Respirationprocess of getting O2 into the body for tissue utilization and removal of CO2 into the atmosphere
Oxygen must be moved into the lungs where it…….diffuses into the pulmonary circulation and is transported into the blood to the tissues
Carbon dioxide builds up into the tissues because of…..metabolism
Carbon dioxide diffuses into….capillary blood before being carried to the lung for exchange with alveolar gasses
Gas movement between lungs and tissues occure by?simple diffusion
What is the diffusion gradient for oxygen?normal atomospheric inspired partial pressure (PIO2) of 159 mm Hg to a low point of 40 mm Hg or less in the capillaries
What is the final gradient for oxygen infusion into the cell? How many mm Hg?intracellular PO2 (5 mm Hg)
What is the diffusion gradient for carbon dioxide?highest in the cells 60 mm Hg and lowest to room air 1 mm Hg
What is the difference of the oxygen diffusion gradient compared to the carbon dioxide diffusion gradient.Oxygen has a cascade gradient moving from atmosphere to Intracellular. Carbon dioxide moves from intracellular to the atmosphere.
The carbon dioxide diffusion gradients cascade causes…..CO2 to move from tissues into the venous blood, which is transported to the lungs and out to the atmosphere
Alveolar partial pressure of carbon dioxide (PACO2)varies directly with the body’s production of CO2 and inversely alveolar ventilation
What factor is used to convert VCO2 from STPD to BTPS?0.863
what is the formula used to convert VCO2 from STPD to BTPS?PACO2= VCO2 * 0.863 ————— VA (alveolar ventilation)
Normally complex respiratory control mechanisms maintain the PACO2 within a range of?35-45mm Hg
If carbon dioxide production increase as with exercise or fever what happens to ventilation?ventilation automatically increases to maintain PACO2 within normal range
What is the most important facto in determining the alveolar partial pressure of oxygen (PAO2)?inspired partial pressure of oxygen (PIO2)
Once oxygen is in the lungs it is diluted by what 2 things?water vapor and carbon dioxide
What is the alveolar air equation formula?PAO2= FIO2*(PB -47)-(PACO2/0.8)
According to Dalton’s law the partial pressure of alveolar nitrogen must….equal the pressure it would exert if it alone were present
What is the formula to compute the partial pressure of alveolar nitrogen (PAN2)?PAN2= PB-(PAO2+PACO2+PH2O)
The only partial pressures that change int he alveolus are? Why?oxygen and carbon dioxide. Because both water vapor tension and PAN2 remain constant.
Based on the alveolar air equation if the FIO2 remains constant the the PAO2 will?vary inversely with PACO2
When a patient is breathing room air what is the sum of the alveolar PO2 and alveolar PCO2?140 mm Hg
Neural control mechanisms and increased work of breathing prevent decreases in PaCO2 much below?15-20mm Hg
If patient is breathing room air at sea level the RT should or shouldn’t exspect to see a PaO2 any higher that 120 mm Hg during hyperventilation?should not exspect any higher than 120 mm Hg
PO2 values higher than 120 mm Hg indicate?patient is breathing supplemental oxygen
Diffusionprocess of gas molecules moving from an area of high partial pressure to low partial pressure
In order for oxygen to diffuse into and out of the lung and tissues, O2 and carbon dioxide must move through….barriers
Alveolar capillary membranethe barrier to gaseous diffusion in the lung
What 3 barriers must be penetrated in order for O2 and CO2 to move btw alveoli and pulmonary capillary blood?alveolar epithelium, intersitial space, capillary endothelium
Fick’s first law of Diffusionthe greater the surface area, diffusion constant, and pressure gradient, the more diffusion will occur
Diffusion in the normal lung mainly depends on?gass pressure gradients
What must exist in order for gas exchange to occure between the alveoli and pulmonary capillaries?difference in partial pressures
In pulmonary diffusion Alveolar PaO2 averages how many mm Hg?100 mm Hg
In pulmonary diffusion Mean PaCO2 is approximately how many mm Hg?40 mm Hg
In pulmonary diffusion PvO2 is how many mm HG?40 mm Hg
In pulmonary diffusion PvCO2 is how many mm Hg?46 mm Hg
The pressure gradient for oxygen diffusion into the blood is approximately?60 mm Hg
Does carbon dioxide diffuse faster or slower across the alveolar-capillary membrane than oxygen? Why?20 times faster. Because of its much higher solubility in the plasma.
Diffusion time in the lungs depends on?rate of pulmonary blood flow
How long does blood take to flow through the pulmonary capilary?0.75 seconds
Low concentrations of what are used more commonly to measure diffusing capacity of the lung?carbon monoxide (0.1%-0.3%)
The PaO2 of healthy person breathing at sea level is approximately how much less than the calculated PaO2?5-10 mm Hg less
2 factors that account for the 5-10 mm Hg difference in calculated PaO2 are?1.right to left shunts in pulmonary and cardiac circulation 2.regional differences in pulmonary ventilation and blood flow
What are the 2 anatomilace right to left shunts that exist in a normal human being?1.bronchial venous drainage 2.thebsian venous drainage
What does a right to left shunt cause poorly oxygenated venous blood to do?causes it to move directly into the arterial circulation, lowering the oxygen content of the arterial blood.
