Acid Base Imbalances

pH

normal range: 7.35 - 7.45

Perfect normal: 7.40

Below: acidotic

Above: Alkalotic

CO2

35 - 45 range

Acts like an acid → high CO2 = high acidity

Changes via ventilation

Dec ventilation (slow breathing): PaCO2 rises

Inc ventilation (faster breathing): PaCO2 falls

Respiratory Acidosis

Inc in PaCO2 and dec in pH

Common causes: COPD, hypovent, opioids (dec RR), neuromus weakness, asthma attack

S/S: confusion, cyanosis, dysrhythmias, somnolence

Treatment: support ABCs, ventilation

Respiratory Alkalosis

Dec in PaCO2 and inc in pH

Common causes: Anxiety/hyperventilation, pain, PE, overventilation (mech vent, high altitude)

S/S: tingling (mouth or extremities), dizzy, tetany, seizures

Treatment: treat underlying cause, adjust ventilation

Metabolic Acidosis

Dec in HCO3 and pH

Common causes: high anion gap - DKA, lactic acidosis, renal failure, toxins, GI bicarb loss, renal tubular acidosis, excess Cl administration

S/S: Kussmaul respirations, confusion, muscle cramps/weakness, hyperK+

Treatment: underlying cause, bicarb therapy

Metabolic Alkalosis

Inc in pH and inc in HCO3

Common causes: vomiting, NG suction, diuretics, excess antacids

S/S: weakness/muscle cramps, hypoK+, dec Ca+

Treatment: replace K+ and Cl-, stop ongoing acid loss

Anion Gap

Normal: 8 to 12

High anion gap (bad): metabolic acidosis; accumulation of unmeasured anions, such as lactate, ketones, toxins

Common causes: GOLDMARK

S/S: kussmaul resps, altered LOC (confusion), hypotension, dysrhythmias (if severe)

HCO3

22 - 36 range

Acts like a base → high HCO3 = alkaline

Changes via long term regulation (days/months) with kidneys (also change H+)

Kidneys hold onto more HCO3 → more basic, blood HCO3 rises

Kidneys release more HCO3 in urine → more acidic, blood HCO3 falls