Truelearn first pass Flashcards
1
Q
Correction of DKA
A
1st. FLUIDS! hydrate
2. Insulin
3. Monitor K throughout
2
Q
Lab to monitor for DKA
A
q1h glucose
q4h BMP, plasma osmolality, venous pH
progress: beta-hydroxybutyrate and anion gap
3
Q
Correction rate of glucose for DKA
A
less than 100 per hour
-brain needs to adapt to changes in plasma osmolality
-if corrected too quickly -> cerebral edema
4
Q
Where to block superficial cervical?
A
midpoint of posterior border of SCM
5
Q
What does superficial cervical block cover?
A
Surgeries w/ neck, anterior shoulder, and clavicle
-distribution of C2-4
6
Q
Superifical cervical block
A
7
Q
Hypoplastic L heart blood circulation
A
dpt on PDA for systemic BF
-balance b/w pulm and systemic BP
8
Q
What happens when pt w/ hypoplastic L heart induced w/ 100% FiO2 -> hypoTN
A
-if dec in PVR -> more blood shunted to pulm not body -> dec in BP -> shock
9
Q
Goal SpO2 of hypoplastic L heart
A
85% -> keep inc PVR
9
Q
Goal SpO2 of hypoplastic L heart
A
85% -> keep inc PVR
10
Q
Determinants of PVR
A
PaO2 (hypoxic pulm vasoconstriction)
PaCO2 (hypercarbic constriction)
temp
intrathoracic pressure
11
Q
Vent changes to inc PVR
A
Dec FiO2
Dec minute ventilation
inc intrathoracic pressure
To dec PVR:
augment w/ preload optimizations and milrinone
12
Q
Order of repair for hypoplastic L heart syndrome
A
Not Gonna Fly
Norwood
Glenn
Fontan
13
Q
pregnant pt w/ CP, hemoptysis, dyspnea
A
PE
14
Q
Pregnant pt concern for PE,normal CXR, what confirmatory test?
A
V/Q scan
15
Q
Pregnant pt concern for PE, abnormal CXR, what confirmatory test?
A
CT pulm angiography
16
Q
Supraglottic jet ventilation
-where to attach
-disadvantages
A
instrument, used for surgeries w/ proximal airway structures
-greater movement of VC
-requires precise alignment of jet w/ axis of trachea
-entrains more ambient air
-no reliable EtCo2
-greater risk of jetting airway contaminants (purulent material, surgical smoke, blood, other debris)
17
Q
What is jet ventilation
A
High pressure bursts of gas into airway -> low TV w/ passive expiration
18
Q
What do we set for jet ventilation
A
Driving pressure
Inspiratory time
Respiratory rate
19
Q
Complications of jet ventilation
A
barotrauma
air trapping
hypercapnia
PTX
20
Q
Subglottic jet ventilation
-advantages
A
-lowe rairway pressures
-tighter control over O2 concentration
-improved EtCO2 monitoring
-minimal airway contamination
21
Q
Subglottic jet ventilation
-disadvantages
A
req special catheter be inserted past VC -> can impair surgeons view
22
Q
High-freq jet ventilation
-what is it?
A
Automated mode
-inspirations at supraphysiologic rates (up to 300 per minute)
-motionless pt
-assessment of ventilation hard, and expensive
23
Q
Low-freq jet ventilation
A
manual
-operation of handheld valve by anesthesia
-low TV controlled manner
-simple and reliable
-higher airway pressures
24
How common is preeclampsia?
5% of all pregnancies
25
MOA of preeclampsia
-abnormal implantation of myometrial spiral arteries
-normally remodel to inc uterine BF
-in preeclampsia -> can't remodel adequately -> high resistance in arterial flow -> stress response -> inc release of vascular mediators -> inc vascular resistance
-b/c uterine BF not autoregulated -> maternal systemic vasculature inc to compensate for optimal BF to uterus
26
What inflammatory cytokine especially involved in preeclampsia
Thromboxane
-inc vascular tone and plt aggregation
27
Why pulm edema or renal prob w/ preeclampsia?
