Anesthesia Midterm Flashcards
1
Q
________ monitors tell us if we are ventilating a patient, while ________ monitors tells us if we are perfusing the patient.
A
CO2; O2 saturation
2
Q
In the OR which monitor will be the first indicator that the patient is not breathing?
A
CO2 monitor. Oxygen levels can remain high for a while before saturation falls but CO2 monitor will show an instantaneous change.
3
Q
Phenylephrine acts on ____ receptors.
A
Phenylephrine is an alpha adrenergic agonist
4
Q
Does phenylephrine cause venous or arterial constriction?
A
Both but mostly venous.
5
Q
Is phenylephrine more or less potent than norepinephrine?
A
Less potent
6
Q
Does phenylephrine last longer or shorter than norepinephrine?
A
Longer lasting
7
Q
Is phenylephrine a direct acting or indirect acting drug?
A
Phenylephrine acts directly on the alpha receptors of blood vessels.
8
Q
What is the typical dose of IV push phenylephrine?
A
50-200mcg
9
Q
What is the typical dose of IV infusion phenylephrine?
A
20-50mcg/min
10
Q
What is the effect of phenylephrine on MAP?
A
increase
11
Q
What is the effect of phenylephrine on SBP?
A
increase
12
Q
What is the effect of phenylephrine on DBP?
A
increase
13
Q
What is the effect of phenylephrine on SVR?
A
increase
14
Q
What is the effect of phenylephrine on HR?
A
decrease, due to baroreceptor response to increase in BP.
15
Q
Why would phenylephrine decrease HR?
A
baroreceptor reflex responding to increase in BP.
16
Q
What is the effect of phenylephrine on CO?
A
decrease. With higher SVR and decreased HR. CO will decrease with phenylephrine.
17
Q
How is phenylephrine in the OR prepared?
A
By double dilution method in a 10mL syringe. or in a 100mL bag.
18
Q
When we use phenylephrine or any drug that increases SVR and afterload, what should we immediately be concerned about?
A
Cardiac Output and afterload on the left ventricle.
19
Q
Is phenylephrine a catecholamine?
A
No, Epinephrine, dopamine and Norepinephrine are the most abundant catecholamines in humans.
20
Q
Is phenylephrine naturally occurring or synthetic?
A
Synthetic
21
Q
Which patients would you be most concerned about increasing SVR and afterload on?
A
Patients with bad hearts. Or any patient over the age of 65, just assume they have some CAD.
22
Q
Is ephedrine a catecholamine?
A
No, epinephrine, dopamine and norepinephrine are the most abundant catecholamines in humans.
23
Q
Which patients would phenylephrine be best for?
A
patients with healthy hearts, with hypotension and high HR. Phenylephrine is good for short term use.
24
Q
Is ephedrine synthetic or natural?
A
synthetic
25
Is ephedrine direct acting or indirect acting?
indirect acting
26
What does indirect acting mean, in regards to ephedrine?
Ephedrine acts on the storage vesicles of the neurotransmitters epinephrine and norepinephrine. it causes the body to release them into the bloodstream causing both alpha and beta effects.
27
Does ephedrine act on alpha or beta receptors?
Both. By causing the release of the bodies natural stores of NE and epi, both beta and alpha receptors will be affected.
28
What is the typical dose of ephedrine?
5-25mg
29
Is ephedrine given IV or IM?
either way.
30
What is ephedrine used to treat?
hypotension in the OR for various reasons.
31
Can ephedrine be used in OB anesthesia?
Yes
32
Can phenylephrine be used in OB anesthesia?
Yes... but this is a new idea. For purposes of boards and questions answer NO.
33
Ephedrine has both alpha and beta effects but which one does it effect more?
B1
34
Ephedrine has CV effects similar to Epinephrine but is 10x (longer acting or shorter acting)
10x longer acting
35
Does ephedrine affect SVR?
minimally
36
The CV effects of ephedrine are mostly due to?
increased contractility
37
What effect does ephedrine have on MAP?
increase
38
What effect does ephedrine have on SBP?
increase
39
What effect does ephedrine have on DBP?
increase
40
What effect does ephedrine have on HR?
increase
41
What effect does ephedrine have on coronary blood flow?
increase
42
What effect does ephedrine have on renal and splanchic blood flow?
decrease
43
What is a good indicator that CO has dropped?
Urine output will decrease
44
What is tachyphylaxis?
When a patient becomes tolerant of a drug requiring higher and higher doses to achieve the same effect.
45
Does ephedrine cause tachyphylaxis?
yes. Due to indirect effect and occupying of receptors.
46
Which gives you more predictable results: phenylephrine or ephedrine?
phenylephrine- because it acts directly on alpha receptors. ephedrine acts on vesicles with varying amounts of epi and norepinephrine stored in them so you get varying results.
47
Would an elderly patient tend to be more responsive or less responsive to ephedrine?
less. Because their stores of NE and epi are likely less due to aging.
48
Would a trauma patient tend to me more or less responsive to ephedrine?
less. Due to the fight or flight response after suffering a trauma, the NE and epi stores are depleted which would cause ephedrine to be less effective.
49
Would patients on tricyclic antidepressants be more or less responsive to ephedrine?
more! They have huge stores of NE and epi and may get into a situation of hypertensive crisis. Do not use ephedrine on patients on either of these two drugs.
50
Does ephedrine cause increased inotrophy or increased chrontrophy?
both. Because it is indirect it will affect both.
51
What class of drug is atropine?
anticholinergic
52
What is another way to think of anticholinergics?
As antiparasympathetics.
53
How does atropine work?
It antagonizes the effect of acetylcholine at the cholinergic, post-ganglionic muscarinic receptors.
54
Name 4 areas that house muscarinic receptors?
Heart, salivary glands, smooth muscles of GI, smooth muscles of GU.
55
does atropine have any effect on nicotinic receptors?
no, or minimal effect.
56
Where are nicotinic receptors found?
more in neuromuscular junction
57
Is atropine synthetic?
no, atropine is naturally occurring
58
Atropine is a _________ amine, and it\_\_\_\_\_\_\_\_ (does, does not) cross the blood- brain barrier.
tertiary; does
59
Atropine is an alkaloid of __________ plant.
belladonna
60
What is the effect of belladonna and atropine on the pupils?
dilate (midriasis)
61
Atropine resembles _________ in structure.
cocaine
62
Does atropine have any analgesic effect?
yes, mild.
63
Does atropine cross the blood-brain barrier?
Yes.because it is a tertiary amine.
64
What is the neurological effect of atropine?
it binds to muscarinic receptors in the brain and can cause confusion, especially in the elderly. It can act as a mild sedative. It can also cause central anticholinergic syndrome which is a combination of sedation, nervousness, confusion, hallucinations, delerium and coma.
65
Is atropine a competitive inhibitor?
Yes. atropine combines reversibly with muscarinic receptors and prevents acH from binding to these sites.
66
How many muscarinic receptor subtypes are there?
5
67
Where are M1 receptors found?
CNS and stomach
68
Where are M2 receptors found?
Lungs and heart
69
Where are M3 receptors found?
CNS, airway smooth muscle, glandular tissue
70
Where are M4 and M5 receptors found?
CNS
71
What is the drug of choice for treating intraoperative bradycardia?
Atropine
72
What is the typical dose of atropine used in the OR?
15-75mcg/kg or 0.4mg-1mg
73
What is the effect of atropine on airway secretions?
It is an antisialagogue, it dries up secretions. But we don't typically use atropine for this in the OR. Robinol is more commonly used for drying secretions.
74
What is atropine's effects on the bronchioles?
bronchodilation
75
What is atropine's effect on the pupils?
midriasis (dilates)
76
What is atropine's effect on GI motility and acid production?
decreases
77
What is atropine's effects on CNS?
mild sedation (not a therapeutic sedative though) and confusion, especially in the elderly.
78
Why is it important to dry secretions in anesthesia?
Secretions can cause laryngospasms
79
Name this structure.
Atropine
80
Name this structure.
Cocaine
81
What type of drug is glycopyrrolate?
Anticholinergic
82
The trade name for glycopyrrolate is:\_\_\_\_\_\_\_\_
Robinol
83
Glycopyrrolate is a ________ amine.
Quaternary
84
Does glycopyrrolate cross the blood-brain barrier?
No. so it has no CNS or sedative effects. It is a quarternary amine.
