Inhaled Anesthetics Flashcards by Lindsay Reynolds

Inhaled Anesthetics

Goal is to have enough pressure so the anesthetic gas goes from a higher pressure to a lower pressure. This involves getting gas from machine to the lungs, then from the lungs to the blood, then from the blood to the brain

Ultimate goal is _______ so the anesthetic level is maintained and doesn’t fluctuate

Equilibrium

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Blood/Gas Partition Coefficient

Halothane (most _____ in blood)

Isoflourane (second most ____ in blood)

Sevoflourane

Nitrous Oxide

Desflourane

4, Soluble
4, Soluble
65
47
42

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Inhaled Anesthetic/GABA

Binding of GABA is _____ by inhaled anesthetics, resulting in greater entry of _____ ions

Entry of Cl- hyperpolarizes the cell, making it more difficult to ______, therefore reducing neuronal excitability

Enhanced, Cl-

Depolarize

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Partial Pressure (P)

Dalton’s Law: The total pressures (P_tot) of a mixture of gases is the ____ of the pressures each gas would exert if it were present _____

The goal is to achieve a _____ and _____ brain partial pressure of inhaled anesthetic

Sum, Alone

Constant and Optimal

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Partial Pressure (P)

Brain (P_br) and all other tissues _____ with the partial pressure of inhaled anesthetics delivered by arterial blood (P_a)

Arterial blood _____ with _____ partial pressure of anesthetics (P_A)

Equilibrate

Equilibrates, Alveolar

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Partial Pressure (P)

P_A mirrors ____

P_A is an index of _____ of anethesia, _____ from anesthesia, and anesthetic equal potency or (____)

P_br

Depth, Recovery, MAC

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Ventilation Rate

Minute Ventilation: ____ of all exhaled gas volume in ___ minute

Minute Ventilation Formula?

Normal minute ventilation?

Ex: At rest, normal person moves about 450 mL /breath at about 10 breaths/minute = 4,500 mL/min = 4.5 L/min

Sum, 1

MV = Tidal Volume x Breaths/min

Around 5L/min

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Alveolar Ventilation

Volume of inspired gases actually taking part in ____ ______

_____ indicates alveolar ventilation

AV = ( ____ _____ - _____ _____) x Breaths/min

Gas Exchange

PC0₂

(Tidal Volume - Dead space)

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Dead Space (V_d)

Any volume of inspired air that does not enter the ____ ______ areas of the lung

Airway (______) dead space: portion of breath which goes to the mouth, pharynx, etc., but does not enter the alveoli

______ dead space: portion of breath that enters alveoli which are ventilated, but not perfused

Gas Exchange

Anatomic

Alveolar

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Determinants of Alveolar Partial Pressure (P_A)

PA is determined by _____ (input) of inhaled anesthetic into alveoli minus the _____ (loss) of drug from alveoli into arterial blood

Delivery depends on: inhaled ______ ______ (PI), ______ ______ (how many lung units are being ventilated), and the ______ of the anesthesia breathing system (delivery)

Uptake (alveoli to pulmonary capillary blood) depends on: ______ of anesthetic in body tissues, _____ _____, and _____ to _____ partial pressure difference (A-vD)

Delivery, Uptake

Partial Pressure, Alveolar Ventilation, Characteristics

Solubility, Cardiac Output, Alveolar to Venous

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Determinants of Alveolar Partial Pressure (PA) **Recap**

_______ ventilation

_______ breathing system

________

______ ______

______ to _____ partial pressure differences

Alveolar

Anesthetic

Solubility

Cardiac Output

Alveolar to Venous

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Inhaled Partial Pressure (PI)

•Concentration Effect•

Impact of PI on the rate of rise of P_A of onhaled anesthetic

The ______ the inspired concentration of the anesthetic agent, the more _____ the relative rise in _______ _______ of the agent

Anesthetic agents follow a ______ ______ from machine to ______ to ______ then to the ______

Higher ____ equals higher ______ ______

Higher, Rapid, Alveolar Concentration

Concentration Gradient, Alevoli, Blood, Brain

PI (inspired pressure of gas), Alevolar Concentration

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Second Gas Effect

Reflects ability of high volume uptake of one gas to ______ the rate of increase of P_A of a _______ administered “companion” gas

Large volume uptake of Nitrous Oxide ______ the rate of rise of P_Aof other gases (O2, volatile anesthetics)

Reflects increased tracheal inflow of all the inhaled gases (1st and 2nd) and concentration of 2nd gas in _____ lung volume due to ____ volume uptake of the 1st gas (concentrating effect)

Accelerate, Concurrently

Accelerates

Smaller, High

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Second Gas Effect

Ability of large volume _____ of one gas (first gas) to _____ the rate of rise of alveolar partial pressure of a co-administered second gas

______ is used as the first gas

The effect is more applicable to an agent with _____ blood:gas solubility (solubility discussed more later)

Uptake, Accelerate

Nitrous (N2O)

Higher

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Alveolar Ventilation

_____ alveolar ventilation promotes ______ (input) of anesthetics to offset uptake

Causes a more ____ rate of _____ in PA toward PI (inhaled partial pressure), resulting in _______