High SVR -> dec renal BF
-pulm edema 2/2 capillary leakage
28
Preeclampsia dx
new-onset HTN after 20 weeks gestation w/ proteinuria OR w/ severe features
1. systolic >140 or diastolic >90 after 20 weeks or 2 occasions 4 hrs apart
AND
2. Proteinuria of 300 mg > 24 hrs or Protein:Cr of > 0.3
OR
thromboctopenia
inc cr
visual symp
AST/ALT inc
pulm edema
29
Preeclampsia w/ severe features
1. systolic > 160 or diastolic > 110
2. visual or cerebral symp (blurry vision, HA, AMS)
3. thrombocytopenia < 100k
4. Cr > 1.1 or greater than 2x baseline Cr
5. AST and ALT >2x normal or RUQ pain (inflammation and stretching of liver capsule)
6. pulm edema
30
Endothelial cells preeclampsia
abnormal and dysfunctional -> produce less nitric oxide and prostacyclin and more thromboxane -> profound vasoconstriction
**why pts at high risk or hx take ASA (dec thromboxane)
31
What med to take if high risk for PEC or hx of PEC?
ASA (dec thromboxane b/c COX inh) -> vasodilating
32
What meds to avoid in Myasthenia Gravis?
-CCB and Mg
-Aminoglycoside Abx (potentiate autoantibodies)
-Neostigmine (combined w/ home pyridostigmine makes it hard to quantify reversal) -> use sugammadex
33
RF for MG post op mechanical ventilation in thymectomy via median sternotomy
1. Dx duration > 6 years
2. Chronic respiratory illness
3. Pyridostigmine dosage > 750 mg/day
4. VC < 2.9 L
RF not specific to surgical approach:
1. EBL > 1L
2. Serum anti-ACh receptor titer > 100 nmol/mL
3. Pronounced dec response (18-20%) on low-freq repetitive n stimulation
34
RF for mechanical ventilation in MG in minimally invasive thymectomy approach
1. Advanced stage of MG (bulbar involvement)
2. BMI > 28
3. Hx of prior myasthenic crisis
4. Assoc w/ pulm resection
RF not specific to surgical approach:
1. EBL > 1L
2. Serum anti-ACh receptor titer > 100 nmol/mL
3. Pronounced dec response (18-20%) on low-freq repetitive n stimulation
35
How do volatile anesthetics inc CBF?
direct effect on vascular smooth m -> dec CVR causing vasodilation -> inc ICP
36
Effects of volatile anesthetics on CBF and CMR
CMR: dec in dose-dpt manner
-< 0.5 MAC red CBF
- > 1 MAC inc CBF due to attenutation of cerebral autoregulation -> vasodilation
37
Vasodilating potency of volatile anesthetics
halothane > enflurane > des = iso > sevo
38
Ketamine ICP, CBF, CMR
increase in all
***blunted if given w/ midaz, prop, volatiles
39
Which one is the inferolateral segment?
B
A: mid inferior segment
C: mid anterior segment
D: mid inferoseptal segment
40
When to use pulse wave doppler on a TEE?
measure BF velocities through pulm veins, mitral v, and in low flow areas of the heart
41
When to use a continuous wave doppler on TEE?
measure BF velocities through aorta, aortic valve, stenotic valve lesions, and regurgitant valvular jets
42
When to use color flow doppler on TEE?
enhance recognition of valvular abnormalities, aortic dissections and intracardiac shunts
43
RF for inc periop anxiety peds
-younger children (1-5)
-higher cognitive fxn w/ shy or withdrawn personalities
-children w/ anxious parents
44
How does a pt get shingles
Get VZV (usually chicken pox) -> dormant in dorsal ganglia -> immunocompromised -> reactivation
45
Which dermatomal distribution MC in acute herpes zoster?
MC:
1. thoracic spinal n
2. ophthalmic division of trigeminal n
3. maxillary division of trigmeinal n
4. cervical spinal roots
5. sacral spinal roots
46
succ and IOP
Increase for 10 minutes (likely due to extraocular m contraction)
47
What dec IOP?
