Anesthesia (Strauss) Flashcards
(201 cards)
0
Q
What is the benefit of inhalation anesthesia over IV drugs?
A
Easier to use and titrate patient
1
Q
What is the term for the use of a gaseous agent to achieve anesthesia from sedation to general anesthesia?
A
Inhalation anesthesia
2
Q
Inhalational anesthesia is generally used for general anesthesia, except for which inhalant?
A
NO (Nitrous oxide?)
3
Q
What is the state of current inhalational drugs?
A
Volatile liquids, not gases, that are non-flammable and non-explosive
4
Q
All current inhalant drugs work on what system?
A
Reticular activating system
5
Q
What is an instrument that adjusts flow to match output of the inhalant, accounts for temperature, and is specific to the agent?
A
Vaporizer
6
Q
What are 4 methods to administer inhalants?
A
- Nasal Hood
- Full face mask
- LMA (laryngeal mask anesthetic)
- Endotracheal intubation
7
Q
What is the method to administer inhalant indicated for oral procedures?
A
Nasal hood
8
Q
What is the method to administer inhalant indicated for short procedures outside the face?
A
Full face mask
9
Q
What are 2 methods to administer inhalant indicated for longer procedures?
A
- Laryngeal Mask anesthetic (LMA)
2. Endotracheal intubation
10
Q
What are the 3 levels of respiration for the patient when on inhalational anesthesia?
A
- Spontaneously
- Assisted
- Controlled
11
Q
What is the level of respiration for ambulatory procedure using inhalational anesthesia?
A
Spontaneous respiration
12
Q
Why would a patient on an inhalational require aide with respiration?
A
Because all inhalationals are respiratory depressants (they also slow the heart rate a bit)
13
Q
Therapeutic ratio is the difference between the therapeutic effect and toxicity, a lower ratio means what?
A
The lower the ration, the more dangerous the drug
14
Q
Which part of respiration is active: inhalation or exhalation?
A
Inhalation
15
Q
What is the reason for a patient needing assisted ventilation when on inhalational anesthesia?
A
Decreased tidal volume and rate
16
Q
A nasal hood is easy to use and allows oral access, but what are its disadvantages?
A
- No positive pressure available
- No airway protection
- Difficult to control how much patient gets
17
Q
A full face mask allows for a good seal, positive pressure ventilation, and 100% gas intake with no mixing, but what are the disadvantages?
A
No airway protection, no mouth access
18
Q
What are some advantages of inhalational anesthesia?
A
- Easy to use
- Easily controllable/titratable
- Predictable effects
- Low toxicity
- Rapid effect
- Continuous dosing so very stable
- Can always add IV drug as needed
19
Q
A full face mask is good for what part of the procedure?
A
Induction or non-oral procedures
20
Q
What instrument gives partial airway protection, is easier to place in a difficult airway, and allows for better airway maintenance?
A
Laryngeal mask anesthetic (LMA)
21
Q
All airway tubes have what at the connector end?
A
Universal 15mm connector at the end
22
Q
On what does the LMA sit when placed?
A
On vocal cords, note: only offers partial (not 100%)airway protection
23
Q
Why does air go into the lungs if you place a small amount of positive pressure onto the patient?
A
The trachea is the path of least resistance
24
An endotracheal tube has what at the end?
A small balloon
25
Where does an endotracheal tube sit when placed?
In trachea right above main bronchi
26
When passing endotracheal tubes between the vocal cords, if go to far, which lung will the tube go into and why?
Into right lung because it is the straighter bronchus
27
What gives the 100% seal for endotracheal tubes?
Inflation of the balloon end
28
Yellow indicates what gas?
Air
29
Green indicates what gas?
Oxygen
30
Blue indicates what gas?
Nitrous oxide
31
Is the anesthesia machine a closed or open system?
Closed, so it has a CO2 scavenger (Soda Lime)
32
What are 4 things that must be considered for inhalation anesthesia?
1. Equilibration
2. MAC
3. Blood gas solubility
4. Stages of anesthesia
33
The partial pressure of all gases will try to do what throughout the body?
Equilibrate (in alveoli, blood, body tissue)
34
Do all body tissues equilibrate to gases at the same rate?
No
35
The movement of gases in the body is determined by what?
Equilibration
36
Which tissues equilibrate quickly?
VRG (vessel rich group) = brain, heart, kidney, gut
37
What tissue is intermediate in its equilibration time?
VIG (vessel intermediate group) = muscle
38
What is the concentration of an anesthetic at which 50% of patients will not respond to a noxious stimulus (considered a measure of potency and is used to guide the correct dosages of agents)?
