Chapter 4: Blood Gases

Question 1

Define Internal Respiration vs. External Respiration

Answer 1

• internal: exchange of gas between the blood and the cells of the tissues
• external: exchange of CO2 and oxygen that takes place in the lungs (or HLM)

Question 2

Hemoglobin-Oxygen Effect

Answer 2

• 97% of bloods O2 is transported by hemoglobin
• every 7 degrees C colder, metabolic rate is decreased by 50% (aka lower oxygen consumption)
• O2 solubility also increases with colder temps

Question 3

Hemoglobin Oxygen Dissociation Curve

Answer 3

• relationship of hemoglobin and oxygen
• shift right= decreased oxygen affinity= hemoglobin will release more oxygen to tissues (hyperthermia, low hgb, increase CO2, decrease pH, increase 2,3 DPG)
• shift to left= increased oxygen affinity= hemoglobin holds on to the oxygen and releases less to tissues (hypothermia, high hgb, decreased CO2, increase pH, decrease 2,3 DPG)

Question 4

P50

Answer 4

• The P50 is the oxygen tension at which hemoglobin is 50% saturated
• increased P50= decreased affinity of hgb to O2
• decreased P50= increased affinity

Question 5

Oxygen Carrying Capacity Calc

Answer 5

= (1.34 x Hgb) + (.003 x pO2)

Question 6

Oxygen Content Calc

Answer 6

= (1.34 x Hgb x %saturation-decimal) + (.003 x pO2)

Question 7

Oxygen Saturation Calc

Answer 7

= O2 content/O2 capacity

Question 8

Oxygen Consumption Calc

Answer 8

= (aO2 content - vO2 content) x (flow L/min) x 10

Question 9

Oxygen Transfer Calc

Answer 9

= [(Art-Ven sat in decimal) x 1.34 x Hgb x flow mL/min] / 100

Question 10

if CO2 increases by 20 mmHg, pH will what?

Answer 10

decrease by .1

and visa versa for decreasing CO2

Question 11

Respiratory Quotient

Answer 11

ratio of CO2 production vs O2 consumption

-average ratio is 4:5

Question 12

3 Ways CO2 is transported

Answer 12

by Hgb, combines with water= carbonic acid (breaks down to form H+ and bicarbonate), dissolves in plasma

Question 13

Bohr Effect and Haldane Effect

Answer 13

• Bohr= addition of CO2 to blood causes O2 to be released from hemoglobin faster
• Haldane= O2 added to blood causes CO2 to be released from hemoglobin faster

Question 14

Four main buffers of the body

Answer 14

Bicarbonate, hemoglobin, phosphate, and serum protein

Question 15

Bicarbonate

Answer 15

• works to minimize the effects of high/low CO2 and changes in pH
• chloride shift= chloride goes into RBC, bicarb leaves to fix increased CO2

Question 16

Carbonic Acid

Answer 16

lowers pH, which bicarb raises pH

Question 17

Respiratory acidosis vs Metabolic acidosis

Answer 17

• respiratory acidosis= build up of CO2, not blowing off enough
• metabolic= CO2 sweep/lungs are adequate, but kidney, liver, organs are keeping the pH low (increase blood flow to fix, give bicarb, make sure peeing)

*this is all visa versa for alkalosis

Question 18

Bicarbonate Formula

Answer 18

(base deficit x kg)/4