85
In elderly patients, which would be the better drug to use for bradycardia?
Glycopyrrolate (because of less post-op confusion) unless the HR it tanking, then go for the atropine.
86
Which is a more potent antisialagogue: atropine or glycopyrrolate?
glycopyrrolate
87
Which has more potent effect on HR: atropine or glycopyrrolate?
atropine
88
What is the typical dose of glycopyrrolate?
0.2-0.4mg IV
89
How is glycopyrrolate supplied and does it require dilution?
It is supplied in 0.2mg/mL vials. It does not require dilution.
90
What are the 2 other common uses of glycopyrrolate?
In combination with anticholinesterases to reverse neuromuscular blockade and to dry secretions
91
Name a common anticholinesterase?
Neostigmine
92
What is the typical dose of glycopyrrolate used for reversal of neuromuscular blockade?
0.005-0.007mg/ kg or 1cc of robinol for each 1cc of reversal
93
Why do we bother giving glycopyrrolate with anticholinesterases to reverse neuromuscular blockade?
anticholinesterases are not selective for nicotinic receptors, they also affect acetylcholine muscarinic receptors which could slow down the HR enough to cause asystole. Because of this effect on muscarinic receptors anticholinesterases could also cause lacrimation and salivation, etc.
94
Why is glycopyrrolate prefered over atropine to use in combination with anticholinesterases when reversing neuromuscular blockade?
Glycopyrrolate and anticholinesterases last about the same amount of time so you don't end up with one's effect lasting longer or shorter than the other.
95
What type of drug is Succinylcholine?
A depolarizing muscle relaxant
96
When you hear stridor, either after extubation or around the LMA, what is the first thing you should suspect?
Laryngospasm
97
What is the first thing you should do to try to break laryngospasm?
Give large breaths with PPV with large pressures: 50- 60 mmHg pressures.
98
If giving PPV with large pressures doesn't break laryngospasm, what is the drug of choice and what is the dose?
20mg - 40mg (adult dose) of Succinylcholine
99
How is Succinylcholine different from Rocuronium or Vecuronium?
Succinylcholine is a depolarizing muscle relaxant. It is the only one in it's class. The others are not depolarizers.
100
What are some common complaints of patients after receiving Succinylcholine?
muscle aches or spasms
101
How does Succinylcholine work?
It attaches to each of the alpha subunits of the nicotinic cholinergic receptor and mimics the action of acetylcholine, depolarizing the post-junctional membrane. Hydrolysis of Succinylcholine is slower than acetylcholine so it maintains a sustained depolarization thereby inhibiting another action potential with acetylcholine, causing paralysis.
102
What substance clears succinylcholine from the neruomuscular junction?
pseudocholinesterases
103
Is there any reversal agent for succinylcholine?
No, it just takes time to be processed.
104
Some patients have a genetic abnormality affecting the way they metabolize succinylcholine. The test to confirm this assigns them a ________ number.
dibucaine
105
A dibucaine number of 20 would mean what for the patient?
They cannot break down succinylcholine
106
A dibucaine number of 40-50 would mean what for the patient?
That they can break down succinylcholine but they will break it down very slowly.
107
What is the typical dose of succinylcholine used for intubation (not the dose for laryngospasm)?
0.5- 1.5 mg/ kg (commonly 1mg/kg)
108
Is succinylcholine given IV or IM?
either
109
What is the onset of action for succinylcholine?
30-60 seconds
110
What is the duration of action for succinylcholine?
3-5 minutes
111
Name 8 side effects you might see with succinylcholine?
1. dysrhythmias (bradycardia, asystole, nodal junctional rhythms, ventricular dysrhythmias) 2. hyperkalemia (due to muscle spasm) 3. Fasiculations and myalgias 4. increased GI pressure (emesis) 5. Increases ICP 6. Increased IOP 7. Masseter spasm 8. Histamine release.
112
What drug has been implicated as a potential triggering agent for malignant hypertension?
succinylcholine
113
How long does a laryngospasm dose of succinylcholine typically last?
about 2 minutes
114
What class of drug is Labetalol?
a non-selective beta blocker as well as alpha blocker
115
Does labetalol provide more beta or alpha blockade?
More beta blockade at a ratio of about 7:1
116
What is the usual IV dose of labetalol?
0.25 mg/kg
117
How frequently can you repeat doses of labetalol?
q 10 minutes
118
What is the typical bolus dose of labetalol?
10mg
119
What is the duration of action of labetolol?
2-18 hours. Genetics plays a role in how people break down labetalol, hence the wide range.
120
What two things should you be acutely aware of before giving labetalol?
1. making sure the patient has an adequate HR, and 2. know if the patient is an asthmatic. Do not give labetalol to asthmatics.
121
What kind of increments should you give repeat dose of labetalol in?
give repeat doses in 2.5-5mg increments.
122
What type of drug is esmolol?
Beta 1 selective (at small doses)
123
What is the onset of action of esmolol?
2 minutes
124
What is the half- life of esmolol?
about 9 minutes
125
How is esmolol metabolized?
by non-specific plasma esterases found in the cytosol of RBCs
126
What is the IV bolus/ loading dose of esmolol?
500mcg/kg
127
In the OR, what is the typical dose of esmolol?
10-15 mg, then dose according to response.
128
What are the 4 main rescue drugs you should have available for every case?
Succinylcholine, Atropine, Ephedrine, and Phenylephrine
129
In addition to the emergency drugs you draw up, you should always have bristojets of what 4 drugs inside your cart?
Lidocaine, Epinephrine, Atropine and Calcium Chloride.
130
If your patient is hypotensive but tachycardic, which drug is preferred for treatment of BP: phenylephrine or ephedrine?
phenylephrine
131
If your asthmatic patient suddenly has hypertension in the OR, which drug would you use: labetalol or esmolol?
esmolol. Labetalol is contraindicated in asthmatics due to the risk of bronchospasm.
132
What other beta- blocker that is similar to esmolol,( in that it is beta 1 selective at low doses), can be used to treat hypertension?
metoprolol 2.5-5mg IV
133
If your elderly patient with heart disease becomes bradycardic in the OR, which drug would you use first: ephedrine or atropine?
ephedrine.
134
The upper airway is divided into the:
nasal passages and the oral cavity
135
The nasal passages include which 3 structures?
septum, turbinates, and adenoids
136
What function do the nasal passages serve?
humidification, filters, warms
137
The teeth, tongue, hard palate, and soft palate belong to which division of the upper airway?
Oral cavity
138
The pharynx is the area between which two structures?
the nose to the cricoid cartilige
139
The pharynx is divided into which 3 regions.
nasopharynx, oropharynx, and laryngopharynx
140
Region 1. of pharynx is the:
Nasopharynx
141
Region 2 of the pharynx is the:
Oropharynx
142
Region 3 of the pharynx is the:
laryngopharynx
143
Which region of the pharynx separates at the soft palate?
nasopharynx
144
which section of the pharynx contains the tonsils, uvula, and epiglottis?
oropharynx
145
Identify the regions of the larynx.
1. Tongue 2. Epiglottis 3. Vocal Cords 4. Trachea 5. Esophagus
146
Identify the 9 areas of the airway
1. Nasopharynx 2. Oropharynx 3. Tongue 4. Epiglottis 5. Laryngopharynx 6.Vocal cord 7. Larynx 8. Trachea 9. Esophagus
147
At which level of the spinal colum is the larynx in the adult?
C3-C6
148
What are the 3 functions of the larynx?
airway protection, respiration, and phonation.
149
Name the muscles and ligaments of the larynx. (4)
Thyroid, Cricoid, Arytenoids, epiglottis
150
The vocal cords are easily distinguished because they appear:
pearly white
151
Where do the vocal cords atttach anteriorly?
to the angles of the thyroid
152
Where do the vocal cords attach posteriorly?
to the arytenoids
153
Identify the areas of the larynx
1. Superior horn of the thryroid cartilige. 2. Cricoid cartilige 3. Corniculate cartilige 4. arytenoid cartilige 5. vocal ligament 6. thyroid cartilige 7. cricoid cartilige (completion of signet ring) 8. Glottis
154
what do you call the triangular fissure between the vocal cords?
the glottic opening
155
What is the narrowest portion of the adult airway?
glottic opening
156
Which number represents the glottic opening? What are the other 2?
