Dr. Milan Kharel and Dr. Madhu Gyawali discussed the history and concepts of inhalational anesthetics. Some key points include:
- Diethyl ether was the first anesthetic used in 1846. Chloroform was also used but discontinued due to toxicity.
- Halothane was synthesized in 1951 and was widely used for decades. Other common agents introduced later include enflurane, isoflurane, sevoflurane, and desflurane.
- Minimal alveolar concentration (MAC) is used to compare anesthetic potency, with halothane having a MAC of 0.75%.
- Inhalational agents are transferred from inspired air to alveoli and tissues based on factors like blood
General principles of pharmacology of inhalational agents(Pharmacokinetics)DR PANKAJ KUMAR
Presentation deals with pharmacokinetics of Inhalational agents , starting from pre-anaesthesia era ,developments of inhalational agents , structural significance.
Discussion #11. What physical findings might be indicative of a .docxmecklenburgstrelitzh
Discussion #1
1. What physical findings might be indicative of a patient with emphysema? The diagnosis is made on patients that usually are long term smokers, and they complaint of dyspnea, cough, and mucus expectoration. Most patients seek medical attention late in the course of their disease, usually ignoring smoldering symptoms that start gradually and progress over the course of years. The cough typically is worse in the morning with finite production of clear-to-white sputum. Dyspnea, emphysema's most significant symptom, does not generally occur until the sixth decade of life. However, patients with emphysema due to alpha 1 -antitrypsin deficit will exhibit the following characteristics: early presentation (< 45 y), predilection of emphysematous changes in the lung bases, and the panacinar morphological pattern.
Although the sensitivity of the physical evaluation in mild-to-moderate disease is relatively poor, the physical signs are quite sensitive and specific in severe disease. Patients with severe disease may experience tachypnea and dyspnea with mild exertion.
The respiratory rate increases in proportion to disease severity with the use of accessory respiratory muscles and paradoxical contraction of lower intercostal spaces becoming evident during exacerbations.
In end-stage emphysema, cyanosis, elevated jugular venous pressure, atrophy of limb musculature, and peripheral edema due to the development of pulmonary hypertension, right-to-left shunting, and/or right heart failure can easily be observed.
Thoracic examination reveals a 2:1 increase in anterior to posterior diameter (“barrel chest”), diffuse or focal wheezing, diffusely diminished breath sounds, hyperresonance upon percussion, prolonged expiration, and/or hyperinflation on chest radiographs.
2. What is the purpose and interpretations of the pulmonary function test? Pulmonary function tests will test the mechanical function of the lungs, chest wall, and respiratory muscles by measuring the total volume of air exhaled from a full lung (total lung capacity [TLC]) to maximal expiration (residual volume [RV]). This volume, the forced vital capacity (FVC) and the forced expiratory volume in the first second of the forceful exhalation (FEV1), In Emphysema, spirometry may show typical obstructive pattern due to the blockage of the air during expiration. As a result of the air trapping, the spirometry will show decreased in FVC, but less than the FEV 1, and increased FRC and RV.(McCance, & Huether, 2013).
3. What are the pathophysiological findings specifying emphysema? As a result of the cellular apoptosis, and early cellular senescence, the alveolar cells are damaged, and a reduced surface of gas exchanged occurred. The destruction of the alveoli creates bullae, which are large spaces in the lung parenchyma and air spaces adjacent to pleurae(blebs). Both elements bullae, and blebs difficult the air exchange. In addition, areas of the lungs that are bad perfused contributes to w.
This presentation deals with the basic physics of human ventillation. I have made an effort to clarify most of the venti lingo , so as to make way for further discussions on ventilator use. Hope it turns out to be helpful for you. Thank you.
General principles of pharmacology of inhalational agents(Pharmacokinetics)DR PANKAJ KUMAR
Presentation deals with pharmacokinetics of Inhalational agents , starting from pre-anaesthesia era ,developments of inhalational agents , structural significance.
Discussion #11. What physical findings might be indicative of a .docxmecklenburgstrelitzh
Discussion #1
1. What physical findings might be indicative of a patient with emphysema? The diagnosis is made on patients that usually are long term smokers, and they complaint of dyspnea, cough, and mucus expectoration. Most patients seek medical attention late in the course of their disease, usually ignoring smoldering symptoms that start gradually and progress over the course of years. The cough typically is worse in the morning with finite production of clear-to-white sputum. Dyspnea, emphysema's most significant symptom, does not generally occur until the sixth decade of life. However, patients with emphysema due to alpha 1 -antitrypsin deficit will exhibit the following characteristics: early presentation (< 45 y), predilection of emphysematous changes in the lung bases, and the panacinar morphological pattern.
