AP 1 Final Flashcards
1
Q
The National Library of Medicine notes people as “elderly” if they are between what ages?
A
65-79
2
Q
For those over the age of 80, what is the terminology used to describe the patients age?
A
AGED, 80 AND OLDER
3
Q
How many people in the United States reach the age of 65 every day
A
10,000
4
Q
By 2030, what percentage of the US population will be 65 or older
A
20%
5
Q
Patients older than 65 account for what percentage of hospital stays across the country
A
43%
6
Q
What type of neurologic problems are patients at increased risk for during the post-operative period?
A
CVA (stroke), post-op delerium, over narcotization, drug-drug interactions (particularly with anti-cholinergic side effects)
7
Q
What is the ASA recommendation for when mental status of the patient should be assessed?
A
Periodically during emergence and recovery
8
Q
What does NSQIP stand for
A
National Surgical Quality Improvement Project
9
Q
What types of surgeries does NSQIP EXclude?
A
NSQIP excludes cardiac, carotid, and neurologic procedures
10
Q
NSQIP states that for ages over __, odds ratio of a CVA is __
A
62, 3.9
11
Q
If a perioperative stroke occurs in an eldery patient, it is associated with an _______ increase in 30 day mortality
A
8-fold
12
Q
Patients with a history of what 2 problems are at highest risk for peri-operative CVA?
A
Prior CVA and Renal Failure
13
Q
What is the definition of an odds ratio
A
The likeliness of an event occurring if exposed to a given variable
14
Q
In an adjusted odds ratio when taking into account other variables, what is the greatest predictor of peri-operative stroke?
A
Age
15
Q
What are the guidelines from the Emory Comprehensive Stroke Center regarding neurologic exams in high-risk patients?
A
- q15min neuro exams x 4, q30min neuro exams x 2
- USE A SCREENING TOOL: FAST (Face, Arm, Speech, Time)
- Don’t hesitate to call an anesthesiologist/surgeon to the bedside or activate a STROKE TEAM
16
Q
What 2 things can we as anesthesists do to monitor neurologic function in high risk patients?
A
Frequent neuro exams and control blood pressure
17
Q
In a perioperative setting, what percentage of decline from baseline blood pressure is associated with stroke?
A
20%
18
Q
Should we manage BP based on a percentage of the patient’s baseline or the absolute number of the patient’s baseline?
A
Percentage
19
Q
Most BP recommendations suggest keeping within 15-20% of ____ ____ ____
A
Mean Arterial Pressure
20
Q
In eldery patients, an episode of delirium in the hospital increases the risk of what 3 things?
A
Longer hospital stay, persistent cognitive decline, placement in nursing home
21
Q
What is the incidence of delirium in the PACU in elderly (age > 70) patients?
A
Up to 45% of patients >70
22
Q
What are the risk factors for post-operative delirium?
A
Age > 70 (OR 3.4) Age > 80 (OR 5.2) Psychiatric/Neurodegenerative disorders (OR 4.2) Current alchol abuse (OR 6.5) COPA/OSA
23
Q
What factors associated with increased risk for post-op delirium do we have control over correcting?
A
Dehydration, abnormal electrolytes, anemia, dysglycemia
24
Q
What are 4 anesthetic risk factors for post-op delirium?
A
Pre-op benzodiazepines, ASA III-IV, fluid fasting > 6 hrs, anticholinergic drug use
25
What are 7 surgical/OR risk factors for post-op delirium?
Hip replacement, abdominal aortic aneurysm repair, neurosurgical procedure, CT surgery, blood loss, intraop hypothermia, intraop hypotension
26
What is the incidence of post-op delirium in hip replacement surgeries?
37%
27
What are the symptoms of HYPERactive delirium?
Agitation, hallucinations, disorientation
28
Why is HYPOactive delirium usually missed in the PACU?
It is subtle, the pt could be cooperative, many pts are asleep or resting
29
What are 4 treatments of post-op delirium?
- Behavioral/environment interventions
- Dexmedetomidine
- Haldol
- Possibly Risperidone/Olanzapine
30
What is the dose and frequency of Haldol to treat post op delirium
1-2mg IV, may repeat every 15 minutes
31
When is the only time you should treat post-op delirium with a benzodiazepienes
In the case of suspected alcohol withdrawal
32
What are some reasons that elderly patients are at higher risk for post-op delirium and pain?
1) Organ changes may compromise renal or liver funtion
2) Liver mass decreases with age and can limit metabolism of drugs
3) Increased body fat causes longer time of action for lipophilic drugs like fentanyl
4) Kidney mass decreases up to 60%
5) Decreased water in the body so hydrophilic drugs have a more profound effect
33
Dose reduction of opioids while treating post-op pain is appropriate to both treat pain and still avoid unwanted effects of pain meds. What are the reduced bolus doses of morphine, fentanyl, and hydromorphone?
Morphine - 1-2mg IV
Fentanyl - 25mcg
Hydromorphone - 0.2mg
34
What is the dose of acetaminophen when using it is a non-narcotic adjunct to treat pain?
1gm IV
35
What is the max daily dose of acetaminophen?
4 grams
36
What is the max daily dose of Ketorolac in patients over 65?
60mg IV or IM
37
You should avoid Ketorolac in patients with what comorbidity?
