Exam 4 Castillo Flashcards
(276 cards)
1
Q
Intubating dose, time to maximum block and clinical duration of response for Rocuronium
A
- Intubating dose: 0.6mg/kg
- Max block: 1.7 min
- Duration of Response: 36 min
2
Q
Intubating dose, time to maximum block and clinical duration of response for Vecuronium
A
- Intubating dose: 0.1mg/kg
- Max block: 2.4 min
- Duration of Response: 44 min
3
Q
Intubating dose, time to maximum block and clinical duration of response for Atracurium
A
- Intubating dose: 0.5mg/kg
- Max block: 3.2 min
- Duration of Response: 46 min
4
Q
Intubating dose, time to maximum block and clinical duration of response for Cisatracurium
A
- Intubating dose: 0.1mg/kg
- Max block: 5.2 min
- Duration of Response: 45 min
5
Q
Intubating dose, time to maximum block and clinical duration of response for Mivacurium
A
- Intubating dose: 0.15mg/kg
- Max block: 3.3 min
- Duration of Response: 16.8 min
6
Q
Intubating dose, time to maximum block and clinical duration of response for Pancuronium
A
- Intubating dose: 0.08 mg/kg
- Max block: 2.9 min
- Duration of response: 86 min
7
Q
Intubating dose, time to maximum block and clinical duration of response for d-Tubocurarine
A
- Intubating dose: 0.6mg/kg
- Max block: 5.7 min
- Duration of response: 81 min
8
Q
For the reversal of neuromuscular blockade purposes, what is the appropriate monitoring tool?
A
Acceleromyograph
9
Q
The best time to establish a baseline for neuromuscular twitches and/or tetany is when?
A
Prior to administration of any neuromuscular blocking agent
10
Q
The most common muscle monitored for assessment of twitches and/or tetany is what?
A
Adductor Pollicis
11
Q
The most common nerve monitored when assessing for neuromuscular blockade is?
A
Ulnar nerve
12
Q
The most common neuromuscular assessment technique utilized intraoperatively by anesthesia providers is?
A
Train of Four
13
Q
4 drugs utilized for NMBD reversal? Which is the most common?
A
- Edrophonium (expensive)
- Neostigmine (most common)
- Pyridostigmine
- Physostigmine
14
Q
Anti-cholinergic agents utilized in conjunction with NMBD reversal agents?
A
- Atropine sulfate
2. Glycopyrrolate
15
Q
MOA of NMBD reversal agents?
A
Inhibit acetylcholinesterase, allowing for more acetylcholine to be available at the NMJ (dislodges the paralytics)
16
Q
What type of antagonist are NMBD reversal agents?
A
Competitive antagonsits
17
Q
What is the max range for Neostigmine before reaching the ceiling effect?
A
60 to 80 mcg/kg
18
Q
What is the max range for Edrophonium before reaching the ceiling effect?
A
1 to 1.5 mg/kg
19
Q
What 5 factors does reversal of neuromuscular blockade depend on?
A
- Depth of NM block
- AchE inhibitor choice
- Dose administered
- Rate of plasma clearance of NMBD
- Anesthesia agent choice and depth
20
Q
Dose, onset of action and duration of action of Edrophonium?
A
- Dose: 0.5 to 1 mg/kg
- OOA: 1 to 2 mins
- DOA: 5 to 15 mins
21
Q
Dose, onset of action and duration of action of Neostigmine?
A
- Dose: 40 to 70 mcg/kg
- OOA: 5 to 10 mins
- DOA: 60 mins
22
Q
With NMBD reversal agents, which show similar elimination half times?
A
- Edrophonium
- Neostigmine
- Pyridostigmine
23
Q
Which NMBD reversal agent shows prolonged elimination half time?
A
Physostigmine
24
Q
Renal excretion percentage of neostigmine?
A
50%
25
Renal excretion percentage of pyridostigmine and edrophonium?
75%
26
How does renal failure effect NMBD reversal agents?
Decreases plasma clearance and prolongs the duration of action so we should give less of the drug
27
Hepatic clearance of NMBD reversal agents?
30 to 50% elimination if no renal function
28
What are the side effects of NMBD reversal agents due to?