Benzos
Barbs (Thiopental)
Inhaled anesthetic
48
RF for PDPH
- young age (peak early 20s)
-pregnancy
-hx of HAs
-smaler guage (larger bore) cutting needles
-greater # of dural punctures
-skill of operator
49
Quincke
Cutting needle
50
Whitacre
blunt needle
51
Early symptoms of ASA toxicity
tinnitus
N/V/D
vertigo
Resp alkalosis (hyperventilation) -> acts directly on resp center in medulla to inc resp drive
52
Late symp of ASA toxicity
-AMS
-hyperthermia
-noncardiogenic pulm edema
-AG metabolic acidosis
53
Why acidosis w/ ASA toxicity
inhibits citric acid cycle and causes uncoupling of oxidative phosphorylation
54
What type of hepatectomy does an adult undergo that is donating to a child?
L hepatectomy
(Segments II, III, and IV)
-technically easier to perform and requires less donor-liver volume
55
What type of hepatectomy does an adult undergo that is donating to an adult?
R hepatectomy
(segments V-VIII)
-more difficult procedure, larger volume of liver
56
When does PT return to normal in a donor hepatectomy?
POD 5
57
What is reported to the National Practitioner Databank?
-malpractice payments and settlements
-punitive action taken by peer-review organizations, professional societies, or accreditation organizations
-administrative actions that occur as a result of a professional review
58
When does EtCO2 conc reach max value w/ laproscopic surgeries?
40 minutes if ventilation constant
59
Why diagnostic lap trendelenberg pulse ox dec to 95% and EtCO2 inc to 40?
inc intraabd pressure -> dec diaphragmatic excusion -> restricting lung expansion -> V/Q mismatch -> pulm shunting
60
Capnothorax
CO2 diffusion into intrapleural space
-inc EtCO2 conc and inc mean airway pressure
**doesn't need chest tube b/c CO2 rapidly absorbed once pneumoperitoneum released
61
Carboprost tromethamine MOA
analogue of prostaglandin-F2 alpha that promotes uterine contractions
62
SE of carboprost
N, V, bronchoconstriction
**avoid in asthma
63
Methylergonovine maleate MOA
ergot derivative -> uterine contraction
64
Methylergonovine SE
severe HTN from vascular smooth m constriction
65
Ritodrine MOA and use
selective beta 2 adrenergic agonist
-inhibits uterine contractions
66
1st line for neuropathic pain
TCAs, SNRIs, gapapentin, and pregabalin
67
MC type of neuropathic pain
diabetic neuropathy
68
Methadone MOA
NMDA antagonist
SSRI
opioid agonist
69
Tramadol MOA
mu opioid receptor agonist
weak SNRI
70
Carotid sinus
contains baroreceptors
71
Why hypoTN and bradycardia w/ carotid stenting
activation of carotid sinus baroreceptor -> glossopharyngeal n to medulla -> inhibits sympathetic neurons -> bradycardia, hypoTN
72
ppx for concern for bradycardia w/ carotid stenting
IV atropine or glyco
-transcutaneous pacing and transvenous pacing are also options
73
Why hypoTN and bradycardia w/ carotid endarterectomy
-have plaque near baroreceptor -> pressure wave detected by carotid sinus is dampened -> to compensate for dec signal, baroreceptors inc their sensitivity
-once plaque removed -> baroreceptors can be overstimulated by small changes in BP -> hypoTN and bradycardia
74
TURP syndrome symp
volume expansion prob (resp distress, pulm edema, CHF, HTN, bradycardia)
hypoNa (confusion)
specific irrigation solution
75
Post TURP Na is 120-130 and symp tx?