Severe renal impairment
38
What must a patients CrCl value be in order to be classified as having severe renal impairment?
Less than 45ml/min
39
Ketorolac is contraindicated in patients with what 2 complications
1) Active peptic ulcer disease
| 2) Recent GI bleed
40
What doses of iv ibuprofen (NSAID) are used for post-op analgesia to decrease opioid requirements
400-800mg
41
What is the range of doses for IV Diclofenac aka Dyloject (NSAID)
3.75-75mg
42
What is the recommended dose for Diclofenac
37.5mg IV
43
What is the recommended dose for Diclofenac for elderly
18.75mg IV
44
What advantage does IV Diclofenac have over ketolorac or aspirin?
Significantly less disruption of platelet function
45
What type of drug is Tramadol
Weak opioid agonist with tricyclic anti-depressant properties
46
What is the onset time for oral Tramadol
One hour
47
What is the peak time for oral Tramadol
2-4 hours
48
When is Tramadol contraindicated
In patients with renal disease and seizure disorders
49
What is the initial dose of Tramadol
50-100mg
50
What channels does Gabapentin work on that creates its analgesic properties
Alpha2delta subunit of calcium channels
51
How is the Gabapentin excreted
Renally
52
What is the starting dose of Gabapentin
300-400mg po
53
What do patients with CAD have a risk of post-operatively?
Tachycardia
54
What is the percent chance for both men and women of developing CAD after age 40?
49% for men, 32% women
55
What is the incidence of post-op cardiac intervention in patients with stable angina
22%
56
What is tachycardia a significant risk for in patients with CAD?
Ischemia
57
What is the J point on an EKG
Where the QRS ends and ST segment begins
58
Where should ST elevation be measured?
From the upper edge of the PR segment to the upper edge of the ST segment
59
What is the most common post-operative dysrrythmia?
Atrial fibrillation
60
What are the 4 risk factors for atrial fibrillation?
1) Cardiac surgery
2) Thoracic surgery
3) Age
4) Male
61
Loss of atrial contraction can increase what
Pulmonary pressures and pulmonary edema
62
A-fib can lead to what 3 poor outcomes
1) Increased risk of stroke
2) Increased hospital length of stay by 2 days
3) Increased mortality
63
What 4 things can we do to prevent a-fib
1) Check and correct abnormal electrolytes
2) Treat hypotension
3) Be watchful of hypervolemia in high risk patients (dialysis, CHF)
4) Monitor respiratory status (hypercarbia/hypoxia)
64
What is the electric cardioversion treatment for unstable a-fib
50-100 J sync
65
What is the pharmacologic therapy for unstable a-fib
Amiodarone load + drop
66
What is a pharmacologic therapy for rate control with stable a-fib
Diltiazem IV
67
What is the target HR for stable a-fib in the immediate period
80-100bpm
68
What is a pharmacologic treatment for stable a-fib if the patient has CAD
Beta blocker
69
What 3 hemodynamic changes can decrease preload
1) Hypovolemia
2) Increased venous capacitance (due to regional anesthesia)
3) Increased intrathoracic/cardiac pressure
70
What 2 hemodynamic changes cause decreased cardiac function
1) Decreased stroke volume
| 2) Change in HR/rhythm
71
What 3 things can cause decreased afterload (SVR)
1) Sepsis
2) Anaphylaxis (also affects preload)
3) Residual medication/anesthetic effect
72
What are 6 causes of hypertension in the PACU?
1) Pain
2) Hypercapnia
3) Urinary retention
4) Pre-existing HTN
5) Hypervolemia
6) Increased ICP
73
Almost 90% of patients in the PACU who will become hypertensive do so within what amount of time
1 hour
74
50% of patients who develop HTN in the PACU will do so within what amount of time
15 minutes
75
What fraction of major PACU complications are respiratory
2/3
76
What are the 3 most common respiratory issues in the PACU
Hypoxia, hypercarbia, aspiration
77
All anesthetic drugs cause a dose dependent reduction in minute ventilation except which 2 drugs
Ketamine and N2O
78
Which part of the minute ventilation equation do opioids affect
Rate - they reduce rate
79
Which part of the minute ventilation equation do volatile agents
Volume - they reduce volume
80
Which part of the minute ventilation equation does propofol effect
Both rate and volume
81
What effects can hypercapnia have on heart rate, heart function, and neurologic function
Tachycardia, arrhythmias, htn headache, confusion, tremor, coma
82
Where are peripheral receptors that detect PaCO2 located
Carotid bodies
83
Where are central receptors that detect PaCO2 located
Medulla
84
How is ventilation affected by a rise in PaCO2
Linear increase in ventilation with increase in PaCO2
85
Ventilatory response to ___ is reduced by almost all anesthetics
CO2
86
What effect does supine positioning, laparoscopic procedures, obesity, and atelectasis have on FRC
Decrease
87
What happens to closing capacity of airways under anesthesia
Increase
88
What aspects of the lung change with age
Lung volumes and elasticity
89
Geriatric patients have an elevated risk of developing what 2 lung problems
Atelectasis
| Pneumonia
90
Deep breathing has not shown to be beneficial in the post-op setting except with what population
Elderly populations, they are benefited with greater pulmonary recovery and prevention of pneumonia
91
What part of the airway does airway obstruction almost always occur in
Pharyngeal
92
Are men or women more at risk for OSA
Men
93
Are post-menopausal or pre-menopausal women more at risk for OSA
Post-menopausal
94
What jaw problems increase risk for OSA
Micrognathia and retrognathia
95
Patients with a neck circumference greater than __cm are at risk for OSA
40cm
96
What is the definition of OSA
Repetitive episodes of upper airway partial/complete obstruction during sleep that are accompanied by sleep disruption, changes in air flow and hypoxemia.