Increased acetylcholine in all NMJ, leading to increased nicotinic or muscarinic activity
29
Cardiovascular side effects of NMBD reversal agents?
1. Bradycardia
2. Dysrhythmias
3. Asystole
4. Decreased SVR
30
Pulmonary side effects of NMBD reversal agents?
1. Bronchoconstriction
2. Increased airway resistance
3. Increased salivation
31
GI side effects of NMBD reversal agents?
1. Hyperperistalsis
| 2. PONV (Castillo contradicts everyone and says this isn't real)`
32
Dose of atropine?
7 to 10 mcg/kg
33
Effect on the eyes of atropine?
Mydrasis (Pupillary dilation)
34
Dose of glycopyrrolate?
7 to 15 mcg/kg
35
What drug dose atropine match the profile of?
edrophonium
36
What drugs does glycopyrrolate match the profile of?
Neostigmine and pyridostigmine
37
What drug is preferred to reverse NMBDs in patients with cardiac disease and how should it be administered with cardiac disease?
Glycopyrrolate may be preferred, administer it slowly, over 2 to 5 minutes
38
What NMBD did purified human plasma cholinesterase show effective reversal for?
Mivacurium
39
What NMBD did cystiene show effective reversal for?
Gantacurium
40
What NMBD did sugammadex show effective reversal for?
Selective relaxant binding agent with amino steroid (Rocuronium)
41
4 descriptors of Sugammadex?
1. gamma-cyclodextrin
2. Dextrose units from starch
3. Highly water soluble
4. Encapsulates the receptor
42
MOA of Sugammadex?
Intermolecular (Van der waal) forces, thermodynamic (hydrogen) bonds, and hydrophobic interactions lead to a very right reversal by encapsulation
43
Drugs in order from best to worst reversal with Sugammadex?
Roc > Vec > Pancuronium
44
What does Sugammadex bind to?
Free drug in the plasma
45
What is the major route of elimination for Sugammadex?
Urine, so avoid using it in renal failure and dialysis patients
46
How much Sugammadex is eliminated in 6 hours? 24 hours?
1. 70% in 6 hours
| 2. 90% in 24 hours
47
What is the elimination half time of Sugammadex?
2 hours
48
Dose of Sugammadex for deep neuromuscular block?
8 to 16 mg/kg
49
Is Recurarization observed with Sugammadex use?
Not with appropriate dosages
50
How deep is the block and what dose of Sugammadex should you administer if spontaneous recovery has reached reappearance of the second twitch in response to train-of-four stimulation?
Moderate block, 2mg/kg
51
How deep is the block and what dose of Sugammadex should you administer if spontaneous recovery of the twitch response has reached 1-2 post-tetanic counts, no twitch response to TOF?
Deep block, 4mg/kg
52
Dose related side effects of Sugammadex?
1. N/V
2. Pruritus
3. Urticaria
53
2 other side effects of Sugammadex?
1. Anaphylaxis
| 2. Bradycardia
54
Re-dosing administration of Rocuronium 5 minutes after reversal agent?
1.2mg/kg
55
Re-dosing administration of Rocuronium and Vecuronium 4 hours after reversal agent?
1. Roc: 0.6 mg/kg
| 2. Vec: 0.1 mg/kg
56
What drug should you administer if neuromuscular blockade is required before the recommended waiting time has elapsed?
Use a non steroidal neuromuscular blocking agent
57
3 Cautions with Sugammadex?
1. It will bind with progesterone for 7 days, need to use other forms of contraception (Oral will not work)
2. Toremifene (non-steroidal anti-estrogen) will displace NMBD from Sugammadex
3. Patient will show elevated aPTT, PT and INR with patients on heparin/LMWH
58
3 uses of Local Anesthetics
1. Treat dysrhythmias
2. Analgesia for Acute and Chronic pain
3. Anesthesia
59
What is the gold standard drug that all local anesthetics are compared to?
Lidocaine
60
Molecular structure of local anesthetics?
1. Lipophilic portion
2. Hydrocarbon chain
3. Hydrophilic portion
61
What determines if a local anesthetic is an ester or an amide?
The bond between the lipophilic portion and the hydrophilic portion
62
What is added to epinephrine to make the drug more stable?