Minimum alveolar concentration (MAC)
39
Induction usually occurs at how many MAC?
2-3 MAC
40
Maintenance after induction usually takes place at how many MAC?
0.5-1.5 MAC
41
Are MACs independent or cumulative?
Cumulative, must consider other drugs used on the patient when considering MAC for a certain drug
42
When determining the stages of anesthesia, what must always be considered?
The drugs that mask/mimic signs, e.g. atropinecauses pupil dilation
43
Guedel’s stages of anesthesia based on what?
Ether
44
What are the 4 stages of anesthesia?
1. Analgesia
2. Excitement
3. Surgical Anesthesia
4. Apnea
45
What are the characteristics of a Stage 1 anesthesia patient?
They are conscious but do not feel pain
46
Stage 2 of anesthesia begins when and why?
Starts at loss of consciousness as patient begins to lose protective reflexes. Jerking caused by inhibition of
inhibitory CNS.
47
At what anesthesia stage is surgery performed?
Stage 3 surgical anesthesia
48
Do current inhalationals induce Apnea (Stage IV anesthesia)?
No
49
What is the coefficient that represents the ability of an agent to dissolve in blood?
Blood gas solubility
50
Only blood that (pick one) is or is not dissolved in blood can see the brain to produce effects?
Only NOT dissolved
51
What Blood Gas solubility / Blood Gas coefficient (BGC) is desired?
Lower the BGC, the faster the rise in arterial gas tension
52
What does a low BGC mean for both onset and recovery?
Both onset and recovery will be fast
53
Nitrous has a high or low BGC?
Low, starts within a few breaths and gone within 5 minutes on 100% oxygen
54
What are 5 minor inhalational agents?
1. Ethyl chloride
2. Chloroform
3. Diethyl ether
4. Methoxyflurane
5. Nitrous oxide
55
What are 5 major inhalational agents?
1. Halothane
2. Enflurane
3. Isoflurane
4. Desflurane
5. Sevoflurane
56
Of the 5 major inhalationals, which has liver toxicity and epinephrine sensitivity?
Halothane
57
Of the 5 major inhalationals, which can have seizure activity?
Enflurane
58
Of the 5 major inhalationals, which has the lowest BGC [0.42], so is very fast in/fast out, but is expensive?
Desflurane
59
What is the MAC of desflurane?
6
60
What are the cardiac actions of desflurane?
Tachycardia, but no change in cardiac output
61
With regards to the breathing associated with desflurane, what is increased?
The breathing is fast and shallow breathing
| The PaCO2 increases
62
All inhalants cause some type of what?
Ionotropism
63
Most inhalants do what to heart stroke volume, and how does the body compensate?
1. Decrease stroke volume
| 2. Compensate with tachycardia to maintain cardiac output
64
What is the concern with tachycardia and the heart (think when the heart gets fed)?
Heart gets fed during diastole. Diastole decreases in tachycardia, so heart is fed less.
65
In what patients is tachycardia a concern and why?
Cardiac patients and elderly. They have less cardiac reserve to compensate for less heart “feeding”during tachycardia.
66
All inhalationals do what to tidal volume: increase or decrease?
Increase Tidal volume
67
If all inhalationals increase tidal volume, why does the patient's PaCO2 increase?
Because they cause tachypnea
68
What is the MAC of Isoflurane?
1.2 (potent)
69
Can induction be done with Isoflurane or Desflurane and why?
No, both are pungent and patient will hold breath
70
What are the cardiac effects of isoflurane?
Isoflurane has minimal cardiac effect, increases the HR by 10%
71
What are 2 positive characteristics of Isoflurane with respect to airway?
1. Good bronchodilator
| 2. Good muscle relaxation
72
Isoflurane, being a good bronchodilator, would be indicated in what type of patient?
Asthmatic
73
What is a consideration as dentists for Isoflurane being a good muscle relaxer?
Makes the mouth easier to open when the patient asleep
74
What is the most common inhalational, besides N2O, used by our OMFS, with a low blood gas solubility (quick in, quick out)?
Sevoflurane
75
Because Sevoflurane has very little irritation, what can it be used for?
Used for induction (breath the patient down)
76
What is the MAC of Sevoflurane?
1.71
77
What are the cardiac effects of Sevoflurane?
Decreases both tidal volume and rate
78
Sevoflurane is a triggering agent for this which hasa high fatality that can only be diagnosed by a family history or muscle biopsy. Occurs when every muscle in body starts moving, producing CO2, and generating heat increasing the overall body temperature?
