Flashcards in Desflurane Deck (29)
What is type of drug the Desflurane (include chemically speaking)?
Volatile inhalation anesthetic
Fluorinated methyl ethyl ether
What is the trade name for Desflurane?
Does Desflurane have lower or higher blood gas solubility? What type of surgery does this make it ideal for?
LOWER blood-gas solubility
Ideal for same day surgery
What does it mean to have lower blood-gas solubility?
-Rapid uptake and elimination
-More precise control over the delivery of anesthesia
-More rapid recovery from anesthesia
Is Desflurance considered a respiratory irritant? Why or Why not?
YES when used for mask induction in concentrations greater than 6%
Is Desflurane good for inducing anesthesia? Why/why not?
Generally NOT used for inducing anesthesia in peds or adult populations b/c of respiratory irritant at >6%
What is Desflurane primarily used for?
What is the MOA? (the current theory they think it works by)
target proteins (most likely ion channels and/or receptors) are the site of action of the inhaled anesthetics. Separate sites of action for loss of consciousness and immobility have been proposed
What is the Myer-Overton Hypothesis? Is this still a current theory of MOA for inhaled anesthetics?
Anesthetic action was attributed to the inhaled anesthetic dissolving into and distorting the lipid cell membrane.
-NO, this theory has largely been disproven
What is the primary metabolism for Desflurane and what is it metabolized to?
-Oxidatively metabolized by the liver CYP450
-Acetylated liver protein adducts
Tell me about the biodegradation of Desflurane.
-Strongly resists biodegradation; only a small amount is metabolized (0.02%)
-Highly stable and resists degradation by soda lime and the liver
Is Desflurane a high risk for promoting Halothane Hepatitis?
No; low risk because it has the lowest level of adduct formation (<1% metabolized)
How is Desflurane redistributed?
What is the Blood/Gas Co-efficient?
-Low blood/gas solubility sooooo......
-Blood/Gas partition co-efficient at 37 degree celsius and therefore has RAPID equilibration between inspired and alveolar concentrations
How is Desflurane eliminated?
Almost entirely unchanged via exhalation from the lungs (Rapid decrease of alveolar concentrations during elimination also related to Blood/Gas solubility
What is the Volume of Distribution of Desflurane?
Rapid uptake and elimination; uptake in the first minute of anesthesia is 146mL
In general, what are the Cardiovascular Side Effects of Desflurane?
-Depresses myocardial contractility
-Associated with transient sympathomimetic activity (Tachycardia, HTN, myocardial ischemia) when used in high concentrations or when rapidly increasing the inspired concentration without opioid adjuvants to prevent this response
-Following transient SNS type activity arterial BP and SVR usually decreases with increase in HR (intact baroreceptor response)
-Reduces MAP, CO, CI in a dose dependent fashion via a reduction in SVR
What happens to the CV system with high concentrations of Des/ or rapidly increased inspired concentration? How can you help to avoid such responses (hint a type of drug might help!)
-Associated with transient sympathomimetic activity (Tachycardia, HTN, myocardial ischemia)
-Give Opioid Adjuvants to prevent the response
What are the Neuro/neuromuscular side effects of Desflurane?
-Increases CBF and ICP (particularly at 1 MAC or >)
-Decreases CPP (particularly at 1 MAC or>)
-Potentiates the effects of NMBs
-High rate of emergence delirium particularly in the pediatric population
What does Des have as an effect with NMBs?
What is something to be aware of with pediatric patients and Desflurane?
High rate of emergence delirium!
What are the Respiratory side effects of Desflurane?
-Dose-related ventilatory depression
-typical: decreased Vt and increased RR
-Pungent and assoc. with adverse Respiratory events during inhalation induction
-Increases PaCO2 and decreases ventilatory response to CO2
-Reduces hypoxic pulmonary vasoconstriction at doses >1 MAC increasing the risk of hypoxia during one lung ventilation
What Adverse Respiratory events is Desflurane associated with during inhalation induction? What is the typical concentration used for induction?
-Bronchospasm/ resp tract irritation
-Increased Secretions with accompanying hypoxia
-Typical concentration used for induction is ~10%
What are the GI/Liver side effects of Desflurane?
-Transient increase in LFTs following administration
-Decreases hepatic blood flow and oxygen reserve capacity of the liver and small intestine
What are the Contraindications with Desflurane?
-should NOT be used in Malignant Hyperthermia- susceptible patients
-Inhalation induction with children has reported high rates of airway reactivity and laryngospasm
-Use caution in pts at risk for CAD and myocardial ischemia, secondary to an increased myocardial oxygen demand and tachycardia with rapid concentration increases
What are the drug interactions associated with Desflurane?
-Dose-related tachycardia, more pronounced in the presence of vagolytic drugs; may be attenuated in neonates and geriatric patients or by the concomitant use of opioids
-Inhibits the frequency and amplitude of myometrial contractions induced by oxytocin in a dose-dependent manner
What is the Dose of Desflurane?
MAC (37C) is 6%
(Blood/Gas partition coefficient at 37C is 0.42; Oil/Gas partition coefficient at 37C is 18.7)
**Doses vary according to patient status, age, procedure, and types of medications co-administered
What are the Vapor pressure and boiling point of Des?
VP: 669mmHg (3-4x that of other inhaled anes.)
What is the specially designated vaporizer used for Des?
Tec 6: electrically heated, pressurized device specifically designed to deliver desflurane