Exam 1: 27 Jan Benzos and EEG Monitoring Flashcards
What is the spectrum of consciousness in relation to anesthesia?
Consciousness and unconsciousness are not binary states but exist on a spectrum.
What is the purpose of EEG monitoring in anesthesia?
To correlate EEG activity with anesthetic depth and cerebral metabolic requirements.
When did the correlation of EEG activity with anesthetic effects begin?
As far back as 1937.
What are the five main effects of benzodiazepines?
- Anxiolytic
- Amnestic
- Sedative
- Anticonvulsant
- Muscle relaxation
What is midazolam used for?
Preoperative sedation and anxiolysis.
Fill in the blank: The reversal agent for benzodiazepines is _______.
flumazenil
What is the significance of processed EEGs?
They gauge the depth of anesthesia to improve patient safety and recovery times.
What did Dr. Kane emphasize about the use of processed EEG data?
The importance of signal quality, EMG, and suppression ratio.
Describe the testing process for processed EEGs.
Involved 1500 subjects for 5000 hours, removing artifacts and testing with various anesthetics.
What are the characteristics of diazepam?
Longer-acting, slower onset, and used for sedation, anticonvulsant therapy, and muscle relaxation.
True or False: Lorazepam has a faster onset than midazolam.
False
What is the importance of monitoring patients closely when administering midazolam?
To avoid overdose and ensure safe recovery.
What is a key risk associated with using flumazenil?
It can reverse chronic benzodiazepine therapy and has a limited duration of action.
What is the relationship between cerebral blood flow and EEG activity?
Higher cerebral blood flow correlates with more alert EEG activity.
What is the role of the mathematical algorithm in processed EEGs?
To interpret processed EEG readings and gauge anesthetic depth.
What should be avoided in patients with processed EEGs?
Brain death, as it can be misleading.
What influences the interpretation of processed EEG readings?
Synergistic drugs and the need for caution in their use.
What is the significance of trending data in processed EEG interpretation?
It is more reliable than relying on a single reading.
What patient factors should be considered when using lorazepam?
Liver function and renal status.
What does a bispectral index (BIS) below 58 indicate?
The patient is not conscious and will not move.
What is the clinical application of benzodiazepines discussed by Dr. Kane?
Sedation, anesthesia, and critical care.
What was highlighted regarding the clinical use of benzodiazepines?
Understanding their pharmacology and clinical effects is essential for optimizing patient care.
Fill in the blank: The first machine for processing EEGs was called _______.
BIS
What is the importance of ongoing learning in anesthesia practice?
To stay updated on the latest research and clinical practices.
What signal quality metrics are monitored during anesthesia?
EMG, EEG, suppression ratio
These metrics help assess brain activity and patient awareness during anesthesia.
What is the range of the suppression ratio that indicates ideal conditions for anesthesia?
40 to 60
Values in this range suggest the patient is less likely to recall the surgical experience.
What effect does the presence of synergistic drugs have on anesthesia monitoring?
They tend to lower the monitored values
This can lead to misleading readings of the patient’s consciousness or responsiveness.
What is the primary action of ketamine in anesthesia?
Sympathomimetic effect, stimulating the CNS
This can lead to increased brain wave activity.
What is the consequence of using benzodiazepines in anesthesia?
They act as anxiolytics, sedatives, and cause anterograde amnesia
This helps in managing patient anxiety and memory of the procedure.
Fill in the blank: Benzodiazepines primarily enhance the action of _______ at GABA receptors.
GABA
What are the five primary effects of benzodiazepines?
- Anxiolytic
- Sedation
- Anterograde amnesia
- Anticonvulsant effects
- Skeletal muscle relaxation
True or False: Benzodiazepines have completely replaced barbiturates in medical practice.
True
Benzodiazepines have largely replaced barbiturates due to fewer side effects and lower risk of addiction.
How do benzodiazepines affect the chloride ion channels at the GABA receptor?
They enhance the affinity of the receptor for GABA, leading to hyperpolarization
This makes it harder for the neuron to depolarize and fire.