What is the ideal ventilation and perfusion ratio?1.0
A high ventilation/perfussion ratio indicates that? Low V/Q?ventilation is greater than normal, perfusion is less than normal, or both. LOW- ventilation is less than normal, perfusion is greater than normal, or both.
In areas with low V/Q the alveolar PO2 is? PCO2 is?alveolar PO2 lower, PCO2 higher than normal
Area with ventilation but no blood flow represent?dead space
Alveolar shuntsV/Q ratio values of zero not normal, distinguished from true anatomical shunts.
Regional differences in V/Q ratios in the normal lung are caused by?gravity and most evident in the upright position
Does perfusion increase or decrease farther down the lung?increases. Bases receive nearly 20 times as much blood flow than the apexes.
Does ventilation increase or decrease farther down in the lung bases?increases. Four times as much ventilation than apexes.
V/Q at apexes of lungsventilation exceeds blood flow resulting in high V/Q (3.3), high PO2 (132 mm Hg), low PCO2 (32 mm Hg).
V/Q at bases of lungsblod flow increases more than ventilation due to gravity
(Oxygen Transport)blood carries O2 in what 2 forms?1.dissolved in plasma and erythrocyte fluid. 2. majority is carried in combination with hemeglobin inside the RBC
Formula for Dissolve oxygen in blood?Dissolved oxygen= PO2*0.003
Deoxygenated hemoglobin serves as a what in transport?important blood buffer for hydrogen ions, important in carbon dioxide transport
Oxyhemoglobinoxygen molecules bind to Hb by way of ferrous iron ion and coverted to it’s oxygenated state
In whole blood each gram of normal Hb can carry how many ml of oxygen?1.34 ml
Hb increases the oxygen carrying capacity of the blood by how much?70 fold as compared to plasma alone
Saturationmeasure of proportion of available Hb that is actually carrying oxygen
Hb saturation formulaSaO2=[HbO2 / Total Hb]*100
HbO2 curverelationship btw PaO2 and SaO2 is S shaped
How to find the total oxygen content of blood?total oxygen content of bloo equals the sum of that dissolved and chemically combined with Hb
Formula for Total oxygen content of bloodCaO2=(0.003*PO2)+(Hbtot*1.34*SO2)
What is the normal CaO2 concentration?16-20 ml/dl
What is the difference between the arterial and venous oxygen contents?5 ml/dl
C(a-v)O2arteriovenous oxygen contents difference. Amount of O2 given up by every 100mL of blood on each pass through thet tissues
Fick equationThe C(a-v)O2 combined with total-body oxygen to calculate cardiac output
Normal range for cardiac output4-8L/min in adult
According to Ficks equation if the O2 consumption remains constant a decrease in cardiac ouput will do what to the arteriovenous oxygen contents difference?increase the C(a-v)o2
According to ficks equation if the cardiac output rises and oxygen consumption reamins constant what will happen to the arteriovenous oxygen contents difference?C(a-v)O2 will decrease
What are some factors other than HbO2 curve that affect oxygen unloading and loading?blood pH, body temp, erythrocyte concentration of certain organic phosphates, variations in the structure of Hb, chemical combinations of Hb with substances other than O2
Bohr effect…..What does it do?impact of changes in blood pH on Hb affinity for O2. It alters the position of the HbO2 dissociation curve.
A low pH shifts a curve to the?right
A high pH shifts a curve to the?left
When blood ph drops and shifts the curve to the right the Hb saturation for a given PO2…falls
As blood pH rises and the curve shifts to the left Hb saturation for a given PO2…rises
As blood in the tissue picks up CO2, pH falls and the HbO2 curve shifts to the? Does it increase or decrease the affinity of Hb for oxygen?right. decreasing the affinity of Hb for O2.
With a lower of the affinity of Hb for O2 Hb readily gives up what to the tissues?O2
Venous blood returns to the lungs and the pH does what? This shifts the curve to the? Does this increase or decrease the affinity of Hb for oxygen?Increases. left. Increasing the affinity of Hb for O2 and enhancing its uptake from the alveoli.
A drop in body temperature shifts the HbO2 cureve to the?left, increasing Hb affinity for O2.
As body temperture rises the curve shifts to the?right, affinity of Hb for O2 decreases.
At the tissues, temperature changes are directly related to?metabolic rate
Organic phosphate 2,3-diphosphoglceratefound in abundance in the RBC’s and forms a loose chemical bond with the globin chains of deoxygenated Hb.
2,3-DPG does what to the molecule in it’s deoxygenated state?It stablilizes the molecule and reuces it’s affinity for oxygen
What would happen if we didn’t have 2,3-DPG?Hb affinity for O2 would be so great that normal O2 unloading would be immpossible
Increased 2,3 DPG concentrations shift the HbO2 curve to the? Promoting what?right. Oxygen unloading
Low 2,3-DPG concentrations shift the curve to the? And does what to the Hb affinity for O2?left. Increasing the Hb affinity of O2
Alkalosis, chronic hypoxemia, and anemia all increase or decrease 2,3-DPG concentrations?increase and promote oxygen unloading
Acidosis does what to 2,3-DPG?lowers the level of DPG and a greater affinity of Hb for O2.