Although the sensitivity of the physical evaluation in mild-to-moderate disease is relatively poor, the physical signs are quite sensitive and specific in severe disease. Patients with severe disease may experience tachypnea and dyspnea with mild exertion.
The respiratory rate increases in proportion to disease severity with the use of accessory respiratory muscles and paradoxical contraction of lower intercostal spaces becoming evident during exacerbations.
In end-stage emphysema, cyanosis, elevated jugular venous pressure, atrophy of limb musculature, and peripheral edema due to the development of pulmonary hypertension, right-to-left shunting, and/or right heart failure can easily be observed.
Thoracic examination reveals a 2:1 increase in anterior to posterior diameter (“barrel chest”), diffuse or focal wheezing, diffusely diminished breath sounds, hyperresonance upon percussion, prolonged expiration, and/or hyperinflation on chest radiographs.
2. What is the purpose and interpretations of the pulmonary function test? Pulmonary function tests will test the mechanical function of the lungs, chest wall, and respiratory muscles by measuring the total volume of air exhaled from a full lung (total lung capacity [TLC]) to maximal expiration (residual volume [RV]). This volume, the forced vital capacity (FVC) and the forced expiratory volume in the first second of the forceful exhalation (FEV1), In Emphysema, spirometry may show typical obstructive pattern due to the blockage of the air during expiration. As a result of the air trapping, the spirometry will show decreased in FVC, but less than the FEV 1, and increased FRC and RV.(McCance, & Huether, 2013).
3. What are the pathophysiological findings specifying emphysema? As a result of the cellular apoptosis, and early cellular senescence, the alveolar cells are damaged, and a reduced surface of gas exchanged occurred. The destruction of the alveoli creates bullae, which are large spaces in the lung parenchyma and air spaces adjacent to pleurae(blebs). Both elements bullae, and blebs difficult the air exchange. In addition, areas of the lungs that are bad perfused contributes to w.
This presentation deals with the basic physics of human ventillation. I have made an effort to clarify most of the venti lingo , so as to make way for further discussions on ventilator use. Hope it turns out to be helpful for you. Thank you.
Explore our infographic on 'Essential Metrics for Palliative Care Management' which highlights key performance indicators crucial for enhancing the quality and efficiency of palliative care services.
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Defecation
Normal defecation begins with movement in the left colon, moving stool toward the anus. When stool reaches the rectum, the distention causes relaxation of the internal sphincter and an awareness of the need to defecate. At the time of defecation, the external sphincter relaxes, and abdominal muscles contract, increasing intrarectal pressure and forcing the stool out
The Valsalva maneuver exerts pressure to expel faeces through a voluntary contraction of the abdominal muscles while maintaining forced expiration against a closed airway. Patients with cardiovascular disease, glaucoma, increased intracranial pressure, or a new surgical wound are at greater risk for cardiac dysrhythmias and elevated blood pressure with the Valsalva maneuver and need to avoid straining to pass the stool.
Normal defecation is painless, resulting in passage of soft, formed stool
CONSTIPATION
Constipation is a symptom, not a disease. Improper diet, reduced fluid intake, lack of exercise, and certain medications can cause constipation. For example, patients receiving opiates for pain after surgery often require a stool softener or laxative to prevent constipation. The signs of constipation include infrequent bowel movements (less than every 3 days), difficulty passing stools, excessive straining, inability to defecate at will, and hard feaces
IMPACTION
Fecal impaction results from unrelieved constipation. It is a collection of hardened feces wedged in the rectum that a person cannot expel. In cases of severe impaction the mass extends up into the sigmoid colon.
DIARRHEA
Diarrhea is an increase in the number of stools and the passage of liquid, unformed feces. It is associated with disorders affecting digestion, absorption, and secretion in the GI tract. Intestinal contents pass through the small and large intestine too quickly to allow for the usual absorption of fluid and nutrients. Irritation within the colon results in increased mucus secretion. As a result, feces become watery, and the patient is unable to control the urge to defecate. Normally an anal bag is safe and effective in long-term treatment of patients with fecal incontinence at home, in hospice, or in the hospital. Fecal incontinence is expensive and a potentially dangerous condition in terms of contamination and risk of skin ulceration
HEMORRHOIDS
Hemorrhoids are dilated, engorged veins in the lining of the rectum. They are either external or internal.