fluid restriction and loop diuretic
76
Post TURP Na < 120 and symp
hypertonic 3% saline and should be stopped once Na reaches 120
77
Complications of TURP solution distilled water
hemolysis, hemoglobinemia, hemoglobinuria, and hypoNa
78
Complications of TURP solution Glycine
hyperammonemia, hyperoxaluria, transient postop visual syndrome
Gly-SEEN -> issues w/ vision
79
Complications of TURP solution Mannitol
hyperglycemiia, lactic acidosis, osmotic diuresis
80
Complications of TURP solution Sorbitol
Osmotic diuresis and intravascular volume expansion
81
Toxicity of Cisplatin, carboplatin
acoustisc n damage, nephrotoxicity
82
Toxicity of Vincristine
peripheral neuropathy
83
Toxicity of Bleomycin
pulm fibrosis
84
toxicity of doxorubicin
cardiotoxicity: dilated cardiomyopathy
85
Toxicity of Trastuzumab
cardiotoxicity
86
Toxicity of cyclophosphamide
hemorrhagic cystitis
(prevent w/ Mesna antioxidant)
87
Toxicity of 5-FU, 6-MP
myelosuppression
88
What happens w/ accidental intrathecal injection of vincristine
ascending radiculomyeloencephalopathy -> almost always fatal
89
mixed venous for met-hg
increases b/c inc affinity for O2, dec unloading of O2 at tissue level and higher % of Hg saturated
90
tx for cyanide poisoning
goal: induce met-Hg, b/c cyanide will bind that readily
-Amyl nitrite and hydroxycobolamin
91
How long after SC injury does it itake to upregulate nicotinic ACh rec?
at least 24 hours, peak 7-10 days
92
When are ICU pts immbolized likely to inc ACh rec upreg?
greater than 16 days
93
How to reduce dilutional coagulopathy
FFP! and plts
-FFP for PT > 1.5x normal
-plts for plts < 75,000 in setting of clinically excessive bleeding
-fibrinogen should be kept greater than 100 w/ FFP or cryo
**plts last longer, FFP first
94
Lethal triad of trauma
hypothermia, acidosis, and coagulopathy
-warm the room!
-warm the fluids
95
Concerns for pts w/ achondroplasia
atlantoaxial instability
OSA
lumbar lordosis w/ leg bowing -> neuraxial can be difficult
96
dx of atlantoaxial instability
anterior atlantodental interval
> 2-3 mm abnormal= unstable
-usually widening will be seen w/ flexion
97
Triggers for hypoK periodic paralysis
Stress
Cold/hypothermia
Carbohydrate load
Infection
Glucose infusion
metabolic alkalosis
alcohol
strenuous exercise
steroids
pregnancy
98
Symp of hypoK periodic paralysis
weakness in limbs and trunk w/ diaphgram sparing
-2/4 TOF w/ airway patency and good O2 sat
99
preferred IVF for hypoK periodic paralysis
Normal Saline
-high Cl causes mild acidosis -> preferred over alkalosis
**avoid glucose containing
100
Epiglottis what to do?
OR -> Deep GA and intubate
-no muscle relaxants!
-use CPAP to maintain airway patency w/ inhalational GA
-ETT 1 size lower, have multiple sizes
101
Goals to dec leakage through Bronchopulm fistula
short inspiratory time
low TV
low RR
low end exp pressure
goal to keep airway pressures below critical opening pressure of BPF
-lung isolation may help
-spontaneous ventilation >> PPV
102
Fast-tracking in ambulatory surgery
bypass phase 1 level of care in PACU
OR -> phase 2 level of care
103
Aldrete score
Activity
Breathing
Circulation
Consciousness
O2 saturation
0 to 2 for all scores
9-10 needed to bypass phase 1 PACU care with no nscore < 1
104
BIS reading for dexmedetomidine
BIS consistent w/ GA
low freq high amplitude EEG w/ BIS of 40-60
105
GA levels BIS
40-60
106
measured cardiac output if injectate is colder than programmed
underestimate cardiac output
107
measured cardiac output if injectate volume is lower than programmed
overestimation
108
When will you get underestimation of thermodilution CO
1. injectate bolus volume is greater than programmed volume
2. large volume of fluid given during reading
3. injectate solution temp is colder than preprogrammed
4. self-measuring Ti probe is warmer than actual injectate temp
109
Overestimation of thermodilution CO
1. injectate bolus volume is less than programmed volume
2. injectate temp is warmer than preprogrammed temp
3. self-measuring Ti probe is colder than injectate temp
110
MC metabolic complication for pts after unclamping of pancreatic transplant
hypoglycemia
111
Radiation equation
1/ radius ^2
-by doubling distance from source, radiation is 1/4th
112
Closed Claims Project to improve pt safety and assist w/ registry studies
advantage?
