Ch8 Circulatory Effects of Inhaled Anesthetics

Question 1

What effects do potent inhaled agents like desflurane have at sub-anesthetic concentrations?

Answer 1

They cause peripheral vasodilation, leading to heat loss

This can affect temperature regulation in the body.

Question 2

How does deeper anesthesia affect blood pressure and systemic vascular resistance?

Answer 2

It decreases blood pressure and systemic vascular resistance

This is linked to vasodilation.

Question 3

What is the relationship between desflurane and temperature control during anesthesia?

Answer 3

Desflurane broadens the range of body temperature control

This can lead to a loss of core body heat.

Question 4

What cardiovascular responses are observed with surgical stimulation under desflurane?

Answer 4

Desflurane and sevoflurane show similar responses, with fentanyl reducing these responses

This indicates a need for careful management of anesthetic concentrations.

Question 5

What is MAC bar?

Answer 5

MAC bar is the point where autonomic response is 50% blocked

It indicates the concentration of anesthetic needed to suppress autonomic responses.

Question 6

What is MAC intubation?

Answer 6

MAC intubation is the concentration at which the response to tracheal tube placement is suppressed

This helps in determining safe anesthetic levels during intubation.

Question 7

How does fentanyl affect the cardiovascular response to surgical stimulation?

Answer 7

Fentanyl decreases MAC bar and MAC intubation

It has a synergistic effect with inhaled anesthetics.

Question 8

What arrhythmogenic concern is associated with sevoflurane?

Answer 8

Sevoflurane is of particular concern in children due to the risk of bradycardia

This highlights the need for careful monitoring in pediatric anesthesia.

Question 9

What is coronary steal?

Answer 9

Coronary steal is the phenomenon where vasodilation in normal coronary arteries diverts blood flow from stenotic areas, leading to ischemia

This can complicate the management of patients with coronary artery disease.

Question 10

What is the effect of anesthetics on cerebral autoregulation?

Answer 10

Anesthetics narrow the range of blood pressures over which cerebral autoregulation occurs

Maintaining blood pressure above a certain level is crucial to avoid cerebral infarction.

Question 11

True or False: All anesthetics decrease systemic vascular resistance except halothane.

Answer 11

True

Halothane is the exception in this regard.

Question 12

Fill in the blank: The clinical implications of anesthesia include a drop in ______ due to vasodilation.

Answer 12

blood pressure

Question 13

What happens to heart rate at deeper levels of anesthesia with desflurane?

Answer 13

It tends to increase at lighter levels but increases at deeper levels of anesthesia

This variation is important for monitoring during procedures.

Question 14

What effect does spontaneous ventilation have on venous return?

Answer 14

It increases venous return

This is due to the negative pressure created in the thoracic cavity.

Question 15

Why is it important to monitor anesthetic concentrations during surgery?

Answer 15

To avoid adverse cardiovascular effects

Proper management is crucial for patient safety.

Question 16

What study was mentioned regarding the effects of anesthetics on blood pressure and heart rate over time?

Answer 16

A study where volunteers were anesthetized for eight hours showed changes in blood pressure and heart rate

These changes were significant over the duration of anesthesia.

Question 17

What is the impact of CO2 on peripheral resistance?

Answer 17

CO2 causes vasodilation

This is relevant in the context of ventilation and anesthetic effects.

Question 18

What is the initial heart rate and blood pressure recorded after incision?

Answer 18

Heart rate: 122, Blood pressure: 122 over 85

Question 19

What changes were observed in heart rate and blood pressure after 12 minutes post-incision?

Answer 19

Heart rate increased slightly, Blood pressure increased to 135 over 89

Question 20

What action was taken to manage the increase in heart rate and blood pressure?

Answer 20

Double the concentration of desflurane and increase flows to 2 and 2

Question 21

What was the end-tidal concentration after increasing the dial to 9%?

Answer 21

End-tidal concentration increased to 7.3

Question 22

What was the heart rate and blood pressure after adjusting the anesthetic concentration?

Answer 22

Heart rate: 61, Blood pressure: almost the same as prior to incision

Question 23

What was the flow rate and anesthetic mixture used during the procedure with sevoflurane?

Answer 23

Flow rate: 1 liter per minute, Mixture: 4% sevoflurane and 50% nitrous oxide

Question 24

What was the heart rate and blood pressure recorded two minutes after incision with sevoflurane?

Answer 24

Heart rate: 90, Blood pressure: 111 over 68

Question 25

What was the change in heart rate and blood pressure after five minutes post-incision?

Answer 25

Heart rate remained above 90, Blood pressure did not return to baseline

Question 26

What concentration was the vaporizer adjusted to in an attempt to return cardiovascular status to baseline?