FLATULENCE
As gas accumulates in the lumen of the intestines, the bowel wall stretches and distends (flatulence). It is a common cause of abdominal fullness, pain, and cramping. Normally intestinal gas escapes through the mouth (belching) or the anus (passing of flatus)
FECAL INCONTINENCE
Fecal incontinence is the inability to control passage of feces and gas from the anus. Incontinence harms a patient’s body image
PREPARATION AND GIVING OF LAXATIVESACCORDING TO POTTER AND PERRY,
An enema is the instillation of a solution into the rectum and sig
CRISPR-Cas9, a revolutionary gene-editing tool, holds immense potential to reshape medicine, agriculture, and our understanding of life. But like any powerful tool, it comes with ethical considerations.
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Health Education on prevention of hypertensionRadhika kulvi
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4. Diethyl ether first used by William T.G. Morton in the USA
in 1846
Chloroform was the next agent to receive attention, by James
Simpson in 1847 it was discontinued due to:-
a. severe cardiovascular depression (sudden death ? VF)
b. dose dependent hepatotoxicity
Cyclopropane was discovered accidentally in 1929 and was
very popular for almost 30 yrs
the increasing use of electronic equipment necessitated the
discontinuation of this inflammable agent.
5. Halothane, synthesized in 1951 by prominent
British chemist, Charles Walter Suckling,
while working at the Imperial Chemical
Industries (ICI). Later in 1956, M. Johnstone
used it clinically first time
Enflurane has been in use since 1970
Isoflurane- (1981), Desflurane-1996
6. a variety of other agents were investigated but
discarded for various reasons
A.Explosive mixtures with oxygen –
-diethyl ether
- ethyl chloride
- divinyl ether
- cyclopropane
b. postoperative liver necrosis / sudden death -
chloroform
c. postoperative renal failure - methoxyflurane
8. MAC Definition
Minimal alveolar concentration (MAC):
Is defined as the conc. At 1 atmosphere of
anesthetic in the alveoli that is required to
produce immobility in 50% of adults patient
subjected to a surgical incision
MAC is important to compare the potencies
of various inhalational anesthetic agents
1.2 -1.3 MAC prevent movement in 95% of
patients
8
9. MAC Value
N2O = 105%
Halothane = 0.75%
Isoflurane = 1.16%
Euflurane = 1.68%
Sevoflurane = 2%
Deslurane = 6%
N2O alone is unable to produce adequate
anesthesia ( require high conc. )
9
11. No Effect on MAC
Gender
Duration of anesthesia
Carbon dioxide tension (21-95 mmHg)
Metabolic Acid base status
Hypertension
Hyperkalemia
11
12. Pressure exerted by the molecules of the vapor phase at
equilibrium of molecules moving in and out of liquid phase
Vapor Pressure dependent on temperature and physical
characteristics of liquid, independent of atmospheric
pressure
↑ Temperature→↑ Vapor Pressure
Vapor pressure is a measure of the agent’s ability to
evaporate (volatility) .The greater is the vapor pressure,
the greater the concentration of inhalant deliverable to
the patient (and environment).
Boiling Point: Temperature at which vapor pressure
equals atmospheric pressure
Vapour Pressure & BP
13. Vapour Pressure & BP
Agent BP (0
C) VP (20 0
C)
Halothane 50 243
Enflurane 56 175
Isoflurane 48 238
Sevoflurane 58 160
Desflurane 23 664
Nitrous Oxide -89
Xenon -107
16. 1. Transfer from Inspired Air to Alveoli
i. the inspired gas concentration FI
ii. alveolar ventilation VA
iii. characteristics of the anaesthetic circuit
2. Transfer from Alveoli to Arterial Blood
i. blood:gas partition coefficient τB:G
ii. cardiac output CO
iii. alveoli to venous pressure difference dPA-vGas
3. Transfer from Arterial Blood to Tissues
i. tissue:blood partition coefficient τT:B
ii. tissue blood flow
iii. arterial to tissue pressure difference dPa-tGas
17.
18.
