Principles of Anesthesia Practice I Unit IV Flashcards
1
Q
Why was ultrasound initially used in the OB population?
A
It provided visualization without exposure to radiation
2
Q
Primary advantages of the use of ultrasound?
A
Identify anatomical structures, you can see where the needle is going (and the spread of LA), may decrease time and/or complications
3
Q
At what frequency does ultrasound travel at? Normal audible sound?
A
Ultra = 2 - 20 MHz
Normal sound = 20 - 20,000 Hz or 0.002 - 2.0 mHz
4
Q
What creates the “picture” when using ultrasound?
A
The sound waves interfacing with a surface and either; transmitting, reflecting or something in between
The sound waves that are reflected back to crystals create impulse recorded by the computer
5
Q
Sound transmits through what in the body?
A
Fluid, which creates no signal and is anechoic/dark
6
Q
Sound is in between transmission/reflection through what in the body?
A
Soft tissue/muscle/fat, creating Iso/hypoechoic pattern, or rather, the various shades of grey
7
Q
Sound is reflected through what in the body?
A
Bones/stones which creates lots of signal = hyperechoic or brightness
8
Q
Solid tissues create what pattern on ultrasound? Soft/hollow?
A
Solid = hyperechoic
Soft/hollow = hypoechoic
9
Q
What is inside the head of the transducer probe?
A
Piezo electric crystals
they change shape with electric impulse and vibrate to generate sound waves
10
Q
What frequency does each ultrasound probe operate at?
A
Linear = 7 - 15 MHz
Curvilinear = 2 - 5 MHz
Phased array = 1 - 3 MHz
11
Q
What is the relationship of MHz to resolution?
A
The higher the MHz, the higher/better the resolution
12
Q
Describe static vs dynamic approach using ultrasound
A
Static = identify the target vessel/assess patency, mark site and insert blind
Dynamic = perform the procedure in real time and visualize the needle puncturing the vessel wall
13
Q
How do you hold the transducer proble?
A
Like a pencil
14
Q
What is gain and depth?
A
Gain = brightness/signal quality (goal is fluid is black, soft tissue is mid grey)
Depth = fairly self explanatory, start at a high depth then work to bring object of interest into the middle of the screen
15
Q
Describe in plane and out of plane?
A
In plane = the probe is parallel to the needle
Out of plane = the probe is perpendicular to the needle
16
Q
In plane is primarily used when inserting a needle, why is out of plane still a necessary view?
A
You can still be behind or in front of the vessel which you can’t see on an in plane view, whereas an out of plane view can tell you if you are behind or in front of the vessel
17
Q
What is the primary disadvantage of out of plane view?
A
Unclear where the tip of the needle is
18
Q
What is the only contraindication to ultrasound for IV access?
A
An emergency situation; it takes too long. Get an IO first
19
Q
When would you use a curvilinear probe to obtain IV access rather than a linear?
A
If the patient is obese
20
Q
Primary goal of a FAST exam?
A
To identify the presence of free fluid in the abdomen
there are virtually no contraindications to this exam. A few studies have linked it to pressure-related injuries but this is not a confirmed issue
21
Q
During a FAST exam, what are you examining in the R/L upper quadrant?
A
RUQ = Morison’s pouch (intraperitoneal space between the right live and the right kidney)
LUQ = Peri-splenic view
22
Q
Describe “heeling” when using ultrasound
A
A unique strategy used primarily in peripheral nerve blocks. You want the probe to be parallel to the nerve you are wanting to access, so you may need to dig in the “heel” of the probe to get it parallel to the nerve
23
Q
What is a key safety step to take when you have the needle in the approximate space to inject LA?
A
Verify the nerve doesn’t move with the needle - you don’t want to inject LA directly into a nerve
24
Q
What would a gastric antrum look like if NPO, clear liquid and solid food?
A
NPO = small, empty thick walls
CL = rounder/distended, “starry night” thinner walls
Solid food = hyperechoic and even thinner walls
25
Indications for central access?
