109 Questions
Which organ system is minimally affected by benzodiazepines?
Cardiovascular
What effect do benzodiazepines have on blood pressure?
Decrease
Which organ system do benzodiazepines primarily affect in terms of reducing oxygen consumption?
Cerebral
What is the effect of benzodiazepines on the ventilatory response to CO2?
Decrease
When can benzodiazepines cause respiratory arrest?
When administered intravenously
What is the primary effect of benzodiazepines on intracranial pressure?
Decrease
What type of seizures are benzodiazepines effective in controlling?
Tonic-clonic seizures
What side effect is commonly associated with sedative doses of benzodiazepines?
Amnesia
Where is the mild muscle relaxation property of benzodiazepines mediated?
Spinal cord
How do benzodiazepines affect the rate of unconsciousness and recovery?
Slower rate of unconsciousness and longer recovery
Which part of the brain does barbiturates depress?
Reticular activating system
What is the main mechanism of action of barbiturates?
Binding to GABAA receptors
What determines the hypnotic potency and anticonvulsant activity of barbiturates?
Substitution at the C5 carbon
Which group of barbiturates is anticonvulsant?
Phenyl group
Which barbiturate is useful for providing anesthesia during electroconvulsive therapy?
Methohexital
What effect does replacing oxygen with sulfur at C2 have on barbiturates?
Increases lipid solubility
What determines the duration of induction doses of thiopental, thiamylal, and methohexital?
Redistribution
What explains the rapid cerebral absorption of thiopental?
High non-ionized fraction
Under what conditions will higher concentrations of barbiturates be reached in the brain and heart?
Hypovolemic shock
How long does it take for plasma and brain concentrations of barbiturates to reduce to 10% of maximum levels?
20-30 minutes
Which organ is responsible for the renal excretion of most agents?
Kidneys
What effect do barbiturates have on blood pressure and heart rate?
Decrease blood pressure and increase heart rate
Which center in the brain do barbiturates depress, leading to a decrease in the ventilatory response?
Medullary ventilatory center
What effect do barbiturates have on cerebral blood flow and intracranial pressure?
Decrease cerebral blood flow and increase intracranial pressure
How do barbiturates affect renal blood flow and glomerular filtration rate?
Decrease renal blood flow and glomerular filtration rate
What effect do barbiturates have on hepatic blood flow?
Decrease hepatic blood flow
Which enzyme system do barbiturates interfere with, affecting the biotransformation of other drugs?
Cytochrome P-450
Which receptor do benzodiazepines bind to in the central nervous system?
GABAa receptor
What is the specific benzodiazepine receptor antagonist?
Flumazenil
Which benzodiazepine has water solubility at low pH due to its imidazole ring?
Midazolam
Which organ system is minimally affected by benzodiazepines?
Cardiovascular
What effect do benzodiazepines have on blood pressure?
Decrease
When do benzodiazepines cause significant respiratory depression?
When administered intravenously
What effect do benzodiazepines have on cerebral oxygen consumption?
Decrease
Which type of seizures are benzodiazepines effective in controlling?
Grand mal seizures
What property of benzodiazepines is mediated at the level of the spinal cord?
Muscle relaxation
Do benzodiazepines have a faster or slower rate of unconsciousness compared to other drugs?
Slower
Which organ system do benzodiazepines have the greatest effect on?
Cerebral
What effect do benzodiazepines have on intracranial pressure?
Decrease
What is a common side effect of sedative doses of benzodiazepines?
Anterograde amnesia
Which receptor do barbiturates bind to in the brain?
GABAA receptor
What is the main mechanism of action of barbiturates?
Enhancing GABA activity
What determines the hypnotic potency and anticonvulsant activity of barbiturates?
The substitution at the C5 carbon
Which barbiturate is specifically useful for providing anesthesia during electroconvulsive therapy?
Methohexital
What happens when the oxygen at C2 in barbiturates is replaced with a sulfur atom?
Increased lipid solubility
Which barbiturate has the greatest potency, rapid onset of action, and shorter duration of action after a single dose?
Thiopental
What determines the duration of induction doses of thiopental, thiamylal, and methohexital?
Redistribution
What explains the rapid cerebral absorption of thiopental?
High non-ionized fraction
Under what conditions will higher concentrations of barbiturates be reached in the brain and heart for a given dose?
Hypovolemic shock
Within how many minutes do plasma and brain concentrations of barbiturates reduce to 10% of maximum levels due to redistribution?
20 to 30 minutes
Which of the following statements about renal excretion is correct?
Renal excretion is limited to the water-soluble end products of hepatic biotransformation.
What effect do barbiturates have on the cardiovascular system?
They cause a decrease in blood pressure and an increase in heart rate.
How do barbiturates affect the respiratory system?
They depress the medullary ventilatory center, decreasing the ventilatory response to hypercapnia and hypoxia.
What effect do barbiturates have on the cerebral vasculature?
They constrict the cerebral vasculature, causing a decrease in cerebral blood flow, cerebral blood volume, and intracranial pressure.
How do barbiturates affect renal blood flow and glomerular filtration rate?
They reduce renal blood flow and glomerular filtration rate in proportion to the fall in blood pressure.
What effect do barbiturates have on hepatic blood flow?
They decrease hepatic blood flow.