Number 2 is the glottic opening. 1. epiglottis. 3. vocal cords
157
How many cartiliges make up the larynx?
9 There are 3 paired and 3 unpaired
158
Name the 3 paired cartiliges of the larynx.
arytenoid, corniculate, and cuneiform
159
Name the 3 unpaired cartiliges of the larynx.
thryoid, cricoid, and epiglottis
160
Identify these 2 sets of paired cartiliges of the larynx
1. cuneiform tubercle 2. corniculate tubercle
161
Identify this pair of cartiliges of the larynx
arytenoids
162
Identify this cartilige of the larynx.
Cricoid
163
What is the narrowest part of the pediatric airway?
the cricoid
164
the laryngeal muscles are divided into 2 subsets:
intrinsic and extrinsic
165
What is the difference between the intinsic and extrinsic laryngeal muscles?
intrinsic are involved with movements of the laryngeal parts (making alterations to length and tension of the vocal cords, size and shape) extrinsic are involved with moving the larynx as a whole.
166
All intrinsic muscles of the larynx are innvervated by the _______________ except for the cricothryoid muscle, which is supplied by the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
recurrent laryngeal nerve; external branch of the superior laryngeal nerve
167
The recurrent laryngeal nerve is a branch of which cranial nerve?
X- Vagus
168
The intrinsic laryngeal muscles are further divided into these two groups:
those that open and close the glottis and those that put tension on the vocal ligaments
169
Which 3 larygeal intrinsic muscles are responsible for opening and closing the glottis?
1. lateral cricoarytenoid- adducts 2. arytenoids- adduct 3. posterior cricoarytenoids- ABduct.
170
The only vocal cord abductor is the:
posterior cricoarytenoid
171
The 3 intrinsic laryngeal muscles that put tension on the vocal ligaments are:
1. cricothryroid- elongates vocal cords 2. vocalis- shortens vocal cords 3. thryroarytenoid- shortens and relaxes the vocal cords.
172
The 4 extrinsic laryngeal muscles are:
1. Sternohyoid, 2. thryohyoid, and 3. omohyoid (these move hyoid bone caudad) and 4. Sternothyroid (moves thryoid cartilige caudad)
173
The trachea, carina, bronchi, bronchioles, terminal bronchioles, respiratory bronchioles, and alveoli make up the:
Lower airway
174
The _________ is the bifurcation of the main bronchus. It occurs at level\_\_\_\_\_\_\_ of the spinal column.
carina; T4
175
After the carina, the angle of the r. bronchus is:\_\_\_\_\_\_\_\_\_\_\_ and the angle of the l. bronchus is:\_\_\_\_\_\_\_\_\_. If the ETT is passed too far, it is more likely to end up in the _____ mainstem bronchus.
right- 25 degrees. left- 45 degrees. It is easier to slip too far in the right mainstem.
176
The two main methods of classifying an airway and identifying a difficult airway are by the:\_\_\_\_\_\_\_\_\_ and \_\_\_\_\_\_\_\_\_
Mallampati score and the Thyromental distance
177
What is Mallampati's hypothesis?
When the base of the tongue is disproportionately large, the tongue overshadows the larynx resulting in difficult exosure of the vocal cords during laryngoscopy.
178
When assessing for Mallampati score, what position should the patient be in?
Sitting upright, head neutral, mouth open as wide as possible and tongue protruding. Do not say AHHHH.
179
Which Mallampati class would this airway fall into?
Class 1, faucil pillars, soft palate and uvula all clearly visible.
180
Which Mallampati class would this airway fall into?
Class II. Uvula is masked by tongue.
181
Which Mallampati class would this airway fall into?
Class III. Soft palate visible but only base of uvula.
182
Which Mallampati class would this airway fall into?
Class IV. only hard palate seen.
183
This is the expected laryngeal view for which Mallampati class?
Class I
184
This is the expected laryngeal view for which Mallampati class?
Class II
185
This is the expected laryngeal view for which Mallampati class?
Class III
186
This is the expected laryngeal view for which Mallampati class?
Class IV
187
What is meant by thryromental distance and what is the normal measurement?
Thyromental distance is the distance from the lower mandible to the thyroid notch with the neck fully extended. Normal is 6-6.5cm (about 4 fingerbreadths).
188
At what thyromental distance would a patient be considered a difficult intubation?
less than 3 fingerbreadths, or a receding mandible.
189
What is the optimal intubating position for the patient?
The sniffing position. Because it aligns the oral axis with both the pharyngeal axis and the laryngeal axis.
190
What is the goal of preoxygenating the patient prior to intubation?
To increase O2 and decrease the nitrogen in the functional residual capacity
191
If a patient is breathing room air, what is the typical percentage of Nitrogen in the alveolus?
79%, by giving a patient 100% O2, we can wash out that nitrogen and occupy it's space with Oxygen.
192
3-5 minutes of tight mask fit normal tidal breathing of 100% O2 at greater than 5Lpm flow should give you ________ minutes of apnea in a healthy patient.
up to 10 minutes
193
Even in an emergency, giving 4 vital capacity breaths of 100% O2 in 30 seconds should give you __________ minutes of apnea in a healthy patient.
up to 5
194
Name the starred area.
Vallecula
195
Name 3 major complications that oral airways can cause.
laryngospasm, soft tissue damage, and bleeding
196
What are the complications of nasal airways (trumpets)?
epistaxis, tissue damage. Use cautiously in epistaxis, nasal or basal skull fractures, adenoid hypertrophy and in patients on anticoagulants.
197
What is the desirable position for ETT placement in the airway?
about 4cm above the carina and 2cm below the cords
198
What are the 2 ideal sizes of ETT for females?
6.5 or 7.0
199
What are the 2 ideal sizes of ETT for males?
7.5 and 8.0
200
How many cm down does the ETT typically go for males and for females?
Males: about 23cm. Females: about 21cm.
201
Which 3 nerves provide sensory innervation to the airway?
glossopharygeal, internal branch of the superior laryngeal, and the recurrent laryngeal nerve.
202
Which 2 nerves provide motor innervation to the airway?
external branch of the superior laryngeal and the recurrent laryngeal.
203
Name the airway nerves.
1. Superior laryngeal 2. Internal laryngeal 3. External laryngeal 4. Recurrent laryngeal
204
Name the nerve that supplies each area.
Blue: Trigeminal Yellow: Glossopharyngeal Pink: Vagus
205
Which nerve supplies the posterior 1/3 of the tongue and oropharynx to vallecula?
Glossopharyngeal CN IX
206
Which nerve supplies sensory innervation to the vocal cords and above?
Internal superior laryngeal (branch of vagus)
207
Which nerve supplies sensory innervation to the mucosa below the vocal cords?
recurrent laryngeal (branch of Vagus)
208
Which nerve supplies motor innervation to the cricothyroid muscle? hint:puts tension on the vocal cords.
External branch of the superior laryngeal
209
Which nerve provides motor innervation to all of the intrinsic muscles of the larynx except for the cricothyroid?
recurrent laryngeal
210
Name the nerves.
1. Mandibular division of the trigeminal nerve 2. Glossopharyngeal nerve 3. Superior laryngeal nerve 4. Recurrent laryngeal nerve
211
Name the areas.
1. Superior laryngeal nerve 2. Vagus nerve 3. Thryoid cartilige 4. left recurrent laryngeal nerve 5. aortic arch
212
What are some of potential cardiovascular responses to layrngoscopy and intubation?
hypertension, tachycardia, myocardial ischemia.
213
What are some potential respiratory responses to laryngoscopy and intubation?
bronchospasm and laryngospasm
214
What are some things you can do prior to laryngoscopy and intubation to decrease risk of cardiovascular and respiratory responses?
give inhaled nitrous oxide, narcotics, prophylactic bronchodilator, effective topical, airway blocks.
215
Name the 15 steps of the induction sequence.
1. preoxygenate 2. position (sniffing) 3.monitors 4. Induction agent 5. Test ventilation 6. Train of 4 working 7. Paralytic drug 8. Tape eyes 9. Bag/ mask ventilation until loss of twitches 10. laryngoscopy 11. intubation 12. Confirm ETT placement 13. Ventilator 14. Maintenance anesthetic 15. Tape ETT
216
What are the two blocks used to block the airway for awake intubation?