What happens to DPG in banked blood?It decreases in concentration over time and after a week of storage there is less than 1/3 of the normal value of DPG. This shifts the HbO2 curve to the left decreasing availability of oxygen to the tissues.
What happens with large transfusions of banked blood that is more that a few days old?It impairs oxygen delivery even in the presence of a normal PO2
When do structural abnormalities of hemoglobins occur?when the amino acid swquence in the molecule’s polypeptide chains varies from normal.
What percent of the circulating hemoglobin are abnormal in a healthy individual?15-40%
Sickle Cell hemoglobin?abnormal hemoglobin that is less soluable and causes the hemoglobin to become suceptible to polymerization and precipitation when deoxygenated
What events cause the hb to crystalize and the RBC to become hardened and curved like a sickle?dehydration, hypoxia, acidosis
Patients with sickle cell are prone to?vaso-occlusive disease and anemia.
Acute chest syndrome? Symptoms?most common cause of death in patients with sickle cell anemia. Symptoms:acute chest pain, cough, dyspnea, infiltrate on the CXR and develops progressive anemia and hypoxemia
Methemoglobinabnormal form of the molecule where the heme-complex normal ferrous iron ion loses an electron and oxidizes to its ferric state.
What happens in the ferric state of methemoglobin?iron ion cannot combine with oxygen
What happens as a result of the iron ion not being able to combine with oxygen in the ferric state of methemoglobin?a special form of anemia results called methhemoglobinemia
What is the most common cause of methemoglobinemia?therapeutic use of medications containg nitrogen. Nitric oxide, nitroglycerine, lidocaine
What color is the blood of a patient who has methemoglobin?brown, slate-gray skin coloration
How do we confirm that a patient has methemoglobin?spectrophotometry
How is methemoglobin treated?reducing agents such as methylene blue or absorbic acid when the blood level exceeds app. 40%
CarboxyhemoglobinHb with carbon monoxide
Hemeglobins affinity for carbon monoxide is how much more greter than it is for oxygen.200 times greater
The combination of carbonmonoxide shifts the HbO2 curve to the?left. Impeding oxygen delivery to the tissues
What is the treatment for carbon monoxide poisoning?giving the patient as muxh oxygen as possible because oxygen reduces the half-life of carboxyhemoglobin. Sometimes a hyperbaric chamber is used
Fetal Hemoglobinblood having a high proportion of an Hb varian during fetal life and for up to 1 year after birth
Fetal hemoglobin causes a shift to the?left. HbF has a greater affinity for oxygen than does normal adult Hb
What does the leftward shift of fetal hemoglobin aid in doing?aids oxygen loading at the placenta
The PO2 values to the fetus in utero are high or low?low
What happens after birth with the Fetal hemoglobin?this enhanced oxygen affinity is less advantageous after birth. Over the first year of life HbF is gradually replaced with normal Hb.
P50partial pressure of oxygen at which the Hb is 50% saturated, standardized to a pH of 7.40
What is a normal P50?26.6 mm Hg
Conditions that cause an decrease in Hb affinity for oxygen cause a shift to the?right.
Conditions with an increase in affinity cause a shift to the? What happens to P50?left. P50 decreases to lower than normal
How much carbon dioxide is carried in the blood?45-55 ml/dl
In what three forms is carbon dioxide carried in the blood?dissolved in physical solution, chemically combined with protein, ionized as bicarbonate
Dissolved carbon dioxide plays an important role in? How much is released at the lungs?transport. 8%
Carbon dioxide hasa the capacity to chemically cobine with free amino groups of protein molecules forming a?carbamino compound
what is carbaminohemoglobin? what percentage does it transport?A compound of carbon dioxide and hemoglobin, which is one of the forms in which carbon dioxide exists in the blood. 12% of the total carbon dioxide.
Approximately what percent of the blood carbon dioxide is transported as bicarbonate?80%
Hydrolysischemical process in which a molecule is cleaved into two parts by the addition of a molecule of water
What does the hydrolysis of CO2 form?carbonic acid
What enzyme enhances the hydrolysis reaction?carbonic anhydrase
Where does the majority of hydrolysis occur?RBC
What happens when hydrolysis of carbon dioxide continues for a while?Bicarbonate begins to accumulate in teh RBC
How is equilibrium obtained when bicarbonate accumulates in the RBC?by the chloride shift
Chloride shiftThe movement of chloride ions from the plasma into red blood cells as a result of the transfer of carbon dioxide from tissues to the plasma, a process that serves to maintain blood pH.
Haldane effectinfluence of oxyhemoglobin saturation on CO2 dissociation
What is the Haldane effect a result of?changes in the affinity of Hb for CO2 as a result of its buffering of Hydrogen ions
A high SaO2 decreases or increases the blood’s capacity to hold carbon dioxide? Does this help in loading or unloading this gas at the lungs?Decreases. unloading
What is the formula for oxygen delivery?DO2=CaO2*Qt
Hypoxiawhen oxygen delivery falls short of cellular needs
In what three ways will hypoxia occur?If the arterial blood O2 content is decreased, if cardiac output or perfusion is decreased, or if abnormal cellular function prevents proper uptake of O2