97
What are the 2 parts of the oropharynx
Palatopharynx (velopharynx) - length of soft palate to the tongue
Glossopharynx - below base of tongue
98
What is the action of the genioglossus muscle
Depress and protrude the tongue
99
What nerve innervates the genioglossus muscle
Hypoglossal (12)
100
After 60 minutes of anesthesia, you should make sure the patients respiratory rate is over
8 breaths/min
101
After 60 minutes of anesthesia, check for apneic episodes over __sec
10
102
After 60 minutes of anesthesia, check for SaO2 over ___% on room air
90
103
What are risk factors for residual NMB
Patient distress, upper airway obstruction, aspiration, hypoxemia, impaired ventilation, re-intubation
104
What was the NMB agent used in 99% of residual NMB cases
Rocuronium
105
What percentage of elderly patients are affected by dysphagia
15%
106
Why are elderly patients more at risk for dysphagia
Muscle mass decreases with age and swallow reflex loses strength
107
In eldery patients with concomitant neurological disease, the percentage with dysphagia rises to
50%
108
What are diseases/conditions that increase risk of oropharyngeal dysphagia?
Alzheimers, tumors, myasthenia gravis, ALS, Parkinson's, achalasia, dementia, history of CVA
109
High risk patients should have an HOB greater than ____
30 degrees
110
What types of drugs should you minimize in patients at risk for dysphagia
Sedatives and opioids, helps limit pharyngeal motor dysfunction
111
What exam can be performed in the PACU to screen for dysphagia
3oz swallow challenge
112
Does the ASA recommend we monitor for urine output in all patients?
No, just select patients
113
What is the biggest risk factor for POUR
Age
114
What surgeries increase risk for POUR
Inguinal hernia repair, colorectal/anorectal, pelvic, hip surgeries
115
What type of drug increases risk of POUR
Opioids
116
Is POUR a risk factor for post op delirium?
Yes
117
How is hypothermia defined in Dr. Duggan's lecture
Less than 36 degrees celsius
118
What are predictors of hypothermia
Age, duration of anesthesia, pain, risk score of CAD, CVA, insulin dependent DM, renal failure
119
A 1.9 degree drop in temperature increases risk of WI by?
20%
120
How does hypothermia affect the incidence of cardiac events
a. Doubles
b. Triples
c. Quadruples
b. Triples
121
What effect does hypothermia have on the blood
Impairs platelet function, decreases fibrinogen, disturbs coagulation enzymes, coagulopathy
122
Why does a 1.9 degree drop in temp increase risk of WI
Impairs antibody and cell-mediated defenses, decreases o2 delivery to peripheral tissues
123
Active warming reduces the time taken to achieve normothermia by how much in comparison to warming blankets
30 minutes
124
Active warming was found to reduce mean time taken to achieve normothermia by how much in comparison to unwarmed blankets
90 minutes
125
What is the difference in shivering of patients who were actively warmed vs. those who were passively warmed
There is no difference
126
What are the triggering agents for MH
Sux, volatile agents (except N2O)
127
What kind of disorder is MH
Pharmacogenetic
128
MH is caused by the abnormal handling of what element in skeletal muscle
Intracellular calcium
129
What is the mortality rate from MH using MH Hot Line in the hospital
7%
130
What is the mortality rate from MH using MH Hot Line outside the hospital
20%
131
MH is normally a defect in what receptor
Ryanodine
132
What is the effect of MH triggers on Ca2+ release
Triggers uncontrolled calcium (Ca2+) release from the sarcoplasmic reticulum (SR) through the ryanodine receptor (RYR1) causing a rapid and sustained rise in myoplasmic Ca2+. The high intracellular Ca2+ activates Ca2+ pumps at the SR and the sarcolemma to reuptake calcium into SR or to transport it into the extracellular space respectively. The energetic cost to regain cellular Ca2+ control causes a need for ATP, which in turn produces heat.
133
How does O2 consumption change with MH
3-5 times the normal O2 consumption
134
How does PaO2 change during MH
142 +/- 10 mmHg
135
How does PvO2 change during MH
36 +/- 4 mmHg
136
How does PaCO2 change during MH
54 +/- 4 mmHg
137
How does PvCO2 change during MH
107 +/- 10 mmHg
138
When is the onset of MH explosive?
During induction
139
When is the onset of MH insidious?
Maintenance, postop
140
Do all patients with MH outbreak have muscle rigidity?
No
141
What is an early sign of MH outbreak?
Unexplained increased etCO2
142
What is a late sign of MH outbreak?
Temperature
143
Does MH cause respiratory/metabolic alkalosis or acidosis?
Acidosis
144
Is hyperthermia an early, intermediate, or late sign of MH?
