Exam 1 Review A

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Questions and Answers

What is the primary characteristic of neuromuscular blockers that exhibit a ceiling effect?

No increase in potency beyond a certain dose (correct)

Increased potency with increased dose

Reversal by anticholinesterases

Spontaneous degradation in plasma

Which inhalation agent is favored in pediatric cases due to its sweet smell?

Nitrous oxide

Sevoflurane (correct)

Desflurane

Isoflurane

What is the primary mechanism of Hoffman degradation?

Enhanced metabolism of inhalation agents

Enzymatic degradation of neuromuscular blockers

Spontaneous degradation of non-depolarizing neuromuscular blockers in plasma (correct)

Reversal of neuromuscular blockers by anticholinesterases

What is the primary contraindication for the use of nitrous oxide?

Pneumothorax Signup and view all the answers

What is the primary characteristic of opioids that exhibit a ceiling effect?

No increase in potency beyond a certain dose Signup and view all the answers

What stage of anesthesia is characterized by a deeply unconscious patient with increasing muscle relaxation and absence of protective airway reflexes?

Stage 3 Surgical Signup and view all the answers

What occurs during emergence when discontinuing N2O administration?

Rapid diffusion of N2O from bloodstream into alveolus Signup and view all the answers

What is an absolute contraindication to regional anesthesia?

Pt refusal Signup and view all the answers

What is the mechanism of action of local anesthetics?

Block generation and conduction of afferent nerve impulses Signup and view all the answers

What is a relative contraindication to regional anesthesia?

Hypovolemia Signup and view all the answers

What is the effect of local anesthetics on the resting transmembrane potential?

It has no effect on the resting transmembrane potential Signup and view all the answers

What is the binding characteristic of local anesthetics to open and inactivated channels?

High affinity Signup and view all the answers

Which characteristic does not make an inhaled anesthetic ideal for use in all patient populations, including pregnancy?

High blood and tissue solubility Signup and view all the answers

What does a lower MAC indicate about an inhaled anesthetic’s potency?

The agent has a higher potency Signup and view all the answers

Which phase of general anesthesia involves administration of a hypnotic agent and confirmation of loss of consciousness?

Induction Signup and view all the answers

What occurs during the MAC bar stage?

Inhibition of adrenergic and CV response to incision Signup and view all the answers

How does nitrous oxide (N2O) affect the cardiovascular system?

Causes myocardial depression and diffusion hypoxia Signup and view all the answers

What is measured to determine the potency of inhaled anesthetic agents?

Minimum alveolar concentration (MAC) Signup and view all the answers

Which of the following is a common result of rapid administration of desflurane?

Increased blood pressure and heart rate Signup and view all the answers

During which stage of general inhalational anesthesia is amnesia typically provided?

Stage 1 Signup and view all the answers

Which property of total intravenous anesthesia (TIVA) is considered advantageous?

decreased cardiac depression Signup and view all the answers

Which of the following sedative-related effects is specific to Etomidate?

decreased cerebral blood flow Signup and view all the answers

What is a primary pulmonary effect of Propofol?

respiratory depression and bronchodilation Signup and view all the answers

Which phenomenon is a disadvantage of the N2O-narcotic technique?

potential for intraoperative awareness Signup and view all the answers

Which general anesthesia technique is characterized by a higher risk of opioid-induced hyperalgesia?

TIVA Signup and view all the answers

Which sedative should be avoided in patients with advanced cardiovascular disease?

Ketamine Signup and view all the answers

Which anesthetic drug is known for causing pain on injection and carries a high incidence of nausea and vomiting?

Etomidate Signup and view all the answers

What type of sedation is characterized by a reversible state of unconsciousness?

General anesthesia Signup and view all the answers

Which component of general anesthesia involves sensory blockade?

analgesia Signup and view all the answers

What is the blood gas coefficient?

the ratio of the amount of anesthetic in blood and gas when the two phases are of equal volume and pressure and in equilibrium at 37°C Signup and view all the answers

What is the relationship between blood gas coefficient, solubility in blood, and rate of onset?

Directly proportional to solubility and inversely proportional to rate of onset Signup and view all the answers

What are the 4 stages of general inhalational anesthesia?

Disorientation, Delirium, Surgical, and Medullary Depression Signup and view all the answers

Where is the local anesthetic (LA) placed in a spinal block?

Into the subarachnoid space L3-L5 Signup and view all the answers

What medications can be used in a spinal block?

All of the above Signup and view all the answers

What are some potential complications of neuroaxial blocks?