Description of rare events
113
Aortic Dissection
114
Aortic Dissection TEE
115
Allodynia
perception of an ordinary nonnoxcious stmulus as painful
116
Anesthesia dolorosa
pain in area that lacks sensation (feared complication of neurolytic blocks for tx of trigeminal neuralgia)
117
When doing spinal anesthesia for TURB what additional n has to be blocked?
Obturator
118
Why additional block of obturator n w/ TURB?
esp w/ monopolar electrocatuery -> current can stimulate the obturator n as it passes ner inferolateral bladder wall -> sudden adduction of adductor m -> bladder rupture
119
Why additional block of obturator n w/ TURB?
esp w/ monopolar electrocatuery -> current can stimulate the obturator n as it passes ner inferolateral bladder wall -> sudden adduction of adductor m -> bladder rupture
120
Indications for hyperbarici O2 therapy
Air embolism, decompression sickness
-Poisoning: carbon monoxide, cyanide, HS, brown recluse spider bides
-Infxn: necrotizing infxn, refracotry chronic osteomyelitis, intracranial abscess, mucormysosis
-Acute ischemia: crush injury, compromised skin flaps, central retinal a/v occlusion
-Chronic ischemia: ischemic ulcers, radiationi necrosis
-Acute hypoxia: O2 support w/ lung lavage, blood loss anemia if transfusion delayed/unavailable
-Burns
121
succ dosing in obese pts
increased dosing b/c inc pseudocholinesterase activity and inc extracellular fluid volume
122
what is dosed on total body weight
maintenance infusion of propofol, succ
123
What is dosed on lean body weight?
Thiopental
induction dose of propofol
fentanyl
124
What is dosed on ideal body weight?
Roc, vec
125
Why dec opioids in elderly?
Increased brain sensitivity
-doses should be cut in half compared to young and healthy pts
126
Remi changes in elderly
Remi more potent in elderly brain b/c inc brain sensitivity, and central clearance decreased
-infusion rates dec by 1/3
127
Morphine changes in elderly
Inc brain sensitivity and dec renal clearance
128
Major anesthesia concern w/ cerebral palsy
inc GERD and esophageal dysmotility -> pulm aspiratory is increased and greater risk for postop pulm complicatios
129
cerebral palsy and succinylcholine
no problem! no issues w/ hyperK
-muscles never fully developed or innervated so no inc in ACh receptors at NM jxn
130
How to inc CO2 removal for VV-ECMO
inc flow of sweep gas through oxygenator (inc sweep)
131
Where are cannulas for VV-ECMO?
internal jugular vein (down into SVC) or femoral vein (IVC)
132
When to use VV ECMO?
profound refractory resp failure
-shunts blood from venous system, through oxygenator, and back to heart
133
V-V ECMO
134
What is the flow through VV ECMO?
Ideally pts cardiac output depending on size of cannulas and resistance
135
Most effective way to treat intraop hypothermia of peds pt
forced warm air blanket
136
Complications w/ intraop hypothermia
-dec wound healing (inc rate of infxn)
-inc O2 consumption -> metabolic acidosis
-delayed awakening
-inc PVR
-inc cardiac arrhythmias
-inc need for transfusion
137
why peds pts highly likely to get hypothermia w/ anesthesia?