Monitoring central venous pressure
Infusion of caustic drugs
Administration of TPN
Aspiration of air emboli
Insertion of transcutaneous pacing leads
Venous access for people with poor peripheral veins
Dialysis access
26
Contraindications to central access?
Renal cell tumor extending into right atrium, tricuspid valve vegetation, site infection and site specific issues (like a femoral line on a patient on tube feed - too much, uh, "rectal flooding")
27
Complications of attempting central access?
Pneumo/hemo, line infection, carotid puncture, dysrhythmias, trauma to nearby nerves
28
What anatomic structures help guide IJ line placement?
A triangle in the neck made by the sternocleidomastoid and the scalene muscle
29
Ideal position for IJ central line insertion?
Trendelenburg (increase venous return and reduce risk of air embolism)
30
What area of the body should be prepped for IJ CVC insertion?
Chin to sternum to shoulder to neck to ear
31
What do you drape prior to CVC insertion?
Head to foot and side to side
32
What is the purpose of the seeker needle?
A small 25 gauge to need to identify if you are in a vein/artery using a small needle so that if you puncture an artery it should self seal
33
Describe the needle with catheter technique
(this is what you commonly saw in the ICU) you hit the desired vessel with the needle, once in, you removed the needle and left the catheter behind to then insert a guidewire (older techniques have you hook up a tube to identify venous vs arterial cannulation)
34
Basic way to identify an artery vs a vein on ultrasound?
A vein is compressible, thinner walled, and generally larger
35
What type of wire is the guide wire?
A J-wire
36
What is the most important step regarding use of the guidewire?
Never let go of the guide wire (J-wire)
37
Why do you try to insert a CVC using a twisting motion?
It helps "screw" itself into the vascular wall
38
What must be done to allow removal of the wire after the catheter has been advanced?
Remove the cap on the CVC
39
What vessel is 14 cm away from the cavo-atrial (costo-phrenic) junction?
RSC
40
What vessel is 15 cm away from the cavo-atrial (costo-phrenic) junction?
RIJ
41
What vessel is 18 cm away from the cavo-atrial (costo-phrenic) junction?
LIJ
42
What vessel is 17 cm away from the cavo-atrial (costo-phrenic) junction?
LSC
43
What 3 factors are you evaluating on CXR after CVC insertion?
Catheter tip position, presence of a wire, and no pneumo/hemo
44
Where has the CVC been inserted?
RIJ
45
Where has the CVC been inserted?
LIJ
46
What complication has occurred here?
Pneumo
47
What complication has occurred here?
Hemo
*note how there is still viable lung tissue above, and the loss of the lower quadrant sharp notch. There is also a solid white mass where lung tissue should be. Those details differentiate this from a pneumo*
48
What is the definition of cutanenous?
Something that is sensory and peripheral
*peripheral motor conduction is different than cutaneous innervation*
49
What is a bundle of neurons/axons in and outside the CNS called?
In the CNS = tracts
Outside the CNS = nerves
50
What is the term for a bundle of cell bodies in the CNS vs the PNS called?
CNS = nuclei
PNS = ganglia
51
Describe how neurons organize themselves as they exit the CNS
They form rootlets, which then come together and form an anterior/posterior root (which may include ganglia, usually in the dorsal root), both roots come together and form a spinal nerve. From that nerve, various other smaller nerves can branch out
52
What is the basic function of the anterior/posterior spinal cord
Anterior = efferent motor function
Posterior = afferent sensory function
53
What is generally the first branch points of the spinal nerve?
It will branch into a posterior and anterior ramus (anterior is bigger)
54
What are the basic functions of the anterior/posterior rami?
Posterior = sensory innervation to the posterior side of the body (it does have some minor motor innervation as well, but is almost exclusively sensory)
Anterior = mixed motor and sensory function for the anterior aspect of the body
55
How does information from the ANS get to the SNS?
Via the pathway that connects the anterior ramus to the sympathetic chain via small projections called the rami communicans
56
What are the types of rami communicans?
White and grey
57
What important structure runs parallel to the spinal cord and connects to the ANS via the rami communicans?
The sympathetic ganglionic chain
58
What is the basic difference between the L/R sympathetic ganglionic chain?