Transtracheal and Superior laryngeal nerve block
217
For what procedures would you perform a transtracheal block?
awake laryngoscopy, awake intubation
218
What are the effects of the transtracheal block?
abolition of gag reflex or hemodynamic responses to layrngoscopy or bronchoscopy. Provides anesthesia below the cords.
219
Which nerve is blocked by the transtracheal block?
recurrent laryngeal
220
What drugs are used in transtracheal blocks?
Lidocaine 4% (3-5mL) most often. But 1%-2% lidocaine with our without epi can also be used.
221
What are the steps to the transtracheal block.
1. locate cricothyroid membrane. 2. clean site 3. raise a skin wheal (optional) 4. place 20 gauge or smaller (23 gauge butterfly) through membrane with syringe of anesthetic attached, continually aspirating as you advance. 5. Once air bubble aspirated you are in the airway. 6. Have the patient take a deep breath 7. Inject quickly and withdraw Warning: this will cause the patient to cough to use caution to prevent needlestick injury
222
Transtracheal blocks should not be used in patients with increased ICP. Why?
Transtracheal blocks will cause coughing. They should be avoided in any patient in whom coughing is undesirable.
223
What does the superior laryngeal nerve block do?
Blocks the internal (sensory) branch of the superior laryngeal nerve. It blocks the supraglottic region. Essentially, the area above the cords.
224
What is the result of a superior laryngeal nerve block?
aboolition of gag reflex or hemodynamic resonses to laryngoscopy or bronchoscopy.
225
What drug is used in a superior laryngeal nerve block?
2-4mL of lidocaine 1% or 2%
226
What position should the patient be in for a superior laryngeal nerve block?
Supine, with neck extended
227
Identify these areas.
1. Superior laryngeal nerve 2. Greater cornu of the hyoid bone 3. Internal laryngeal nerve 4. Hyoid bone 5.Thyrohyoid membrane 6. Thyroid cartilige 7. Cricoid cartilige 8. Recurrent laryngeal nerve
228
What are the steps to the Superior Laryngeal nerve block?
1. Palpate hyoid bone 2. displace the hyoid toward the side to be blocked. 3. Using a 23ga 2.5cm needle inserted perpendiucular to skin 1/4 inch caudad and 1/4 medial to inferior border of the cornu (if you hit bone you can walk off the cornu inferiorly) 4. You will feel a slight loss of resistance when you pass through the thyrohyoid membrane 5. At this point aspirate to confirm no air or blood. 6. Inject 1-2mL of local 7. withdraw needle to just outside the thyrohyoid membrane and inject an additional 1mL of local here.
229
How is phenylephrine supplied?
1% solution. 10mg/mL
230
Should you use NS or D5W when double diluting phenylephrine?
you can use either
231
What is the final concentration of phenylephrine after double dilution?
100mcg/mL
232
What is the onset of phenylephrine?
immediate
233
What is the duration of action of phenylephrine?
5-20 minutes
234
how is phenylephrine metabolized?
hepatic
235
Name 5 effects of ephedrine.
increases systolic and diastolic BP, vasoconstriction, increased myocardial contractility, increased HR, bronchodilation. Ephedrine causes minimal change to SVR.
236
What 2 drugs require dilution?
ephedrine and phenylephrine
237
How is ephedrine supplied?
25mg/mL vial or 50mg/mL vial
238
Name 7 effects of atropine
1. increase HR 2. decrease salivary, bronchial, gastric secretions 3. relaxes bronchial smooth muscles 4. reduced GI tone and motility 5. decreases lower esophageal sphincter pressures 6. midriasis 7. urinary retention
239
What is Central Anticholinergic Syndrome?
Severe CNS effects as a result of anticholinergic. Sedation, nervousness, confusion, hallucinations, delirium, and coma
240
How is atropine supplied?
0.05mg/mL, 0.1mg/mL, 0.3mg/mL, 0.4mg/mL, 0.5mg/mL, 0.8mg/mL, 1mg/mL
241
What is the onset of action of atropine?
immediate
242
What is the duration of action of atropine?
1-2 hours
243
How is atropine metabolized?
50-70% hepatic
244
Can atropine cause bradycardia?
Yes. If given at very low doses, atropine can have a paradoxical effect and cause bradycardia.
245
What is the basic structure of succinylcholine?
basically 2 Ach molecules stuck together. So it mimics acH at the postsynaptic membrane (nicotinic receptors) of the neuromuscular junction
246
How is succinylcholine supplied?
20mg/mL
247
When is a glossopharyngeal nerve block used?
to abolish gag reflex or hemodynamic resoonse to laryngoscopy when topical application is not effective.
248
What branch does the glossopharyngeal nerve block affect?
the lingual branch of the glossopharyngeal nerve which supplies sensory innervation to the back of the tongue.
249
What is the procedure for blocking the glossopharyngeal nerve?
1. Move tongue to opposite side of the mouth with a tongue blade 2. Insert 25ga spinal needle at the base of the palatoglossal arch 0.5cm deep and 0.5cm lateral to the tongue base 3. Aspirate before injecting 1cc- 2cc of 2% lidocaine. If you hit air, you are too deep. If you get blood, withdraw and redirect needle medially.
250
How many vertebral curves are there and where do they occur?
There are 2 verterbral curves. The high curve is concave and runs from C5-L3 The low curve is convex and runs from T5-S2.
251
Why is important to be aware of the spinal curves when administering epidural and spinal blocks?
anesthetic tends to pool in the curves.
252
Name the 5 ligaments that stabilize the vertebral column.
1. Supraspinous 2. Interspinous 3. Ligamentum flavum 4. Longitudinal 5. Ligamentum nuchae
253
Which ligament of the spine is known as the yellow ligament?
ligamentum flavum
254
How much of the spinal column contains ligamentum flavum?
it runs from the foramen magnum to the sacral hiatus
255
Label the layers.
1. Supraspinous ligament 2. Interspinous ligament 3. Ligamentum flavum 4. Epidural fat 5. Dura Mater 6. Arachnoid 7. Pia Mater 8. Spinal cord
256
How many cervical vertebrae, thoracic vertebrae, lumbar vertebrae, sacral vertebrae, and coccygeal vertebrae are there?
7, 12, 5, 5 (fused), 4 (fused)
257
Does the curvature of the spine affect the distribution of the anesthetic in a spinal or epidural block?
Yes. Local anesthetic will pool in the curves of the spine.
258
At what level does the spinal cord terminate?
L1- L2
259
How many pairs of spinal nerves are there?
31
260
The portion of the spinal cord that gives rise to all of the rootlets of a single spinal nerve is called a \_\_\_\_\_\_\_\_\_\_\_\_.
segment
261
A ___________ is the skin area innervated by a spinal nerve and its segment.
dermatome
262
Which has the slower onset, spinal or epidural?
epidural
263
Which level spinal nerve provides cutaneous distribution at the nipple level?
T4
264
Which level spinal nerve provides cutaneous innervation to the xiphoid level?
T6
265
Which level spinal nerve provides cutaneous innervation at the last rib level?
T8
266
Which level spinal nerve provides cutaneous innervation at the level of the umbilicus?
T10
267
What is the volume of CSF in the subarachnoid space at any given time?
150cc
268
What is the specific gravity of CSF?
1.004-1.008
269
If the patient feels numbness or tingling in their pinkie finger, how high do we suspect our spinal/ epidural block is?
C8
270
If the patient feels numbness or tingling at the middle finger, how high do we suspect our spinal/ epidural block is?
C7
271
If our patient feels numbness or tingling in the pointer finger or thumb, how high do we suspect our spinal/ epidural block is?
C6
272
Why is it concerning if the patient is feeling numbness in the hand or hands after spinal/epidural block?
The block is creeping up dangerously close to the phrenic nerve!
273
What's the first thing you can do if you fear your spinal/ epidural block is creeping up too high?
Raise the head of the bed, let gravity drag the anesthetic back down.
274
In what order do we lose nervous system impulses after spinal/ epidural block?
autonomic, nocicieption, motor, then proprioception
275
The blood supply to the spinal cord is carried by?
The anterior spinal artery, the posterior spinal arteries, and the radicular artery.
276
Which artery provides the majority of the blood flow to the spinal cord (as much as 2/3rds)?
The anterior spinal artery
277
Name 9 absolute contraindications for Spinal/ epidural.