Late
145
Is venous cyanosis an early, intermediate, or late sign of MH?
Late
146
Is MMR an early, intermediate, or late sign of MH?
Early
147
Hyperthermia was the 1st sign of MH in what fraction of patients
1/3
148
What are the main causes of death within the first few hours of MH manifestation
Hyperkalemia, v-fib
149
What are the main causes of death within several hours of MH manifestation
Pulmonary edema, acid/base abnormalities, electrolyte imbalance, coagulopathy
150
A high incidence of disseminated intravascular coagulopathy occured when temperatures were above
41.5 degrees celcius
151
What are the main causes of death days after MH manifestation
Multi-organ failure, brain damage, renal decompensation
152
What 2 diseases associated with MH are due to a mutation with Ca2+ release via muscle isoform ryanodine receptor RYR 1 gene (Chromosome 12q13)
Central Core Disease
| King-Denborough Syndrome
153
What disease associated with MH is due to a mutation with Excitation-Contraction Coupling Protein on STAC3 Gene (Chromosome 12q13.13)
Native American Myopathy (NAME)
154
What 2 diseases associated with MH are due to a mutation in the Ca2+ channel voltage dependent 1S subunit CACNA1S (Chromosome 1q32)
Hypokalemic periodic paralysis
| Multiminicore Disease
155
What disease/symptom that is possibly associated with MH is caused by an RYR1 mutation
Exertional heat stroke
156
What disease that is possibly associate with MH is found in patients that were CHCT + and had an RYR1 mutation
Exercise induced rhabdomyolysis
157
What deficiency is possibly associated with MH
Carnitine palmitoyl transferase
158
What are some differential diagnoses associated with MH
```
NMS
Hypoxic encephalopathy
Ionic contrast agents in CSF
Baclofen withdrawl
Amphetamine toxicity
Cocaine toxicity
ETOH withdrawal
Myopathy /rhabdomyolysis with Statins
Hypoxia
Iatrogenic overheating
Transfusion reaction
Thyrotoxicosis
Pheochromocytoma
Anticholinergic syndrome
```
159
What is the first thing you should do if you suspect MH
Stop all volatile agents/sux
160
After stopping volatile agents/sux, what should you do in cases with suspected MH manifestation
- Call for assistance
- Hyperventilate with 100% O2 and flows over 10L/min
- Communication/halt procedure
- Give dantrolene
161
Whats the dose of Dantrolene
2.5mg/kg
162
How should you dilute a 20mg bottle of Dantrolone
Dissolve with 60ml sterile water, each bottle has 3gm mannitol
163
What are some side effects of Dantrolene
Cardiac arrest, thrombophlebitis (pH 9), synergistic action with NMB
164
After Dantrolene, what should you begin to treat
Hyperkalemia, arrythmias, hyperthermia, electrolyte imbalances
165
What is the endpoint of the treatment of hyperthermia
38 degrees celsius
166
What should you keep the UOP at
Greater than 2cc/kg/hr
167
What is the Dantrolene dosage/frequency for post-acute phase therapy
1) 1mg/kg IV every 4-6 hours OR 0.25mg/kg/hr - give for 24-36 hrs
2) After step 1, oral Dantrolene 1mg/kg every 6 hours for the next 24 hours
168
What tests/electrolyte levels should you check to watch for signs of recrudescence, myoglobinuria, renal failure, DIC
ABG, CPK, K+, Ca+, urine/serum myoglobin, clotting
169
How often should you check ABG/CPK/K+/Ca+/etc. for post-acute phase therapy
Every 6 hours until normal and stable
170
How long should you observe MH patients in the ICU
24-48 hours
171
Where should you refer patient and families for counseling
MHAUS
172
Children less than __ years old who experience a sudden cardiac arrest after sux, in the absence of hypoxia, should be treated for what first?
9 years old, acute hyperkalemia
173
What test is indicated with family or personal history of MH or MH-like events
Halothane-Caffeine Contracture Test
174
What are the contraindications for the Halothane-Caffeine Contracture Test?