What is the role of the alpha subunits in the action of benzodiazepines?
They determine the specific effects, including sedation and muscle relaxation
Different alpha subunits are associated with different effects.
What are the common uses of midazolam in anesthesia?
Pre-operative sedation due to its quick onset and offset
This makes it suitable for outpatient procedures.
What is the pharmacological antagonist for benzodiazepines?
Flumazenil (Romazicon)
It can reverse the effects of benzodiazepines but does not selectively target specific drugs.
What can cause a misleading suppression ratio during anesthesia monitoring?
Artifacts, improper electrode placement, or patient movement
These factors can distort the readings of brain activity.
What is the significance of a suppression ratio of zero?
Indicates potential brain death
A ratio of zero is never desired in conscious patients.
What is the difference between anterograde and retrograde amnesia?
Anterograde amnesia prevents recall of events after drug administration, while retrograde amnesia affects memories formed before
Benzodiazepines primarily cause anterograde amnesia.
What are the common side effects associated with barbiturates?
- Tolerance
- Addiction
- More severe side effects
These complications led to their decline in use compared to benzodiazepines.
What can happen if too much anesthetic is administered?
Bradycardia and hypotension
Excessive anesthetic can lead to serious cardiovascular side effects.
What receptors do benzodiazepines primarily act on?
GABA A receptors
Benzodiazepines act on GABA A receptors with chloride, hyperpolarizing the membrane.
What are the factors that differentiate various benzodiazepines?
Onset, peak effect, duration of action, offset time
Understanding these factors helps in selecting the appropriate benzodiazepine for treatment.
What is the effect of low albumin levels on benzodiazepine pharmacokinetics?
Decreased protein binding leads to more free drug available
Patients with low albumin may require albumin supplementation before surgery.
What change occurs in EEG activity with benzodiazepine use?
Decreased Alpha activity
Some benzodiazepines can produce an isoelectric state in EEG.
What effect do benzodiazepines have on memory?
They cause anterograde amnesia
Patients may not recall events even if they appear awake.
How do benzodiazepines interact with other drugs?
They are synergistic with alcohol, opioids, and alpha-2 agonists
Example of an alpha-2 agonist: Clonidine.
What is the significance of the imidazobenzodiazepine ring in Versed?
Helps stabilize the structure and rapid metabolism
The ring’s state is pH-dependent, affecting its activity.
What is the onset and peak effect time for Versed?
Onset: 1-2 minutes; Peak: 5 minutes
Rapid onset and peak effect are important for patient management.
What is the elimination half-life of Versed?
Approximately 2 hours
Variability in elimination can occur with altered liver function, renal function, and patient age.
What factors can alter the metabolism of benzodiazepines?
Liver function, renal function, age, obesity
Common drugs affecting metabolism include Tagamet and erythromycin.
What effect do benzodiazepines have on cerebral blood flow?
Decreases cerebral blood flow in a dose-dependent manner
They also decrease cerebral metabolic oxygen requirements.
What is Status Epilepticus?
Continuous seizure activity without recovery
Benzodiazepines can effectively break Status Epilepticus.
How do benzodiazepines affect the cardiovascular system?
They cause a dose-dependent increase in heart rate and decrease in blood pressure
This is a compensatory mechanism for maintaining cardiac output.
What dose of Versed is typically used for pediatric sedation?
0.25 to 0.5 mg/kg, usually 0.5 mg orally
Oral Versed peaks in about 20-30 minutes.
True or False: Benzodiazepines can inhibit the response to intubation.
False
Benzodiazepines do not inhibit the cardiovascular response to intubation.
Fill in the blank: Benzodiazepines are metabolized by the _______ system.
cytochrome P450 system
Specifically, CYP3A4 is involved in the metabolism of benzodiazepines.
What is the primary goal of using sedation in patients?
To take away anxiety and make patients sleepy without causing unconsciousness.
What is the typical oral dose of Versed for children?