When does hypoxemia occur?when partial pressure of O2 in the arterial blood (PaO2) is decreased to lower than normal.
What things might a decreased PaO2 be caused by?low ambient PO2, hypoventilation, impaired diffusion, V/Q imbalances, right to left anatomical or physiological shunting, aging, altitude
What is the approximate PaO2 at the age of 60?85 mm Hg
Mountain sicknesstraveling to high altitudes which decrease the PaO2 causing hypoxia
Alveolar PO2 varies directly or indirectly with alveolar PCO2?indirectly
Even when alveolar PO2 is normal disorders of the alveolar capillary membrane may limit diffuion of oxygen into the pulmonary bed thereby lowering the? Diseases that do this are?PaO2. Interstitial edema, Pulmonary fibrosis
What is the most common cause of hypoxemia in patients with lung disease?Ventilation perfusion imbalances
What happens when ventilation is greater than perfusion?there is wasted ventilation, alveolar dead space
What happens when ventilation is less than perfusion?ventilation perfusion ratio is low and blood leaves the lungs with abnormally low oxygen content
What does ventilation perfusion imbalances usually occur in lung disease? Why?both excess wated ventilation and poor oxygentation. Because the imbalance impairs O2 exchange and PaO2 is reduced
What does a ventilation perfusion imbalance of 0 represent?there is blood flow but no ventilation and is equivalent to a right to left anatomical shunt
To differentiat between hypoxemia caused by a V/Q imbalance and hypoxemia caused by shunting what do you do?If the O2 is more than 50% and the PaO2 is less than 50% significant shunting is present. otherwise it is a V/Q imbalance
Formula for estimating the expected PaO2 in older adultsExpected PaO2=100.1-(0.323*Age in years)
For the arterial oxygen content to be adequate there also must be?enough normal Hb in the blood
Can hypoxia occur if the Hb is low even when the PaO2 is normal? Why?Yes. Because of low oxygen content in the arterial blood
What are the 2 hemoglobin deficiencies?absolute, relative
What is absolute hemoglobin deficiency?occurs when Hb concentration is lower than normal due to a low blood Hb concentration by either loss from hemorrhage or inadequate erythropoesis.
What is relative Hb deficiency?caused by either displacement of O2 from normal Hb or prescence of abnormal Hb variants.
What can a low Hb content do to the oxygen carrying capacity of the blood?seriously impair the oxygen carrying capacity of the blood
Hypoxia can still occur when the CaO2 is normal if?blood flow is reduced
What are the 2 types of reduced blood flow?circulatory failure(shock), local reduction in perfusion(ishemia)
What happens with prolonged shock?causes irreversible damage to the central nervous system and eventual cardiovascular collapse
What 3 things can result from ishemia?anaerobic metabolism, metabolic acidosis, eventual death of tissue
Dysoxiaform of hypoxia in which cellular uptake of O2 is abnormally decreased
What is an example of dysoxia?cyanide poisoning. It disrupts intracellular system preventing cellular use of oxygen
Dysoxia also may occur when…tissue oxygen consumption becomes dependent on O2 delivery
What leads to lactic acid accumulation and metabolic acidosis?tissue extraction reaches a maximum and decreases delivery of O2 resulting in a oxygen debt due to oxygen demand exceeding oxygen delivery
In sepsis and ARDS oxygen debt may occur at normal levels of?oxygen delivery
Any disorder that lowers alveolar ventilation relative to metabolic need impairs?carbon dioxide removal
What does impaired CO2 removal by the lungs cause?hypercapnia and respiratory acidosis
When does a decrease in alveolar ventilation occur?minute ventilation is inadequate, dead space ventilation per minute increases, or a ventilation perfusion imbalance exists
Inadequate minute ventilation is caused by?decreased tidal volume
Inadequate minute ventilation occurs in what types of conditions?restrictive conditions: atelectasis, neuromuscular disorders, or conditions that impede thoracic expansion (kyphoscoliosis)
A decrease in RR is less common but may be present with respiratory center depression as in?drug overdose
An increased dead space ventilation is caused by either?rapid shallow breathing, or increased physiologic dead space (V/Q 0)
What does increased dead space ventilation cause?the proportion of wasted deadspace increases and lowers alveolar ventilation and impairs CO2 removal
IN theory V/Q imbalance should cause a rise in PACO2. However many patients who are hypoxemic because of a V/Q imbalance have a low or normal PaCO2. What does this suggest?V/Q imbalances have a greater effect on oxygenation than on carbon dioxide removal.
To compensate for high PCO2 values with V/Q imbalances what must happen?patients minute ventilation must increase
Patients who can increase their minute ventilation with V/Q imbalance then to have?normal or low PaCO2 combined with hypoxemia
Patients with an V/Q imbalance who cannot increase their minute ventilation are? when does this occur?hypercapnic. This occurs only when V/Q imbalance is severe and chronic like with COPD
When a patient is hypercapnic what must happen for them to maintain a normal PaCO2?they must sustain a higher than normal minute ventilation