All of the above Signup and view all the answers

What are fascial plane blocks?

A type of regional anesthesia that targets specific fascial planes Signup and view all the answers

What are common sites of fascial plane blocks?

All of the above Signup and view all the answers

What is a Bier block?

A type of nerve block used to anesthetize a limb Signup and view all the answers

How is a Bier block performed?

By injecting a small amount of local anesthetic and applying a tourniquet to the extremity Signup and view all the answers

Which is a component of general anesthesia?

all of the above Signup and view all the answers

What is the most cardiostable sedative?

Etomidate Signup and view all the answers

What complication can etomidate cause?

Adrenal insufficiency Signup and view all the answers

What is neostigmine used for?

Reversing non-depolarizing neuromuscular blockers Signup and view all the answers

What are examples of non-depolarizing neuromuscular blockers?

Rocuronium, vecuronium, and atracurium Signup and view all the answers

What is the least potent inhalation agent?

Nitrous oxide Signup and view all the answers

Which inhalation agent can prolong QT?

Sevoflurane Signup and view all the answers

What does minimum alveolar concentration (MAC) mean?

The lowest concentration of a drug that is required to prevent 50% of pts from moving in response to painful stimuli Signup and view all the answers

What is the effect of inhaled anesthetics on blood pressure?

Decrease blood pressure Signup and view all the answers

How long should a procedure using a Bier block last?

30-60 minutes Signup and view all the answers

What is the effect of a higher blood-gas partition coefficient on the rate of induction of anesthesia?

It increases the rate of induction i.e. slows the rate Signup and view all the answers

Which of the following anesthetic agents is likely to have a faster onset of anesthetic action due to its lower blood-gas partition coefficient?

Desflurane Signup and view all the answers

What is the relationship between the partial pressure of a volatile anesthetic agent and its blood-gas partition coefficient?

A lower blood-gas partition coefficient results in a higher partial pressure Signup and view all the answers

Why do newer anesthetic agents tend to have a faster onset of anesthetic action compared to older agents?

Because they have a lower blood-gas partition coefficient Signup and view all the answers

What happens when more anesthetic is taken into the blood, resulting in a higher BGC?

The blood acts as a reservoir for the anesthetic, reducing the alveolar concentration Signup and view all the answers

What is anesthesia?

A type of medication that induces a loss of sensation in all or part of the body with or without loss of consciousness Signup and view all the answers

What is the balanced anesthesia technique?

A combination of sedatives, analgesics, and muscle relaxants Signup and view all the answers

What is the goal of inhalational anesthesia?

To have a constant brain partial pressure of anesthetic Signup and view all the answers

Alveolar partial pressure mirrors the brain partial pressure

True Signup and view all the answers

Which of the following inhalational anesthetics are known to cause airway irritation?

Desflurane and isoflurane Signup and view all the answers

What is ataraxia?

A state of freedom from mental or bodily pain Signup and view all the answers

What is the mechanism of action of propofol?

Activation of GABA receptors Signup and view all the answers

What is the drug class of etomidate?

Imidazole sedative Signup and view all the answers

What is a complication of etomidate?

Myoclonic activity Signup and view all the answers

What is the mechanism of action for ketamine?

N-methyl-D-aspartate (NMDA) receptor antagonist Signup and view all the answers

What is the mechanism of action of midazolam?

Potentiating the activity of GABA by binding to benzodiazepine receptors Signup and view all the answers

What is a pulmonary complication of midazolam?

Prolonged respiratory depression when combined with other agents , especially opioids Signup and view all the answers

What is a renal complication of sevoflurane administration?

Formation of nephrotoxic compound A Signup and view all the answers

What are bispectral index (BIS) monitors used for?

Measuring the depth of anesthesia Signup and view all the answers

What level of anesthesia is conscious sedation?

Moderate Sedation Signup and view all the answers

What characteristics do patients in deep sedation have?

Depressed consciousness with purposeful responses to stimulation Signup and view all the answers

What medications are used in a Bier block?

Lidocaine without epinephrine Signup and view all the answers

What local anesthetics are commonly used in peripheral nerve blocks?

All of the above Signup and view all the answers

Order these inhalational anesthetics from the least to the most potent: nitrous oxide, sevoflurane, isoflurane, desflurane

Nitrous oxide, desflurane, sevoflurane, isoflurane Signup and view all the answers

What is a common characteristic of inhalation anesthetics?

CO preserved but myocardial depression can occur Signup and view all the answers

Where can local anesthetic be placed in an epidural?