Decreased ______ is produced by ________ of the lungs, resulting in a decrease in _____ ______ ______

Increased, Delivery

Rapid, Rise, Induction

PaCO2, Hyperventilation, Cerebral Blood Flow

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Alveolar Ventilation

A ______ in alveolar ventilation decreases ______ (delivery) and slows the establishment of P_A and P_br for ______

The ______ the alveolar ventilation: FRC ratio, the more rapid the rise of P_A

5:1 in neonates (greater metabolic rate) and 1.5:1 in adults

_____ is _____ in neonates because of the ______ _____

Decrease, Input, Induction

Greater

Induction, Quicker, Metabolic Rate

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Alveolar Ventilation

Inhaled anesthetics have a _____ dependent ______ effect on alveolar ventilation

______ _______ protective mechanism exists to prevent excessive depth of anesthesia when high PI is administered with _______ breathing

______ decreases parallel to _______ ventilation; anesthetic is _______ from tissues of high _______ to tissues of low _______

When concentration in brain falls below a certain threshold, ventilation _______ and the delivery of anesthetic to lungs is _______

Dose, Depressive

Negative Feedback, Spontaneous

Input (delivery), Decreased, Redistributed

Concentration, Concentration

Increases, Increased

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Alveolar Ventilation

When a patient is breathing in a volatile anesthetic, you will typically see a ______ tidal volume and ______ respiratory rate (shallow, rapid breathing pattern)

Alveolar minute ventilation ______ because more anesthetic is going to the dead space. Low tidal volume breaths _____ alveolar minute ventilation

______ ______ is reduced by all volatile anesthetics. All inhaled anesthetics ______ the natural ventilatory response to ____ and ____

If CO2 increases, normally you would breathe _____, but inhaled anesthetics _____ that response

Decreased, Increased

Decreases, Decrease

Airway Resistance, Depress, CO2 and O2

Faster, Depress

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Alveolar Ventilation

Normally, if we become ______, our body will respond with _______, but this response is greatly ______ by volatile anesthetics

Inhaled anesthics are altering peripheral and chemoreceptor functioning in a ____ dependent manner

The body’s protective ______ ______ mechanism (discussed earlier) is _____ with mechanical ventilation, especially when you ______ them and assume control for all of the patient’s _______

Hypoxic, Hyperventilation, Depressed

Dose

Negative Feedback, Lost, Paralyze, Breathing

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Impact of Solubility

Alveolar ventilation influences the rate of rise of P_A toward PI _____ in _____ anesthetics than in _____ soluble ones

In ______ soluble anesthetics, the rise of P_A is _____, regardless of other factors (less soluble gas is in blood, faster it enters alveoli)

More soluble anesthetics have a greater _____ (in the blood), so increase in _____ will ______ rate of rise of P_A;Hence why mechanical ventilation _____ the depth of anesthesia produced by a more blood _____ anesthetic

More, Soluble, Poorly

Poorly, Rapid

Uptake, Ventilation, Increase

Increases, Soluble

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Solubility

Solubility in tissues and blood is denoted by a _____ _____; a ______ ratio describing how inhaled anesthetic distributes itself between two phases of _______

A blood:gas partition coefficient of _____ = the concentration of inhaled anesthetic in blood is ____ that of alveolar gases when _____ _____ is equal in both phases

A blood:brain partition coefficient of ___ = the concentration in blood is ____ that in the _____

Partition Coefficient; Distribution

Equilibrium

0.5, 1/2, Partial Pressure

2, Twice, Brain

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Solubility

Partition coefficient reflects the relative ______ of each phase to ______ anesthetic, and is _______ dependent

Capacity, Accept, Temperature

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Blood:gas Partition Coefficent

Rate of increase of P_A toward PI is _____ ______ to the solubility of anesthetic in the blood

If blood:gas partition coefficient is high, a _____ amount dissolves in blood before _____ can occur between P_A and P_a toward PI; meaning induction is _____

If blood:gas partition coefficent is low, a _____ amount dissolves in blood before _____ is reached; meaning rate of rise of P_A and P_a is _____, and induction is _____

Inversely Proportional

Larger, Equilibrium, Slow

Smaller, Equilibrium, Rapid, Rapid

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Blood:gas Partition Coefficent

Can offset high blood:gas partition coefficient (slower induction) by increasing ___ above that required for maintenance of anesthesia. This is called an ______ ______

This _____ induction, but sustained delivery at this level can cause _______

PI, Overpressure Technique

Speeds, Overdose

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**Blood:gas Partition Coefficent** ## Footnote Blood:gas partition coefficient is influenced by variations in \_\_\_\_, \_\_\_\_, and _____ content, as well as ____ of blood There is ______ solubility of anesthetics in ______ blood, meaning these patients will have a more _____ induction (anesthetic agent won't stay in blood- it will quickly move to lungs/brain)