The left chain is more posterior and lateral than the right because the aorta forces the left chain to be more posterior/lateral
59
What branches of the posterior ramus tend to stay midline and provide cutaneous innervation to the back?
The medial branches of the posterior ramus
60
What branches of the posterior ramus are further out to the side of the body?
The lateral branches of the posterior ramus
61
What does the anterior ramus form at the sternum?
It branches out at the sternum creating the anterior cutaneous branches
62
What branch of the anterior ramus covers the sides of the body (think ribs)?
The lateral branches of the anterior ramus
63
What is the other name for the anterior ramus at the thoracic level?
The intercostal nerve (1 per level of the spinal cord)
64
The 3rd rib would have what intercostal nerve associated with it?
The 3rd intercostal nerve
65
How many cervical dermatomes are there?
7
*C1 does NOT have any sensory function, so it does not have a dermatome associated with it*
66
What general region do the clunial nerves innervate?
The lower back and to top of the butt
67
What are the 3 primary thoracic dermatome landmarks Schmidt mentioned in lecture?
T4 = nipple line
T6 = xiphoid
T10 = umbilicus
68
The phrenic nerve arises from what vertebrae?
C3 - 5 (they are all anterior rami as well)
69
How does breathing change with a high T-spine lesion?
Phrenic nerve is still intact; so you would lose respiratory accessory muscle function. You could still breath, but your ability to increase respiratory effort would be impaired
70
Describe the location of the lesser occipital nerve relative to the greater occipital nerve
It is a smaller nerve and is positioned lower and slightly more lateral than the greater occipital nerve
71
What level does the greater occipital, suboccipital and 3rd occipital nerve emerge from?
GO = C2
3rd = C3
Sub = C1 (purely motor)
72
Primary function of the trapezius muscle?
Assist with ventilation
73
What is the name of the posterior ramus of C1?
The suboccipital nerve - innervates motor function of deep muscle packages
74
What is the highest dermatome in the body?
The C2 dermatome = innervated by the greater occipital nerve
75
What area does the greater occipital nerve innervate?
It innervates the area around/down from the ear
76
What are the anterior rami nerves that branch off of C2 - 4?
Lesser occipital, greater auricular, transverse cervical and supraclavicular nerve
77
What anterior rami emerges from C2?
Lesser occipital nerve
78
What anterior rami emerges from C2/3?
The great auricular and transverse cervical nerves
79
What anterior rami emerges from C3/4?
Supraclavicular nerve
80
What are the 4 nerves of the cervical plexus?
The lesser occipital, greater auricular, transverse cervical and supraclavicular nerves
81
Of the cervical plexus, what nerve(s) contributes to the phrenic nerve and innervates the diaphragm and pericardium?
Supraclavicular nerve
82
Of the cervical plexus, what nerve(s) form the motor part of the cervical plexus and innervate the infrahyoid muscles except the thyrohyoid muscle?
The lesser occipital, great auricular and transverse cervical nerves
83
What muscle does the phrenic nerve sit on?
The anterior scalene muscle
*per lecture, it "rides" next to the middle scalene muscle*
84
What levels of the spine contribute to the brachial plexus?
C5 - T1
85
What type of nerves exclusively make up the brachial and cervical plexi?
Anterior rami
86
What muscles create the interscalene space?
The middle scalene and anterior scalene muscle
87
What structures do the rami combine to form as you go further and further down a plexus?
Rami -> trunks -> divisions
88
What levels does the upper trunk emerge from?
C5/6
89
What levels does the middle trunk emerge from?
C7
90
What levels does the lower thoracic trunk emerge from?
C8/T1
91
Describe how the nerves branch off the trunks of the brachial plexus
Each trunk creates 2 divisions, an anterior and posterior division
92
What brachial plexus divisions make up the posterior cord?
The 3 posterior divisions of each trunk
93
What brachial plexus divisions make up the lateral cord?
The 2 anterior divisions of the upper/middle trunk
94
What brachial plexus divisions make up the medial cord?
The anterior division of the lower trunk
95
After the divisions of the brachial plexus become cords they become what?