Sodium Bisulfite
63
Potency, onset, DOA, and maximum single dose for infiltration of Procaine
1. Potency: 1
2. Onset: slow
3. DOA: 40-60 min
4. Max single dose for infiltration: 500mg
64
Potency, onset, DOA, and maximum single dose for infiltration of Chloroprocaine
1. Potency: 4
2. Onset: Rapid
3. DOA: 30-45 min
4. Max single dose for infiltration: 600mg
65
Potency, onset, DOA, and maximum single dose for infiltration of Tetracaine
1. Potency: 16
2. Onset: slow
3. DOA: 60-180 min
4. Max single dose for infiltration: 100 (topical)
66
Potency, onset, DOA, and maximum single dose for infiltration of Lidocaine
1. Potency: 1
2. Onset: rapid
3. DOA: 60-120 min
4. Max single dose for infiltration: 300mg
67
Potency, onset, DOA, and maximum single dose for infiltration of Prilocaine
1. Potency: 1
2. Onset: slow
3. DOA: 60-120 min
4. Max single dose for infiltration: 400mg
68
Potency, onset, DOA, and maximum single dose for infiltration of Mepivicaine
1. Potency: 1
2. Onset: slow
3. DOA: 90-180 min
4. Max single dose for infiltration: 300mg
69
Potency, onset, DOA, and maximum single dose for infiltration of Bupivicaine
1. Potency: 4
2. Onset: slow
3. DOA: 240-480 min
4. Max single dose for infiltration: 175mg
70
Potency, onset, DOA, and maximum single dose for infiltration of Levobupivicaine
1. Potency: 4
2. Onset: slow
3. DOA: 240-480 min
4. Max single dose for infiltration: 175 mg
71
Potency, onset, DOA, and maximum single dose for infiltration of Ropivacaine
1. Potency: 4
2. Onset: slow
3. DOA: 240-480 min
4. Max single dose for infiltration: 200mg
72
pK and protein binding % of Procaine
1. pK: 8.9
| 2. Protein binding: 6%
73
pK and protein binding % of Chloroprocaine
1. pK: 8.7
| 2. Protein binding: unknown
74
pK and protein binding % of Tetracaine
1. pK: 8.5
| 2. Protein binding: 76%
75
pK and protein binding % of Lidocaine
1. pK: 7.9
| 2. Protein binding: 70%
76
pK and protein binding % of Prilocaine
1. pK: 7.9
| 2. Protein binding: 55%
77
pK and protein binding % of Mepivicaine
1. pK: 7.6
| 2. Protein binding: 77%
78
pK and protein binding % of Bupivacaine
1. pK: 8.1
| 2. Protein binding: 95%
79
pK and protein binding % of Levobupivacaine
1. pK: 8.1
| 2. Protein binding: >97%
80
pK and protein binding % of Ropivacaine
1. pK: 8.1
| 2. Protein binding: 94%
81
Which local anesthetics are liposomes utilized with?
lidocaine, tetracaine, and bipivacane
82
Why do we use liposomes with local anesthetics?
To upload higher amount of LA into a molecule and have a consistent release of LA in the tissues
83
What is the effect of using liposomes with local anesthetics?
prolonged duration of action and decreased toxicity
84
MOA of local anesthetics?
Blocks/inhibits Na+ passage in nerve membranes by binding to Na+ channels on the INSIDE of the cell to prevent action potentials
85
3 factors affecting blockade caused by local anesthetics?
1. Lipid solubility or non-ionized form
2. Repetitively stimulated nerve
3. Diameter of the nerve, the large the diameter the more LA needed
86
3 other site of action targets for local anesthetics?
1. Potassium channels
2. Calcium ion channels
3. G protein-coupled receptor
87
Why do we not see a block when using local anesthetics on infected areas?
the pH is too low for the local to work, it becomes ionized before entering the cell
88
Compare the requirement of LA for motor vs sensory nerves
Motor nerves have 2x the diameter and require higher concentration of LA
89
How many Nodes of Ranvier must be blocked for adequate blockade?
2, preferably 3 nodes blocked
90
Which are the fastest sensory fibers?