Age less than 4 years old (20kg), less than 3 months from the event
175
How should you prepare the anesthesia machine for an MH susceptible patient
- New fresh gas outlet hose and circle system tubing
- Remove vaporizers
- Flush system with >10L/min O2 for 10 min
- Flush for 20min if fresh gas can't be replaced
176
What should you have in or near the OR when you have an MH susceptible patient
MH cart
177
What type of temperature should be monitored in an MH susceptible patient
Core temp
178
When should Dantrolene be given as a pre-med
Cases of stress-induced MH
179
How often should you monitor RR, BP, HR, temp in the PACU with an MH susceptible patient
every 15 minutes for 1 hour
180
What vitals/tests should be monitored on an MH susceptible patient in Phase II of PACU
Pulse ox, urine color, HR, temp, and BP every 30 min for at least 1.5 hours
181
What muscle often becomes rigid during MH manifestation
Masseter
182
What are early signs of MH outbreak
Increased CO2, increase HR, resp/met acidosis, venous desaturation, masseter rigidity, electrolyte imbalance
183
Halstead and Hall injected what anesthetic into peripheral sites in the 1880's
Cocaine
184
In 1885, Corning used what device to arrest local circulation and prolong the block
Esmarch tourniquet
185
What did Braun invent in 1903
Chemical tourniquet
186
Who wrote the definitive text on regional anesthesia in 1920
Labat - Regional Anesthesia: Its Technique and Application
187
What are 3 risks of regional anesthesia
Nerve injury, LA toxicity, site specific risks
188
What are 4 contraindications of regional anesthesia
Uncooperative, coagulopathy, infection, LA allergy
189
What are hypoechoic structures and how do they appear on an ultrasound
Structures through which sound passes easily, appear dark or black
190
What are hyperechoic structures and how do they appear on an ultrasound
Structures reflecting more sound waves, appear white
191
High frequency waves have ______ resolution but _____ tissue penetration when compared to low frequency waves
Higher resolution, poorer tissue penetration
192
Low frequency sound waves have _____ resolution but _____ tissue penetration when compared to high frequency sound waves
Poorer resolution, better tissue penetration
193
Is low frequency better for shallow or deep structures
Deep structures
194
What type of probe is better for shallow structures
Linear
195
When is the needle best seen with a linear probe
When its perpendicular to the transducer and parallel to the surface
196
What probe/needle angle is best for deeper structures
Low resolution curvilinear probe, steeper needle angle
197
What does an In Plane technique look like
Needle inserted from the side of the transducer
198
What does an Out of Plane technique look like
Needle inserted at the front side of the transducer, midline
199
What 4 blocks block portions of the brachial plexus
1) Interscalene
2) Supraclavicular
3) Intraclavicular
4) Axillary
200
The cervical plexus is derived from what spinal nerves
C1-C4
201
Cervical plexus supplies branches to what 2 muscle groups
Prevertebral muscles, strap muscles of the neck
202
The cervical plexus supplies branches to what nerve
Phrenic nerve
203
What are some examples of surgeries where cervical plexus blocks are useful
Lymph node dissections, plastic repairs, carotid endarterectomy
204
Bilateral cervical plexus blocks are used for what surgeries
Tracheostomy, thyroidectomy
205
What is an advantage of the cervical plexus block
The ability to monitor the awake patient's neurologic status continuously
206
What are some complications and side effects of cervical plexus blocks
Intravascular injection, blockage of phrenic nerve and SLN, spread of anesthetic into epidural and subarachnoid spaces
207
Nerve roots of musculocutaneous nerve
C5-C7
208
Nerve roots of axillary nerve
C5-C6
209
Nerve roots of radial nerve
C5-T1
210
Nerve roots of median nerve
C5-T1
211
Nerve roots of ulnar nerve
C8-T1
212
What cord innervates musculocutaneous nerve
Lateral
213
What cords innervate median nerve
Lateral and medial
214
What cord innervates ulnar narve
Medial
215
What cord innervates radial nerve
Posterior
216
What type of surgeries are interscalene blocks indicated for
Shoulder and upper arm surgeries
217
What type of surgeries need an interscalene block to be supplemented with an ulnar nerve block
Forearm and hand surgeries
218
What are some complications of interscalene blocks
Ipsilateral phrenic nerve block, vagus/RLN/cervical sympathetic nerves can be blocked, PTX
219
What trunk levels does the interscalene block occur at
Superior and middle trunks
220
What dermatomes is the interscalene block most intense at
C5-C7
221
What dermatomes is the interscalene block least intense at
C8-T1
222
What types of surgeries are supraclavicular blocks indicated for
Elbow, forearm, hand
223
What trunk level do supraclavicular blocks occur at
Distal trunk-proximal division
224
What are some complications of supraclavicular blocks
PTX, phrenic nerve block, Horners syndrome
225
What are symptoms of Horners syndrome
Ptosis, miosis, anhydrosis
226
What surgeries are infraclavicular blocks used for
Arm and hand
227
What level do infraclavicular blocks block
At the level of the cords, arranged around axillary artery
228
Relative to supraclavicular blocks, what do infraclavicular blocks have less of a risk for
Pneumothorax
229
Are the shoulder and upper arm anesthesized with an infraclavicular block?