Malignant hyperthermia
79
High flow rate of Sevoflurane is required to prevent what?
Compound A toxicity (compound A is degradation product of Sevo, shown to cause renal necrosis in rats
80
What is the disdavantage of oral medication dosing?
It is upredictable
81
Giving a drug via the floor of the mouth is equivalent to giving it through what other method?
via IV
82
What is the disadvantage of subcutaneous dosing?
slow absorption
83
Intrathecal is dosing where?
Into dural spaces
84
What is the disadvantage of intramuscular dosing?
1. Predictable
2. Titratable (small doses to patient until the patient is at the sedation level you desire)
3. IV allows possibility of quick dosing of reversal agents
85
What are 8 general IV agents?
1. Narcotics
2. Benzodiazepines
3. Barbiturates
4. Non-barbiturates Induction Agents
5. Ketamine
6. Anticholinergics
7. Reversal agents
8. Muscle relaxants
86
What stage do you want patients in for general anesthesia?
Stage 3
87
What stage do you NOT want patients in for general anesthesia?
Stage 2
88
What stage do you want to be in if you are on NO2?
Stage 1
89
What are two reasons to give narcotics?
1. Sedation
| 2. Analgesia
90
All narcotics are in what category of drugs?
Analgesics
91
Narcotics acting on Mu receptors cause what?
Analgesia
92
Narcotics acting on Kappa receptors cause what?
1. Analgesia
2. Nausea and vomiting
3. Dysphoria
4. Decreased motility (autonomic)
93
Narcotics acting on sigma receptors can cause what?
Dysphoria
94
All narcotics are___ and induce ____?
All narcotics are ADDICTING and induce TOLERANCE
95
Is the major effect of narcotics on the reaction to pain or perception of pain?
The reaction to pain
96
What are 3 things all narcotics cause?
1. Respiratory distress
2. Nausea
3. Constipation
97
Narcotics are indicated for treatment of what pain type: severe, sharp or constant dull?
Severe, sharp (e.g. not indicated for TMD patient)
98
What is the term for the need for increasing doses to get same effect of a narcotic?
Tolerance
99
What is the term for the onset of physiological symptoms following the removal or lack of a narcotic?
Withdrawal
100
What is the term for the physical need for repeated doses of narcotic to prevent withdrawal?
Dependence
101
What are the 3 divisions of narcotics?
1. Opiates
2. Synthetic opiates
3. Opiodes (synthetic compounds)
102
Morphine and codeine are what type of narcotics?
Opiates
103
Diluadid and Heroine are what type of narcotics?
Synthetic opiates
104
Fentanyl, Demerol, Alphaprodine are what type of narcotics?
Opioides
105
What is THE prototypical narcotic?
Morphine (opiate)
106
What is 1 symptom of narcotic use that does not have tolerance?
Meiosis (pupil constriction/pinpoint pupils)
107
What is a single dose of morphine?
2-13 mg, IV is shorter lasting (1-2 hrs) than IM (8 hrs)
108
Morphine is indicated in what patient?
Myocardial infarction patient due to minimal CVS effects when supine
109
Demerol (synthetic opiod) has an anticholinergic effect which means it will sedate WHICH autonomic system more: parasympathetic or sympathetic?
Parasympathetic because acetylcholine is the final transmitter in PNS, sympathetic takes over
110
What is the dosing of demerol?
50-100 mg IM
| 25-50 mg IV slowly
111
Demerol indicated when in surgery?
Postop analgesia
112
Which narcotic is 1000X stronger than morphine with a fast onset (3 min) and short duration (15-30 min IV)?
Fentanyl
113
What is the dosage of fentanyl?
1 microgram/kg or
| 50-100 mc (.05 mg-.1mg) not to exceed 100 mcg
114
What syndrome is associated with fentanyl dose exceeding 100 mcg, which makes them unable to ventilate?
Stiff chest syndrome
115
What class of drugs that are sedative hypnotics are used for relaxation and reduction of anxiety?
Benzodiazepines
116
What 2 systems to benzodiazepines act on?
1. Limbic system
| 2. Reticular activating system
117
Benzodiazepines increase what neurotransmitter in the limbic and reticular activating system?
GABA (inhibitory neurotransmitter)
118
What are 2 short-acting (2-5 hrs) benzodiazepines?
1. Midazolam (Versed)
| 2. Triazolam (Halcion)
119
What is 1 medium-acting (10-20 hrs) benzodiazepine?
