Inhaled Anesthetics - Isoflurane (used solely for ICU patients that will stay intubated) Flashcards
Which of the following accurately describes the chemical structure of Isoflurane? (Select 3)
A) It is an ether with a structure represented as R-O-R’
B) It is a liquid at standard temperature and pressure (STP)
C) It contains 5 chlorine atoms and no fluoride ions
D) It contains 5 fluoride ions and 1 chlorine atom
E) It is a solid at standard temperature and pressure (STP)
A) It is an ether with a structure represented as R-O-R’
B) It is a liquid at standard temperature and pressure (STP)
D) It contains 5 fluoride ions and 1 chlorine atom
What is the MAC (minimum alveolar concentration) of Isoflurane?
A) 1.2% (1.17%)
B) 2.5%
C) 0.5%
D) 3.0%
E) 1.0%
A) 1.2% (1.17%)
MAC (dose): 1.2% (most potent)
What is the Blood
Partition Coefficient of Isoflurane, and what does it indicate about its onset?
A) 1.46, indicating it is most soluble in blood and has the slowest onset
B) 0.68, indicating it has a rapid onset
C) 2.50, indicating it is least soluble in blood and has a fast onset
D) 0.85, indicating moderate solubility and intermediate onset
E) 1.20, indicating a moderate onset time
A) 1.46, indicating it is most soluble in blood and has the slowest onset
Blood:Gas Partition Coefficient (onset): 1.46 (most soluble in blood = slowest onset)
What is the primary mechanism of action (MOA) of Isoflurane?
A) Increased frequency/duration of Cl⁻ pore opening at GABAA receptors
B) Inhibition of NMDA receptors
C) Potentiation of K⁺ channels
D) Activation of serotonin receptors
E) Blockade of voltage-gated sodium channels
A) Increased frequency/duration of Cl⁻ pore opening at GABAA receptors
BRAIN
GABAA (MAIN–Increased frequency/duration of Cl- pore opening–inhibits NT release presynaptically to decrease membrane potential post-synaptically)
Which of the following mechanisms of action contributes to Isoflurane’s ability to produce immobility in the spinal cord? (Select 4)
A) Glycine receptor stimulation
B) NMDA receptor inhibition
C) Sodium channel inhibition
D) Potentiation of potassium channels
E) Increased frequency/duration of Cl⁻ pore opening at GABAA receptors
A) Glycine receptor stimulation
B) NMDA receptor inhibition
C) Sodium channel inhibition
D) Potentiation of potassium channels
-Glycine-R stimulation, NMDA-R inhibition, Na+ channel inhibition, & K+ Channel Potentiation in SPINAL CORD to produce immobility in ventral horn (NOT d/t GABAA)
What factors primarily influence the half-life of Isoflurane? (Select 2)
A) Cardiac output (CO)
B) Ventilation (Vm)
C) Hepatic metabolism rate
D) Plasma protein binding
E) Renal clearance
A) Cardiac output (CO)
B) Ventilation (Vm)
Action:
SVR -,
HR +,
CVP +,
SV -,
prolongation of QT interval
How is Isoflurane primarily eliminated from the body? (Select 3)
A) Alveoli (via exhalation)
B) Hepatic biotransformation
C) Percutaneous loss (through the skin)
D) Renal excretion
E) Biliary excretion
A) Alveoli (via exhalation)
B) Hepatic biotransformation
C) Percutaneous loss (through the skin)
What precaution must be taken when using Isoflurane in conjunction with dehydrated soda lime?
A) Dehydrated soda lime can interact with Isoflurane to produce carbon monoxide
B) Dehydrated soda lime can neutralize Isoflurane, reducing its effectiveness
C) Isoflurane should not be used if the soda lime is expired
D) Dehydrated soda lime can enhance the potency of Isoflurane
E) There is no known interaction between Isoflurane and dehydrated soda lime
A) Dehydrated soda lime can interact with Isoflurane to produce carbon monoxide
Why should Isoflurane be avoided for induction in patients?
A) Due to its pungent smell
B) Because it causes severe hypotension
C) Due to its high risk of causing malignant hyperthermia
D) Because it leads to prolonged sedation
E) Because it is contraindicated in patients with liver disease
A) Due to its pungent smell
Which of the following are common side effects of Isoflurane?
A) Postoperative nausea and vomiting (PONV)
B) Malignant hyperthermia (MH)
C) Postoperative shivering
D) Respiratory depression
E) Hepatic dysfunction
A) Postoperative nausea and vomiting (PONV)
B) Malignant hyperthermia (MH)
C) Postoperative shivering
Which of the following conditions would not be an appropriate indication for using Isoflurane?
A) Bronchodilation during an asthma attack
B) Long-term management of anesthesia in ICU patients
C) Maintenance of general anesthesia in surgeries requiring prolonged intubation
D) Short-term sedation for minor surgical procedures
E) Induction of anesthesia for rapid recovery procedures
A) Bronchodilation during an asthma attack