Egan’s Chapter 11 Practice Questions:

1. 2 types of deadspace ventillation: deadspace ventilation

2. Disoders leading to alveolar deadspace: Pulmonary edema, Partial obstrution of the pumonary vasculatture, Destroyed pulmonary vasculature, Reduceded cardiac output

3. Gas moves across the system by: Simple Diffusion

4. How long is pulmonary blood exposed to alveolar gas: 0.75 second

5. How long is pulmonary blood exposed to alveolar gas during exercise: 0.25 second

6. How many times greater is ventilation at the bases: 4

7. How many times higher is blood flow at the bases?: 20

8. In what two forms are oxgen transported?: 1. Dissolved in blood, 2. Bounded by Hemeglobin

9. The portion of inspired air that is exhaled without being exposed ot perfused alveoli is _______________.: deadspace

10. Reduction of blood flow may be due to: Shock, Prolonged shock becomes irreversbible, Ishemica – local reductions in blood flow may reult in Hypoxia & tissue death, i.e., myocardial infarction & storke

11. Respiration: The process of moving oxygen to tissues for aerobic metabolism & removal of carbon dioxide. It involves gas exchange at lungs & tissues

12. T or F: A pressure gradient must exist for gas to move between the alveolus and pumonary capilary: True

13. T or F: Assuming a constant FIO2 and carbon dioxide productioon, alveolar ventilation incresases, PACO2 decreases and PAO2 increases.: True

14. Ventilation that doesn’t participate in gas exchange: deadspace ventilation

15. Ventilation that enters into alveoli without any perfusion: Alveolar deadspace

16. Ventilation that never reaches aveoli for gas exchange: Becomes problematic in conditions where tidal volumes drop significantly. Significant % of inspired gas remains in anatomic deadspace.