Answer 26

Vaporizer concentration adjusted to 3.2

Question 27

What were the vital signs after nine minutes of adjusting the sevoflurane concentration?

Answer 27

Blood pressure: 96 over 64, Heart rate: 78

Question 28

What does MAC bar refer to in anesthetic practice?

Answer 28

MAC bar refers to the minimum alveolar concentration required to prevent cardiovascular response to surgical stimulation

Question 29

What effect does fentanyl have on MAC bar?

Answer 29

Fentanyl synergistically decreases MAC bar

Question 30

What was the blood pressure and heart rate recorded after administering minimal narcotics during surgery?

Answer 30

Blood pressure: 177 over 116, Heart rate: 221

Question 31

What is the primary concern with high concentrations of sevoflurane in children?

Answer 31

Bradycardia

Question 32

What effect do potent inhaled anesthetics have on baroreflexes?

Answer 32

They blunt or decrease baroreflexes

Question 33

What was the response of the cardiovascular system to a step change in alveolar concentration from 4% to 8%?

Answer 33

Dramatic increase in blood pressure, returning to control levels within six minutes

Question 34

Which inhaled anesthetic is known to be arrhythmogenic?

Answer 34

Sevoflurane

Question 35

What observation was made by Ebert regarding desflurane and sevoflurane when increasing concentrations?

Answer 35

Desflurane caused cardiovascular stimulation, while sevoflurane caused cardiovascular depression

Question 36

What effect does increasing desflurane concentration have on heart rate and blood pressure?

Answer 36

Heart rate and blood pressure increase transiently

Question 37

What management strategies can be employed to minimize cardiovascular stimulation from desflurane?

Answer 37

* Never go above 6% * Increase concentration slowly * Administer opioids

Question 38

What was the heart rate and blood pressure after administering fentanyl before increasing desflurane concentration?

Answer 38

Blood pressure: 90 over 66, Heart rate: 57

Question 39

What cardiovascular response was observed after increasing sevoflurane concentration to 12%?

Answer 39

Small increase in blood pressure to 118 over 76, increase in heart rate to 72

Question 40

What is the effect of death strain on induction of anesthesia?

Answer 40

10% increase in induction of anesthesia ## Footnote This increase may lead to hyperdynamic circulation and increased blood pressure.

Question 41

What was observed regarding ischemia during induction with death strain?

Answer 41

Greater incidence of ischemia ## Footnote This suggests that induction with death strain may heighten the appearance of ischemia.

Question 42

What was found during maintenance with sufentanil?

Answer 42

More severe ischemia during maintenance ## Footnote There was less severity of ischemia during maintenance compared to death strain.

Question 43

What were the outcomes regarding mortality and myocardial infarction between groups?

Answer 43

No difference in outcomes ## Footnote This includes no difference in mortality, myocardial infarction, or need for significant circulatory support.

Question 44

What is ischemic preconditioning of the heart?

Answer 44

Making the heart ischemic to decrease vulnerability to subsequent ischemic episodes ## Footnote This may explain the protective effects of inhaled anesthetics.

Question 45

Which inhaled anesthetic has a greater protective effect according to studies?

Answer 45

Desflurane ## Footnote Studies suggest desflurane is more protective than propofol or isoflurane.

Question 46

What does coronary steel refer to?

Answer 46

Vasodilation of normal coronary arteries diverting blood flow from stenotic areas ## Footnote This can result in ischemia in areas that are already compromised.

Question 47

What can cause myocardial ischemia during anesthesia?

Answer 47

Hypotension ## Footnote Hypotension can decrease coronary vascular resistance and compromise myocardial perfusion.

Question 48

What is the general effect of inhaled anesthetics on resistance to blood flow through the heart?

Answer 48

Decreases resistance ## Footnote This is due to a reduction in metabolic rate across tissues.

Question 49

What happens to metabolic rate when anesthetics are administered?

Answer 49

Lowered metabolic rate ## Footnote This leads to decreased CO2 and lactate production, affecting vascular resistance.

Question 50

What is cerebral autoregulation?

Answer 50

Ability to maintain blood flow within a certain range of blood pressures ## Footnote This involves vasoconstriction or vasodilation within a set range.

Question 51

What happens to the range of cerebral autoregulation with potent inhaled anesthetics?

Answer 51

Narrowed range of autoregulation ## Footnote Autoregulation is lost below certain blood pressure levels, typically below 50 mmHg.

Question 52

What are the approximate limits for cerebral autoregulation?

Answer 52

About 50 mmHg and 150 mmHg ## Footnote Below 50 mmHg, autoregulation fails, leading to potential ischemia.

Question 53

Can you go below 50 mmHg without causing cerebral infarct?

Answer 53

Not necessarily, with protection ## Footnote Cerebral protection methods may allow for lower blood pressures without infarct.