-anesthesia abolishes thermoregulatory reflexes
-bigger body surface area relative to total body volume -> inc heat loss
-less subq fat
-thinner skin
138
Neonate nonshivering thermogenesis
metabolism of brown fat -> uncouples oxidate phosphorylation in mitochondria to get heat
(1st 3 months of life)
139
Chronic pain meds that dec sz threshold
Tramadol
TCA (Amitriptyline)
140
Butorphanol MOA
mixed opioid agonist-antagonist w/ partial agonism of mu and kappa opioid receptors
***if used w/ full agonist -> will be antagonist
141
Meperidine and sz threshold
does NOT lower sz threshold
-sz b/c of buildup of metabolite normeperidine
142
Early management of hemorrhagic shock
limited crystalloid admin (1L)and early intervention w/ balanced blood product administration
143
"lethal triad" of trauma
hypothermia
acidosis
poor perfusion
-hypothermia and acidosis -> depletion of fibrinogen -> development of DIC
144
MAP goals during early hemorrhagic shock 2/2 trauma
>40 -> can be that low for 2 hours to prevent clot disruption and red blood loss
-limits fluid admin until hemostasis can be achieved
145
Periop RF for a fbi
atrial injury
ischemia
inflammation
inc catecholamines
hypovolemia
atrial stretch from volume overload
electrolyte disturbances
146
Patient factors inc risk of postop a fib
Advanced age
male
HTN
prior hx of A fib
obesity
COPD
asthma
valvular dx
left atrial size
LVEF
147
Consequences of postop a fib
longer hospital stay
hemodynamic derangements
stroke
MI
development of vent arrhythmias
HF
148
Greatest RF for development of postop a fib
Volume status -> hyper or hypovolemia
149
ppx to prevent postop a fib
Beta blockers
150
omphalocele, hypoglycemia, large body, large tongue, dx?
Beckwith-Wiedemann syndrome
151
Beckwith-Wiedemann syndrome
congenital d/o caused by overgrowing of tissues
-omphalocele
-macroglossia (diff intubation)
-hypoglycemia (large pancreas)
152
Down Syndrome MOA, assoc
trisomy 21
low muscle tone
cardiac defects (endocardial cushion defects)
large tongue
unstable atlantoaxial joint
153
VATER
or VACTERL
vertebral
anal imperforate
TE:tracheoesophageal fistula
Renal abnormalities
Congenital cardiac condition
Limb abnormality
154
Williams syndrome MOA, symp
deletion on chromosome 7
-"elf-like"
supravalvular aortic stenosis
155
Risks of sedatio nand anesthesia in DMD and Becker MD
-inc risk of aspiration (resp m weakness, inc oral secretions, gastric hypomotility)
-upper airway obstruction
-hypoventilation
-atelectasis
-CHF
-dysrhythmias
-resp failure
-diff weaning from mechanical ventilation
156
What gets reported to the National Practitioner Databank
Malpractice Payments and Settlements
Punitive action taken by peer-review org, professional societies or accreditation org
-administrative actions that occur as a result of a professional review
157
1st action when taking someone out of a cold body of water?
Rescue breaths -> then CPR
-vomiting occurs frequently, consider airway protection
158
Normal plasma levels of Mg
1.8-2.5
159
Therapeutic goals of Mg for OB
5-10
160
SE of Mg at 5-10
flushing
N/V
sedation
dizziness
m weakness
hypoTN, bradycardia
prolonged PR, wide QRS
161
Mg level loss of DTR
12
162
Complete heart block Mg level
18
163
Cardiac arrest mg level
20-25
164
Tx of hyperMg
IV calcium
165
surge after ECT?
parasymp -> then symp
166
SE of ECT
parasymp -> symp
HA
short term memory loss
nausea
myalgias
167
PaO2 goal ARDS
60 or greater w/ adequate Hg at FiO2 of less than 50%
168
ARDS dx
noncardiogenic pulm edema w/ hypoxemia
169
ARDS TV
lower TV 6 cc/kg predicted body weight
170
ARDS severity
partial pressure of arterial O2/FiO2
mild: P/F 200-300
mod: P/F 100-200
severe: P/F lower than 100
171
laproscopic surgery and ICP
increase b/c dec cerebral drainage
172
laparoscopic surgery and afterload
inc afterload, inc in SVR, inc in BP
-causes a dec in end organ perfusion (esp renal)
173
pulm and laparoscopic surgery
-pulm compliance dec
-diaphragm moves cephalad -> dec TV and inc insp pressures
-inc atelectasis -> dec in FRC
174
At what pressure w/ laparoscopic surgery do you start seeing compromised perfusion?
