Respiratory acidosis

Revision as of 10:36, 20 July 2015 by Rossdonaldson1 (talk | contribs) (Rossdonaldson1 moved page Respiratory Acidosis to Respiratory acidosis over redirect)

Background

  • acidemia = pH < 7.38
  • respiratory acidosis = pCO2 > 42
  • Acute respiratory acidosis: Change in pH = 0.008 X (40 - PaCO2)

vs. Chronic respiratory acidosis: Change in pH = 0.003 X (40 - PaCO2)

  • determine if another primary acid/base disturbance is occurring
    • calculate AG
    • if HCO3 < 24 + (pCO2-40)/10 x 3(+/-1) then there is a superimposed primary metabolic acidosis
      • for every 10mm increase in pCO2 >40, HCO3expected increases by 2-4mEq (2 if acute/limited time for metabolic compensation, 4 if chronic i.e. COPD)
    • if HCO3 > 24 + (pCO2-40)/10 x 3(+/-1) then suspect primary metabolic alkalosis


Etiology

Hypoventilation - acute vs chronic

DDX

  1. COPD
  2. Drugs (Opioid Overdose)
  3. Chest wall dz
  4. Pleural dz
  5. Trauma

Treatment

  1. Improve alveolar ventilation
    1. Bronchodilators
    2. CPAP
    3. Intubation (esp of pH < 7.25)
      1. Do not reduce pH too quickly (>5Hg/h)
        1. Can lead to abrupt Hypocalcemia/Hypokalemia

See Also

Acid-Base

Source

Tintinalli, KAJI 2011

Retrieved from "https://www.wikem.org/w/index.php?title=Respiratory_acidosis&oldid=42258"