Acute [[diarrhea]]
***(May be assoc with gap if hypoperfusion -> lactic acidosis)
*CKD
*Intestinal, pancreatic, biliary fistula
*Hyperchloremic IVF infusions
*Hyperalimentation


==Diagnosis==
==Evaluation==
;Osm gap = measured osm - calculated osm (normal 10-15)
;Osm gap = measured osm - calculated osm (normal 10-15)
;Calculated Osm = 2(Na)+(glucose/18)+(BUN/2.8)+(BAL/5)
;Calculated Osm = 2(Na)+(glucose/18)+(BUN/2.8)+(BAL/5)
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**Delta-Delta = (AG - 12) + HCO3
**Delta-Delta = (AG - 12) + HCO3


== Treatment ==
==Management==
*Treat source
*Treat source
*Correct any [[respiratory acidosis]]
*Correct any [[respiratory acidosis]]
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*[[Acid-base disorders]]
*[[Acid-base disorders]]


==References ==
==References==
 
<references/>
[[Category:FEN]]
[[Category:FEN]]
[[Category:Toxicology]]
[[Category:Toxicology]]

Latest revision as of 15:12, 22 July 2017

Clinical Features

  • Compensatory respiratory tachypnea

Differential Diagnosis

Anion gap metabolic acidosis

Non-gap

Evaluation

Osm gap = measured osm - calculated osm (normal 10-15)
Calculated Osm = 2(Na)+(glucose/18)+(BUN/2.8)+(BAL/5)
  • Primary acidosis if pH <7.38
  • HCO3 <24 = metabolic acidosis
  • Always determine if there is another acid/base process occurring
    • Primary respiratory acidosis if pCO2 > pCO2expected
    • Primary respiratory alkalosis if pCO2 < pCO2expected
      • use Winter's formula: PCO2 (expected) = (1.5 x [HCO3–] + 8) ± 2
      • In acute setting PCO2 should fall by 1 mmHg for every 1 mEq fall in HCO3
    • Concurrent metabolic alkalosis if delta-delta > 28
    • Delta-Delta = (AG - 12) + HCO3

Management

  • Treat source
  • Correct any respiratory acidosis
  • Bicarbonate
    • HCO3 dose in mEq = 0.5(wt in kg) x (24 - measured HCO3)
    • Each bicarb 0.5mEq/kg causes 1 meq/L rise in HCO3
    • Consider for:
      • Bicarb <4
      • pH <7.20 AND shock/myocardial irritability
      • Severe hyperchloremic acidemia
      • lower threshold with non-AG acidosis (greater HCO3 loss)
        • Lost bicarbonate would take days to replenish

See Also

References