test 7 diagnosis of acid-base disorders

Question 1

Step 1

Answer 1

• Look at pH to identify the most appropriate disorder
  - Acidosis (pH < 7.35)
  - Alkalosis (pH > 7.45)
• Look at bicarbonate concentration
  - If pH indicates acidosis
  - Metabolic (bicarbonate concentration low)
  - Respiratory (bicarbonate concentration high)
  - If pH indicates alkalosis
  - Metabolic (bicarbonate concentration high)
  - Respiratory (bicarbonate concentration low)

Question 2

Step 2

Answer 2

• Determine if a second disorder co-exists by looking at compensation for the primary disorder
  - If primary problem is metabolic acidosis or alkalosis look at the actual
  pCO2 value
  - If primary problem is respiratory acidosis or alkalosis look at [HCO3-]
• If compensation appropriate, there is no secondary problem.
• USE CALCULATIONS TO DETERMINE

Question 3

Step 3

Answer 3

• Calculate the anion gap (AG)
  AG = [Na+] – ([Cl-] + [HCO3-])
• AG normal value = 9 to 16 mEq/L
• AG > 30 mEq/L
  - High anion gap metabolic acidosis
• AG > 20 mEq/L
  - probably high anion gap metabolic acidosis
• AG >=16 and <=20 mEq/L
  - abnormal but may be due to variety things other than anion gap acidos

Question 4

correcting severe metabolic acidosis

Answer 4

• Not all acidosis should be treated with bicarbonate

- If the pH is below 7.10 bicarbonate should be given regardless of cause

Question 5

Bicarbonate equation

Answer 5

HCO3- dose = [(Kg x 0.3) / 2] x base excess