## Footnote Water, Lipid Protein, Hct Decreased, Anemic, Rapid

**Blood:gas Partition Coefficent** **(Recap)** States how ______ the anesthetic is in the blood It is ______ related to ______ time of the anesthetic agent \_\_\_\_\_ ______ gas in the blood = ______ induction via inhalation \_\_\_\_\_\_ ______ gas in the blood = ______ induction via inhalation

Soluble Inversely, Induction Less Soluble, Faster More Soluble, Slower

**Tissue:blood Partition Coefficient** ## Footnote Determines _____ of anesthetic into ______ and time necessary for ______ of tissues with P_a Time for _______ is estimated calculating a _____ \_\_\_\_\_\_ for each tissue For volatile anesthetics, __ time constants (5-15 minutes for P_a and P_brto equilibrate and cause induction)

## Footnote Uptake, Tissues, Equilibration Equilibration, Time Constant 3

**Tissue:blood Partition Coefficient** \_\_\_\_ has a large anesthetic holding capacity with ____ blood flow, so time to equilibrate is ______ (25-46 hours) Clinical Example: ________ may be a better agent for obese patient's (quick off time) versus \_\_\_\_\_\_\_, which has more of a tendency to harbor in fat when gas is turned off

## Footnote Fat, Low Prolonged/Slower Desoflurane, Sevoflurane

**Tissue:gas Solubility** ## Footnote Concerns ____ tissues (muscles, vessel rich organs: heart, liver, kidney, brain) _____ for a given anesthetic agent Predicts ______ \_\_\_\_\_\_ from anesthesia \_\_\_\_\_\_ tissue:gas ratios indicate that the gas is relatively ______ in tissues, therefore, emergence will be more \_\_\_\_\_

## Footnote Lean, Affinity Emergence Time Lower, Insoluble, Rapid

Stages of Anesthesia _Stage 1_ Begins with \_\_\_\_\_\_ Ends with loss of _______ (no _____ reflex) Patient can still sense _____ (evidenced by increased HR and BP)

Induction Consciousness, Eye-lid Pain

Stages of Anesthesia _Stage 2_ Delerium \_\_\_\_\_\_, uninhibited \_\_\_\_\_\_ Pupils ______ with divergent gaze Potentially ______ response to noxious stimuli (Do not want patient stimulated at this time) Stimulation may lead to ______ holding, muscular \_\_\_\_\_, \_\_\_\_\_\_, or \_\_\_\_\_\_\_\_

Excitement, Excitation Dilated Dangerous Breath, Rigidity, Vomiting, Laryngospasm

Stages of Anesthesia _Stage 3_ Where we want to be for \_\_\_\_\_\_ Centralized gaze with ______ of pupils Regular \_\_\_\_\_\_ Anesthesia depth is ______ for noxious stimuli (when the noxious stimuli does not cause an increase in ______ response)

Surgery Constriction Respirations Sufficient, Sympathetic

Stages of Anesthesia _Stage 4_ Stay ____ from, this is too \_\_\_\_ Will cause \_\_\_\_\_ Pupils are ______ and \_\_\_\_-\_\_\_\_\_\_ \_\_\_\_\_\_\_ resulting from complete CV collapse is possible

Away, Deep Apnea Dilated, Non-Reactive Hypotension (may be a big sign that you need to turn your gas down)

Cardiac Output and Induction Represented by ______ blood flow Influences uptake and P_A by _____ \_\_\_\_\_ either more or less anesthetic from alveoli Increased CO: More _____ uptake and _____ induction Decreased CO: speeds rate of rise in P_A, _____ uptake and _____ induction

## Footnote Pulmonary Carrying Away Rapid, Slowed Less, Faster

Cardiac Output and Induction Increased cardiac output ______ capacity of the blood to ____ anesthetic. This has the most infuence on _____ anesthetics Some volatile agents _____ cardiac output, resulting in a ______ \_\_\_\_\_\_ response (Decreased CO due to excessive _____ leads to increased P_A, increased \_\_\_\_, and subsequently, further reduced CO and cardiac ______ secondary to the increased anesthetic depth

## Footnote Increases, Hold Soluble (agents prone to dissolve more in blood) Decrease, Positive Feedback Dose, Depth, Depression

Recovery from Anesthesia Rate of _____ of P_br is reflected by decrease in P_A At conclusion of anesthesia, ______ of anesthetic in ______ depends on its _______ in the tissue and ______ of administration Some tissues may not reach _____ with P_A during maintenance This is seen mostly in ______ anesthetics; Time to recover is ______ proportional to the duration of administration mostly in ______ anesthetics Exhaled gases will be \_\_\_\_\_, unless fresh gas flow rate is \_\_\_\_\_

## Footnote Decrease Concentration, Tissues, Solubility, Duration Equilibrium Soluble, Prolonged, Soluble Rebreathed, Increased

Recovery from Anesthesia If your patient is not waking up, make sure you turned gas \_\_\_\_ Also make sure that you _____ oxygen flow rate (8-10 L/min)

