10. Acid,Base Balance and Disorder Case Studies (Chaffer) PDF

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Acid/Base Balance and Disorder Case Studies (Chaffer)

DDx for AGMA: MUDPILES-methanol, uremia, DKA, paraldehyde, INH (isoniazid)/iron, lactate, ethylene glycol, salicylate - You have to go through MUDPILES to get all ddx

Case 1 History: 44 y/o M with hx of chronic alcohol abuse/Suicide attempts found non-responsive; spontaneous respirations (can’t protect airway)  intubation and bagged Labs:

Diagnosis: AGMA, Respiratory Alkalosis, Associated nonanion gap metabolic acidosis - Most common test question = salicylate OD (aspirin)

Case 2a History: 22 y/o M deployed to Iraq, found down, nonresponsive with generalized tonic-clonic seizure activity; last seen 4 hours ago Hospital: status epilepticus, not resolved with lorazepam/fosphenytoin; during resuscitation – patient intubated and given 400 mEq of Na/HCO3 Labs:

Diagnosis: AGMA, Respiratory Alkalosis, Metabolic Alkalosis

1) Complete History/PE 2) ABG and tCO2 internally consistent?  YES pCO2 = 9 HCO3 (tCO2) = 9 – w/n 10% of one another 3) Acidemia or alkalemia? pH < 7.4  ACIDEMIA 4) AG? HIGH Na – (Cl – tCO2)  134 – (103 + 9) = 22 (>12) Normalized AG =12 (no adjustments bc albumin = 4.5) Δ AG = 22-12 = 10 5) Primary disorder? AGMA (bc there is an elevated AG) METABOLIC ACIDOSIS (pH and tCO2 both decreased) 6) Appropriate physiologic responses? NO  RESPIRATORY ALKALOSIS Winter’s: 1.5 (tCO2) + 8 +/-2 1.5(9) + 8 +/-2 = 19.5-23.5 – expected pCO2 Actual < expected pCO2 7) In setting of AGMA, Δ/Δ gap? ASSOCIATED NON-ANION GAP METABOLIC ACIDOSIS Δ/Δ gap = AG/tCO2 (22-12)/(24-9) 10/15 ...