Preglangionic B fibers w/ the SNS
91
Which fibers are the usual targets of LAs?
myelinated A-alpha and unmyelinated C fibers perceiving pain and temperature
92
What is the effector pregnancy on local anesthetics?
Increased sensitivity
93
Describe local anesthetics
Weak bases with pK values above physiologic pH
94
What is the lipid solubility of LA in the nonionized form?
50%
95
When do LA show the most rapid OOA?
pKs closest to physiologic pH
96
What intrinsic effect of LAs effect potency and DOA??
Intrinsic vasodilator activity
97
Which LA shows greater systemic absorption?
Lidocaine
98
4 factors that influence the aborption of local anesthetics?
1. Site of injection
2. Dosage
3. Use of epinephrine
4. Pharmacologic characteristics of the drug
99
How much epinephrine is in 1:200,000 solution?
5mcg/mL
100
What is the primary determinant of drug potency?
Lipid solubility
101
What factor of pharmacokinetics is effected by Cardiac Output?
Rate of tissue distribution and rate of clearance
102
What is the metabolism of Amide LAs?
Microsomal enzymes in the liver, these show slower metabolism than Esters
103
Which LA shows the most rapid metabolism?
Prilocaine
104
What is the metabolism of Ester LAs?
Hydrolysis by cholinesterase enzyme in plasma is greater than the liver except with Cocaine
105
What is the metabolite of Ester LAs that predisposes them to allergic reactions?
Paraminobenzoic Acid (PABA)
106
Which LA show first-pass pulmonary extraction?
Lidocaine, bupivicaine, and prilocaine
107
Renal elimination and clearance of LAs?
Poor water solubility
108
Which LA shows 10 to 12% elimination in the urine?
Cocaine
109
What is the effect of pregnancy on LA metabolism?
1. Lower levels of plasma cholinesterases
| 2. Significant transplacental transfer
110
Which is the effect of LA from transplacental transfer?
1. Amides, this is not significant with esters
2. Ion trapping
3. Protein binding = rate and degree of diffusion
111
When will we see more nonionized LAs?
with a basic pH
112
When will we see more ionized LAs?
with acidic pH
113
Metabolism of Lidocaine?
Oxidative dealkylation in liver, then hydrolysis; hepatic disease will affect metabolism and elimination
114
What is the metabolite of Lidocaine?
Xylidide
115
What is the effect of pregnancy induced hypertension on lidocaine?
Prolonged clearance
116
What is the metabolite of Prilocaine?
Orthotoluidine
117
What does the metabolite of Prilocaine cause?
Conversion of hemoglobin to methoglobin
118
At what dose of Prilocaine would we see methemoglobinemia?
> 600 mgs
119
Signs and symptoms of Methemoglobinemia?
Cyanosis due to decreased O2 carrying capacity
120
What is the treatment for Methemoglobinemia?
Methylene Blue 1 to 2 mgs IV over 5 minutes, total dose not to exceed 7 to 8 mg/kg
121
Compare Mepivacaine to Lidocaine
1. Longer duration of action
2. Lacks vasodilator activity
3. Prolonged elimination in fetus and newborn do not give in OB patients
122
Metabolism for Bupivacaine?
aromatic hydroxylation, N-dealkylation, amide hydrolysis and conjugation
123
What dose Bupivacaine bind to?
alpha1-acid glycoprotein
124
Metabolism of Ropivacaine?
P450 enzymes
125
What can occur with Ropivacaine metabolites in uremic patients?
Accumulation with uremic patients, but lesser toxicity than Bupivacaine
126
What does Ropivacaine bind to?
alpha1-acid glycoprotein
127
Where is Dibucaine metabolized?
The liver
128
MOA of Dibucaine?
Inhibit the activity of normal butyrylcholinesterase by more than 70%
129
Metabolite of Procaine?
PABA, excreted unchanged in urine
130
Metabolism of Chloroprocaine?
Plasma cholinesterase 3.5x faster (fastest of all the LA)
131
Metabolism of Tetracaine when compared with Procaine?
Slower than procaine
132
Rank the hydrolysis of chloroprocaine, procaine, and tetracaine from greatest to least?
Chloroprocaine > procaine > tetracaine
133
What is unique about benzocaine?