## Footnote Off Increase

Diffusion Hypoxia Happens _____ use of nitrous When the nitrous is discontinued, nitrous diffuses rapidly out of the \_\_\_\_\_, into the \_\_\_\_\_, subsequently into the \_\_\_\_\_ This rapid _____ into the alveoli _____ alveolar gas and ______ oxygen, causing \_\_\_\_\_\_ Net result will be \_\_\_\_\_\_\_

## Footnote After Tissues, Blood, Alveoli Flood, Dilutes, Displaces, Hypoxia Hypoventilation

EEG Effects of Anesthetics At \_\_\_\_\_\_, increase in frequency and voltage similar for all anesthetics (all gases have same effect at this point) At \_\_\_\_\_\_, shift of voltage activity from ______ to ______ portions of brain At \_\_\_\_\_\_, ______ in cerebral O2 requirement (may reflect transition from wakefulness to unconsciousness)

## Footnote \< 0.4 MAC ~ 0.4 MAC, Posterior to Anterior ~ 0.4 MAC, Decrease

CNS Effects - Seizure Activity \_\_\_\_\_\_ has fast frequency and high voltage on EEG, indistinguishable from changes produced by _____ activity Twitching of ______ and ______ muscles occurs and can be initiated by repetitive ______ stimuli \_\_\_\_\_, \_\_\_\_\_, and _____ are agents that have no seizure activity on EEG; they actually ______ convulsant properties \_\_\_\_\_ may induce increased motor activity; withdraw in animals may indicate _____ \_\_\_\_\_\_

## Footnote Enflurane, Seizure Facial, Extremity, Auditory Iso, Sevo, Des; Suppress N20, Acute Dependence

CNS Effects Evoked Potential Volatile anesthetics cause a dose-related ______ in amplitude and ______ in latecy of cortical component of the ______ nerve somatosensory, visual, and auditory evoked potentials

Decrease, Increase Medial

Cerebral Blood Flow Volatile anesthetics at \_\_\_\_\_\_, produce cerebral \_\_\_\_\_\_\_, decreased cerebral vascular \_\_\_\_\_\_, and dose-dependent _____ in cerebral blood flow At \_\_\_\_\_\_, _______ is most potent CNS vaodilator, secondary to \_\_\_\_\_\_, with ______ and _______ producing equal and less significant CNS effect \_\_\_\_ also increases CBF Increased CBF occurs within _____ of anesthetic administration Increased CBF and dilation not good for what patient population?

## Footnote **\> 0.6 MAC**, Vasodilation, Resistance, Increase **At 1.1 MAC**, _Halothane_, Enflurane Isoflurane and Desoflurane _N2O_ Minutes Patient's with increased ICP or brain bleeds

Cerebral Metabolic O2 Requirements Dose dependent \_\_\_\_\_\_ Decreases _______ requirement, leading to _____ CO2 production, causing ______ and ______ in CBF Agents such as \_\_\_\_\_\_, \_\_\_\_\_\_, and ______ will equally reduce _____ and decrease CO2 production, causing _______ effects For **Neuro** patients, use \_\_\_\_, \_\_\_\_\_, or ____ and **avoid** ______ or \_\_\_\_\_

## Footnote Decrease Metabolic, Decreased, Vasoconstriction, Decrease Iso, Sevo, Des, CBF, Vasocontricting Iso, Sevo, Des, Halothane, N2O

Cerebral Protection In humans undergoing carotid endarterectomy, _______ appears to provide a degree of cerebral ______ (The CBF at which _____ changes appear is lower during administration, compared to other agents) (may reduce the transient cerebral ischemia that happens with this procedure) For **carotid** **endarterectomies**, use \_\_\_\_\_\_

## Footnote Isoflurane Protection, Ischemic Isoflurane

Intracranial Pressure Increases in ICP parallel increased ____ that is produced by anesthetics \_\_\_\_\_\_\_ of lungs decreases PaCO2, therefore producing _______ and reducing tendency for increased \_\_\_\_ \_\_\_\_ increases ICP ____ \_\_\_\_\_ volatile anesthetics (mostly because of the low dose it's given in) (N2O _safer_ than volatiles) Avoid elevated ICP in _____ \_\_\_\_\_

## Footnote CBF Hyperventilation, Vasocontriction, ICP **N2O**, Less Than Head Injuries

Circulatory Effects _Mean Arterial Pressure_ Agents \_\_\_\_, \_\_\_\_, \_\_\_\_, and ____ have dose dependent ____ on MAP due to decrease in the \_\_\_\_\_ \_\_\_\_\_\_ decreases map due to decrease in cardiac \_\_\_\_\_\_ True circulatory affect of agents may not be reflected by BP since the BP may be elevated due to _____ stimulation elicited from surgery

Halo, Iso, Des, Sevo Decrease, SVR Halothane, Contractility SNS

Circulatory Effects _Heart Rate_ Agents that increase HR are \_\_\_\_, \_\_\_\_, and \_\_\_\_ Confounding Variables: increased HR with ____ only with \_\_\_\_\_\_ Increased HR may also be due to _____ or _____ activity \_\_\_\_\_\_ may disrupt baroreceptor reflex and decrease ______ system of the heart \_\_\_\_\_ affect on HR not determinable (it's always given with other drugs)