0.25 to 0.5 milligrams per kilogram, usually 0.5 orally.
How long does it take for the peak effect of oral Versed to occur?
20 to 30 minutes.
What is the adult sedation dose range for Versed?
1 to 5 milligrams.
How quickly does IV Versed peak compared to oral Versed?
IV Versed peaks in about 5 minutes, significantly faster than oral.
What is the recommended approach when dosing Versed?
Start with a smaller dose and titrate as needed.
What is the safety profile of doses from 0.25 to 1 milligram per kilogram of Versed in children?
It is considered a safe and conservative dose.
What is the induction dose range for using Versed?
0.1 to 0.2 milligrams per kilogram over 30 to 60 seconds.
What is a key consideration when maintaining patients on a Versed drip?
Decrease doses of other synergistic drugs to avoid excessive effects.
What is the elimination half-life of Versed?
Short, making it suitable for quick recovery after sedation.
True or False: Versed is associated with nausea and vomiting post-anesthesia.
False.
What are the effects of long-term use of Versed on the immune system?
There is some T cell suppression and potential immune issues.
What is the primary reason Valium is not commonly used in anesthesia?
It has a longer onset and elimination half-life compared to faster alternatives.
What is the elimination half-life of Valium?
20 to 40 hours.
What formulation of Valium is less painful upon injection?
Soybean formulation.
What is the effect of Valium on cerebral blood flow and oxygen requirements?
Similar to other benzodiazepines, with minimal effects on ventilation.
What is the typical IV dose range for Valium during induction?
Seziures?
0.5 to 1 milligram per kilogram.
0.1mg/kg
What is the main advantage of using Lorazepam compared to Valium and Versed?
More potent as a sedative and amnestic.
What is a notable property of Lorazepam regarding water solubility?
It is insoluble in water and requires a solvent for injection.
What is the relationship between Lorazepam’s onset of action and its lipid solubility?
Slower onset due to lower lipid solubility.
True or False: Lorazepam has a faster metabolic clearance than Valium.
False.
What is the effect of benzodiazepines on the spinal cord?
They cause spinal cord inhibition, leading to muscle relaxation.
What is the definition of potency in the context of medications?
Potency refers to the strength of a drug’s effect, with Valium being insoluble in water requiring a solvent for IV injection.
How does the onset of action for Valium compare to that of Versed?
Valium has a slower onset of action compared to Versed.
What is the peak effect time for Valium?
The peak effect of Valium is 20 to 30 minutes.
What is the peak effect time for Versed?
The peak effect of Versed is 5 minutes.
What is the elimination half-life of Ativan?
The elimination half-life of Ativan is 14 hours.
True or False: Versed completely depends on microsomal enzymes for metabolism.
False
What are the typical doses of Ativan for IV administration?
Doses are typically 1 to 4 milligrams IV as a single dose.
What is the role of flumazenil?
Flumazenil is a non-specific antagonist that reverses all benzodiazepines.
What is the initial dose of Romazicon (flumazenil) for reversal?
The initial dose of Romazicon is 0.2 milligrams IV.
Fill in the blank: The maximum total dose of Romazicon is _______.
1 milligram
What should be monitored if flumazenil is administered?
Monitor for potential seizures if benzodiazepines were used for seizure control.
What happens if a patient does not regain consciousness after receiving the maximum dose of flumazenil?
It suggests the presence of other substances in the system, such as narcotics or alcohol.
What is the duration of action for flumazenil?
Flumazenil lasts for 30 to 60 minutes.
What are the potential side effects of Romazicon?
Romazicon has no real side effects, but it can reverse chronic anxiety medications.
What is a consideration when using Ativan in older patients with liver issues?
Ativan can be a suitable long-term sedative due to its metabolism not entirely depending on microsomal enzymes.
- It self-conjugates into inactive metabolites over time.
What is the significance of lipid solubility in drug action?
Lipid solubility affects how quickly a drug crosses the lipid bilayer and reaches its effect site.
True or False: Ativan is more expensive than newer sedation medications.
True
