Acid-Base Balances

Question 1

pH

Answer 1

pH: indirectly measures H+ concentration & reflects balance between CO2 (which is regulated by the lungs), and HCO3¯ (a base regulated by the kidneys).

Question 2

Acid-Base Balance

Answer 2

normal arterial blood values = 7.35-7.45
Represents balance between the percentage of hydrogen ions & bicarbonate ions

Acid-molecule that releases, or donates, H+: Carbonic acid (H2CO3)
Base-molecule that accepts H+: Bicarbonate (HCO3-)

Question 3

Acidosis

Answer 3

pH < 7.35
Contains greater amounts of H+
Results from too much CO2 or not enough HCO3ˉ

CO2 = acid. Mental status changes/lethargy

Question 4

Alkalosis

Answer 4

pH > 7.45
Contains lesser amounts of H+
Results from too much HCO3ˉ or not enough CO2

Question 5

Chemical Buffer Systems

Answer 5

Bicarbonate-buffer system
Kidneys: HCO3-
Lungs: H2CO3

Question 6

Respiratory System Function

Answer 6

Regulate CO2 (& thus H2CO3)
Control the elimination of CO2
Chemoreceptors

Hyperventilation leads to “blowing off” CO2
Hypoventilation leads to “retaining” CO2
If CO2 is elevated, hydrogen ion concentration is elevated and pH decreases
Rapid acting/not fully return pH

Question 7

Kidney Function

Answer 7

Make long-term changes to pH
Produce HCO3-
Reabsorb or excrete acids / bases

Question 8

Renal System Regulation of pH

Answer 8

Eliminate H+ and regulates the elimination and production of HCO3-

Bicarbonate secretion/excretion
Hydrogen ions secretion/excretion
Regulate urine pH
Can fully return pH to normal

Question 9

PaO2 Value

Answer 9

80-100 mmHg

Question 10

pH Value

Answer 10

7.35-7.45

Question 11

PaCO2 Value

Answer 11

35-45 mmHg

Question 12

HCO3 Value

Answer 12

22-26 mEq/L

Question 13

O2Stat Value

Answer 13

96-100

Question 14

Respiratory Acidosis

Answer 14

Increase in PCO2, carbonic acid
Hypoventilation
Decrease in pH
Compensatory mechanism
Kidneys conserve bicarbonate and secrete hydrogen ion into the urine.

Question 15

Respiratory Acidosis Causes

Answer 15

Lung disease 
Chest injury
Respiratory failure
Non functioning respiratory muscles
Sepsis
Airway obstruction
COPD

Question 16

Respiratory Alkalosis

Answer 16

Decrease in PCO2
Increase in pH
Hyperventilation
Anxiety/Panic attacks   
Fever 
Mechanical ventilation

Question 17

Metabolic Acidosis

Answer 17

Base bicarbonate deficiency
Compensatory mechanism
Increase in respiratory rate (Kussmaul respiration)
“blow off” CO2 & H2CO3

Question 18

Metabolic Acidosis Causes

Answer 18

Diabetic ketoacidosis
Lactic acid accumulation
Starvation 
Renal Failure 
Severe diarrhea 
Increases in chloride

Question 19

Metabolic Alkalosis

Answer 19

Base bicarbonate excess
Prolonged vomiting
Gastric suction
Compensatory mechanism
Decrease in respiratory rate in order to increase CO2
Renal excretion of bicarbonate

Question 20

Oxygen saturation

Answer 20

Has absolutely nothing to do with acid base balance
Adequate saturation may not be indicative of adequate oxygenation
Hypoxemia: Look at PaO2 value/O2 Stat/Total Hemoglobin