What effect does chronic exposure to barbiturates have on liver enzymes?
Chronic exposure to barbiturates leads to the induction of liver enzymes and an increased rate of metabolism.
What effect do barbiturates have on the binding of other drugs to the cytochrome P-450 enzyme system?
The binding of barbiturates to the cytochrome P-450 enzyme system interferes with the biotransformation of other drugs.
What effect do benzodiazepines have on the GABAa receptor?
The binding of benzodiazepines to the GABAa receptor increases the frequency of openings of the associated chloride ion channel.
Which of the following is a potential effect of propofol infusion in critically ill children or young adult neurosurgical patients?
Hyperlipidemia
What is the main cardiovascular effect of propofol?
Decrease in blood pressure
Which factors are associated with propofol-induced hypotension?
Large doses, rapid injection, and old age
What is the respiratory effect of propofol?
Respiratory depression
What effect does propofol have on the hypoxic ventilatory drive?
Inhibits the hypoxic ventilatory drive
What effect does propofol have on cerebral blood flow?
Decreases cerebral blood flow
What effect does propofol have on intracranial pressure?
Decreases intracranial pressure
Which organ system is minimally affected by propofol?
Renal system
What effect does propofol have on the normal arterial baroreflex response to hypotension?
Markedly alters the normal arterial baroreflex response to hypotension
Who should administer propofol for sedation?
Appropriately trained and qualified personnel
Which of the following is a contraindication for the administration of ketamine?
Arterial aneurysms
What effect does sympathetic blockade have on the myocardial depressant effects of large doses of ketamine?
Enhances the depressant effects
Which combination can produce apnea when administered with ketamine?
Ketamine with opioids
Which type of patients may require intubation during general anesthesia with ketamine?
Patients at increased risk for aspiration pneumonia
What is the effect of racemic ketamine on bronchodilation?
Potent bronchodilation
When combined with a benzodiazepine and controlled ventilation, what effect does ketamine have on intracranial pressure?
Decreases intracranial pressure
Which receptor does etomidate bind to in the central nervous system?
GABAA receptor
What is the primary use of etomidate?
Induction of general anesthesia
What effect does etomidate have on peripheral vascular resistance?
Decreases peripheral vascular resistance
What effect does etomidate have on cerebral blood flow?
Decreases cerebral blood flow
Which of the following is a known effect of ketamine on the central nervous system?
Inhibition of N-methyl-D-aspartate (NMDA) channels
What is the controversial aspect regarding ketamine's mechanism of producing anesthesia or analgesia?
Its effect on sensory inputs
In which condition is ketamine widely used to treat severe treatment-resistant depression?
Patients with suicidal ideation
For what purpose are small doses of ketamine infusion used during and after surgical procedures?
To supplement general anesthesia
In which situation is ketamine useful for intramuscular induction of general anesthesia?
Uncooperative children and adults
With which agents can ketamine be combined for conscious sedation during procedures such as nerve blocks and endoscopy?
Propofol or midazolam
What effect does ketamine have on the sympathetic nervous system and norepinephrine reuptake?
Central stimulation and inhibition, respectively
What are the cardiovascular changes that accompany the indirect cardiovascular effects of ketamine?
Increases in pulmonary artery pressure and myocardial work
What is the primary effect of ketamine on organ systems?
Cardiovascular
In which setting is ketamine's tendency to produce sympathetic stimulation useful for intravenous induction of anesthesia?
Hypovolemia
Which opioid receptor is responsible for supraspinal analgesia?
μ
Which opioid receptor is associated with respiratory depression?
κ
Which opioid receptor is responsible for sedation?
κ
Which opioid receptor is associated with dysphoria and hallucinations?
σ
Which opioid receptor is responsible for analgesia?
δ
Which opioid receptor is associated with muscular stiffness?
μ
Which opioid receptor is responsible for respiratory stimulation?
σ
Which opioid receptor is associated with epileptic behavior?
δ
Which opioid receptor is responsible for spinal analgesia?
μ
Which opioid receptor is associated with physical dependency?
μ
Which receptor do opioids bind to in the respiratory centers of the brainstem?
Opioid receptors
What is the effect of opioids on respiratory rate?
Decrease
What is the role of respiratory rate and end-tidal CO2 tension in detecting respiratory depression in patients receiving opioid analgesia?
They provide simple metrics for early detection of respiratory depression
What happens to the CO2 response curve as a result of opioids binding to neurons in the respiratory centers of the brainstem?
Shifts downward and to the right
What effect do opioids have on the apneic threshold?
Increases
Which opioids can induce chest wall stiffness severe enough to make bag-mask ventilation nearly impossible?
Fentanyl and sufentanil
What effect do opioids have on cerebral blood flow and intracranial pressure compared to propofol, benzodiazepines, or barbiturates?
Lesser reduction
What effect do opioids have on gastrointestinal motility?
Decrease
Which opioid-induced condition can mimic a common bile duct stone on cholangiography?
Biliary spasm
Which hormones are inhibited more completely by large doses of fentanyl or sufentanil compared to volatile anesthetics?
Catecholamines, antidiuretic hormone, and cortisol
Test your knowledge on barbiturates and their mechanism of action in this quiz. Learn about their effects on the brain's reticular activating system and their interaction with the GABAA receptor.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