In the epidural space of thoracic, lumbar, and sacrum Signup and view all the answers

Epidural blocks can be adjusted

True Signup and view all the answers

Patient must be able to maintain their airway in monitored anesthesia care

True Signup and view all the answers

What are the indications for a combined spinal/epidural block?

rapid analgesia/anesthesia followed by extended postop analgesia Signup and view all the answers

Study Notes

Phases of General Anesthesia

Pre-operative anesthesia evaluation: transport from holding area to PACU
Pre-induction: baseline vitals, preoxygenation/denitrogenation, administration of a hypnotic agent, confirmation of LOC, attempt PPV, administration of muscle relaxant, intubation, confirmation of intubation
Induction: GA induction steps
Maintenance
Emergence: post-operative anesthesia evaluation, transport from OR to PACU

Potency of Inhaled Agents

Measured via MAC (minimum alveolar concentration), blood gas coefficient, or bispectral index monitors (BIS)
MAC: minimum alveolar concentration of inhaled anesthetic required to prevent 50% of patients from moving in response to painful stimuli
Lower the MAC, the more potent the agent is
Variations of MAC:
- MAC awake: allowing of eye opening on verbal command (seen during emergence and induction)
- MAC asleep: loss of consciousness and recall
- MAC bar: MAC to prevent adrenergic and CV response to incision
- MAC intubation: MAC to inhibit movement and coughing during intubation
- MAC incision: MAC to prevent movement during initial incision

Characteristics of Ideal Inhaled Anesthetics

Potent
Low blood and tissue solubility
Resistant to physical and metabolic degradation
Stable (non-flammable or explosive)
Odorless and pleasant to inhale
Rapid onset and offset
Safe for all ages and in pregnancy

Inhaled Anesthetics

Characteristics:
- Provide amnesia and immobility
- Decrease BP and SVR
- CO preserved but myocardial depression can occur
- Rapid administration of desflurane can increase BP and HR
Examples:
- Nitrous oxide:
  - Blood gas coefficient: 0.47
  - MAC: 104 (least potent)
  - Has analgesic and anesthetic properties
  - Cautions: pneumothorax, dilated bowels, laparoscopic surgeries, cases with hollow organs
- Isoflurane:
  - Blood gas coefficient: 1.4
  - MAC: 1.2
  - Cardiovascular: increased HR, hypotension, potent coronary artery vasodilator
- Sevoflurane:
  - Blood gas coefficient: 0.65
  - MAC: 2
  - Favored in pediatric cases due to sweet smelling
  - Cautions: prolonged QT or other medications that can do the same
- Desflurane:
  - Blood gas coefficient: 0.45
  - MAC: 6
  - CNS: quick induction and recovery
  - CV: increased HR and catecholamine production
  - Pulmonary: irritating
  - Cautions: pediatric pts or reactive airway disease

Non-Depolarizing Neuromuscular Blockers

Benzylisoquinolinium Compounds:
- Atracurium
- Cisatracurium
- Mivacurium
- Doxacurium
Aminosteroid Compounds:
- Pancuronium
- Vecuronium
- Rocuronium
- Pipecuronium
Chlorofumarate diesters:
- Gantacurium
Reversal agents:
- Neostigmine
- Sugammadex
- Calabadion

Stages of General Anesthesia

Stage 1: Disorientation, analgesia without amnesia
Stage 2: Delirium/excitement, pt is unconscious but responds reflexively and irrationally to stimuli
Stage 3: Surgical, ideal stage for surgery, characterized by a deeply unconscious pt with increasing degrees of muscle relaxation and absence of protective airway reflexes
Stage 4: Medullary depression, life-threatening condition characterized by cardiovascular and respiratory collapse due to depression of the associated centers in the brain

Blood-Gas Partition Coefficient (BGC)

A higher BGC indicates greater solubility of the anesthetic in blood and tissues, which slows the rate of induction.
A higher BGC means more anesthetic is taken into the blood, acting as a reservoir for the agent, reducing the alveolar concentration.
Volatile agents with a lower BGC are less soluble and exert a higher partial pressure.
A lower BGC leads to a more rapid onset and offset of anesthetic action due to the higher partial pressure.
Newer anesthetics, such as desflurane, typically have smaller BGCs than older ones, such as ether.
A smaller BGC leads to a faster onset of anesthesia.

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Description

Identify and define the different levels of anesthesia and analgesia, including minimal sedation, moderate sedation, deep sedation, and general anesthesia. Learn about the differences between each type of anesthesia.