Basics of Acid/Base Balance

Question 1

normal range for pH

Answer 1

7.35-7.45

Question 2

normal range for bicarbonate (HCO3)

Answer 2

20-24 mEq/L

Question 3

normal range for carbon dioxide (pCO2)

Answer 3

35-45 mmHg

Question 4

normal range for sodium (Na)

Answer 4

135-145 mEq/L

Question 5

normal range for potassium (K)

Answer 5

3.5-4.5 mEq/L (4)

Question 6

normal range for chloride (Cl-)

Answer 6

96-106 mEq/L (100)

Question 7

how does bicarbonate (HCO3) act as a buffer

Answer 7

combines with H+ ions to become carbonic acid (H2CO3) which can be further broken down to water and CO2 (quick); lungs can remove CO2 and kidneys excrete extra H+ to preserve HCO3 (slow)

Question 8

ratio of bicarbonate ions to carbonic acid

Answer 8

20:1 (body’s more efficient at responding to changes that make the body more acidic like cellular waste products)

Question 9

how much buffering do proteins do

Answer 9

2/3 of buffering power if blood and most of buffering within cells

Question 10

define metabolic acidosis

Answer 10

excessive build-up of acid OR excessive loss of HCO3 (pH: LOW, CO2: ok, HCO3: LOW); pick one cause by looking at anion gap

Question 11

define anion gap

Answer 11

difference between cation and anion ratios in blood; normal gap ~ 12mmol/L

Question 12

low pH, low HCO3, but normal anion gap

Answer 12

too little/loss of HCO3

Question 13

Causes of loss of HCO3

Answer 13

Chronic diarrhea, pancreatic issues, renal tube acidosis

Question 14

low pH, low HCO3, larger anion gap value

Answer 14

excessive buildup of acid

Question 15

causes of excessive acid build up

Answer 15

lactic acidosis, ketoacidosis, renal failures, medications, inherited metabolic disorder

Question 16

define metabolic alkalosis

Answer 16

loss of acid from blood resulting in excess of HCO3 (pH: high, CO2: ok, HCO3: high)

Question 17

common causes for metabolic alkalosis

Answer 17

excessive vomiting (lessening HCL acid in stomach), hyperaldosteronism (excess retention of water), diuretic meds

Question 18

define respiratory acidosis

Answer 18

excess build up of CO2 (pH: low, CO2: high, HCO3: ok)

Question 19

common causes of respiratory acidosis

Answer 19

hypoventilation (meds, drugs, CNS depression), diffusion issues, obstructive lung disease

Question 20

define respiratory alkalosis

Answer 20

excessive loss of CO2 (pH: high, CO2: low, HCO3: ok)

Question 21

common causes of respiratory alkalosis

Answer 21

hyperventilation, altitude sickness, panic attacks

Question 22

steps for acid/base balance solution

Answer 22

1. look at pt hx
2. look at pH: acidosis vs alkalosis
3. look at HCO3 level
4. look at CO2 level
   pH and HCO3/CO2 in same direction –> metabolic problem
   pH and HCO3/CO2 in opposite directions –> respiratory problem