The infraclavicular branches of the brachial plexus
96
What are the terminal branches of the posterior cord?
The axillary and radial nerves
97
What does the lateral cord divide into?
The musculocutaneous nerve and lateral root
98
What structures combine to form the median nerve?
The lateral root of the lateral cord and the medial root of the medial cord
99
What does the median cord divide into?
The ulnar nerve and a portion of the median nerve
100
What level(s) does the radial nerve originate?
C5 - T1
101
What level(s) does the axillary nerve originate?
C5/6
102
What level(s) does the ulnar nerve originate?
C7 - T1
103
What level(s) does the median nerve originate?
C6 - T1
104
What level(s) does the musculocutaneous nerve originate from?
C5 - 7
105
What does the axillary nerve cutaneously innervate?
The lateral deltoid
106
What does the radial nerve provide cutaneous innervation to?
Anterior = The lateral/anterior biceps/triceps of the upper arm and a small part of the lateral wrist
Posterior = the thumb and index/middle finger and much of the middle posterior arm
107
What sensory area does the ulnar nerve primarily innervate?
The medial wrist and pinky/ring finger
108
What does the median nerve primarily innervate?
Anterior = the palm and pads of the thumb and first 3 fingers
Posterior = the middle 3 fingertips
109
What does the anterior thoracic rami branch into?
The anterior and lateral cutaneous branches
110
What are the nerves that branch off anteriorly off the T-spine that do not directly run in line with the ribs?
The subcostal nerves (though they are still technically intercostal nerves)
111
What parts of the spine contribute to the lumbar plexus? Sacral plexus?
L = L1 - 4
S = L4 - S4
112
What thoracic nerve(s) may be able to connect to the lumbar plexus?
T12 (connecting to the iliohypogastric nerve)
113
How many nerves make up the lumbar plexus?
6
114
List the lumbar plexus nerves from top to bottom
Iliohypogastric
Ilioinguinal
Genitofemoral
Lateral cutaneous
Obturator
Femoral nerve
*I I Get Leftovers On Fridays*
115
What spinal level(s) contribute to the iliohypogastric nerve?
L1
116
What spinal level(s) contribute to the ilioinguinal nerve?
L1
117
What spinal level(s) contribute to the genitofemoral nerve?
L1 - 2
118
What spinal level(s) contribute to the lateral cutaneous nerve of the thigh?
L2 - 3
119
What spinal level(s) contribute to the obturator nerve?
L2 - 4
120
What spinal level(s) does the femoral nerve originate from?
L2 - 4
121
What is the primary function of the Psoas major?
Helps with posture
122
What muscle does the iliohypogastric, ilioinguinal and genitofemoral all run in close to proximity to?
The Psoas major muscle
123
What do the branches of the iliohypogastric innervate?
The lateral cutaneous branch innervating the lateral hip
The anterior cutaneous branch follows the inguinal ligament and borders the reproductive organs
124
What is the motor function of the iliohypogastric?
It innervates the transversus abdominis and the internal abdominis (primary one is the transversus)
125
What are the sensory branches of the ilioinguinal nerve?
One heads inferiorly to cover a small patch of the medial upper thigh, the other provides sensory innervation to the reproductive organs
126
What is the motor function of the ilioinguinal nerve?
Innervates the internal oblique
127
What are the 2 branches of genitofemoral nerve?
Femoral and genital
Femoral = upper part of the thigh
Genital = provides sensory innervation to the reproductive organs
128
What does the genitofemoral nerve uniquely innervate in men?
It provides a motor connection to the cremasteric reflex (stroking the upper/inner thigh causes the cremaster muscle to contract)
129
What anatomic structure surrounds the obturator foramen?
The ischial tuberosity
130
What muscles make up the femoral triangle?
The sartorius, iliopsoas pectineus and the adductor longus
131
What nerve branches off the femoral nerve that contributes to the majority of sensory innervation to the lower extremity?
The saphenous nerve
132
What muscles surround the adductor canal?
The sartorius muscle, adductor longus and the vastus medialis
133
What nerve are we targeting in the adductor canal?
