Acid-Base and ABG

Card Set Information

Acid-Base and ABG
2011-09-21 22:12:37
Massey Test

Test 2
Show Answers:

  1. Blood pH ranges from ____ to ____
    • 7.35
    • 7.45
  2. Regulatory mechanisms of Acid-Base balance include what 3 things?
    • Buffers
    • Respiratory System
    • Renal System
  3. Buffers
    Act chemically to neutralize acids or change strong acids to weak acids
  4. Respiratory imbalance
    Affect carbonic acid concentration
  5. Metabolic imbalance
    Affect bicarbonate
  6. 2 Causes of Carbonic acid excess
    • Hypoventilation
    • Respiratory Failure
  7. How does the body compensate for carbonic acid excess?
    Kidneys conserve HCO3 (bicarb) and secrete H+ into urine
  8. Respiratory Acidosis
    Carbonic Acid Excess
  9. Metabolic Acidosis
    Base bicarbonate deficit
  10. Causes of base bicarbonate deficits
    • Ketoacidosis
    • Lactic Acid accumulation (shock)
    • Severe diarrhea
    • Kidney Disease
  11. How does the body compensate during metabolic acidosis?
    • Increases CO2 excretion by the lungs (Kussmaul Respirations)
    • Kidneys excrete acid
  12. Respiratory Alkalosis
    Carbonic acid deficit
  13. Causes of Respiratory Alkalosis
    • Hyperventilation
    • Hypoxemia from acute pulmonary disorders
  14. How does the body compensate during respiratory alkalosis?
    Rarely occurs due to aggressive treatment of causes of hypoxemia
  15. Metabolic Alkalosis
    Base bicarbonate excess
  16. Causes of metabolic alkalosis
    • Prolonged vomiting
    • Gain of HCO3
  17. How does the body compensate during metabolic alkalosis?
    • Decreases repiratory rate to increase plasma CO2
    • Kidneys excrete HCO3
  18. What information do ABG values provide?
    • Acid-base status
    • Underlying cause of imbalance
    • Body's ability to regulate pH
    • Overall oxygenation status
  19. 6 steps used to Diagnose acid-base disturbances from ABG
    • Evaluate pH (acidic or alkalotic?)
    • Analyze PaCO2 (Respiratory acidosis/alkalosis? Increased CO2 = acidosis)
    • Analyze HCO3 (Metabolic acidosis/alkalosis? Increased HCO3=Alkalosis)
    • Determine if CO2 or HCO3 matches the alteration of the pH (ex. pH < 7.35, CO2 high, but HCO3 is high, condition would be respiratory acidosis b/c it matches the pH)
    • Decide if the body is attempting to compensate (parameter that doesn't match the pH is moving in the opposite direction as in above example then body is trying to compensate)
  20. Interpretation of ABG
    pH: 7.36
    PaCO2: 67 mm Hg
    PaO2: 47 mm Hg
    HCO3: 37 mEq/L
    Respiratory Acidosis
  21. PaCO2 Normal Parameters
    32-48 mm Hg
  22. Bicarbonate (HCO3) Normal Parameters
    22-26 mEq/L
  23. PaO2 Normal Parameters
    80-100 mm Hg
  24. pH: 7.18
    PaCO2: 38 mm Hg
    PaO2: 70 mm Hg
    HCO3: 15 mEq/L
    Metabolic acidosis
  25. pH: 7.60
    PaCO2: 30 mm Hg
    PaO2: 60 mm Hg
    HCO3: 22 mEq/L
    Respiratory Alkalosis
  26. ROME
    • Respiratory- the pH and PaCO2 go in
    • Opposite- directions (increased pH and decreased PaCO2 = alkaolisis)
    • Metabolic- the pH and HCO3 go in the same direction or are
    • Equal (increased pH and increases HCO3= alkalosis)
  27. Symptoms of Respiratory Acidosis
    • Fatigue, lethargy, sleeplessness
    • SOB, wheezing, high pitched breath sounds, cough
    • Altered mental Status
  28. Symptoms of Respiratory Alkaolosis
    • Hyperventilation
    • Dizziness, light headedness
    • Tingling and numbness around mouth, fingers and hands
    • Muscle twitching and spasms
  29. Symptoms of Metabolic Acidosis
    • Severe diarrhea
    • Kussmaul Repirations (deep, rapid breathing)
  30. Symptoms of Metabolic Alkalosis
    • Decreased breathing is initial symptom
    • Cyanosis
    • N/V, diarrhea
    • Irritability
    • Altered Mental Status
    • Tachycardia and cardiac arrhythmias
  31. Treatment of Respiratory Acidosis
    • Treat underlying lung disorder
    • Bronchodilators, steroids
    • CPAP (continuous positive airway pressure)
    • Mechanical Ventilation
    • Smoking Cessation
  32. Treatment of Respiratory Alkalosis
    • Treat underlying condition
    • Provide Carbon Dioxide Rebreather Oxygen Mask
  33. Treatment of Metabolic Acidosis
    • Correct underlying cause (ex. give insulin for diabetic ketoacidosis)
    • Administer sodium bicarbonate IV
    • Dialysis
  34. Treatment of Metabolic Alkalosis
    Administer IV fluids (NS) and potassium chloride to restore normal fluid and electrolyte balance