1. Patient refusal 2. Infection at injection site 3. Increased ICP 4. Clotting defects/anticoagulant therapy 5. Severe hemorrhage or hypovolemia 6. CNS disease or meningitis 7. Hysteria/ inability to remain still for block placement 8. Bacteremia 9. Septicemia
278
The cardioaccelerators of the autonomic nervous system are located at what level?
T1-T4
279
At what spinal level is the autonomic nervous sytem?
T1 - L2
280
What are some of the cardiovascular effects of spinal/epidural blockade spreading over the autonomic nervous system?
Venous and arterial dilation (mostly venous), 15-25% decrease in SVR, 10-15% decrease in CO, Decrease in HR due to unoposed vagal stimulation and decreased stimulation of right atrial baroreceptors, decrease in MAP
281
Some patients will report a difficulty taking a deep breath but their phrenic nerve is not compromised, what's the deal?
Some of the accessory muscles for respiration may be blocked and give the patient that sensation. Be very careful in COPD patients who use these accessory muscles to breathe!
282
If the patient experiences profound hypotension after spinal/ epidural, how might that affect the pulmonary system?
profound hypotension could cause ischemia to the central respiratory centers and cause respiratory arrest.
283
Your patient with aortic stenosis requires surgery. What would be a major concern with this patient and spinal/epidural anesthesia?
Patients with AS have a fixed cardiac output. They cannot compensate for drops in SVR and can spiral downward quickly. Administering Spinal/ epidural anesthesia is risky in these patients.
284
What is generally considered an acceptable drop in blood pressure during surgery?
about 20% of pre-op pressure
285
What are some of the GI responses to spinal/ epidural anesthesia?
Nausea and vomiting (20%), hyperperistalsis (due to unopposed parasympathetic activity).
286
Is blood flow to the liver affected by spinal/ epidural anesthesia?
blood flow to the liver is BP dependent. If you maintain the MAP you will maintain flow to the liver and have no untoward effects.
287
What is the effect of spinal/epidural anesthesia on the urinary system/ bladder?
You may have urinary retention. If you don't have a catheter, avoid excessive IV fluids. If the patient has no catheter and reports right shoulder referred pain, it might be due to a full bladder.
288
What are some of the metabolic effects of spinal/epidural anesthesia?
blocked stress response to surgery, catecholamine release from adrenal medulla may be blocked, cortisol secretion is delayed.
289
Why do patients sometimes shiver with spinal/epidural anesthesia?
shivering occurs due to altered thermoregulation with vasodilation
290
What are the 2 positions a patient can be in for placement of epidural/ spinals?
lateral decubitus, sitting. Sitting is preferred because of the improved midline anatomy
291
Placing your hands on the iliac crests of either hip and drawing your thumbs across in a straight line creates ___________ line. and indicates that you are on or near level _____ of the spine.
Tuffier's line; L4- L5
292
Before placing any block or for any procedure we must prepare. MSMAID is an acronym for:
Monitors, suction, means of PPV, airway, IV, Drugs (emergency). Even if we are performing a block outside of the OR area, we must have these things available to us.
293
Why do we administer a fluid bolus to patients prior spinal or epidural placement?
we anticipate a drop in BP after placement so giving fluid helps boost BP
294
There are 2 styles of needles available for spinals/ epidurals. They are:
bevel edged, or pencil point.
295
Would you use a bevel edged (Quincke) needle for a spinal?
No, bevel edged needles do more cutting. The more cutting you do, the greater the risk of spinal headache from CSF leak.
296
What are 5 perks to using a pencil point needle (Sprotte or Whitacre)?
1. they tend to spread the dural fibers as opposed to slice through them 2. they give a distinct 'pop' when you cross the ligamentum flavum 3. they have stronger tips that resist breaking 4. the side hole allows for directional flow of anesthetic 5. tracks in a straight line when advancing through ligaments.
297
What are the two approaches to placing a spinal or epidural?
Median or Paramedian
298
Why would you ever use the paramedian approach?
In patients who cannot adequately flex because of pain or whose ligaments are ossified. The paramedian approach is at a 10-15 degree angle off center.
299
What are the 5 layers traversed for epidural placement?
1. skin 2. subQ tissue 3. Supraspinous ligament 4. intraspinous ligament 5. ligamentum flavum ---- epidural space
300
What are the 9 layers/ spaces traversed for spinal placement?
1. skin 2. subcutaneous tissue 3. supraspinous ligament 4. intraspinous ligament 5. ligamentum flavum 6. epidural space 7. dura mater 8. subdural space 9. arachnoid matter ---- subarachnoid space
301
What is baricity?
Baricity compares the density of a solution to the density of another substance.
302
What is a hyperbaric solution and when would you use it?
Hyperbaric solutions have specific gravities of \> 1.11, making it heavier than CSF. You can mix the local anesthetic with dextrose to achieve this. The anesthetic will settle in the dependent areas and is used for low level blocks.
303
What is a hypobaric solution and when would you use it?
A hypobaric solution has a specific gravity of \< 1.005, making it lighter than CSF. You can make a hypobaric solution by mixing local anesthetic with sterile water. It is used if you want the block to go high, but it is the least reliable block.
304
What is an isobaric solution and when would you use it?
An isobaric solution has a specific gravity around 1.006. You can make it by mixing the local anesthetic with CSF. It gives a more local and controlled spread of the block.
305
Name 6 factors affecting the spread of local anesthetic within the CSF.
1. baricity of the solution 2. position of the patient 3. concentration and volume injected 4. level of injection 5. barbotage/rate of injection 6. direction of needle and bevel.
306
After spinal anesthesia, when can the patient be discharged?
From PACU to the floor after a 4 dermatome regression. To home after ambulating without orthostatic changes and after voiding.
307
The quality and extent of the epidural block is dependent upon:
the volume and concentration of the local anesthetic.
308
What is the volume of local anesthetic used in epidurals?
1.25-1.6 cc per segment
309
Caudal anesthesia is most commonly used in what patient population?
Pediatrics, in adults the anatomy is more variable.
310
Caudal anesthesia is used for what sorts of procedures?
post-op pain from hypospadius repair, inguinal hernia repair, procedures of the perineal and sacral areas.
311
Name some major complications of spinal/ epidural anesthesia
1. hypotension 2. bradcardia 3. sudden cardiac arrest 4. nausea and vomiting 5. unintentional vascular injections 6. unintentional intrathecal injection 7. catheter shearing 8. post-dural puncture headache 9. high blockade 10. inadequate blockade 11. neurologic complications 12. backache 13. infections-septic meningitis 14. urinary retention 15. epidural hematoma.
312
Post dural puncture headaches are most frequently seen in:
younger, female, caucasian patients but can also be seen in cases where larger needle size is used, pregnancy, dehydration, cutting tip needles used, and multiple puncture attempts required.
313
What is the incidence of post-dural headache?
1-4%
314
When does a post-dural puncture headache typically present?
anywhere from 1 day after to 1 week after spinal or epidural anesthesia.
315
What is the treatment for post dural puncture headache?
bedrest, hydration (keep the brain buoyant), oral analgesics, abdominal binder, epidural saline injection, caffeine (constrict cerebral vessels), or epidural blood patch.
316
How is a blood patch performed?
10-20 mL of autologous blood placed in epidural space at level of injection or more caudad. Forms a clot over the meningeal hole preventing further leak.
317
How well does a blood patch work for post-dural headache?
\>90% effective
318
What are some side effects from blood patches?
backache and radicular pain
319
What is the primary cause of epidural hematoma?
coagulation defect
320
How does epidural hematoma present?
with numbness and lower extremity weakness
321
You must consult neurosurgery immediately if you suspect epidural hematoma. Permanent injury will set in at ____ hours.
6-8. waiting \>8 hours makes the odds of decompression less successful.
322
Can your patient receive lovenox if they are going to have an epidural or spinal?
You must hold low molecular weight heparin 12 hours pre-placement and for 12 hours post surgical procedure.
323
What are the signs of neurologic local anesthetic toxicity from spinal or epidural?
circumoral numbness, tinnitius, vision changes, dizziness, slurred speech, restlessness, muscle twitching, seizure followed by CNS depression, apnea, hypotension, transient radicular irritation, cauda equina syndrome.
324
Why is it important to perform an epidural test dose? What drug would you use?
Performing an epidural test dose will let you know if you are in the subarachnoid space or in an epidural vein. The preferred drug is local with epi. Injecting into a blood vessel will give you immediate HR changes. If you inject into the subarachnoid space you will see immediate spinal effects. Negative aspiration of CSF is not enough to confirm.