The saphenous nerve
134
What is the primary function of the LCA (lateral cutaneous nerve of the thigh)?
Sensory innervation of the anterior/lateral thigh
135
What is the basic function of the obturator?
Primarily motor in function
136
What is the area of sensory innervation of the obturator?
A small cutaneous branch that covers a small part of the medial thigh
137
What muscles does the femoral nerve innervate?
Iliopsoas, pectineus, sartorius and quadriceps femoris
138
What are the sensory branches of the femoral nerve?
Anterior cutaneous = innervates the medial thigh
Saphenous nerve = medial side of the lower leg and part of the posterior thigh
139
What levels does the superior gluteal nerve emerge from?
L4 - S1
140
What levels does the inferior gluteal nerve emerge from?
L5 - S2
141
What levels does the posterior cutaneous nerve of the thigh emerge from?
S1 - 3
142
What levels does the sciatic nerve emerge from?
L4 - S3
143
What levels does the pudendal nerve emerge from?
S2 - 4
144
What muscles does the superior gluteal nerve innervate?
The gluteus medius, tensor fasciae latae and the gluteus minimus
145
What muscle does the inferior gluteal nerve primarily innervate?
The gluteus maximus
146
What nerves provide sensory innervation to the gluteal region?
The superior/middle/inferior clunial nerves and the lateral branch of the iliohypogastric nerve
147
What nerves combine to make the sciatic nerve?
The tibial nerve and the common fibular nerve
148
What is the other/older name of the common fibular nerve?
Peroneal nerve
149
What is the largest diameter nerve in the body?
Sciatic nerve
150
What are the branches of the common fibular (peroneal) nerve?
Lateral sural cutaneous (sensory innervation of the lateral and back of calf and part of the lateral front of the shin)
Superficial fibular nerve (innervates the top of the foot and has it's own 2 branches: the medial dorsal cutaneous nerve and intermediate dorsal cutaneous nerve)
Deep fibular nerve (innervates the space in-between the big toe and index toe via 2 branches, the lateral cutaneous and medial cutaneous nerve)
151
What are the 4 branches of the tibial nerve?
Medial sural cutaneous, medial calcaneal, lateral calcaneal and lateral dorsal cutaneous branch
152
What does the medial sural cutaneous branch innervate?
Sensory innervation to the back part of the leg
153
What does the medial calcaneal branch innervate?
Innervates the heel and bottom of the foot
154
What does the lateral calcaneal branch innervate?
Innervates the lateral side of the foot
155
What does the lateral dorsal cutaneous branch innervate?
Covers a portion of the back of the leg
156
Primary functions of the pudendal nerve?
It has sensory function in the pelvis, rectum/colon and reproductive functions of men
157
What does the posterior cutaneous nerve of the thigh innervate?
It takes care of of the sensory innervation of the superficial hamstring, mostly pain
158
What cranial nerves are primarily motor?
Oculomotor (III)
Trochlear (IV)
Abducent (VI)
Accessory (XI)
Hypoglossal (XII)
159
What cranial nerves are pure sensory?
Olfactory (I)
Optic (II)
Vestibulocochlear (VIII)
160
What cranial nerves are primarily involved with ocular motor function?
The oculomotor (III), trochlear (IV) and abducent (VI)
161
What cranial nerve controls 4/6 muscles of the eye?
Oculomotor
*Trochlear controls the superior oblique of the eye and the abducent controls the lateral rectus*
162
What muscle(s) does the accessory (XI) nerve innervate?
sternocleidomastoid and the trapezius
163
What areas does the hypoglossal (XII) innervate?
Motor innervation to the tongue and floor of the mouth
164
What is the primary function of the vestibulocochlear (VIII) nerve?
It assists with our hearing and balance
165
What type of neurons send information to the olfactory bulbs?
2nd order neurons - they go through the cribriform plate
166
What are the bones of the eardrum?
Malleus, incus and stapes
167
What are the mixed function cranial nerves?
Trigeminal (V), Facial (VII) Glossopharyngeal (IX) and Vagus (X)
168
Primary innervation of the trigeminal (V) nerve?