Iso, Des, Sevo Sevo, \> 1.5 MAC Opioids, SNS Halothane, Conduction N2O

Cardiac Output/Stroke Volume \_\_\_\_\_\_ has dose dependent decrease in _____ \_\_\_\_\_\_ \_\_\_\_ and ____ have no effect on CO/SV \_\_\_\_\_\_\_\_ decreases CO up to \_\_\_\_\_, but when \_\_\_\_\_\_, CO recovers Left SV _____ with all anesthetics \_\_\_\_ increases CO slightly

## Footnote Halothane, Cardiac Output Iso, Des Sevoflurane, **2 MAC**, **\> 2 MAC** Decreases N2O

Systemic Vascular Resistance Decreased SVR reflects increased ______ \_\_\_\_\_\_ and ______ blood flow (patient may appear flushed), which results from excess ______ relative to O2 needs Decreased SVR also reflects loss of ____ \_\_\_\_, with enhanced drug delivery to the ______ \_\_\_\_\_\_ \_\_\_\_\_\_\_ dilates ONLY _____ and _____ vessels

## Footnote Skeletal Muscle, Cutaneous Perfusion Body Heat, Neuromuscular Junction Halothane, **Cerebral**, **Cutaneous**

Pulmonary Vascular Resistance Volatile anesthetics have ____ to ____ effect \_\_\_\_ increases PVR; exaggerated effect in those with ______ \_\_\_\_\_\_, \_\_\_\_\_\_, and patients with congenital _____ \_\_\_\_\_\_

## Footnote Little to No N2O, Pulmonary HTN, Neonates, Heart Disease

Cardiac Dysrhythmias Anesthetics ______ the dose of ______ required to produce ______ dysrhythmias Effect greatest with \_\_\_\_\_\_ Interference with _______ rate of cardiac impulses through conduction system of heart

## Footnote Decrease, Epinephrine, Ventricular Halothane Transmission rate

Coronary Blood Flow Volatile anesthetics cause coronary \_\_\_\_\_, mostly in vessels 20-200 um ( ______ vessels) \_\_\_\_\_\_ dilates small coronary vessels more than larger conductance vessels \_\_\_\_ is capable of causing a maldistrubution of blood flow from ______ to ______ areas. This is called _____ \_\_\_\_\_\_ \_\_\_\_\_ Ischemia has resulted in patients with CAD when ____ and ____ were used

## Footnote Vasodilation, Small Isoflurane Iso, Ischemic, Non ischemic Coronary Steal Sydrome N2O and Isoflurane

Coronary Blood Flow No increased risk of acute ___ with volatile anesthetics as long as _______ are maintained \*\*May need to pretreat patients with _____ or a ____ \_\_\_\_\_ (If patient is already on beta blocker, ask if they took their dose the morning of surgery. If not, esmolol or similar agent may need ti be administered)

## Footnote MI, Hemodynamics Opioids, Beta Blocker

Neurocirculatory Response \_\_\_\_\_\_'s solubility make it a good choice to treat abrupt increases in systemic ___ and ____ associated with changes in intensity of _____ stimulation (This does NOT occur with Sevo) Pre-existing _____ may influence the significance of ______ effects produced by inhaled anesthetics A decrease in ______ associated with anesthetics is significant if there is diseased or ______ cardiac muscle Neurocirculatory responses are a concern for patients with \_\_\_\_

## Footnote Desflurane BP, HR, Surgical Disease, Circulatory Contractility, Failing CAD

Mechanism of Circulatory Effects Direct myocardial \_\_\_\_\_\_\_ Inhibition of ____ \_\_\_\_\_ outflow Peripherla autonomic _____ blockage Attenuation of _____ \_\_\_\_\_ reflex activity Decreased formation of \_\_\_\_, Decreased release of \_\_\_\_\_\_, Decreased influx of ____ ion

## Footnote Depression CNS Sympathetic Ganglion Carotid Sinus cAMP, Catecholamines, Ca++

All volatiles produce dose dependent _____ in BP \_\_\_\_\_ produces the most profound _____ in SVR \_\_\_\_\_ does NOT cause decrease in BP when administered \_\_\_\_\_

Decrease Isoflurane, Decrease Nitrous, Alone

Heart Rate HR increases the most with the use of \_\_\_\_, closely followed by \_\_\_\_ \_\_\_\_, \_\_\_\_, and ____ produce coronary vasodilation \_\_\_\_\_ causes least amount of coronary vasodilation \_\_\_\_\_\_ is the most _____ of the volatile anesthetics, and is also a potent coronary \_\_\_\_\_\_\_

## Footnote Des, Iso Iso, Des, Sevo Sevo Isoflurane, Potent, Vasodilator

Cardiac Preconditioning Can use concentrations of Isoflurane as low as \_\_\_\_\_\_ May protect against ______ \_\_\_\_\_\_ and _____ \_\_\_\_\_\_ injury APC limits infarct \_\_\_\_ \_\_\_ ______ elevation decreases \_\_\_\_\_\_ production decreases