325
What are the steps to the loss of resistance technique of epidural placement?
1. Find landmarks (Tuffier's line) 2. Choose widest interspace 3. Prep skin 4. Place a skin wheal 5.Using an epidural needle with stylet traverse the layers until the interspinous ligament is entered (increased tissue resistance) 6. Remove stylet 7. Attach glass syringe with 2-5cc of air. 8. Slowly advance needle by mm, stopping to tap tap tap after each move, or while applying continuous pressure to the syringe. 9. When epidural space is entered you will get a sudden loss of resistance and air with shoot right in. 10. Give an epidural test dose to confirm you are not in a vessel or in the subarachnoid space. 11.Thread the catheter in through the needle and advance approximately 2-3cm beyond end of needle. (possibly 4-6cm in parturients) 12. Remove needle and secure tubing. 13. Administer dose (1.25- 1.6ml for every segment block) always aspirate and give in incremental doses.
326
Why would you use an alcohol pad to determine block level?
Cold alcohol preps can be used to test a patients level of temperature sensation. This tests the sympathetic level of blockade, which is useful for hemodynamics but not a great indicator for sensory blockade. Sensory blockade can be as many as 2-6 segments below where loss of temperature sensation is.
327
What is the best way to test for sensory level of blockade?
using a sharp object tests the sensory level of blockade. This level can be 2 segments higher than motor blockade.
328
What are some of the disadvantages of epidural anesthesia when compared to spinal anesthesia?
1. Induction is slower because of more complex placement, the necessity of incremental dosing of the local, and the slow onset of anesthesia in the epidural space. 2. There is a higher risk of local anesthetic toxicity if a vein is entered due to the greater amounts of local used 3. epidurals are less realiable, not as dense, and can be patchy.
329
What are the layers traversed if the paramedian approach is used?
1. skin 2. subQ 3. Paraspinous muscle 4. Interlaminar space 5. Ligamentum flavum (from here on in it is the same)
330
How is the hanging drop method of epidural placement different than the loss of resistance method?
Advance the needle with stylet as usual. Stop, as you would with LOR, when you reach increased resistance, then remove stylet. Place a drop of preservative free NS in the hub of the needle. Then advance slowly. When you reach the epidural space the fluid will be sucked into the subatmospheric negative pressure of the epidural space.
331
What is the procedure for placing a spinal?
1. Anatomic landmarks identified (Tuffier's line) 2. sterile field established 3. skin wheal with 2cc of lidocaine 4. 17ga introducer passed angled slightly cephalad until you reach the ligamentum flavum. 5. place a 25ga spinal needle into the introducer. 6. slowly advance until 'pop' is felt as you enter the subarachnoid space. 7. Remove stylet and attach syringe of 2cc of anesthetic. 8. Aspirate CSF and watch it mix. it will look oily 9. slowly inject dose 10. aspirate one more time to make sure 11. withdraw entire set up and position patient.
332
When using a beveled needle, how should it be positioned?
The bevel should be parallel to the longitudinal fibers so as to not damage the layers as it enters.
333
Name the 3 possible epidural sites.
thoracic, caudal, and lumbar
334
The ligamentum flavum is usually how deep to the skin?
About 4cm. In 80% of patients it is 3.6 - 6cm deep.
335
When is Cricothyrotomy indicated?
for rapid emergency creation of percutaneous airway due to severe respiratory distress when intubation attempts have failed. It may even be used electively in patients with limited tracheal access. ex. severe cervical kyphoscoliosis.
336
In which patients would cricothyrotomy be contraindicated?
Patients under the age of 12 and patients with laryngeal fractures.
337
What is the procedure for placing a cricothryrototomy airway?
1. Clean and give a local as time permits (this is usually an emergency) 2. stand to the patient's right side stabilize the layrnx with left thumb and middle finger. 3. palpate the cricothyroid membrane. 4. insert cannula through membrane then direct downward toward carina. 5. confirm placement by aspirating air. 6. attach ventilation system while stabilizing new airway Caution: if using a jet ventilator air will not leave via the cricothyrotomy. You must open the mouth to allow for exhalation or barotrauma can occur.
338
How long can a cricothyrotomy stay in place?
72 hours
339
What are the 3 major complications of cricothyrotomy?
esophageal perforation, subQ emphysema, and hemorrhage
340
What does the interscalene block provide anesthesia to?
The brachial plexus at the roots and the trunks (more often the upper branches), and the lower cervical plexus.
341
What nerve is frequently missed with an interscalene block?
Ulnar nerve. The interscalene block provides ansthesia to the upper branches of the brachial plexus but frequently misses the inferior fibers.
342
What sorts of procedures are interscalene blocks good for?
Shoulder, clavicle, upper arm and elbow. Procedures proximal to the elbow.
343
Name 2 absolute contraindications to an interscalene block?
contralateral recurrent laryngeal nerve palsy, phrenic nerve palsy. Some relative contraindications are preexisting nerve injury, brachial plexus pathology, significantly impaired pulmonary function.
344
At what level do you insert the needle for an interscalene nerve block?
C6
345
Name the areas.
1. Sternal notch 2. Clavicle 3. Sternal head of the sternocleidomastoid muscle 4. clavicular head of the sternocleidomastoid 5. mastoid process
346
347
What is the biggest contraindication to regional anesthesia?
Patient refusal
348
What is the role of the brachial plexus?
Provides ALL motor function to the upper extremity and almost all of the sensory function.
349
What part of the upper extremity is not supplied with sensory innervation from the brachial plexus?
The posterior shoulder. It is supplied by the caudad branches of the cervical plexus.
350
What are the 5 regions of the brachial plexus?
Roots, Trunks, Division, Cords, Branches
351
The roots originate from:
C5, 6,7,8 and T1
352
After the roots pass between the _________ they reorganize into trunks.
Scalene muscles
353
The trunks continue from the scalene muscles to the \_\_\_\_\_\_\_\_\_\_\_\_.
edge of the first rib
354
How many trunks are there and what are they called?
3 Superior, Middle and Inferior (lower)
355
The superior trunk is supplied by which cervical nerves?
C5-6
356
The middle trunk is supplied by which cervical nerve?
C7
357
The inferior trunk is supplied by which spinal nerves?
C8 and T1
358
Label areas 1-5.
1. Roots 2. Trunks 3. Divisions 4. Cords 5. Branches
359
Label areas 1-5
1. C5 2.C6 3. C7 4. C8 5. T1
360
Label the trunks.
1. superior 2. middle 3. inferior
361
The trunks divide into ___________ as they pass over the lateral border of ___________ and under the \_\_\_\_\_\_\_\_\_\_\_.
the ventral and dorsal divison (anterior/ posterior) first rib clavicle
362
How many divisions are there?
6 divisions 3 ventral and 3 dorsal.
363
As the divisions emerge below the __________ they form the cords.
clavicle
364
How many cords are there? and what are their names?
3 cords. Lateral, posterior, and medial. (named for their relationship to the axillary artery)
365
Name the cords
1. Lateral 2. Posterior 3. Inferior
366
The __________ cord is the sole contributor t the musculocutaneous nerve.
Lateral
367
The _________ cord is the sole contributor to the ulnar and medial cutaneous nerves of arm and forearm.
Medial/ Inferior Cord
368
The _________ cord forms the axillay and radial nerves.
Posterior
369
The terminal nerves of the brachial plexus are:
Musculocutaneous, Axillary, Radial, Median, Ulnar
370
Label areas 1-15
1. Dorsal Scapular 2. Suprascapular 3.Nerve to subclavius 4. Long thoracic nerve 5. Lateral pectoral 6. Medial pectoral 7. Medial cutaneous nerve of arm 8. Medial cutaneous nerve of forearm 9. thoracodorsal 10. subscapular 11. musculocutaneous 12. axillary 13. radial 14. median 15. ulnar
371
The musculocutaneous nerve is unique because:
it exits the sheath high in the axilla
372
The musculocutaneous nerve supplies motor innervation to:
coracobrachialis, brachialis, and biceps. (flexes forearm)
373
the musculocutaneous nerve supplies sensory innervation to:
the lateral and mid-forearm up to the wrist
374
The _______ nerve leaves the brachial plexus at the lower border of the pectoral muscle.
axillary
375
The axillary nerve supplies motor innervation to:
deltoid and teres minor
376
The axillary nerve supplies sensory innervation to:
the inferior shoulder and the upper lateral arm
377
The radial nerve supplies motor innervation to:
triceps, supinator and extensors of the forearm
378
The radial nerve supplies sensory innervation to:
posterior arm and forearm, lateral border of the elbow, thumb and dorsal surface of the hand.