Sensory to the front of the head and muscle innervation for chewing
169
Primary innervation of the facial (VII) nerve?
Sensory for taste, salivation and crying. Motor innervation of the face
170
What are the muscles of chewing?
Masseter and temporalis muscles
171
What cranial nerve is involved with the submandibular, lingual and lacrimal glands of the face?
The facial (VII) nerve
172
What nerve innervates the parotid gland?
Glossopharyngeal (IX) nerve
173
What is the sensory function of the glossopharyngeal (IX) nerve?
Posterior 1/3 of the tongue, oropharynx soft palate, chemoreceptors of the carotid body and baroreceptors of the carotid sinus
174
What is the outer covering of the nerve?
Epineurium
175
What surrounds the nerve fascicles?
Perineurium
176
What surrounds the individual axons?
Endoneurium
177
What is the starting point for our high neck blocks?
The supraclavicular fossa
178
What are the ECF compartments?
Interstitial: lymphatics and protein-poor fluid around cells
Intravascular: plasma volume
Transcellular: GI tract, urine, csf, joint fluid, aqueous humor
179
What is the difference between diffusion and osmosis?
Diffusion = movement of solutes from high to low concentration across a semi-permeable membrane
Osmosis = movement of water from and area of low solute concentration to an area of high solute concentration
180
What is the primary ECF cation? Primary ICF cation?
ECF = Na
ICF = K
181
What factors can affect osmotic pressure?
Temperature, number of molecules and volume
P = nRT / V
182
What is the difference between osmolarity and osmolality?
Osmolarity = number of osmotically active particles/L of solvent
Osmolality = Number of osmotically active particles per kg of solvent
183
Normal osmolality range?
280 - 290 mOSM
184
What are the primary molecules that contribute to oncotic pressure?
Albumin, globulins and fibrinogen
185
What is the definition of oncotic pressure?
The component of total osmotic pressure due to colloids
186
What is the average daily liquid intake from solids, metabolism and liquid intake?
Solids = 750 ml
Metabolism = 350 ml
Liquid = 1400 ml
187
What is the average output from insensible loss, GI loss and urine output?
Insensible = 1000 ml
GI = 100 ml
UOP = 0.5 - 1 ml/kg/hr
188
How much does urinary secretion account for total daily water loss?
About 60%
189
What 3 hormones control our UOP?
ADH - renal H2O excretion in response to plasma tonicity
ANP - activated with ↑ fluid volume, so increased atrial stretch = increased renal excretion
Aldosterone - If Na+ and fluid volume ↓ aldosterone is released causing Na+ and H2O conservation
190
What sensors help control our overall fluid balance?
Hypothalamic osmoreceptors, low pressure baroreceptors and high pressure baroreceptors
*all trigger increased thirst and/or ADH release*
191
Where would you find high/low pressure baroreceptors?
High = carotid sinus and aortic arch
Low = large veins and RA
192
What are some compensatory mechanisms the body can use to compensate for lost volume?
Venoconstriction
Mobilization of venous reservoir
Autotransfusion from ISF to plasma
Reduced urine production
Maintenance of CO…tachycardia, increased inotropy
193
Where is renin released from? What does it do?
Released from JGA cells and cleaves angiotensinogen to make angiotensin I
*AG I then turns into AG II which causes vasoconstriction and aldosterone release*
194
Where is aldosterone released from?
Adrenal cortex - retains salt and water
195
Assuming no other loss of volume, how long does it take for the RAAS to restore lost volume?
12 - 72 hours
196
How long does it take the body to restore lost RBCs?
Via erythropoiesis, it takes 4 - 8 weeks
197
What fluids have the greatest (top 3) osmolarity?
Albumin, hetastarch then NS
198
What fluids have the lowest osmolarity (list 3)?
D5, LR then plasmalyte
199
What fluid does NOT have an osmolarity value?
Isolyte P
200
How long do crystalloids stay in the ECF?
70% is still in after 20 minutes, only 50% after 30 minutes
201
What can occur to coagulation with excess fluid administration?
It dilutes anticoagulant factors, making it easier to create blood clots (hypercoagulable state)
202
What are some of the negative effects of NS usage?