It is a weak acid with pK of 3.5
134
Uses of benzocaine?
Topical anesthesia of mucous membranes for tracheal intubation, endoscopy, TEE, and bronchoscopy
135
OOA, Duration and Dose of Benzocaine?
1. OOA: rapid
2. DOA: 30 to 60 minutes
3. Dose: 200 to 300 mgs of 20% spray
136
Metabolism of Cocaine?
Plasma and liver cholinesterases
137
When is the metabolism of cocaine decreased?
Parturients, neonates, elderly, severe hepatic disease
138
Peak and duration of cocaine?
1. Peak: 30 to 45 minutes
| 2. Duration: 60 minutes after peak
139
Cautions with Cocaine use? (5)
Coronary vasospasm, ventricular dysrhythmias, HTN, tachycardia, CAD
140
Average pKa of LA?
8
141
What is the purpose of alkalinizing LAs?
alkalization increases the % of lipid-soluble form
142
Benefits of Alkalization of LAs? (3)
1. Shortens onset of action (epidural by 3 to 5 minutes)
2. Enhance the depth
3. Increases the spread
143
Effect of administering dexmedetomidine with LAs?
Increases the duration of both motor ands sensory blocks, providing a longer time between the spinal and first request for analgesic meds
144
Effect of administering magnesium with LAs?
Increases duration with SAB or with opioids
145
Effect of administering dexamethasone with LAs?
Increased duration of either IV or mixed with LA
146
What 2 effects does mixing Chloroprocain and Bupivacaine show?
1. Produces rapid onset
| 2. Tachyphylaxis
147
Describe the mixing of Sodium Bicarbonate to LAs? (3)
1. 8.4% of Sodium Bicarb
2. 1mL only added
3. Mixed with 30mL of local anesthetics
148
Are the toxic effects of LAs additive or synergistic?
Additive
149
What is the duration of action of LA proportional to?
The time the drug is in contact with nerve fibers
150
What is the benefit of Vasoconstrictors administered with LAs? (3)
1. Limit systemic absorption and maintain drug concentration in the vicinity of the nerve fibers
2. Increased neuronal uptake of LA
3. alpha-adrenergic effect may have some degree of analgesia
151
What effect do vasoconstrictors have on the onset rate of LAs?
none, just keeps them localized
152
Effect on cardiac irritability of vasoconstrictors administered with LAs and inhaled anesthetics?
enhanced cardiac irritability
153
What is the expected side effect if vasoconstrictors administered with LAs are systemically absorbed?
HTN
154
Recommended topical single max dose Lidocaine?
300mg
155
Recommended single max dose Lidocaine for infiltration?
300mg or 500mg with epi
156
Recommended single max dose Lidocaine for PNB?
300mg or 500mg with epic
157
Recommended single max dose Lidocaine for IVRA (IV regional anesthesia)?
300mg
158
Recommended single max dose Lidocaine for epidural?
300mg or 500mg with epi
159
Recommended single max dose Lidocaine for spinal?
100mg
160
Recommended single max dose Bupivacaine for infiltration?
175mg or 225mg with epi
161
Recommended single max dose Bupivacaine for PNB?
175mg or 225mg with epi
162
Recommended single max dose Bupivacaine for epidural?
175mg or 225mg with epi
163
Recommended single max dose Bupivacaine for spinal?
20mg
164
What places can LAs be applied for topical anesthesia?
Mucous membranes of the nose, mouth, tracheobronchial tree, esophagus, or GU tract
165
Benefits of using cocaine for topical anesthesia?
Localized vasoconstriction, decreases blood loss and improves surgical visualization
166
Benefits of using lidocaine for topical anesthesia?
Great with surface anesthesia, inhalation does not alter airway resistance but does cause vasodilation
167
Which two LA are ineffective as topical agents?
Procaine and chloroprocaine due to poor penetration of mucous membranes
168
Give an example of a eutectic mixture of LA? (EMLA)
Lidocaine 2.5% + prilocaine 2.5% = 5% LA (additive effects, not synergistic)
169
Dose of EMLA?
1 to 2gms/10cm^2 area
170
Onset of Action of EMLA?
45 minutes
171
Readiness of EMLA for skin grafting?