No
230
Axillary blocks are useful for what type of surgeries
Forearm and hand
231
What level does an axillary blockade occur at
Terminal nerve branches
232
What are some complications of axillary blocks
Nerve injury, systemic toxicity, hematoma, infection
233
Why are multiple injections needed for an axillary block
The nerves are separated by fascia
234
Where is an axillary block more intense
C7-T1 (ulnar nerve)
235
What are the 5 types of terminal nerve blocks
Median, ulnar, radial, musculocutaenous, digits
236
What cords are blocked with a terminal nerve block of the median nerve
Lateral and medial cords
237
What cords are blocked with a terminal nerve block of the ulnar nerve
Medial cord
238
What cords are blocked with a terminal nerve block of the radial nerve
Posterior cord
239
What drug do you not use with a terminal nerve block of the digits
Epi
240
Are Bier Blocks useful for short or long procedures
Short
241
What are the benefits of a Bier Block
Easy to administer, rapid onset
242
What is the dose and concentration of Lidocaine needed for a Bier Block
25-50 ml of 0.5% Lidocaine
243
What type of tourniquet is used for a Bier Block
Pneumatic
244
What is an example of a surgery that would use a Bier Block
Carpal tunnel (45-60min)
245
Tourniquet pain occurs after how long
20-30min
246
The tourniquet must be up for at least 15-20 min to reduce risk of what
Rapid bolus of local anesthetic and systemic toxicity
247
What are some complications of a Bier Block
Phlebitis, compartment syndrome, loss of limb
248
What are the nerve roots of the femoral nerve
L2-L4
249
What are the nerve roots of the obturator nerve
L2-L4
250
What are the nerve roots of the lateral femoral nerve
L1-L3
251
What are the nerve roots of the sciatic nerve
L4-S3
252
What 3 nerves are part of the lumbar plexus
Femoral, obturator, lateral femoral
253
The lumbar plexus lies within what muscle
Psoas
254
The 2 nerves are continuations of the sciatic nerve
Common peroneal and tibial
255
What type of surgeries are femoral nerve blocks useful for
Anterior thigh, knee, medial foot
256
Why are femoral nerve blocks used for knee surgery
Post op pain control
257
What are some examples of surgeries that call for a femoral nerve block
Patellar surgery, knee scopes, skin grafting
258
What groups of muscles/nerves does the femoral nerve innervate
Hip flexors, knee extensors, sensory of hip and thigh
259
Can a femoral nerve block provide surgical anesthesia by itself?
No
260
Where is a femoral nerve block placed?
Below the inguinal ligament
261
An obturator nerve block provides anesthesia to what region
Medial thigh
262
An obturator nerve block provides muscle relaxation to what muscles
Adductor muscles of the hip
263
An obturator nerve block is used in combination with what 2 blocks
Femoral and sciatic
264
For complete anesthesia of the knee, what block do you need
Obturator
265
A sciatic nerve block provides sensory anesthesia to which areas
Posterior hip, knee, and low extremity
266
A sciatic nerve block provides a motor block to what muscles
Hamstrings and low muscles
267
A sciatic nerve block is useful for what type of surgeries
Knee, calf, achilles tendon, foot, ankle
268
A sciatic nerve block is used for post op pain control in what surgeries
Knee, posterior knee
269
A popliteal block is useful for what surgeries
Foot and ankle
270
What muscles are spared in a popliteal nerve block
Hamstrings
271
What 5 nerves are involved in an ankle block
Superficial peroneal, deep peroneal, saphenous, tibial, sural
272
What type of surgeries are ankle blocks used for
Foot surgeries
273
What drug cannot be used with ankle blocks
Epi
274
How many injections are required for an ankle block
5
275
Area innervated by sural nerve
Posteror lateral leg below the knee
276
Area innervated by saphenous nerve
Medial leg below the knee
277
Area innervated by superficial peroneal nerve
Anterior lateral leg below the knee, top of foot except small region between 1st and 2nd toe
278
Area innervated by deep peroneal nerve
Region between 1st and 2nd toe on top of foot
279
What nerves does a lumbar plexus (psoas) block include
Lateral femoral cutaneous, femoral, obturator
280
What area does the lumbar plexus block provide complete analgesia for
Total hip and total knee
281
What type of needle is required for lumbar plexus block
Long needle
282
What is another name for a lumbar plexus block
Psoas
283
The saphenous nerve is a terminal extension of what nerve
Femoral
284
Saphenous nerve block blocks sensory innervation of what area
Medial aspect of lower leg
285
Is saphenous nerve block an isolated block?
No
286
Saphenous block is used with what other block to achieve complete analgesia in what region
Sciatic, Below the knee
287
Clinical activity of local anesthetics (LA) are based on what 3 physiochemical properties
1. Lipid solubility
2. Ionization
3. Protein binding
288
Lipid solubility deals what 2 aspects of LAs
Duration of action and potency
289
How does increased lipid solubility affect duration of action and potency
Increased lipid solubility=increased duration and increased potency
290
What 3 LAs have the highest degree of protein binding
Tetracaine > Bupivacaine > Ropivacaine
291
What aspect of LAs does ionization affect
Speed of onset
292
How is speed of onset affected if pH of a solution is close to the pKa
Speed of onset is increased
293
LAs affect what channels
Na+ channels
294
List the pKas of Mepivicaine, Lidocaine, Bupivicaine, Ropivicaine
7.6, 7.9, 8.1, 8.1
295
How does infected tissue affect the speed of onset of LAs
Decreased pH in infected tissues, more LA will be in the charged, hydrophilic form and not cross to the Na+ channels - so decreased speed of onset
296
Do LAs with Epi have a higher or lower pH
Lower, so it takes longer to cross the cell membrane and bind to Na+ channels
297
What part of the LA crosses the cell membrane
The unbound fraction
298
How does increased lipid solubility and duration of action affect protein binding
Increase protein binding
299
What 2 proteins bind LAs
Albumin, alpha acid glycoprotein
300
How does decreased pH affect protein binding
Decreased pH=decreased protein binding=more unbound LA, risk of toxicity
301
Where are amides metabolized
Liver
302
What LAs are in the amide class
Bupivacaine, Lidocaine, Mepivacaine, Prilocaine, Ropivacaine
303
What are the longest acting amide LAs?