Lazepam
120
What is 1 long-acting benzodiazepine?
Diazepam (Valium)
121
What is a benzodiazepine used for oral sedation?
Triazolam (Halcion) (short-acting 2-5 hrs)
122
What benzodiazepine is used for IV sedation?
Midazolam (Versed) (short-acting 2-5 hrs)
123
What is the "gold-standard" benzodiazepine?
Diazepam (Valium) (long-acting 20-80 hrs)
124
Benzodiazepines are good for what beyond sedation and anxiolysis?
1. Anticonvulsant
| 2. Muscle relaxant
125
Which is more potent: versed or valium?
Versed
126
Which has more pain on injection: versed or valium?
Valium because it is oil-soluble and therefore is mixed with propylene glycol which also risks thrombophlibitis
127
Which produces more anterograde amnesia: valium or versed?
Versed
128
Which produces more respiratory depression: valium or versed?
Versed
129
What are the only characteristics in which Valium exceeds Versed?
1. Risk of thrombophlibitis
| 2. Duration (Valium 8-24 hrs)
130
Valium and Versed are both metabolized into what?
An active metabolite
131
What is the active metabolite of benzodiazepam that can be given to liver patients to sedate them so as to not work the liver?
Oxazepam (Serax)
132
Barbiturates can be used as what type of agents?
1. Induction
| 2. Sedation
133
What is the principle method of action of barbiturates?
Redistributeion: goes to brain, puts to sleep, then goes to rest of body from the brain
134
What is the principle area of metabolism for barbiturates?
Liver at 20%/hr
135
What are 3 categories of barbiturates?
1. Ultra-short acting
2. Short acting
3. Long-acting
136
What is the site of action for barbiturates?
Reticular activating system
137
If you give a barbiturate, will the patient feel pain?
Yes
138
At low doses, barbiturates will cause the patient to do what?
Release inhibitions
139
What is the character of the solution of barbiturates?
High pH = caustic
140
What is acute intermittant porphyria, a contraindication for giving a barbiturate?
Can't break down the hemoglobin ring, causing CNS problems
141
What barbiturate used for induction in a GA case?
Thiopentol (Pentothal)
142
The barbiturate thiopental/pentothol can cause what?
Severe histamine release
143
What is the induction dose for barbiturate pentothol?
3-4 mg/kg
144
What is the standard solution for barbiturate methohexital (brevital)?
1% solution
145
What are the cardiac effects of the barbiturate methohexital?
1. Increased HR
2. Decreased total peripheral resistanct
3. Decreased BP
4. Level cardiac output due to the compensatory tachycardia
146
What is common with barbiturate methohexital (brevital)?
Hiccups
147
Can barbiturate methohexital (Brevital) affect laryngeal/pharyngeal reflexes?
Yes
148
Will barbiturate methohexital (Brevital) depress respiration?
Yes it is dose dependent
149
What non-barbiturate induction agent is short-acting (and was involved in Michael Jackson's death)?
Propofol
150
What is a consideration for propofol injection?
It burns (suspended in soybean fat). Consider giving lidocaine.
151
What depresses with non-barbiturate induction agent propofol?
1. Tidal volume decreases for 4 minutes
2. BP decreases 25%
3. Cardiac output decreases
152
What is a non-narcotic, non-barbiturate, rapid-acting induction or sedative agent that gives profound analgesia (and the patient does not appear asleep)?
Ketamine
153
Ketamine does what to CVS and CNS?
1. Stimulates CVS increasing HR and BP
| 2. Stimulates CNS
154
Why does a patient on ketamine patient appear to be awake?
It is a dissociative anesthetic
155
Why is the fact that ketamine is a cardiac stimulant a consideration?
Consider for trauma with high blood loss: do not want to desate with barbiturate as those will decrease BP
156
What are 2 patients that ketamine is contraindicated in?
1. Epileptic
| 2. High blood pressure
157
Why is ketamine better for children and not adults?
Adults can have hallucinations
158
Anticholinergics can be used as what agents?
1. Antisialologue
| 2. Positive chronotrope (increased HR)
159
Anticholinergices inhibit what system and why?
Parasympathetic because the postganglionic transmitter is acetylcholine
160
Anticholinergics allow which system to take over and exert its effects?
Sympathetic
161
What are 2 anticholinergics (things that will increase the sympathetic nervous system by inhibiting the parasympathetic nervous system)?
1. Atropine
| 2. Robinol (glycopyrrolate)
162
Atropine, an anticholinergive, is given to adults for what reason?
