acid base

OBJECTIVES:

KNOWLEDGE - The student should know and understand :

1. Identify and discuss the normal homeostatic mechanisms which maintain pH in the normal range
2. Describe the principles of the Henderson-Hesselbach equation.
3. Describe the effect on pH of:
   • metabolic acidosis
   • metabolic alkalosis
   • respiratory acidosis
   • respiratory alkalosis
4. Discuss the renal and/or respiratory adaptation to the abnormalities (3) above.
5. Calculate the anion gap and explain its relevance to determining the cause of a metabolic acidosis.
6. Define and describe the pathophysiology of:
   • Simple and mixed acid-base disorders
   • Respiratory acidosis and alkalosis
   • Metabolic acidosis and alkalosis
7. Discuss presenting symptoms and signs of the above disorders.
8. List the differential and identify the most common causes of respiratory acidosis, respiratory alkalosis, non-anion gap metabolic acidosis, anion gap metabolic acidosis, and metabolic alkalosis.
9. Discuss how altered mental status can contribute to electrolyte disorders.
10. Discuss tests to use in the elevation of fluid, electrolyte, and acid-base disorders.
11. Predict acid-base abnormalities from the clinical picture.
12. Identify acid-base abnormalities that medicines can cause.
13. List and discuss indications for obtaining an ABG.

CLINICAL SKILLS:

1. The student should be able to take the appropriate history in a patient with a known acid-base disturbance.   Specifically, the student should be able to look at and interpret the abnormality and then tailor the history to look for possible causes of the abnormality.   An example would be the search for causes of an increased-anion-gap metabolic acidosis, which would include questions about the presence of CHF, DM, infection, volume depletion, etc.
2. The student should be able to make a prediction about a patient's acid-base status after taking a thorough history.   For example, the student should be able to predict possible disturbances in a patient with COPD and known CO2 retention, or a diabetic patient with pneumonia.
3. The student should develop a systematic approach to the analysis of an acid-base problem.   (This will be covered in the lecture).

PROCEDURAL SKILLS:

1. The student should be able to perform an arterial puncture for the determination of an arterial blood gas.
2. Proficiency with venipuncture is assumed.

PROFESSIONAL BEHAVIOR:

• There are no specific items for this topic.