2 hours
172
Procedures where EMLA is ready in 10 minutes? (4)
1. Cautery of genital warts
2. Venipucture, lumbar puncture
3. Arterial cannulation (Nitroglycerine)
4. Myringotomy
173
3 factors associated with EMLA?
1. Caution with methemoglobinemia d/t prilocaine
2. Not recommended for skin wounds d/t vasodilation
3. Contraindicated with amide allergies
174
What kind of injection is used for extravascular placement of LA?
SubQ
175
Concentration of lidocaine for inguinal operative site?
1% or 2%
176
Concentration of ropivacaine and bupivacaine for inguinal operative site?
0.25%
177
How do we double the duration of action when administering local anesthetics for infiltration?
by adding epinephrine 1:200,000
178
When is local infiltration of LA contraindicated?
Not intracutaneously or into tissues at end arteries
179
Examples for areas where we do not administer LA for local infiltration? (5)
fingers, toes, ears, nose, penis
180
How is a PNB achieved with LA?
Injection of LA into tissues surrounding individual peripheral nerves or nerve plexuses
181
MOA of PNB?
LA diffusion from outer mantle to central core of nerve along a concentration gradient
182
What is affected first with PNB administration?
peripheral affected first then central, which is the site of action wanted
183
What sensation comes back first with PNB?
Peripheral comes back first and then central
184
Which fibers come back first after PNB?
Smallest sensory and ANS fibers first, and then larger motor and proprioceptive axons
185
What is the OOA of PNB dependent on?
LA pKa
186
OOA of lidocaine PNB?
3 minutes
187
OOA of bupivacaine PNB?
15 minutes
188
What does the duration of PNB depend on?
The dose of the LA
189
What is the DOA of bipivacaine with epi/fentanyl/clonidine?
12 to 18 hours
190
2 factors associated with Continuous infusion PNB?
1. improved pain control, less nausea, and greater satisfaction
2. Additives are used
191
4 types of peripheral nerve blocks
1. interscalene
2. axillary
3. femoral
4. sciatic
192
mA used for nerve stimulator with PNB?
0.1-1
193
What benefit does ultrasound guided PNB give?
in plane vs out of plane
194
Describe the (August) Bier Block
IV injection of LA into an extremity isolated from the rest of the systemic circulation with a tourniquet
195
What does sensation and muscle tone depend on with Bier Block?
Tourniquet
196
What is the most commonly used LA for Bier Block? Which shows greater effect?
Lidocaine is the most common, but mepivacaine shows a greater effect
197
Where do we inject the LA for spinal anesthesia block (SAB)
Subarachnoid
198
What confirmation do we look for before administering a SAB?
CSF
199
Principle site of action for SAB?
preganglionic fibers
200
Where is the sensory effect when administering a SAB?
same level of denervation
201
Where is the SNS effect when administering SAB?
2 spinal segments cephalad of sensory
202
Where is the MOTOR effect when administering SAB?
2 spinal segments below sensory
203
5 most common LA for SAB?
1. Tetracaine
2. Lidocaine
3. Bupivacaine
4. Ropivacaine
5. Levobupivacaine
204
What is the dosage of SAB according to? (3)
1. Height of patient (volume of SA space)
2. Segmental level of anesthesia desired
3. Duration of anesthesia desired
205
What is more important in SAB, dose, concentration of the drug or volume of drug injected?
Dose is more important
206
How many mL of LA do we give per every inch above 5 ft?
0.1mL up to 2 cc totally for 1.5 to 2 hours
207
What is important in determining the spread of LA in SAB?
Specific gravity of the LA
208
Describe hyperbaric SAB (3)
1. LA specific gravity is > CSF
2. Glucose 5% is the additive
3. If Left hip arthroscopy is wanted site of action, want it below the injection site
209
Describe hypobaric SAB (3)
1. LA specific gravity is < CSF
2. Distilled water is the additive
3. If left hip arthroscopy, want left hip up
210
What is the target of SAB, anterior or dorsal nerves?
anterior
211
What is the most common LA used for Epidural anesthesia?
Lidocaine
212
Which drugs used for epidurals are like bupivcaine but have less cardiac and CNS toxicity?