19. A)Inspired Gas Concentration FI:-
according to Dalton's law of partial pressures, the
tension of an individual gas in inspired air is equal to,
PIgas = FIgas x Atm
the greater the inspired pressure the greater the
approach of FA to FI = the concentration effect
this is only significant where FI is very high, as is
the case for N2O (or cyclopropane)
when another gas is used in the presence of such an
agent, there is increased uptake of the second gas, the
Second gas effect
20. each inspiration delivers some anaesthetic to the
lung and, if unopposed by uptake into the blood,
normal ventilation would increase FA/FI to 95-98%
in 2 minutes
this rate of rise is dependent upon minute
ventilation and FRC
the greater the FRC, the slower the rise in FA
hyperventilation will decrease CBF, and this tends
to offset the increased rise of FA/FI
21. A) Blood:Gas Partition Coefficient
the solubility of a gas in liquid is given by its
Ostwald solubility coefficient, τ
this represents the ratio of the concentration in blood
to the concentration in the gas phase
lower B:G coefficients are seen with,
haemodilution ,obesity , hypoalbuminaemia and
starvation
higher coefficients are seen in, adults versus
children, hypothermia & postprandially
22. Solubility of Inhaled Drugs
solubility (partition) coefficient - the extent to
which a gas will dissolve in a given solvent
Predicts the speed of induction, recovery, and change in
anesthetic depth for an inhalant.
Ideal inhaled anesthetics should have low blood/gas and
low tissue/blood solubility and low solubility in plastic
and rubber.
Low solubility means rapid induction and emergence and
more precise control
25. Effective pulmonary blood flow determines the
rate at which agents pass from gas to blood
an increase in flow will slow the initial portion of
the arterial tension/time curve by delaying the
approach of FA to FI
a low CO state, conversely, will speed the rise of
FA/FI
these effects are greater for highly soluble
agents
26. this represents tissue uptake of the inhaled
agent
blood cannot approach equilibrium with alveolar air
until the distribution of anaesthetic from the blood
to the tissues is nearly complete
with equilibration, the alveolar/mixed venous
tension difference progressively falls as tissue
tensions rises
since diffusion is directly proportional to the tension
difference, the rate of diffusion into the blood
progressively slows
27. A) Tissue:Blood Partition Coefficient:-
the rate of rise of tension in these regions is
proportional to the arterial-tissue tension difference
conversely, their solubility in lipid tissues is far
greater than that for blood
at equilibrium the concentration in lipid tissues will be
far greater than that in blood
the tissue concentration will rise above that of blood
well before pressure equilibrium, even though the
tissue tension is lower
29. the higher the blood flow to a region, the faster the
delivery of anaesthetic and the more rapid will be
equilibration
the body tissues have been divided into groups
according to their level of perfusion and tissue
blood flow,
30. a. vessel rich group VRG - brain, heart,
kidney & liver
b. the muscle group MG - muscle & skin
c. the fat group FG - large capacity/minimal
flow
d. vessel poor group VPG - bone, cartilage,
CT
31. with equilibration tissue tension rises and the rate
of diffusion slows, as does uptake in the lung
the rate is determined by the tissue time constant,
which in turn depends upon both the tissue
capacity (τT:B) and the tissue blood flow
TC(τ)= Tissue Capacity / 100g
Blood Flow/ 100g
32. Concentration and Second Gas Effects
- increasing the inspired concentration not only
increases the alveolar conc but also increases the
rate of rise of volatile anaesthetic agents in the
alveoli
eg., during the inhalation of 75% N2O/O2, initially
as much as 1 l/min may diffuse into the
bloodstream across the lungs ,this effectively draws
more gas into the lungs from the anaesthetic circuit,
thereby increasing the effective minute
ventilation
33. this effect is also important where there is a
second gas, such as 1% halothane, in the
inspired mixture
the removal of a large volume of N2O from the
alveolar air increases the delivery of the second
gas, effectively increasing its delivery to the alveoli
and increasing its diffusion into arterial blood K/A
Second Gas Effect
34. 1. Rapid and pleasant induction
2. Rapid changes in the depth of anesthesia
3. Adequate muscle relaxation
4. Wide margin of safety
5. Absence of toxic/adverse effects
CHARACTERISTICS OF AN
IDEAL ANESTHETIC
No single agent yet identified is an ideal anesthetic
38. PHARMACOLOGY:
- Good Analgesic
- Weak anesthetic
- Excreted via lungs
- MAC = 105%
- Lower water solubility
- Not Metabolized in the body
38
39. SIDE EFFECTS:
- Diffusion Hypoxia.
- Effects on closed gas spaces.(nitrous oxide can
diffuse 20 times faster into closed spaces than it can be
removed, resulting in expansion of pneumothorax, bowel
gas, or air embolism or in an increase in pressure within
noncompliant cavities such as the cranium or middle ear.