Bupivacaine, Ropivacaine (1.5-8hrs)
304
Duration of Lidocaine
0.75-2hrs
305
Duration of Mepivacaine
1-2hr
306
Duration of Prilocaine
0.5-1hr
307
What enzyme are esters metabolized by
Pseudocholinesterase
308
What LAs are esters
Benzocaine, Chloroprocaine, Cocaine, Procaine (Novocaine), Tetracaine
309
All esters have a duration of 0.5-1hr except which one?
Tetracaine - 1.5-6hr
310
What is a complication of benzocaine
Methemoglobinemia - decreases ability of hemoglobin to carry o2
311
What are 3 major risks of nerve blocks
Systemic toxicity, infection, peripheral nerve damage
312
Which needles decrease the risk for peripheral nerve damage
B bevel needles (short bevel)
313
What 6 things determine risk of LAST
1. Site of injection
2. Which LA used
3. Dose
4. Degree of protein binding
5. Degree of acidosis
6. Epinephrine?
314
How does epinephrine affect local anesthetic affect
Slows the rate of absorption via vasoconstriction
315
Peak blood concentrations of LA depend on what
Site of injection
316
Absorption of LA is related to _______ of injection site
Vascularity
317
List injection sites from most to least vascular
Tracheal > intercostal > caudal > epidural > brachial plexus > femoral/sciatic > subcutaneous
318
What is the 1st stage of LAST on the CNS
CNS excitation
319
What pathways are blocked during CNS excitation due to LAST
Inhibitory
320
What are symptoms of LAST during CNS excitation (phase 1)
Dizziness, tinnitis, circumoral numbness, muscle twitches, slurred speech, seizures
321
What is the 2nd stage of LAST on the CNS
CNS depression
322
What pathways are blocked during CNS depression due to LAST
Inhibitory and excitatory pathways
323
What are the symptoms of LAST during CNS depression (phase 2)
Respiratory depression, obtundation, coma
324
What are cardiovascular signs of LAST
Depress myocardial conduction/contractility, arterial vasodilation, hypotension, bradycardia, VT or VA, AV block, PVCs, PACs
325
Whats the only local anesthetic that doesn't produce arterial vasodilation
Cocaine
326
Which local anesthetic avidly blocks cardiac Na+ channels and has a high degree of protein binding, thus making resuscitation difficult
Bupivacaine
327
What are some methods for prevention of LAST
Incremental injection, frequent aspiration, adding a marker, limiting LA dose/concentration, communicate w/ patient
328
What is a good marker for preventing LAST
Epi - 5mcg/ml
329
Patients with which 3 conditions should we proceed with caution when administering local anesthetics
Cardiac conduction problems, kidney/liver disease, acidosis (increases free LA)
330
In what 2 ways does epinephrine improve the quality of the block
Increased neuronal uptake, alpha 2 adrenergic receptor
331
By what percent does HR increase with epinephrine
20%
332
Epinephrine decreases absorption/prolongs action of what types of local anesthetics
short acting LAs like lidocaine and mepivacaine
333
What amount of epinephrine is normally added to Las
5mcg/ml (1:200,000), 2.5mcg/ml (1:400,000)
334
What are 3 pharmacologic treatment options for seizures due to LAST
Midazolam, propofol, thiopental
335
What are treatments for cardiac toxicity/respiratory depression due to LAST
Manage airway, ACLS/BLS (avoid B blockers, Ca+ blockers, lidocaine), IV lipid infusion, cardiopulmonary bypass
336
What drug is used as a lipid treatment for LAST
20% intralipid
337
What is the per kilo dose for a bolus of Intralipid
1.5ml/kg
338
What is the per kilo dose for Intralipid after the inital bolus
0.25ml/kg/min for 30-60min
339
How many times can a bolus of Intralipid be repeated for persistent cardiac collapse
1-2 times
340
Infusion rate of Intralipid could be increased if what declines
Blood pressure
341
What is used during the placement of nerve blocks to test motor response
Peripheral nerve stimulator
342
What is used during the placement of nerve blocks to test sensory response
Paresthesia technique
343
What are the roots of the brachial plexus
Ventral rami
344
Where are the supraclavicular nerves
Cape of the neck, anteriorly to second rib, top of the scapula
345
The intercostobrachial nerve is at what vertebral level
T2
346
Which block provides analgesia for shoulder, humerus, clavicle
Interscalene block
347
Where is an interscalene block performed
At the level of the roots/trunks of brachial plexus, between anterior and middle scalene muscle
348
What are adverse effects and possible complications associated with interscalene blocks
Phrenic nerve palsy, Horner's syndrome, cervical plexus block, RLN palsy, vertebral artery injection, pneumothorax, epidural/spinal injection
349
What is caused from an inadvertant block of the recurrent laryngeal nerve
Hoarseness
350
How many ccs of LA injected into the vertebral artery can lead to seizures
1-3mL
351
What is the most common adverse event following an interscalene block
Phrenic nerve palsy
352
What is referred to as the "spinal of the arm"
Supraclavicular block
353
What block is performed at the level of the divisions of the brachial plexus
Supraclavicular block
354
What block is indicated for surgeries of the entire arm, below the level of the shoulder
Supraclavicular block
355
What risks associated with supraclavicular blocks
Pneumothorax, phrenic nerve palsy, Horner's syndrome, RLN block, vascular puncture
356
What block is indicated for surgeries involving the elbow, forearm, and hand
Infraclavicular
357
What block deals with nerve cords situated around the axillary artery
Infraclavicular
358
What are complications associated with infraclavicular blocks
Vascular puncture, pneumothorax
359
What block is indicated for surgeries involving the elbow, forearm, and hand and is performed at the terminal branches of the medial, ulnar, radial, and musculocutaneous nerves?