Levobupivacaine and ropivacaine
213
Why is lidocaine good for epidurals?
good diffusion through tissues and safer
214
General onset of action of epidurals?
15 to 30 minutes
215
Why does adding epi not show an advantage with epidurals?
because the epidural space is not that vascular
216
Between bupivacaine and lidocaine, which will cross the placental barrier more?
Lidocaine because bupivacaine shows higher protein binding
217
How long does the effect of LA last on the fetus?
24 to 48 hours
218
Difference between SAB and epidural?
1. No differential zone of SNS, sensory and motor blockade with epidural
2. Large doses required for epidural
219
What type of effect do opioids show when administering concurrently with SAB or epidural?
Synergistic effect
220
What volume of fluid is infiltrated during Tumescent Liposuction?
SQ infiltration of 5L or more
221
Solution for SQ infiltration for Tumescent Liposuction?
1. Doluted lidocaine 0.05% or .10%
| 2. Epinephrine 1:100,000
222
What does SQ infiltration of fluid during tumescent liposuction cause?
Causes taut stretching of overlying blanched skin d/t large volume and vasoconstriction
223
Plasma peak of LA for tumescent liposuction?
12 to 14 hours s/p injection
224
Site of tumescent liposuction?
Thigh, abdomen, hips, buttocks
225
Recommended dose of regional anesthesia lidocaine with epi?
7mg/kg with 500mg max
226
Recommended dose of highly diluted lidocaine with epic for tumescent liposuction?
35 to 55 mg/kg
227
How much lidocaine is absorbed by 1 gm SQ?
1 mg of lidocaine
228
What are allergic reactions to LAs attributed to?
Manifestations of excess plasma levels
229
Which type of LA are we more likely to have an allergic reaction to and why?
Esters due to PABA
230
Do we see cross sensitivity between esters and amides?
no
231
What do allergic reactions to LA look like? (6)
1. Rash
2. Urticaria
3. Laryngeal edema
4. Hypotension
5. Bronchospasm
6. IgE anaphylaxis
232
What test do we use to determine if the allergic reaction was due to LA or not?
Intradermal test using preservative free LA
233
Describe LA system toxicity (3)
1. Due to excess plasma concentration of the drug
2. Entrance into the systemic circulation from inactive tissue redistribution and clearance metabolism
3. Accidental direct IV injection
234
Other factors that could have a hand in LA toxicity? (5)
1. Patient co-morbidities
2. Medications
3. Location and technique
4. LA use
5. Dose
235
What does the magnitude of systemic absorption of LA depend on? (4)
1. Dose
2. Vascularity of site
3. Epinephrine use which reduces systemic absorption by 1/3
4. Physicochemical properties
236
List the sites of highest blood concentration risk for LA admin from greatest to least (8)
1. IV
2. Tracheal
3. Caudal
4. Paracervical
5. Epidural
6. Brachial
7. Sciatic
8. SQ
237
CNS effects of LA toxicity?
Drowsiness, facial twitch prior to seizure, seizure
238
What metabolic abnormality promotes seizures with LAs?
hyperkalemia
239
At what dose of lidocaine epidural should we monitor plasma levels?
>900 mgs
240
What type of treatment is hyperventilation for LA CNS toxicity?
temporary measure
241
What is the effect of high plasma levels of Lidocaine on the heart?
Slows conduction of cardiac impulses due to blockade of Na+ channels, which leads to prolonged PR interval and QRS widening
242
Effects of accidental IV injection of Bupivacaine?
1. Precipitous hypotension
2. AV block
3. Almost immediate cardiac dysrhythmias including SVT, PVC, widened QRS and V-tach
243
4 predisposing factors for cardiovascular system toxicity from LA?
1. Pregnancy
2. Arterial hypoxemia, acidosis, or hypercarbia
3. Beta blockers, digitalis, Ca+ Channel Blockers
4. Epinephrine and phenylephrine use
244
Compare Lidocaine, Bupivacaine and Ropivacaine for CNS toxicity risk
Bupivacaine > Ropivacaine > Lidocaine
245
Goals of treatment for systemic toxicity of LAs?
1. Prompt airway management
2. Circulatory support
3. Removal of LA from receptor sites
246
Treatment of seizures caused by systemic toxicity from LAs?