20
175
MCC of death in pts w/ duchennes muscular dystrophy
CHF or aspiration PNA
-dysrhymias common b/c fibrosis in cardiac conduction system
176
Induction for peds congenital emphysema
spontaneous respiration
-inhalational -> nitrous oxide CI
-likely lung isolation to prevent bleb burst
-have surgeon present in event of bleb rupture and PTX
177
Best way to improve myocardial O2 supply and dec demand
dec HR
-less work, dec demand
-perfusion in diastole -> longer in diastole -> improved supply
178
O2 content of blood
CaO2 = (Hg x 1.34 x SaO2) + (.003 x PaO2)
179
Coronary perfusio npressure
CPP = Aortic DBP - LVEDP
180
Cardiac wall tension
wall tension = (LVEDP x radius) / (2 x LV wall thickness)
-wall tension correlated to myocardial work
181
Changes in lung volumes w/ pregnancy
TV inc
IRV inc
so IC inc
Dead space inc
FRC dec
ERV dec
RV dec
182
Lung volumes and capacities
183
Where does transcranial doppler u/s measure blood flow velocities?
MCA
184
Why use transcranial doppler u/s w/ carotid endarterectomies?
measure flow velocities in MCA
-Mean flow velocity following clamping of the cartoid artery correlates w/ degree of cerebral ischemia
-if >40% of preclamped value, absent ischemia
-mild if 15-40% preclamped
-severe <15% preclamped
185
Hyperperfusion syndrome CEA
>100% inc in CBF relative to preop
-postop neuro dysfxn -> HA, sz, focal deficits, intracerebral hemorrhage, cerebral edema
***detect w/ transcranial doppler in early postop
186
What is transcranial doppler used for?
Periop CEA
-BF velocities
-detect embolization to the brain
-identify shunt fxn of malfunction
-detect asymp carotid artery occlusion and/or hyperperfusion syndrome
187
Adults 1st symp total spinal
cardiovascular signs 1st!
-hypoTN and tachycardia (brief reflex) and then progresses to bradycardia
-resp failure/LOC 2nd
188
Neonates 1st symp total spinal
resp depression!
-supportive w/ intubation for controlled ventilation
if fails to oxygenate -> hypoxic cardiac arrest
-no sympathetic blockade b/c immature symp NS w/ predominant parasymp tone
189
Unilateral nonradiating lower back pain exacerbation w/ rotation to affected side
facet syndrome
190
What exacerbates facet syndrome
lumbar extension and rotation toward the affected side
191
low back pain worse on 1 side, radiation to posterior buttock and thigh
sacroiliac joint dysfunction
192
unilateral lower extremity numbness/weakness, worse w/ lumbar extension
spinal stenosis
-relieved w/ flexion
193
sitting intolerance relieved by lateral recumbent position
discogenic disease
-exacerbated w/ sneezing, coughing, strainging
194
Low back pain exacerbated w/ palpation of posterior superior iliac spine
sacroiliac joint dysfunction
195
Why edema w/ sepsis?
Glycocalyx disruption
196
Glycocalyx
mesh-like structure covering endothelial cells in blood vessels that:
-regulate vascular permeability
-maintain laminar blood flow
-prevent inappropriate activation of clotting cascade and immune response
197
Changes in SSEPs that indicate ischemia
dec amplitude
inc latency
198
small cell carcinoma of lung, new onset muscle weakness, improves w/ repetition
antibody to presynaptic calcium channel
-Lambert Eaton myasthenic syndrome
199
Why is weakness improved w/ repeated repetition in lambert eaton
antibodies to presynaptic VG Ca channels at NMJ
-dec release of ACh -> weakness -> needs repetition to build up ACh
200
Which myasthenia gravis or myasthenic syndrome more likely to affect bulbar muscles (mouth, throat), and eyes
myasthenia gravis
201
Treatment for lambert ateon
Tx malignancy (likely small cell lung cancer)
-3,4-diaminopyridine (amifampridine) -> inc presynaptic release of ACh
202
Lambert eaton and muscle relaxants
myasthenic syndrome: sensitive to both succ and roc
myasthenia gravis: resistant to succ, sensitive to roc
203
stridor 24-96 hours post thyroidectomy
hypocalcemia (from destruction of parathyroid glands)
204
stridor weeks after extubation
tracheomalacia
-acquired from inc pressure on the trachea from ETT
205
What muscle does the superior laryngeal n innervate
cricothyroid muscle
-change in pitch of pt's voice
206
What happens to IV bicarb when given?