- CVS depression
- Toxicity
- Teratogenic
39
40. What is diffusion hypoxia?
Diffusion hypoxia is a decrease in PO2 usually
observed as the patient is emerging from an
inhalational anesthetic where nitrous oxide (N2O)
was a component. The rapid outpouring of
insoluble N2O can displace alveolar oxygen,
resulting in hypoxia. All patients should receive
supplemental O2 at the end of an anesthetic and
during the immediate recovery period.
40
41. Second gas effect: The ability of the large
volume uptake of one gas (first gas) to
accelerate the rate of rise of the alveolar
partial pressure of a concurrently
administered companion gas (second
gas) is known as the second gas effect.
41
45. •Pharmacodynamics:
Lungs: Stimulates resp, increases secretion, not
good in respiratory diseases
Kidney: decreases urine output
Liver: Minimum effect, decreases liver glycogen
Heart: Initially increases cardiac output, then
decreases card. output, suppresses
vasomotor center.
46. Ether as an anesthetic
•Advantage: CNS depression, excellent muscle
relaxant, causes surgical anesthesia
•Disadvantage: Flammable, irritates mucus
membrane, breath holding, induces nausea &
vomiting
•Contraindications: Resp., kidney and liver
diseases
•Better agents are available now, so not used now.
48. Synthesized in 1951.
* Most potent inhalational anesthetic
•MAC of 0.75%
It has low blood/gas solubility coeffient of 2.5 and
thus induction of anasthesia is relatively rapid.
49. Chemical and Physical Properties
Halogenated compound chemically:
2-bromo-2-chloro-1,1,1-tri fluoro
ethane
Volatile, so kept in sealed bottles
Colorless, Pleasant odor, Non-irritant
Non-explosive, Non-inflammable
Light-sensitive
Corrosive, Interaction – rubber and plastic tubing
50.
51. Potency is
defined(determined)
quantitatively as the minimum
alveolar concentration (MAC),
Numerically, MAC is small for
potent anesthetics such as
Halothane and large for less
potent agents such as nitrous
oxide.
52. Halothane is a potent anesthetic but a relatively
weak analgesic. Thus, it is usually coadministered
with nitrous oxide, opioids, or local anesthetics.
It is a potent bronchodilator.
Halothane relaxes both skeletal and uterine muscles
and can be used in obstetrics when uterine relaxation
is indicated.
Halothane is not hepatotoxic in children (unlike its
potential effect on adults).
Combined with its pleasant odor, it is suitable in
pediatrics for inhalation induction, although
sevoflurane is now the agent of choice.
53. No specific receptor has been identified as the locus of
general anesthetic action –generally-.
It appears that a variety of molecular mechanisms may
contribute to the activity of general anesthetics.
Halothane activates GABAA , glycine receptors, 5-HT3and
twin-pore K+ channels
.
It antagonizes NMDA receptor.
It inhibits nACh(block excitatory postsynaptic currents of
nicotinic receptors) and voltage-gated sodium channels.
---------------------------------------------------------------------------------------
--
At clinically effective concentrations, general anesthetics
increase the sensitivity of the γ-aminobutyric acid (GABA-A)
receptors to the inhibitory neurotransmitter GABA. This
increases chloride ion influx and cause
Hyperpolarization Decrease Excitability CNS Depression
54.
55. 20% metabolized in liver by oxidative
pathways.
Major metabolites : bromin, chlorine,
Trifloroacetic acid, Trifloroacetylethanl
amide.
56. The induction dose varies from patient to patient.
The maintenance dose varies from 0.5 to 1.5%.
Halothane may be administered with either
oxygen or a mixture of oxygen and nitrous oxide.
57. Indications
Halothane is indicated for the induction and
maintenance of general anesthesia.
Contraindications
Halothane is not recommended for obstetrical
anesthesia except when uterine relaxation is
required.
58. Respiratory system:
Halothane anesthesia progressively depresses
respiration.
Its cause inhibition of salivary & bronchial secretion.
Its may cause tachypnea & reduce in tidal volume and
alveolar ventilation .
Its cause decrease in mucocillary function which lead
to sputum retention.
It causes bronchodilation. Hypoxia, acidosis, or apnea
may develop during deep anesthesia.
59. Cardiovascular system:
Halothane anesthesia reduces the blood pressure, and cause
bradycardia.(atropin may reverse bradycardia.).
It cause myocardial relaxation & Hypotention.