## Footnote 0.25 MAC Prolonged Ischemia, Reperfusion Injury Size ST Segment Lactate

Possible mechanisms of Cardiac Preconditioning Release of ______ (a vasodilator substance) that binds to adenosine receptors A1 and A2 Binding to A2 receptors: increased ____ leads to stimulation of ___ channels, leading to \_\_\_\_\_\_\_\_, causing relaxation of vascular _____ \_\_\_\_\_ Binding to A1 receptors: decreased ____ leads to inhibition of ___ entry, causing a decreased _____ \_\_\_\_\_ of the ___ \_\_\_\_\_

## Footnote Adenosine cAMP, K+, Hyperpolarization, Smooth Muscle cAMP, Ca++, Action Potential, SA Node

Possible mechanisms of Cardiac Preconditioning Opening of ___ channels is critical for beneficial cardioprotective effects of IPC K+ channels can be closed by \_\_\_\_\_\_, abolishing anesthetic preconditioning (Should be discontinued 24-48 hours prior and administer sliding scale \_\_\_\_) \_\_\_\_\_\_\_ also antagonizes the function of K+ channels

## Footnote K+ Sulfonylureas, Insulin Ketamine

Possible mechanisms of Cardiac Preconditioning \_\_\_\_\_ and _____ may mimic IPC \_\_\_\_\_\_ antagonizes APC, use in caution in patients at risk for _______ \_\_\_\_

## Footnote Adenosine, Opioids Ketamine, Perioperative MI

Pulmonary Effects Inhaled anesthetics cause a dose dependent _____ in frequency of breathing \_\_\_\_\_ _____ decreases with increased _______ (rapid and shallow breathing pattern) This causes decreased ______ \_\_\_\_\_\_ and increased \_\_\_\_\_, leading to _______ \_\_\_\_\_\_

## Footnote Increase Tidal Volume, Frequency Minute Ventilation, PaCO2 Respiratory Acidosis

Pulmonary Effects Inhaled agents cause dose dependent ______ in ______ evidenced by decreased ventilatory response to CO2 and _____ in PaCO2 \_\_\_\_\_ may accentuate increased _____ production Mechanism of depression pertains to depressant effects on the ______ \_\_\_\_\_ \_\_\_\_\_\_

## Footnote Depression, Ventilation Increases COPD, PaCO2 Medullary Ventilatory Center

Pulmonary Effects Anesthetics produce decreased ______ \_\_\_\_\_\_ Nitrous causes an ______ incident of pulmonary vascular resistance, but ______ agents cause a decrease in PVR (except Des)

## Footnote Airway Resistance Increased, Volatile

Hypoxic Pulmonary Vasocontriction Ability of pulmonary vasculature to ______ in response to \_\_\_\_\_\_\_ Results in more optimal ______ to ______ match Volatile agents mildly _____ the HPV mechnism Read Flood, Page 599

Hepatic Effects Anesthetics may interfere with _____ due to decreased ______ blood flow or inhibition of \_\_\_\_\_\_\_ Inhibition may be _______ specific; more important than ______ in blood flow Transient ______ in LFT's (surgical stimulation increases all LFTs Increase in _____ with ______ and \_\_\_\_\_\_, none with \_\_\_\_\_\_

## Footnote Clearance, Hepatic, Enzymes Enzyme, Decrease Increase ALT, Enflurane, Des, None with Iso

Hepatic Effects Anesthetics produce mild _____ \_\_\_\_\_ due to inadequate hepatic \_\_\_\_\_\_ Metabolism of anesthetic agent can result in _____ liver protein which can produce a _____ \_\_\_\_\_\_ response Potential for hepatic \_\_\_\_\_\_, is _______ proportional to the degree of \_\_\_\_\_\_

## Footnote Hepatic Dysfunction Acetylated Severe Antibody Injury, Directly, Metabolism

Hepatic Effects \_\_\_\_ is NOT metabolized to _____ \_\_\_\_\_, so no antibody production to _____ liver proteins can occur \_\_\_\_\_ can be degraded by CO2 absorbents to produce \_\_\_\_\_\_\_, which is hepatotoxic in animals, but the concentration in the breathing circuit is ______ toxic levels

## Footnote Sevo, Acetyl Halide, Acetylated Sevo, **Compound A**, Below

Renal Effects Anesthetics cause ______ renal blood flow, decreased \_\_\_\_, and decreased _____ \_\_\_\_\_, which is most likely related to the effects that anesthetic agents have on ____ and \_\_\_\_ Preoperative _______ helps prevent this

## Footnote Decreased, GFR, Urine Output BP and CO Hydration (IV Fluids)

Renal Effects \*Fluoride Induced Nephrotoxicity\* Observed with \_\_\_\_\_\_\_\_, which is highly metabolized to ______ \_\_\_\_\_, which is a renal toxin Current volatile anesthetics have decreased solubility, so most are _____ and never metabolize into _____ \_\_\_\_\_\_ Toxicity may include \_\_\_\_\_, \_\_\_\_\_\_, \_\_\_\_\_\_\_, increased serum \_\_\_\_\_, and the inability to concentrate ______ (think dehydration symptoms)