combines with hydrogen ion -> carbonic acid -> dissociates into CO2 and water
207
What happens to CO2 when giving IV bicarb?
transient inc in EtCO2
-combines with hydrogen ion -> carbonic acid -> dissociates into CO2 and water
-theoretical inc in cerebral vasodil -> inc ICP
208
What happens to calcium when giving IV bicarb?
bicarb -> alk -> H+ kicked off albumin -> uptake of Ca for neutrality -> hypoCa
209
What happens to K when giving IV bicarb?
H+ low -> uptake of K+
210
Caudal dosing for peds
-volume determines block height
-.5 cc/kg sacral
-1 cc/kg low thoracic dermatomes
-1.25 cc/kg cover mid-thoracic dermatomes
211
when does dural sac end in newborns
S3
212
conus medullaris in newborns
ends at L3
213
adults dural sac ends at
S1-2
214
Conus medullaris in adults
L1-2
215
Extracellular fluid volume in infants
40% of total body weight
216
Total body weight in infants
term: 75%
preterm 85%
-that's why requires larger weight-based dosing of m relaxants
217
extracellular fluid volume adults
20%
218
total body waterin adults
60%
219
when do peds reach adult extracellular fluid volume
18-24 months
220
Why give larger doses of succ in peds
larger volume of distribution
(2-2.5 mg/kg)
221
When is the NMJ mature in peds?
2 months
-prior to that, diaphgram and peripheral muscles paralyzed at the the same time
222
Why dec in FRC w/ trendelenberg
FRC = ERV + RV
-red in lung compliance and cephalad shift
223
initial compensatory mechanism for acute respiratory acidosis
plasma protein buffers
-Hg in RBC and phosphates -> CO2 reacts w/ H2O to form bicarb and H+ ions -> bicarb exchanged for Cl so bicarb in plasma
-kidneys do most of the work, but they need time
224
How do kidneys react to resp acidosis?
inc excretion of Cl -> inc in bicarb reabsorption
-can take hours to days
225
Adenosine MOA
transiently blocks the AV node
226
Atrial tachycardia and adenosine
Regular SVT w/ ventricular rate b/c 150-250
-micreo-reetrant circuit or automatic atrial focus
227
AV nodal reentrant tachycardia
reentrant pathway adjacent to or directly w/i AV node
-since involves AV node, adenosine will terminate
228
AV reciprocating tachyardia
reentrant circuit including theAV node and an accessory pathway w/i cardiac musculature b/w atrium and ventricle
-will terminate w/ adenosine
229
What rhythms will adenosine terminate?
SVTs caused by a reentrant circuit involving the AV node
230
Adenosine and a fib
will slow ventriclar rate but will not terminate
231
Adenosine and a flutter
will not terminate, just slow ventricular rate
232
Why get burns w/ pulse ox probe in MRI
heat is generated w/ induction of electrical current w/i the probe
233
Which metals are dangerous during MRI?
Ferromagnetic metals
-nickel, iron, cobalt
ALUMINUM IS SAFE
234
Blood supply TEE
235
Which papillary m most likely to rupture and why?
Posteromedial b/c single blood supply (PDA)
-anterolateral has dual blood suppl (LAD and LCx)
236
What causes hoarseness following cervical spine surgery
vocal cord palsy
-result of direct pressure of the ETT on RLN during surgical retraction
237
how to reduce hoarseness following cervical spine surgery
adjust ETT cuff pressure after surgical exposure most beneficial
238
What happens w/ damaged RLN?
cricothyroid innervated by SLN -> unopposed -> VC adduction
-unilateral: dysphonia
-b/l: complete airway obstruction
239
dysphonia/hoarseness w/ anterior cervical surgery prognosis
transient, spontaneous over weeks-months
-only 10% symp at 3 months
-if not better in 6 weeeks -> w/u