Axillary
360
What are complications associated with axillary blocks
Infection, hematoma
361
The arm must be in what position for an axillary block
Abducted
362
Since an axillary block is transarterial, what adjuncts should be used during insertion
Peripheral nerve stimulator, ultrasound
363
Which nerve of the brachial is the most difficult to locate
Radial
364
Blocking the ulnar nerve provides good analgesia for which finger
5th digit
365
Bier Blocks provide anesthesia for surgeries lasting how long
45-60 minutes
366
What block is used for short surgeries of the forearm, hand, or leg
Bier block
367
What type of tourniquet and bandage is required for a bier block
Double pneumatic tourniqet, eschmark elastic bandage
368
What dose/concentration of lidocaine is needed for a bier block
50mL 0.5% lidocaine
369
The lumbar plexus is comprised of the _____ _____ of vertebral levels ___ - ___
ventral rami, L1-L4
370
What are the 4 blocks associated with the lumbar plexus
Iliohypogastric/ilioinguinal
Femoral
Obturator
Lateral femoral cutaneous
371
The sacral plexus is comprised of the ______ _____ of vertebral levels ____ - ____
ventral rami, L4-S3/S4
372
The sciatic nerve branches into what 2 nerves
Common peroneal, tibial
373
Over the last 10 years there has been an increased interest in lower extremity block for what 3 reasons
1) transient neurologic symptoms with spinal anesthesia
2) increased use of thromboembolic prophylaxis
3) evidence of increased early rehabilitation with CPNBs
374
What nerve block is used for surgeries of the hip, anterior thigh, and knee
Lumbar plexus
375
A lumbar plexus block covers what 3 nerves
Femoral, lateral femoral, obturator
376
Whats the distance from skin to lumbar plexus of a deep block
5-10cm
377
What are complications of lumbar plexus blocks
Renal puncture, spinal or epidural injection, hematoma, LAST
378
What is the largest branch of the lumbar plexus, that arises from L2-L4
Femoral
379
What nerve is the posterior division of the femoral nerve and most medial
Saphenous
380
The posterior division of the femoral nerve is associated with what muscles of the leg
Quadriceps
381
The articular branches of the femoral nerve feed what parts of the lower extremity
Hip and knee
382
What nerve is the anterior division of the femoral nerve
Middle cutaneous
383
What muscle is associated with the anterior division of the femoral nerve
Sartorius
384
The femoral nerve emerges from what muscle
Psoas muscle
385
The femoral nerve enters the leg under which ligament
Inguinal
386
In general, femoral nerve blocks fail if the anesthetic is injected superior to what tissue layer
Fascia iliaca
387
What types of knee surgery utilize a femoral nerve block
TKA, ACL reconstruction, patellar surgery
388
What block is used for femoral ORIF, skin grafting, and muscle biopsy surgeries
Femoral
389
Surgeries involving the medial aspect of the lower leg would use what block
Femoral
390
What is the largest branch of the femoral nerve
Saphenous nerve
391
What are the 4 main locations where we can block the saphenous nerve (BAMF)
Below the knee, adductor canal, medial malleolus, femoral
392
For any surgery involving medial aspect of foot/ankle, what nerve must be blocked
Saphenous
393
A saphenous block is usually used in conjunction with what other 2 blocks
Popliteal, sciatic
394
What are the landmarks for a traditional saphenous nerve block
Anterior edge of medial head of gastrocnemius muscle and tibial tuberosity
395
While traditional techniques all have low success rates for saphenous blocks, what approach has high success
Paravenous
396
What 4 areas are good for imaging the sciatic nerve
Popliteal, mid-thigh, subgluteal, transgluteal
397
Which image is hardest to visualize/access the sciatic nerve
Transgluteal b/c of depth
398
What is the largest nerve in the human body
Sciatic
399
What nerve provides sensory innervation to the knee, hip, and below the knee (except medial)
Sciatic
400
The sciatic nerve blocks motor function to what area/muscles
Hamstrings, lower leg below the knee
401
In which surgeries are sciatic nerve blocks indicated
TKA, foot, ankle
402
What are some complications associated with sciatic nerve blocks
Partial block, nerve injury
403
Where is the ultrasound probe placed during a popliteal approach of a sciatic block
Popliteal crease
404
Where are incomplete sciatic blocks common due to anatomical variations
Popliteal fossa
405
The sciatic nerve divides into which 2 nerves above the popliteal fossa
Tibial and peroneal
406
What is the main obstable while doing a subgluteal approach to a sciatic nerve block
Depth of nerve
407
Where is the palpable groove used in a subgluteal approach to a sciatic block
Just lateral to the upper portion of the biceps femoris muscle
408
What block is used for foot and toe surgeries
Ankle
409
What 5 nerves are blocked with an ankle block (DPSSS)
deep peroneal, posterior tibial, sural, sapheous, superfical peroneal
