Morgan and Mikhail's Clinical
Anesthesiology Part 2 questions with
answers
A ______ shift in the O2-Hemoglobin dissociation curve results in
decreased oxygen/hemoglobin dissociation, meaning that
Hemoglobin will have a higher affinity for O2. - CORRECT
ANSWERS ✔✔Left shift
A ______ shift in the O2-Hemoglobin dissociation curve results in
*increased oxygen/hemoglobin dissociation*, allowing more O2 to be
dropped off at the tissues. - CORRECT ANSWERS ✔✔Right shift
4 things which cause a *rightward shift* in the hemoglobin-O2
dissociation curve? - CORRECT ANSWERS ✔✔Increased [H+]
(acidosis)
Increased [CO2]
Increased [2,3-DPG] Accumulates during anaerobic respiration
Increased temperature (hyperthermia)
4 things which cause a leftward shift in the hemoglobin-O2
dissociation curve? - CORRECT ANSWERS ✔✔Decreased [H+]
(alkalosis)
,Decreased [CO2]
Decreased [2,3-DPG]
Decreased temperature (hypothermia)
Treatment for methemoglobinemia? - CORRECT ANSWERS
✔✔Methylene blue
Ascorbic acid (vitamin C)
Normally, the body only consumes ____ % of O2 carried on
hemoglobin. - CORRECT ANSWERS ✔✔25%
- *When O2 demand exceeds supply, the extraction fraction exceeds
25%.*
- When O2 supply exceeds demand, the O2 extraction fraction falls
below 25%.
The central chemoreceptors in the brain responsible for maintaining
the respiratory rate respond primarily to changes in the
concentration of what molecule in the CSF? - CORRECT ANSWERS
✔✔[H+] in the CSF
,- Increases in paCO2 elevate CSF hydrogen ion concentration and
activate the chemoreceptors. Results in increased alveolar ventilation
- Central chemoreceptor activity is DEPRESSED by hypoxia
2 Peripheral chemoreceptors that sense CO2 levels in the body? -
CORRECT ANSWERS ✔✔Carotid bodies:
- Principal peripheral chemoreceptors
- Sensitive to changes in *PaO2, PaCO2, pH, and arterial perfusion
pressure*
- Carotid bodies are most sensitive to changes in *PaO2*
Aortic bodies (surrounding the aortic arch)
Cranial nerve responsible for transmitting information from the
carotid bodies and aortic bodies to the central respiratory centers to
produce reflex increases in alveolar ventilation? - CORRECT
ANSWERS ✔✔CN IX (glossopharyngeal)
Reflex increases in alveolar ventilation are in response to:
- Reductions in PaO2
- Reductions in arterial perfusion
, - Elevations in H+
- Elevations in PaCO2
Most important effect of most general anesthetics on breathing? -
CORRECT ANSWERS ✔✔Promote hypoventilation
- Likely due to central depression of the chemoreceptor and
depression of external intercostal muscle activity.
- The peripheral response to hypoxemia is even more sensitive to
anesthetics than the central CO2 response and is nearly abolished by
even subanesthetic doses of most inhalation agents (including N2O)
Ominous sign during an asthma exacerbation which indicates a
patient will soon no longer be able to maintain the necessary work of
breathing to maintain O2 saturations? - CORRECT ANSWERS
✔✔Normal or high PaCO2
- Patients during an asthma exacerbation are typically tachypneic
and will have a low PaCO2
Pulsus paradoxus and EKG signs of right heart strain (ST changes,
right axis deviation, RBBB) are also indicative of severe airway
obstruction
Anesthesiology Part 2 questions with
answers
A ______ shift in the O2-Hemoglobin dissociation curve results in
decreased oxygen/hemoglobin dissociation, meaning that
Hemoglobin will have a higher affinity for O2. - CORRECT
ANSWERS ✔✔Left shift
A ______ shift in the O2-Hemoglobin dissociation curve results in
*increased oxygen/hemoglobin dissociation*, allowing more O2 to be
dropped off at the tissues. - CORRECT ANSWERS ✔✔Right shift
4 things which cause a *rightward shift* in the hemoglobin-O2
dissociation curve? - CORRECT ANSWERS ✔✔Increased [H+]
(acidosis)
Increased [CO2]
Increased [2,3-DPG] Accumulates during anaerobic respiration
Increased temperature (hyperthermia)
4 things which cause a leftward shift in the hemoglobin-O2
dissociation curve? - CORRECT ANSWERS ✔✔Decreased [H+]
(alkalosis)
,Decreased [CO2]
Decreased [2,3-DPG]
Decreased temperature (hypothermia)
Treatment for methemoglobinemia? - CORRECT ANSWERS
✔✔Methylene blue
Ascorbic acid (vitamin C)
Normally, the body only consumes ____ % of O2 carried on
hemoglobin. - CORRECT ANSWERS ✔✔25%
- *When O2 demand exceeds supply, the extraction fraction exceeds
25%.*
- When O2 supply exceeds demand, the O2 extraction fraction falls
below 25%.
The central chemoreceptors in the brain responsible for maintaining
the respiratory rate respond primarily to changes in the
concentration of what molecule in the CSF? - CORRECT ANSWERS
✔✔[H+] in the CSF
,- Increases in paCO2 elevate CSF hydrogen ion concentration and
activate the chemoreceptors. Results in increased alveolar ventilation
- Central chemoreceptor activity is DEPRESSED by hypoxia
2 Peripheral chemoreceptors that sense CO2 levels in the body? -
CORRECT ANSWERS ✔✔Carotid bodies:
- Principal peripheral chemoreceptors
- Sensitive to changes in *PaO2, PaCO2, pH, and arterial perfusion
pressure*
- Carotid bodies are most sensitive to changes in *PaO2*
Aortic bodies (surrounding the aortic arch)
Cranial nerve responsible for transmitting information from the
carotid bodies and aortic bodies to the central respiratory centers to
produce reflex increases in alveolar ventilation? - CORRECT
ANSWERS ✔✔CN IX (glossopharyngeal)
Reflex increases in alveolar ventilation are in response to:
- Reductions in PaO2
- Reductions in arterial perfusion
, - Elevations in H+
- Elevations in PaCO2
Most important effect of most general anesthetics on breathing? -
CORRECT ANSWERS ✔✔Promote hypoventilation
- Likely due to central depression of the chemoreceptor and
depression of external intercostal muscle activity.
- The peripheral response to hypoxemia is even more sensitive to
anesthetics than the central CO2 response and is nearly abolished by
even subanesthetic doses of most inhalation agents (including N2O)
Ominous sign during an asthma exacerbation which indicates a
patient will soon no longer be able to maintain the necessary work of
breathing to maintain O2 saturations? - CORRECT ANSWERS
✔✔Normal or high PaCO2
- Patients during an asthma exacerbation are typically tachypneic
and will have a low PaCO2
Pulsus paradoxus and EKG signs of right heart strain (ST changes,
right axis deviation, RBBB) are also indicative of severe airway
obstruction