379
The median nerve supplies motor innervation to:
flexors and pronators of the forearm (flexion of the wrist)
380
The median nerve supplies sensory innervation to:
the palmar surface of the hand, index and middle fingers.
381
Name the nerve that provides the sensory innervation to each area.
1. supraclavicular (cervical plexus) 2. Axillary 3. Radial 4. Musculocutaneous 5. Radial 6. median 7.Ulnar 8. Median antecubital 9. Intercostobrachial and median brachial cutaneous.
382
Which type of needle is preferred for blocks?
B- bevel
383
What is the procedure for placing an interscalene block?
1. Locate the interscalene groove just behind the clavicular head of the sternocleidomastoid muscle (locate the carotid pulse and go lateral to it) (about 2cm above and lateral to the clavicle). 2. Clean and prep the area. 3. insert the needle caudad at C-6 level with nerve stimulator at 1mA. 4. Once you get a twitch of the biceps or distal hand, drop to 0.5mA or 0.4mA. (the more distal the twitch, the more reliable the block will be) 5. If twitch is still good aspirate to make sure you don't have heme, CSF, or air and inject 3-40mL of local in 5mL increments, aspirating inbetween each injection.
384
If the nerve stimulator is down as low as 0.2mA and you are still getting a good twitch, what would you expect?
Even if the patient hasn't yelled, you are probably in the nerve, back up a little.
385
What are some complications of interscalene block?
Bleeding, leakage of CSF, pneumothorax, phrenic nerve block, and Horner's syndrome
386
Name 4 local anestetics you could use in an interscalene block.
Lidocaine (lasts 2-3 hrs, Mepivacaine (lasts 2-3 hrs), Bupivacaine (lasts 4-6hrs) , and Ropivacaine (lasts 8-10hrs).
387
What drug could be added to the local anesthetic to make it last longer?
Epinephrine. Epi will vasoconstrict vessels in the region and decrease absorption, thereby prolonging it's effects at the nerves.
388
How would you evaluate an interscalene block?
Push (radial nerve), Pull (musculocutaneous nerve), Close fingers (median nerve), Open fingers (Ulnar nerve)
389
When would a superficial cervical plexus block be used?
Unilateral surgical procedures of the neck. May be combined with deep cervical plexus block for carotid endarterectomy. Also for posterior shoulder (scapular area)
390
What is the procedure for placing a cervical plexus block?
1. locate the posterior border of sternocleidomastoid. 2. Insert needle midpoint of the posterior border of the sternocleidomastoid. 3. Tunnel needle superiorly then inferiorly along posterior border of sternocleidomastoid. Inject 5cc of local subcutaneously in both directions. Volume is important for this block, the drug concentration, not so much, so lower concentrations (0.2%- 1%) can be used.
391
For which procedures would you perform a supraclavicular block?
surgery of the upper extremity that does not involve the shoulder. Excellent choice for upper arm, elbow, forearm, and hand.
392
What does a supraclavicular block anesthetize?
It blocks the brachial plexus at the trunks, before it divides into the divisions
393
Name 3 contraindications for supraclavicular nerve blockade.
contralateral phrenic paralysis, recurrent nerve paralysis, and contralateral pneumothorax
394
What is meant by 'margin of safety' when placing a supraclavicular block?
Moving 1" over from lateral border of sternocleidomastoid clears you from the major vessels. (example: EJ) and away from the pleural dome.
395
What is the procedure for placing a supraclavicular block?
1. Locate posterior border of sternocleidomastoid, trace to it's insertion on the clavicle. 2. Move 1" laterally and 1 fingerbreadthy above the clavicle. 3. Insert needle with neuromuscular stimulator at 1 mA, enter perpendicularly then aim laterally eliciting muscle twitch in the fingers. (do not aim medially - pneumo!) 4. Drop the mA to 0.5mA or 0.4mA, if you are still getting a twitch inject 35-40 mL of local anesthetic in 5mL increments aspiration before each injection.
396
The \_\_\_\_\_\_\_\_\_\_\_\_ muscle inserts on the medial 3rd of the clavicle, the \_\_\_\_\_\_\_\_\_\_\_\_ muscle on the lateral 3rd, leaving the middle 3rd for the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
sternocleidomastoid; trapezius; neurovascular bundle
397
What are some complications of supraclavicular block?
pneumothorax (as high as 6%!), Horner's sydrome, Phrenic nerve block, recurrent laryngeal nerve paralysis, neuropathy.
398
What is Horner's Sydrome?
When sympathetic nervous system is blocked, stroke-like symptoms can occur in the face. ptosis, miosis, anhydrosis, red conjunctiva.
399
A ________ block almost always causes Horner's syndrome?
stellate ganglion
400
If you see a small bulge in the sternocleidomastoid muscle near the clavicle, is is not likely to be a deviation of the sternocleidomastoid, but more frequently it is \_\_\_\_\_\_\_\_\_\_\_
the omohyoid muscle
401
Phrenic nerve block occurs in about _______ of supraclavicular nerve blocks, but:\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.
50%; but it is not associated with respiratory dysfunction in healthy patients.
402
Would a pneumothorax after supraclavicular block give you immediate symptoms?
Not necessarily, it may have a delayed onset, so post op x-ray may not catch it, but most are diagnosed before discharge.
403
What would an infraclavicular block be used for?
surgery on elbow, forearm and arm.
404
What is the procedure for performing an infraclavicular block?
1. find medial clavicular head and coracoid process. 2. insert needle with nerve stimulator at 45 degree angle pointing laterally and parallel to clavicle. 3. look for median or ulnar twitch. 4. inject 30-40ml, aspirating before each injection.
405
As long as the needle is pointed ________ in an infraclavicular block, neuraxial and pulmonary complications are rare.
laterally
406
What are the indications for an axillary block?
forearm and hand surgery. Procedures below the elbow.
407
What are the contraindications to axillary block?
Lymphangitis- absolute contraindication! others are preexisting nerve injury and brachial plexus pathology.
408
The axillary approach will anesthetize which 3 terminal branches of the brachial plexus?
median, ulnar, and radial nerves.
409
It is important to position the patient neutrally and comfortably for this block. Abducted with the arm bent at a 90 degree angle. Excessive abduction of the shoulder could complicate block placement by:\_\_\_\_\_\_\_\_\_\_\_\_
excessive abduction will make the artery difficult to palpate and might fix the plexus and make nerves more likely to be struck by needle. rather than roll away.
410
What are the steps to the transarterial approach to axillary block?
1. Palpate axillary artery 2. Insert 22ga B-bevel needle until aspirate bright red blood 3. Pass through artery, clear tubing with small injection of local. 4. Re-enter artery to verify and pass through again clearing again. 5. Aspirate for blood, if none, inject 35-40mL of local in 5mL increments, aspirating before each injection.
411
Which nerve is often missed in axillary nerve block and requires separate injection?
musculocutaneous. You can cover this by injecting into the belly of the coracobrachialis.
412
how would you test the effectiveness of an axillary block?
Push (radial nerve) Pull (musculocutaneous nerve) Close hand (medial nerve) Open hand (ulnar nerve)
413
Name 3 complications of axillary blocks.
hematoma, intravascular injection, infection
414
How would you 'touch up' blockage of the radial nerve?
Insert needle into brachioradialis muscle lateral to the biceps tendon. Inject 4-6mL of local in a fan like pattern
415
How would you touch up blockage of the median nerve?
Needle placed 1cm medial to brachial artery. Inject 3-5mL of local.
416
How would you touch up blockage of the ulnar nerve?
With forearm flexed, introduce needle 1cm proximal to the ulnar groove and inject 3-5mL. Warning- do not inject directly into the ulnar groove.
417
How would you touch up blockage of the musculocutaneous nerve?
Inject more local deep in the body of the coracobrachialis muscle.
418
What are the basics of the Bier block?
