Acid Base Metabolism Flashcards
Osmolality
Normal is 265-285
= 2* Na (mEq/L) +
BUN (mg/dL)/2.8 +
glucose (mg/dL)/18
How much bicarbonate to correct metabolic acidosis?
Bicarbonate = Wt * 0.3 * base deficit
Normal pCO2
40
Metabolic alkalosis
Vomiting
Prolonged NG suction
Pyloric stenosis
Cystic fibrosis
Metabolic acidosis
Diarrhea
Respiratory alkalosis
Pneumonia
Child moved to Colorado (thin air)
Anything that –> hypoxia
Hyperventilation
Respiratory acidosis
CNS dysfunction
Hypoventilation
Pyloric stenosis
Hypochloremic hypokalemic metabolic alkalosis
Hyponatremia
+/- hyperbilirubinemiaa
Anion gap
= serum Na - (Cl + bicarbonate)
Normal = 8 to 12
Measures anions like protein, organic acids, phosphate, sulfate, and lactic acid. These aren’t accounted for in routine labs.
Normal anion gap metabolic acidosis
USED CARP
Ureterostomy Small bowl fistula Extra chloride Diarrhea Carbonic anhydrase inhibitor use Adrenal insufficiency Renal tubular acidosis Pancreatic fistula
RTA clinical and lab features
FTT Constipation Polyuria Normal anion gap metabolic acidosis Hyperchloremia
Type 1 RTA
Distal tubular acidosis
The distal tubule Arranges for Acid to leave the building (normally)
Therefore, urine pH in RTA type 1 > 5.5 (high)
Hyperchloremic hypokalemic metabolic acidosis
Type 2 RTA
Proximal tubular acidosis
The proximal tubule Boxes and takes Bicarb Back in (normally)
Type 2 RTA–>excess bicarb in urine, but distal tubule still works so –>acid in urine
Urine pH < 5.5
Type 4 RTA
Aldosterone insufficiency
Resistance to Aldosterone
Hyperkalemia
Elevated anion gap
MUDPILES
Methanol Uremia Diabetic ketoacidosis Paraldehyde Ingestion (iron, isoniazid (INH) Lactic acid Ethanol / Ethylene glycol Salicylates