Methoxyflurane, Inorganic Fluoride Exhaled, Inorganic Fluoride Polyuria, Hyper Na+, Hyperosomlarity, Creatinine, Urine

Renal Effects \_\_\_\_\_ is metabolized to ______ \_\_\_\_\_\_, which doesn't impair renal function in patient's without pre-existing ______ \_\_\_\_\_\_ \_\_\_\_\_ has greater _______ metabolism of inorganic fluoride \_\_\_\_\_\_ has greater ______ metabolism of inorganic fluoride

## Footnote Sevo, Inorganic Fluoride Renal Disease Enflurane, Intrarenal Sevoflurane, Hepatic

Renal Effects \*Vinyl Halide Nephrotoxicity\* CO2 absorbents such as ______ or _____ \_\_\_\_\_, react with ______ to form breakdown product known as \_\_\_\_\_\_\_\_, a vinyl ether Need to use at least ______ fresh gas flow rate with Sevo to minimize concentration of ______ that may accumulate in the breathing circuit

Baralyme, Soda Lime, Sevo Compound A 2L/Minute, Compound A

Skeletal Muscle Effects Skeletal muscle ______ produced with most \_\_\_\_\_-derived anesthetics, but not with ______ or \_\_\_\_\_ \_\_\_\_\_ derivates can cause dose dependent _______ of NM blockers

## Footnote Relaxation, Ether Halothane, N2O Ether, Enhancement

Skeletal Muscle Effects Malignant Hyperthermia \_\_\_\_\_\_ susceptible patients \_\_\_\_\_\_ is the most potent trigger

Genetically Halothane

Malignant Hyperthermia Can develop _____ or _____ GA Volatile anesthetics and ________ cause an increase in _______ \_\_\_ concentration in susceptible patient, resulting in persistent _____ contraction \_\_\_\_\_\_\_\_ state with increased ___ and unexplained increase in \_\_\_\_\_ Will also see \_\_\_\_\_\_, \_\_\_\_\_\_, \_\_\_\_\_, and \_\_\_\_ Rise in temperature is a _____ sign

## Footnote During, After Succinylcholine, Sarcoplasmic Ca++ Muscle Hypermetabolic, HR, ETCO2 Acidosis, Rhabdo, Arrythmias, Hyper K+ Late

Malignant Hyperthermia Unexplained increase in _____ (most sensitive indicator in the OR) \_\_\_\_\_ _____ fever Skeletal _____ rigidity Lactic ______ (hyper metabolism) Constant leak of SR ____ through defective ______ receptor

## Footnote ETCO2 High Grade Muscle Acidosis Ca++, **Ryanodine**

Malignant Hyperthermia Must use ____ \_\_\_\_ anesthesia for these patients Notify _____ immediately, _____ triggering agents, ______ with 100% O2 (with \_\_\_\_, not anesthesia circuit) \_\_\_\_ procedure IV ______ (prevents release of Ca++ from the SR) Give \_\_\_\_\_, Cool patient, _____ and _____ for Hyper K+, Monitor _____ output to watch for _____ to kidneys or \_\_\_\_\_

## Footnote Total IV Surgeon, Stop, Hyperventilate, TANK Abort Dantrolene Bicarb, Insulin and D50, Urinary, Shock, ATN

Obstetric Effects Dose dependent ______ in _____ smooth muscle contraction and blood flow Relaxation is beneficial and may help remove retained \_\_\_\_\_, but may also contribute to blood loss in _____ \_\_\_\_\_\_ Anesthetics rapidly enter \_\_\_\_\_, but are rapidly \_\_\_\_\_

## Footnote Decrease, Uterine Placenta, Uterine Atony Fetus, Exhaled

Resistance to Infection Normal functions of the immune system may be _____ after anesthesia and surgery Causes decreased ____ \_\_\_\_\_; affecting influenza and measles viruses Inhaled anesthetics do not have ______ effects, but the liquid form of volatile anesthetics may be \_\_\_\_\_\_

## Footnote Decreased DNA Synthesis Bateriostatic, Bactericidal

Metabolism Metabolites may be toxic to \_\_\_\_, \_\_\_\_\_, or ______ organs (always check a _______ test in women of child bearing age) Degree of metabolism may be influenced by rate of decrease of P_A at end of anesthesia case Assess magnitude of metabolism by measuring ______ or a comparison of total amount recovered in exhaled gases with amount taken up during administration (\_\_\_\_\_ \_\_\_\_\_)

## Footnote Kidney, Liver, Reproductive, Pregnancy Metabolites, Mass Balance

Metabolism of Volatile Agents Metabolism is affected by what four main factors?