Antisialolgue
163
Atropine, an anticholinergic, given to children for what reason?
Increased HR
164
What is the dosage of atropine (anticholinergic)?
0.4-1.0mg
165
Robinul (glycopyrrolate) (anticholinergic) is stronger/weaker than atropine and what is the dose?
1. Stronger (increased drying and HR)
| 2. Does is 1/2 atropine (i.e. 0.2-0.5 mg)
166
Drugs that reverse the effects of other drugs and are used in emergencies or for emergence (from sedation)?
Antagonists
167
What narcotic is a pure antagonist (the only pure antagonist in clinical use)?
Narcan/Naloxone
168
If you give a narcotic antagonist (Narcan/naloxone) to a patient with no narcotic on board, will there be an effect?
No
169
What is the dosage of narcan/naloxone?
0.4mg
170
What is a narcotic antagonist that is a mixed agnoist-antagonist?
Pentazocine (Talwin)
171
What are the primary bad effects of narcotics?
Respiratory depression
172
What is an ER patient given who is unconscious for an unknown reason?
Naloxone (Narcotic reversal agent)
173
What is a reversal agent for most benzodiazepines?
Flumazenil (Romazicon)
174
Will Flumazenil (benzodiazepine reversal agent) work on narcotics, barbiturates, or ethanol?
No
175
If a patient is addicted to benzodiazepines (valium, versed), what will flumazenil dose trigger?
Withdrawal symptoms and seizures
176
Will flumazenil reverse both the sedative and respiratory depression of benzodiazepines or just one of these?
Just sedation, will not reverse respiratory depression
177
Muscle relaxants paralyze what muscles?
Skeletal
178
Depolarizing muscle relaxant acts how?
Acetylcholine analogue attaches to skeletal motor end plate, causing it to depolarize
179
How will a patient act when given a depolarizing muscle relaxant?
Twitch (depolarization) then go flaccid
180
What is an example of a depolarizing agent?
Succinylcholine
181
What is the duration and the reason for use of a depolarizing muscle relaxant succinylcholine?
5 minute duration
| Paralyze vocal cords to put in endotracheal tube
182
Repeated doses of the depolarizing muscle relaxant succinylcholine will cause what?
Bradycardia
183
How do non-depolarizing muscle relaxants work?
Block the motor end plate so no acetylcholine can activate them
184
List the non-depolarizing muscle relaxants from shortest to longest-acting.
Mivacurium < Atracurium < Rocuronium < Vecuronium < Pancuronium
185
Non-depolarizing muscle relaxants can be reversed with what?
Neostigmine (acetylcholinesterase inhibitor)
186
What was the first muscle relaxant (derived from poison dart frogs)?
Curare (note that all the non-depolarizers have tha in the middle of their name)
187
What are the advantages and disadvantages of using the antecubital fossa for IV?
A large vein better for caustic drug admin (e.g. barbiturates) Disadv for long term IV
188
What are some vital sign monitors for sedation/GA?
```
BP
O2 saturation
CO2
ECG
Temperature
```
189
Is there a certain amount of a drug that always corresponds to every level of sedation every time?
No
190
When doing sedation, what should you always plan for?
To get deeper than expected (patient unable to breathe for themselves)
191
What is the level of sedation where the patient is awake and responsive?
Conscious sedation/light-moderate IV sedation
192
What is the cocktail normally used for conscious sedation?
Benzodiazepine +/- narcotic
193
Why would fentanyl be preferred as the narcotic in conscious sedation over demerol?
Because Demerol has anticholinergic effects, raising the HR and lasting longer
194
What type of sedation may result in the patient not being able to respond to commands but they should be able to maintain their own airway?
Deep IV sedation
195
What is the cocktail for deep IV sedation?
1. Heavy dose benzodiazepine
2. Heavier dose of narcotic
3. Small dose barbiturate or propofol
196
Why is the barbiturate or propyphol given for a deep IV sedation?
To get the patient to sleep
197
What type of sedation results in the patient being unresponsive and unable to maintain his or her own airway and a loss of protective reflexes?
General anesthesia
198
What is the cocktail for GA?
5mg Midozalam (Benzodiazepine)
100 mcg Fentanyl (Narcotic)
30 mg propofol or Brevital (barbiturate) to induce, then give bolus of propofol every 5 min
199
When planning Laryngeal Mask Airway (LMA) anesthesia, what can be inhaled to aide while placing the LMA?
Sevoflurane 3-4 MAC, then maintain with 1-1.5 MAC
200
Is airway security absolute with LMA even if you can ventilate?
No