Its also causes dilation of the vessels of the skin and skeletal
muscles
Halothane maybe advantages In pts with CAD , bcz of
decrease of oxygen demand.
Arrhythemias are very common .(especially with
epinephrine).
◦ To minimize effects :
Avoid hypoxemia and hypercapnia
Avoid conc. Of adrenaline higher than 1 in 10000
60. Gastro intestinal tract:
Inhibition of gastrointestinal motility.
Cause sever post. Operative nausea & vomiting
Uterus:
Halothane relaxes uterine muscle, may cause postpartum
hemorrhage .
Concentration of less than 0.5 % associated with increase
blood loss during therapeutic abortion.
Skeletal muscle:
Its cause skeletal muscle relaxation .
Postoperatively , shivering is common , this increase oxygen
requirement>>> which cause hypoxemia
61. Hepatic dysfunction:
Two type of dysfunction:
1- Type I hepatotoxicity ,mild, associated with derangement
in liver function test , this result from metabolic of Halothane
in liver. results from reductive (anaerobic) biotransformation
of halothane rather than the normal oxidative pathway.
2- Type II hepatotoxicity: fulminate (uncommon); sever
jaundice ,fever,progressing to fulminating hepatic necrosis,
Its increased by repeated exposure of the drugs.
high mortality 30-70%
62. 1- A careful anasthetic history .
2- repeated exposure of halothane within
3 months should be avoided.
3- History of unexplained jaundice or
pyrexia after previous exposure of
halothane.
64. Poor analgesia.
Arrhythmias.
Post operatively shivering.
Possibility of liver toxicity.
65. Enflurane
•MAC =1.68%
•Potent cardiovascular depressant
Sweet and ethereal odor.
Generally do not sensitizes the heart to
catecholamines.
Seizures occurs at deeper levels –
contraindicated in epileptics.
Caution in renal failure due to fluoride.
67. Isoflurane
Properties
- Least soluble of the modern inhalational agent
equilibrate more rapidly
- Induction rapid theoretically (pungency??)
- pungency cough, breath holding.
68. Isoflurane
effects on systems:-
Respiratory:
dose dependent depression of vetilation.
CVS:
- myocardial depressant (vitro Vs Clinical),
coronary vasodilatation (coronary steal
syndrome).
uterus: relaxation of uterine muscles (same).
69. Isoflurane
effects on systems:-
CNS:
low concentration Vs High concentration.
Low : no change on the flow.
High : increase blood flow by
vasodilatation of the cerebral arteries.
-Muscles: relaxation (dose-dependent).
72. Sevoflurane
effects on systems
-
- Respiratory:
-non-irritant, depression.
-CVS: same as isoflurane (slightly lower
effect)
-CNS: same as halothane and isoflurane.
-Muscle relaxation: same as isoflurane.
73. Sevoflurane
Advantages and Disadvantages
Advantages
1
.
Well tolerated (non-irritant, sweet odor), even at high
concentrations, making this the agent of choice for
inhalational induction
.
2
.
Rapid induction and recovery (low blood:gas coefficient
)
3
.
Does not sensitize the myocardium to catecholamines as
much as halothane
.
4
.
Does not result in carbon monoxide production with dry
soda lime
.
74. Sevoflurane
Disadvantages
1
.
Less potent than similar halogenated agents
.
2
.
Interacts with CO2
absorbers. In the presence of soda lime
(and more with barium lime) compound A (a vinyl ether) is
produced which is toxic to the brain, liver, and kidneys
.
3
.
About 5% is metabolized and elevation of serum fluoride
levels has led to concerns about the risk of renal toxicity
.
4
.
Postoperative agitation may be more common in children
then seen with halothane
.
75. Desflurane
MAC =6 %
It is delivered through special vaporizer.
It is a popular anesthetic for day care surgery.
Induction and recovery is fast, cognitive and
motor impairment are short lived
It irritates the air passages producing cough and
laryngospasm.
76. Anesthetic Blood: Gas
Partition
Coefficients
Oil: Gas
Partition
Coefficients
Features Notes
Halothane 2.3 220 PLEASANT Arrhythmia
Hepatitis
Hyperthermia
Enflurane 1.9 98 PUNGENT Seizures
Hyperthermia
Isoflurane 1.4 91 PUNGENT Widely used
Sevoflurane 0.62 53 PLEASANT Ideal
Desflurane 0.42 23 IRRITANT Cough
Nitrous oxide 0.47 1.4 PLEASANT Anemia