The arm to be operated on is exsanguinated and 50mL of 0.5% lidocaine is injected through an IV into the exsanguinated arm. It can last for 60-120 minutes. Be very careful if you let the tourniquet down too early, you risk local anesthetic toxicity from the washout.
419
What could you do to decrease risk of hematoma at injection sites?
avoid multiple sticks, apply firm pressure to the site after needle withdrawal.
420
What could you do to decrease the risk of local anesthetic toxicity?
Inject slowly to avoid 'channeling' of local into smaller veins/ lymphatics that may have been punctured during needle placement. Frequently aspirate to avoid intravascular injection, limit the volume if possible.
421
What could you do to decrease the risk of nerve injury during blocks?
Use a nerve stimulator, stop injection of you meet high pressures and stop if the patient complains of pain on injection.
422
What is my silly mneumonic for induction sequence?
Pretty Please Make Intubation Totally Tolerated Perfectly Timed Between Larynx Inferior & Carina Via My Training
423
What are some risks of peripheral nerve blocks?
local anesthetic toxicity, allergic response, permanent or transient nerve damage, uncomfortable positioning during surgery, incomplete blocks.
424
What are the 2 classes of local anesthetics?
Esters and Amides
425
Which class of local anesthetic has greater potential for producing allergic reactions?
Esters
426
How are Esters metabolized?
by plasma cholinesterases
427
How are amides metabolized?
liver
428
Chloroprocaine is an (ester or amide)
Ester. Remember one-eyed esters. Esters have only one 'i' in their spelling.
429
Name 4 amides.
lidocaine, bupivicaine, ropivacaine, mepivacaine
430
Anesthetic potency is primarily determined by:\_\_\_\_\_\_\_\_\_\_\_\_
lipid solubility
431
Duration of action of local anesthetic is related to:\_\_\_\_\_\_\_\_\_\_\_
protein binding, the higher the binding, the longer the duration of action.
432
The onset of action of the local anesthetic is related to ______ and \_\_\_\_\_\_\_.
pKa and hydrophilicity. The lower the pKa and the higher the hydrophilicity, the easier the anesthetic diffuses through the neuronal sheath.
433
The rate of systemic absorption from regions of greatest absorption to least are:
intercostals, caudal, epidural, brachial plexus, sciatic, lumbar plexus and femoral.
434
Systemic absorption of local anesthetics can result in:
CNS and cardiac toxicity
435
Does local anesthetic cross the blood/ brain barrier?
Yes, it crosses readily
436
What are the signs and symptoms of CNS toxicity of local anesthetic?
tongue numbness, lightheadedness, dizziness, tinnitus, disorientation, visual disturbances, seizures leading to CNS depession, respiratory depression, and respiratory arrest.
437
What are the signs and symptoms of cardiac toxicity of local anesthetic toxicity?
Initial increase in HR and BP. With higher levels, hypotension, arrhythmias, and cardiac arrest.
438
What is the treatment for local anesthetic toxicity?
stop the administration of local. maintain airway, give oxygen. treat seizures with versed, propofol, or thiopental. treat hypotension with ephedrine, epi and or/ fluids, consider lipids. provide cpr and cpb if needed.
439
How can you prevent local anesthetic toxicity?
vigilant monitoring, limit dose accordingly, aspirate before each injection, inject small volumes
440
What are some additives you can use to prolong the activity of the anesthetic?
epinephrine- vasoconstricts and decreases absorption. Sodium bicarbonate- increases pH of local and decreases the ionized/non-ionized ratio. (30-50% reduction in onset time). Clonidine- alpha 2 agonist has synergist effects with local anesthetics.
441
Name 4 areas you would never use epinephrine.
fingers, toes, nose, hose (penis) Epinephrine should not be used in distal extremities.
442
If you are injecting a large volume of local anesthetic, you should use (high or low) concentrations of drug.
Low
443
What two major nerve plexuses innervate the lower extremity?
lumbar plexus (ventral) and lumbosacral plexus (dorsal)
444
The lumbar plexus is formed from?
L1-L4
445
What 3 major nerves come from the lumbar plexus?
lateral femoral cutaneous, femoral, and obturator
446
Name the 3 minor nerves that come from the lumbar plexus.
iliohypogastric, ilioinguinal, and genitofemoral
447
What 2 nerves come from the lumbosacral plexus?
sciatic (L4-S3) and posterior femoral cutaneous
448
Name the nerves that provide sensory innervation to these regions.
1. Lateral femoral cutaneous 2. Femoral 3. Obuturator 4. Peroneal 5. Saphenous 6.Sural 7. Deep Peroneal 8. Superficial peroneal
449
Name the nerves that provide sensory information to the numbered areas.
1. Lateral femoral cutaneous 2. posterior femoral cutaneous 3. femoral 4. obturator 5. peroneal 6. saphenous 7. Sural 8. Calcaneous 9. Medial plantar
450
For what procedures would you use the lumbar plexus approach?
surgery of the lower knee, hip, femur, inguinal hernia repair, vasectomy
451
What is the largest branch of the lumbar plexus?
femoral nerve
452
A femoral nerve block will provide anesthesia to what part of the lower extremity?
anterior portion of the thigh, knee, medial side of calf (saphenous side) and small part of the foot.
453
How would you test to see if a femoral block has taken effect?
the patient will not be able to abduct the leg or extend the lower extremity.
454
What is the procedure for placing a femoral nerve block?
1. Palpate the femoral artery just below the ilioinguinal ligament. 2. Move 2cm lateral and 1cm caudal 3. raise a skin wheal 4.Angle needle at 45 degree angle cephalad 5. Using the nerve stimulator look for the patellar snap of the quadraceps. 6. aspirate and if no blood, inject 25-35cc of local anesthetic, 5cc at a time, aspirating between each injection.
455
What are some complications of femoral nerve block?
intravascular injection, hematoma, direct nerve injury
456
Which nerve provides pure sensory innervation to the lateral aspect of the thigh?
lateral femoral cutaneous nerve
457
A lateral femoral cutaneous nerve block provides anesthesia over:
the lateral aspect of the thigh
458
What is the procedure for a lateral femoral cutaneous block?
1. Injection site is 2cm medial and caudad to anterior superior iliac spine. 2. Insert needle until you feel the fascia pop, aspirate and inject 5-7mL in a fan like pattern.
459
When would you perform a poplieal block?
for ankle or foot surgery
460
In a popliteal block it is important to block the sciatic nerve before:
it bifurcates into the common peroneal and tibial nerves.
461
If the common peroneal nerve is stimulated you will see:
dorsiflexion and eversion of the foot
462
If the tibial nerve is stimulated you will see:
plantar flexion and inversion of the foot
463
When using a nerve stimulator in a popliteal block, what are you looking for?
use stimulator at 1.5mA. Keep one hand on the biceps. You do not want twitching of the biceps or hamstring. You are in the muscle if you see this. You do want to see dorsiflexion, plantarflexion, eversion or inversion of the foot. The foot action should continue as you drop the mA to 0.4-0.5 mA. Then you can inject 20-30ml of anesthetic slowly, aspirating before each 5cc injection.
464
When placing a popliteal block, if you feel twitching in the biceps muscle you need to move your needle more:\_\_\_\_\_\_\_\_
medially
465
When placing a popliteal block, if you feel twitching in the semitendanosus muscle you need to move your needle more:\_\_\_\_\_\_\_\_\_\_\_\_\_\_
laterally
466
What is a 3 in 1 Winnie block?
It is a block of all 3 (femoral, lateral femoral cutaneous, and obturator). By following the same procedure for femoral nerve block then holding firm pressure, forcing the anesthetic upward under the ilioinguinal ligament for better spread over all 3 nerves.
467
Name the 5 nerves blocked by an ankle block.
Posterior tibial, Deep peroneal, Saphenous, Superficial Peroneal, and Sural Nerves.
468
Is it Ok to use epinephrine in a sciatic nerve block?
No
469
Is it Ok to use epi in an ankle block?
No
470
What is the procedure for placing an ankle block?
Block posterior tibial by going in at posterior tip of medial malleolus and injecting 5cc. Then block deep peroneal by going into lateral side along extensor hallucis longus and extensor digitorum longus and injecting 5cc. Then start at the dorsum of the foot and place 3cc at the dorsalis, turn 90 degrees to the lateral aspect and place 1.5cc at the sural nerve and then 180 degrees back the other way and place 1.5cc at the saphenous nerve.
471
