Acid Base Interpretation Flashcards
For every 10 mmHg of PaCO2, how much does pH change?
0.08
What does low serum bicarbonate suggest? (metabolic cause)
metabolic acidosis
What does high serum bicarbonate suggest? (metabolic cause)
metabolic alkalosis
Winter’s formula
provides the expected PaCO2 when metabolic acidosis is present
What does an anion gap of greater than 20 meq/L suggest?
an identifiable metabolic acidosis from acid accumulation (MUD PILES)
What are the common causes of acid accumulation?
Methanol
Uremia
Diabetic ketoacidosis
Propylene glycol
Isoniazid
Lactic acidosis
Ethylene glycol
Salicylates
What are the common causes of non-elevated AG metabolic acidosis?
Uretero-enterostomy
Saline adiminstration
Endocrine disorders
Diarrhea
Carbonic anhydrase inhibitors (acetazolamide)
Ammonium chloride
Renal tubular acidosis
Spironolactone
What is the primary problem in metabolic alkalosis?
elevation of serum bicarbonate with compensatory hypoventilation
What are the two types of metabolic alkalosis
chloride responsive and chloride non responsive
chloride responsive metabolic alkalosis
associated with decreased extracellular volume
the primary consideration should be vomiting with volume depletion
volume depletion leads to reabsoprtion of NaCl and H2O
loss of chloride from vomiting causes retention of NaHCO3
chloride unresponsive metabolic alkalosis
occurs from too much aldosterone
causes H+ secretion in renal epithelial cells by activating the Na/H exchange
also follows intracellular shift of H for K as occurs in hypokalemia
delta-delta analysis
the delta anion gap from normal (10 meq/L) should be equal to the delta bicarbonate unless other conditions are present
if the serum bicarbonate is lower than expected by this analysis, then consider a concurrent bicarbonate wasting condition
if the bicarbonate is higher than expected, then consider a concurrent bicarbonate excess state