17. What are the abrriers to Gas diffusion: Alveolar epithelium, Instersitial space & structures, capillary endothelium and RBC membrane.

18. What are the transport mecanisms for Carbon Dioxide?: Dissolved in blood
Combined with Protein
Inonized as HCO

19. What are the values for normal partial pressure of arterial blood?: O2= 100 mmHG
C02= 40 mmHG

20. What are the values for normal partial pressure of venous blood?: O2= 40 mmHG
CO2= 46 mmHG

21. What happents to CO2 and PaO2 levels if you increase deadspace?: CO2 increases and Pao2 decreases

22. What is the approximate normal level of carbon dioxide production for an adult?: 200ml/min

23. What is the most common cause of V/Q mismatch? Impaired oxygen delivery (DO2): 8% dissovled in blood
12% combined with protein
80% ionized with HCO3

24. What is the normal range for SaO2?: 95% – 100%

25. What is the percentage of HG that is carrying Oxgen?: SaO2 (saturation)

26. What is the portion of cardiac output that returns to left heart without being oxygnated by exposure ot ventilated alveoli?: Anatomic shunt (natural shunt)

27. What is the primary determinant of PAO2: PIO2

28. What ratio represents the perfect V/Q balance?: 1:1

29. Where does CO2 move from and to?: Moves from Intracellular to atmosphere via expiration

30. Where does Oxygen move from and to?: Inhaled from the atmosphere PIO2 to Intracellular PAO2

31. Which transport route transports more O2?: Hemeglobin transports 70 times more Oxygen than the blood

Egan’s Chapter 11 Test Bank

1. 2 forms in which O2 is transported: Physically dissolved in plasma, Chemically bound to hemoglobin (Hb)

2. Additional costs of Increased Ventilation: Increased WoB, Increased O2 Consumption, Higher burden of external ventilation

3. Alveolar air equation (based on Dalton’s law): PAO2=FiO2 x (PB-47)-(PACO2/0.8) [do not do shortcut from slide 13]

4.Atmosphere O2 cascade: PO2= 159 mm/hg

5. Break down of HbO2 curve shifts:: LEFT/Alkaline is for LESS (except when dealing with pH/O2:levels increase) for example in near drowning victims. RIGHT/Acidic is for MORE (except when dealing with pH/O2:levels decrease) for example in COPD patients. LESS/MORE Values= Temperature & 2,3-DPG.

6. Carbonic Acid Reaction Formula (Dissociation): CO2+H2O<==>H2CO3<==>HCO3+H

7. CO2 Diffusion vs. O2 Diffusion?: CO2 Diffusion = O2 Diffusion x 20

8. CO2 gradient: Reverse of O2 cascade gradient (HIGH) ~60mm Hg

9. Define 2,3-DPG: 2,3-Diphosphoglycerate: A highly anionic organic phosphate present in human RBCs. Binds to Deoxyhemoglobin (Hb without O2)