## Footnote Chemical structure, Enzyme activity, Blood concentration, Genetic factors

Metabolism **N2O** Very _____ metabolism, mainly by ______ bacteria in the GI tract An O2 concentration of _____ than ____ inhibits metabolism of N2O

Little, Anaerobic Greater, 10%

Metabolism **Halothane** 15-20% metabolized by _______ enzymes Oxidative metabolism produces ______ \_\_\_\_\_ that may acetylate hepatic proteins resulting in formation of \_\_\_\_\_\_\_ Reductive metabolism in hepatocyte hypoxia produces _____ \_\_\_\_\_

Cytochrome P-450 Enzymes Trifluoroacetyl Halide, Antibodies Inorganic Fluoride

Metabolism **Enflurane** 3% metabolized by _______ enzymes Oxidative metabolism may produce _______ hepatic ______ complexes Low _____ in tissues \_\_\_\_\_\_\_ increases nephrotoxic potential

Cytochrome P-450 Fluoroacetylated, Protein-Ab Solubility Isoniazid

Metabolism **Isoflurane** 0.2% metabolized by ______ enzymes Oxidative metabolism to _______ \_\_\_\_, possibility of producing acetylated hepatic ______ complexes Low \_\_\_\_\_\_ Concentration of inorganic flouride produced is less than with \_\_\_\_\_

Cytochrome P-450 Trifluoroacetric acid, Protein-Ab Solubility Enflurane

Metabolism **Desflurane** 0.02% metabolized by _______ enzymes Oxidative metabolism to _______ \_\_\_\_\_, possibility of producing acetylated hepatic ______ complexes Low \_\_\_\_\_\_

Cytochrome P-450 Trifluoroacetic acid, Protein-Ab Solubility

Metabolism **Sevoflurane** 5% metabolozed by _______ enzymes Oxidative metabolism does NOT produce _____ \_\_\_\_\_, therefore, there is no possibility of hepatic _______ complexes Degraded by CO2 ______ to potentially nephrotoxic \_\_\_\_\_\_\_, which is more likely to happen with \_\_\_\_\_\_\_ Renal exposure to flouride concentration is not concerning because most ______ is through the lungs

## Footnote Cytochrome P-450 Acetyl Halides, Protein-Ab Absorbents, Compound A, Baralyme Elimination

Carbon Monoxide Toxicity CO formation is a product of _____ of anethetics \_\_\_\_\_, followed by \_\_\_\_\_, have the highest production of CO \_\_\_\_\_ and _____ have no _____ group, therefore, they do not produce CO CO toxicity increases intraoperative _______ concentration \_\_\_\_ detection difficult since oximeter can't detect Carboxy-Hgb versus Oxy-Hgb CO toxicity may produce delayed ________ effects (cognitive effects), ______ changes, _____ distrubance - can occur 3-21 days later

## Footnote Degradation Desflurane, Enflurane Halothane, Sevoflurane Carboxyhemoglobin CO Neurophysiological

Metabolism (Factors that increase magnitude of CO production) Dryness of ___ \_\_\_\_\_\_ - Prevented by \_\_\_\_\_\_ High ______ of absorbent - occurs during _____ fresh gas flows or increased metabolic production of \_\_\_\_ Prolonged ____ fresh gas flows (contribute to _____ of absorbent) \_\_\_\_\_\_ absorbent predispositioned to CO production more than ______ absorbent

CO2 Absorbent, Hydration Temperature, Low, CO2 High, Dryness Baralyme, Soda Lime

CO2 Absorber Fires \_\_\_\_\_\_ reacts with dessicated CO2 absorbents to produce CO and ______ organic compounds such as ______ or \_\_\_\_\_\_\_ This reaction produces \_\_\_\_\_, which increases chemical reaction _____ so that _____ breaks down rapidly \_\_\_\_\_\_\_ metabolites can spontaneously ______ at high temperatures Most often associated with \_\_\_\_\_\_

## Footnote Sevoflurane, Flammable, Methanol, Formaldehyde Heat, Speed, Sevoflurane Flammable, Combust Baralyme

Minimal Alveolar Concentration Each gas has a different \_\_\_\_\_ A _____ (or 1 MAC) is the % of anesthetic agent (gas) which ceases movement in response to noxious stimuli in _____ of patients An increase to a MAC of ____ will prevent movement in _____ of patients See Table 4.6 in Stoelting Book MAC is _____ in women with natural red hair due to mutations of the _______ receptor gene

## Footnote MAC MAC, 50% 1.3, ~95% Increased, Melano-cortin-1

MAC MAC _____ : opposite of MAC MAC Awake is where ____ of patients will respond appropriately to verbal command and stimuli Nitrous (About 60%) will decrease the MAC by ____ (roughly) \_\_\_\_\_\_ of a MAC should produce MAC Awake for volatiles

## Footnote Awake 50% 1/3 1/10

**Xenon** (Inert Gas) ## Footnote MAC is gender dependent, being less in \_\_\_\_\_\_ Non-explosive, Not pungent, minimal ______ depression Main issue is the high _____ & needs more studies to prove \_\_\_\_\_\_ Lowest blood:gas coefficient of \_\_\_\_\_\_ Does have a tendency to \_\_\_\_\_, like N2O Does not contribute to ______ \_\_\_\_\_\_ Emergence is _____ faster than nitrous or Sevo

## Footnote Females Cardiac Cost, Morbidity 0.115 Bubble Malignant Hyperthermia 2-3 x