Labs and Levels
Regulation
Metabolic Acidosis
Aspirin Toxicity
100

The normal blood pH is between these values. 

7.35-7.45

100

This is the acid-base metabolism equation. 

CO2+H2O↔H2CO3↔H++HCO3−

100

This is the first step in differentiating acid-base disorders.

Determine if the pH is low or high (acidosis/alkalosis)

100

This respiratory acid-base disorder develops in early aspirin toxicity. 

Respiratory alkalosis, Low CO₂

200

This is how you calculate the anion gap, and this is the normal range. 

Na+−(Cl−+HCO3−), 8-12

200

This is the name of the type of breathing that occurs with hyperventilation.

Kussmaul breathing

200

This is how you determine if the disorder is a metabolic or respiratory acid-base disorder. 

Look at: carbon dioxide and bicarbonate levelsRespiratory = CO₂ problem, Metabolic = HCO₃⁻ problem

200

This response is triggered in early aspirin toxicity. 

Respiratory center in brain is stimulated→ patient hyperventilates

300

A patient has pH 7.51, CO₂ 28, HCO₃⁻ 22. The primary disorder is this. 

Respiratory alkalosis

300

The lungs regulate this compound to compensate for metabolic acid-base disorders. 

Carbon dioxide (CO2)

300

These are normally the causes of normal anion gap acidosis. 

Bicarbonate loss or impaired acid secretion

300

This response is triggered in late aspirin toxicity. 

Salicylates accumulate → organic acid production

400

A patient with diarrhea develops metabolic acidosis, but the anion gap remains normal because this electrolyte increases to compensate. 

Chloride

400

This respiratory mechanism occurs when the pH is too low.

Hyperventilation, blow off CO2, decrease acid

400

In acidosis, this is how the kidneys regulate bicarbonate resorption and hydrogen ion excretion respectively. 

increase HCO₃⁻ reabsorption, increase H⁺ secretion

400

These two acid-base disorders occur in response to late aspirin toxicity. 

Metabolic acidosis + respiratory alkalosis

500

Aspirin toxicity is more likely than panic attack in a tachypneic patient whose ABG shows low CO₂ and whose chemistry panel demonstrates this additional abnormality.

Low bicarbonate level- elevated anion gap

500

These are the three ways the kidneys maintain pH.

1. Reabsorbing bicarbonate in the PCT 

2. Excreting H+ ions 

3. Generating new bicarbonate (ammonium buffering and phosphate buffering) NH₃ + H⁺ → NH₄⁺ (trapped in urine), HPO₄²⁻ + H⁺ → H₂PO₄⁻

500

These are the common causes of high anion gap metabolic acidosis (list 3). 

Glycols, Oxoproline, L-lactate, D-lactate, Methanol, Aspirin (salicylates), Renal failure (uremia), Ketoacidosis

500

This is how the values of bicarbonate and carbon dioxide would appear in a mixed disorder secondary to aspirin toxicity. 

Low CO₂, low HCO₃⁻, pH may be low OR near normal