Dilutes hct and albumin
Increases cl- and K+ concentrations
Late onset of diuresis
Causes hyperchloremic metabolic acidosis
Increased AKI and RRT in critical care patients
203
What is the primary contraindication to LR?
Liver patients
*LR has lactate in it as a buffer, which requires hepatic metabolism to process*
204
Why does LR lead to faster water excretion than NS?
LR suppresses ADH secretion which allows for diuresis
205
What are the 2 categories of colloids we administer?
Semi-synthetic colloids and human plasma derivatives
206
What are 2 concerns with IV colloid administration?
May cause hemodilution (decreasing plasma viscosity which inhibits RBCs aggregation) and may have effects on the immune, coagulation and renal systems (these uncertain effects are mitigated with strict maximum dosages)
207
How long does hydroxyethyl starch stay in the ECF?
70 - 80% is still present at the 90 minutes mark
208
Metabolism of hydroxyethyl starch is dependent on what?
The molecular weight of the molecules
209
What are some general side effects to watch for related to the molecular weight of colloids?
Coagulopathy d/t dilution of clotting factors and renal dysfunction
210
How long can dextran stay in the ECF?
6 - 12 hours
211
What type of colloid is popular in microvascular surgery?
Dextran-40, by inhibiting clotting factors it can help keep blood flowing to small vasculature, valuable if trying to reattach small limbs
212
What is the MOA of dextran-40 interfering with cross-matching?
By coating the RBC it can interfere with the cross-matching test
213
What are the common human plasma derivatives?
5% albumin and immunoglobulin solution
*valuable as volume replacement for trauma, sepsis or replacement s/p paracentesis*
214
What are the common preop and intraop causes of fluid alterations?
*enjoy a chart*
215
What are some s/sx of low intravascular volume?
Tachycardia, decreased pulse pressure, hypotension and decreased cap refill (these generally do not occur until 25% of volume is lost), drop in UOP, decreased CVP and lab values indicating poor tissue perfusion (lactate, mixed venous)
216
What are the negative outcomes of high intravascular volume?
↑ capillary hydrostatic pressure
Excessive fluid development in lungs, bowel, muscle
Decreased gut motility
Reduced tissue oxygenation
Poor wound healing
Hypo/hyper coagulopathy
217
What are the 3 factors classic fluid therapy focuses on?
NPO deficit, ongoing maintenance and anticipated surgical loss
218
How long do you need to be NPO for: clear liquids, breast milk, infant formula, light meal, meat/fatty fried food?
Clear liquids: 2 hours
Breast milk: 4 hours
Infant formula: 6 hours
Light meal: 6 hours
Meat/fatty, fried: 8 hours
*ERAS is changing this, it's starting to become more acceptable to administer carbohydrate solutions like Gatorade prior to surgery*
219
What is the classic approach for NPO/maintenance fluid?
4 ml/kg/hr for first 10kg
2 ml/kg/hr for 2nd 10 kg
Each kg over 20 kg is 1 ml/kg/hr
220
Using the 4:2:1 rule, what is the hourly fluid rate for: a 160 kg patient, 120 kg patient and 55 kg patient
160 kg = 200 cc/hr
120 = 160 cc/hr
55 = 95 cc/hr
221
What would be the total deficit if NPO for 6 hours for a 200 kg patient? 35 kg?
200 = 1440 cc
35 = 450 cc
*hours npo x the fluid need using the 4:2:1 rule*
222
For a fluid deficit calculated using the 4:2:1 rule, during what timeframes would you replace each fraction of the fluid deficit?
½ in the 1st hour of surgery.
¼ in the 2nd hour.
¼ in the 3rd hour.
223
How much blood does a lap sponge absorb? A raytech? 4x4?
Sponge = 100 ml
Raytech = 20 ml
4x4 = 10 ml
224
How much fluid do you lose to evaporative/redistribution losses?
Minimal= 0-2 ml/kg/hr
Moderate = 2-4 ml/kg/hr
Severe = 4-8 ml/kg/hr
225
When do you apply the parkland formula to guide burn related fluid resuscitation?
