Chapter 6
What is the name of the pressure that is commonly used as a clinical indicator of left ventricular function?
Wedge Pressure
When breathing 21% oxygen, what is the inspired oxygen partial pressure?
Approximately 160 mm Hg
Where is most of the oxygen in blood?
Erythrocyte
What is the average amount of CO2 produced by the body at rest?
200 mL/min
What is the pH of a chemical neutral solution?
7.0
What respiratory center controls the length of inspiration?
The Pneumotaxic Center
Why should the balloon of the PAC be left inflated when inserted in the right atrium?
To allow the blood flow to catch the balloon and carry the catheter forward.
The DLCO is useful in differentiating emphysema from what other obstructive diseases? Asthma, Pneumonia, ARDS, Bronchiectasis
Asthma
What term describes the unoxygenated hemoglobin?
Deoxygemoglobin
The affinity of hemoglobin for CO2 is greater when it is not combine with oxygen. What is the name of this phenomenon?
The Haldane Effect
What three variables are computer by the H-H equation?
pH, HCO3, PCO2
When stimulated, the stretch receptors will have what effect on respiration?
During the insertion of a PAC, it is observed that the waveform increases in height and that the pressure is about 25/0 mm Hg. Where is the catheter likely located?
RV
How many times faster does oxygen diffuse through a gas medium than CO2?
1.2
What are the normal values for hemoglobin saturation and oxygen partial pressures?
PO2 is 100 mm Hg and SaO2 of 97.5%
Which of the following is considered the clinical marker of alveolar ventilation adequacy? PaCO2, HbO2, HCO3-, PaO2
PaCO2
What non-bicarbonate buffer is the most important?
Hb
What reflex may be involved in periodic deep sighs and stimulating the first breaths of a newborn baby?
Head's reflex
In what group of patients has NO been especially beneficial in treating pulmonary hypertension?
Infants
CO2 is how many times more soluble than O2?
24
What is the name of the phenomenon associated with the decreased affinity of Hb for oxygen when PCO2 is high?
The Bohr Effect
What is the average tissue blood CO2 gradient?
6 mm Hg
What organ is responsible for the physical removal of H+?
Kidneys
What is the clinical importance of the periodic deep sighs during quiet breathing?
Help prevent alveolar collapse or atelectasis
What is the PaO2 at which the maximal vasoconstrictive response occurs when the pH is 7.40?
50 to 60 mm Hg
When combining Graham's Law and Henry's Law, how many times faster does carbon dioxide diffuse across the alveolar capillary membrane than oxygen?
20
What is the best explanation for the presence of peripheral cyanosis?
Low venous oxygen saturation
The majority of CO2 is transported in which of the following forms? Plasma HCO3-, RBC HCO3-, Plasma H2CO3, RBC H2CO3
Plasma HCO3-
What is considered a rapid compensatory mechanism to restore the pH back to normal levels in the presence of a metabolic acidosis?
CO2 elimination
How would you describe Biot's breathing?
RR gradually increases and then gradually decreases to complete apnea, but Vt has essentially the same depth. Then the breathing frequency gradually increases again.
What is the name of the force tending to move fluid into the capillary?
Oncotic Pressure
What is the most common cause of resting hypoxemia?
A mismatch between ventilation and blood flow
What is the normal amount of oxygen delivered to the tissues?
1000 mL/ min
What is the approximate percentage of dissolved CO2?
8%
What is the normal ration of HCO3- to dissolved CO2 necessary to maintain a pH of 7.40?
20:1
What is the primary mechanism that drives ventilation in humans?
PCO2