10. Dysoxia is…: when cells are unable to adequately utilize oxygen (Histotoxic Hypoxia)

11. FiO2: Inspired fractional O2 (0.21 if value is not given)

12. Formula for figuring out how much O2 is dissolved in the plasma: (Henry’s Law) Dissolved O2(ml/dl)=PO2 x 0.003

13. Hamburger Phenomenon: Not important but very delicious (see figure on menu)

14. HBO2 dissociation curve describes what?: The relationship between PAO2 and SaO2 and it’s “S” Shaped

15. Hemoglobin Saturation is defined as:: Saturation is the % of Hb that is carrying O2 compared to total Hb

16. Histotoxic Hypoxia is…: Cyanide Poisoning

17. How many O2 receptors does Hemoglobin (Hb) have?: Four!

18. How much O2 is bound to hemoglobin: 1.34 ml of O2 per gram of Hb

19. Ideal ventilation Ratio equation: VD/VT= PaCO2-PÉCO2/PaCO2

20. Intracellular O2 cascade: PO2= ~5mm/hg

21. Normal CO2 pressure in vein: 46 mm Hg (40 mm Hg after passing Alveolus [Arterial])

22. Normal O2 pressure in vein: 40 mm Hg (100 mm Hg after passing Alveolus [Arterial])

23. PB: Barometric Pressure (760 Torr @ sea level)

24. PH2O: Alveolar Water Vapor Pressure (47 Torr @ 100% RH)

25. Respiration: process of moving oxygen to tissues for aerobic metabolism & removal of CO2 (involves gas exchange @ lungs & tissues

26. Right-Left Shunt: Malfunction in septum that causes deoxygenated blood to travel from RIGHT atrium to LEFT atrium

27. Silent Unit is defined as:: No perfusion and no ventilation

28. Total O2 content of blood equation:: CaO2=(0.003 x PaO2) + (Hb x 1.34 x SaO2)

29. What are disorders that lead to alveolar deadspace?: Pulmonary emboli, partial obstruction of the pulmonary vasculature, destroyed pulmonary vasculature (ie COPD), and reduced cardiac output.

30. What causes RELATIVE SHUNTS?: COPD, Restrictive disorders, and any condition resulting in hypoventilation

31. What does the FLAT portion of the HbO2 dissociation curve show: SaO2>90% Facilitates O2 loading at lungs even with low PaO2

32. What does the STEEP portion of the HbO2 dissociation curve show: SaO2<90% Occurs in capillaries facilitating O2 unloading at tissues 33. What effect does Body Temp(T) have on the HbO2 curve?: -HIGH T shifts curve to the LEFT (LOWER metabolic demands not requiring much O2) -LOW T shifts curve to the RIGHT (facilitates more O2 unloading to meet HIGHER metabolic demands) 34. What factors significantly affect O2 loading and unloading?: pH, body temperature, the amount of 2,3 DPG in RBCs 35. What happens when perfusion exceeds ventilation?: PHYSIOLOGIC SHUNT: capillary, absolute anatomic and relative shunts seen in disease states that diminish pulmonary ventilation 36. What happens with an ANATOMIC SHUNT?: a portion of cardiac output returns to the left heart without being oxygenated (perfusion in excess of ventilation) 37. What has a downward stepwise gradient (cascade) from normal atmospheric partial pressures to intracellular?: O2 38. What is Carboxyhemoglobin?: (HbCO) Hb binds CO (Carbon Monoxide) has 200x > affinity than O2. Results in Bound O2 not being able to unload (Left shift in HbO2 curve)

39. What is Deadspace Ventilation: Ventilation in excess of perfusion

40. What is methemoglobin?: Ferric iron that cannot bind with O2 & ALTERS HbO2 AFFINITY (LEFT SHIFT IN HbO2 CURVE)

41. What is needed for CaO2 to be adequate: Sufficient normal Hemoglobin (Hb). If hemoglobin (Hb) is absolute low, will result in anemia.

42. What is P50 in regards to the HbO2 Dissociation curve: shows what the PO2 is when the Hb is 50% saturated with O2 <27 Torr>

43. What is reduction in blood flow called?: Shock/Ischemia

44. What is sickle cell?: HbS- Abnormal hemoglobin that is fragile that leads to hemolysis (H2O goes in until cell ruptures) & thrombi.

45. What is the best number for ventilation: PaCO2

46. What is the difference between Ferrous and Ferric Iron?: Ferrous (Fe2+) is good iron that binds to O2. Ferric (Fe3+) is bad iron, RUST

47. What is the formula for alveolar minute ventilation: f x (VT-VD)
frequency x (Tidal Volume – Physiological Deadspace)

48. What is the importance of the Bohr effect on Oxygen Transport.: pH has an effect of Hemoglobin’s affinity for O2. LOW pH shifts HbO2 curve RIGHT and HIGH pH shifts the curve to the left.

49. What is the majority of the O2 in the body carried in: bound to Hemoglobin (Hb)

50. What is the normal Methemoglobin % reading: 1% – 2% (Co-Oximeter Reading)

51. what leads to an increased PaCO2?: decrease VA, increased VCO2, increased VD

52. What’s with that CO2 Transport?: CO2 is ionized as bicarbonate:~80% transported as HCO3