When 20% BSA or greater has 2nd or 3rd degree burns (LR is generally the fluid of choice)
226
How much fluid do you give for a burn patient who meets the criteria for fluid based on the parkland burn resuscitation formula?
4 ml/kg/%BSA burned
1/2 over the first 8 hours, 1/2 over the next 16 horus
227
What factors help guide goal directed fluid therapy?
Cvp: not super specific
Swan: use declining
Svo2: measures o2 extraction
TEE: quantify LV cavity size/EF
CO
Lactate levels: decreasing level signals successful resuscitation
SV
Svv
228
Why is goal directed therapy gaining traction as a guide for fluid resuscitation?
It gives us a framework to decide if we need more fluid, pressors, inotropes or blood products
*Studies: less AKI, respiratory failure, wound infection, and improved mortality rates*
229
How much fluid replacement does goal directed therapy devices assume the patient is receiving in the OR?
1 - 3 ml/kg/hr of crystalloid
230
What are the limits to SVV mechanics?
LIMITS
Low hr/rr
Irregular heart beats
Mechanical ventilation (with low tidal volume)
Increased abdominal pressure
Thorax open
Spontaneous breathing
231
What are the 3 types of monitoring commonly used in goal directed therapy?
Systolic pressure variation
Max systolic pressure - minimal systolic pressure
during one cycle of mechanical breath
Pulse pressure
Difference between systolic and diastolic BP
Stroke volume variance
The variation of SV in 30 seconds
Normal SVV is 10-15%
232
List the structures in the femoral triangle from most lateral to medial
Femoral nerve, artery then vein
*so from lateral to medial is NAV*
233
What nerve(s) are branches of the posterior cord?
Axillary and radial nerves
234
What nerve(s) receive innervation from the lateral cord?
Musculocutaneous and median nerve
235
What nerve(s) receive innervation from medial cord?
Median and ulnar nerve
236
List the supraclavicular structures of the brachial plexus
The anterior rami, the trunks and the divisions
*so everything from the cords and further distal is part of the infraclavicular structures of the brachial plexus*
237
What structure(s) is immediately proximal to the origin of the median nerve?
The lateral/median root
*where the lateral cord and medial cord meet before combining to become the median nerve*
238
What nerve of the brachial plexus receives innervation from more levels of the c-spine than the other nerves of the plexus?
Radial nerve - receives innervation from C5 - T1
*next one would be the median nerve - receives innervation from C6 - T1*
239
What are the motor cranial nerves of the eyes?
Oculomotor (III), Trochlear (IV) and Abducent (VI)
*Oculomotor innervates 4 muscles, Trochlear innervates the superior oblique and the Abducent innervates the lateral rectus*
240
Why do signals from the olfactory system have the ability to be tied/related/combined to memories?
Because they are processed in the frontal cortex - where memories are also processed
241
Where is sound processed in the brain?
Temporal lobe - the vestibulocochlear system lies close to the temporal bone
242
What is the primary sensory nerve of the ophthalmic division of the trigeminal nerve?
The supraorbital nerve
*the supratrochlear is the other and covers the top of the nose, the supraorbital has more coverage*
243
What is the primary sensory nerve of maxillary division of the trigeminal nerve?
The infraorbital nerve
*The other nerve coming off this are the palatine nerves that supply innervation to the roof of the mouth*
244
What opening allows the primary sensory nerve of the maxillary division of the trigeminal nerve to exit the skull?
The infraorbital foramena - allowing the infraorbital nerve to exit
245
What branch of the trigeminal nerve innervates most of the lower jaw?
The inferior alveolar nerve - a branch of V3
246
What is the exit point for the sensory nerve covering most of the lower jaw?
The mental foramena - allowing the inferior alveolar nerve, a branch of V3, to exit and once it has exited it is now the mental nerve
247
What nerve gives us anterior coverage of 2/3 of the tongue?
The lingual nerve - a branch of V3
248
What is the first laryngeal branch?
A pharyngeal constrictor branch
249
What is the layer in between the epineurium and the perineurium?
Inner perineurium