1. Supplemental oxygen
2. Benzo (midazolam or diazepam)
3. Propofol: if hemodynamically stable
4. Muscle relaxant (succinylcholine or NMDA)
5. Intralipid: Lipid emulsion
247
Intralipid, lipid emulsion dose for treatment of systemic toxicity of LAs? (bolus and infusion doses)
Bolus: 1.5 mL/kg of 20% lipid emulsion
Infusion: 0.25 mL/kg/minute for at least 10 minutes
248
What dose of lipid emulsion should be administered within the 1st 30 minutes of LA systemic toxicity?
3.8mL/kg (1.2 to 6 mL/kg)
249
Epinephrine dose for treatment of LA systemic toxicity?
10 to 100mcg
250
What is the last resort for treatment of systemic toxicity due to LAs?
cardiopulmonary bypass
251
3 categories of neural tissue toxicity
1. Transient neurologic symptoms
2. Cauda Equina Syndrome
3. Anterior Spinal Artery Syndrome
252
Describe neural tissue toxicity
either transient or permanent neurologic injury
253
Describe transient neurologic symptoms associated with neural tissue toxicity from LAs
Moderate to severe pain (lower back, buttocks and posterior things) within 6 to 36 hours after uneventful single shot SAB
254
What LA shows greater risk of transient neurologic symptoms?
Lidocaine
255
Treatment for transient neurologic symptoms with LA neural tissue toxicity?
Trigger point injections and NSAIDS as well as a neuro consult
256
Recovery time for transient neurologic symptoms from LA neural tissue toxicity?
1 to 7 days
257
Describe Cauda Equina Syndrom
Diffuse injury at lumbosacral plexus with varying degrees of sensory anesthesia, bowel and bladder sphincter dysfunction, and paraplegia
258
Associated risk factors for Cauda Equina Syndrome? (2)
Large lumbar disc herniation, prolapse or sequestration with urinary retention
259
Describe anterior spinal artery syndrome
Lower extremity paresis with a variable sensory deficit
260
Cause of anterior spinal artery syndrome?
uncertain if its thrombosis or spasm of the bilateral anterior spinal artery
261
3 other etiologies thought to cause anterior spinal artery syndrome (3)
1. Effects of HTN or vasoconstrictor drugs
2. PVD
3. Spinal cord compression due to epidural abscess or hematoma
262
Describe Methemoglobinemia
Potentially life-threatening complication due to decreased carrying capacity (metHgb >15%)
263
Causes of Methemoglobinemia? (6)
1. Prilocaine
2. Benzocaine
3. Lidocaine
4. Nitroglycerine
5. Phenytoin
6. Sulfonamides
264
Treatment for Methemoglobinemia?
Methylene blue 1 to 2 mg/kg over 5 min with a max 7 to 8mg/kg
265
What is the reversal from metHgb (Fe 3+) to Hgb (Fe 2+) timing?
within 20 to 60 minutes
266
What effect does lidocaine have on the ventilatory response to arterial hypoxemia?
lidocaine depresses it
267
Which patients are susceptible to depression of ventilatory centers with lidocaine administration?
CO2 retainers
268
What is the cause of hepatotoxicity due to LAs?
continuous or intermittent epidural bupivacaine to treat postherpetic neuralgia
269
What do we wait for after stopping LA infusion that causes hepatotoxicity?
Normalization of liver transaminase enzymes
270
MOA of Cocaine?
SNS stimulation by blocking presynaptic uptake of NE and dopamine, causing increased postsynaptic levels
271
Adverse effects of Cocaine can last for how long?
up to 6 weeks
272
CV side effects of cocaine? (5)
1. HTN
2. Tachycardia
3. Coronary vasospasm
4. Myocardial infarction or ischemia
5. Ventricular dysrhythmias including Vfib
273
Parturient side effects of cocaine?
Decreased uterine blood flow and fetal hypoxemia
274
What could hyperpyrexia from cocaine use lead to?
Seizures
275
Patients taking which medication should be shown extra caution if they are also taking cocaine?
Patients taking MAO-inhibitors
276
Medication for myocardial ischemia caused by cocaine use?
IV nitroglycerine
