ITE TL Block 4 Flashcards
inc risk of hypoTN after spinal
BP < 120
age > 40
spinal at or above L2-3
concurrent GA
sensory block >T5
Aprepitant
neurokinin 1 receptor antagonist
-duration of action: 24 hours
-PONV ppx
Dropierdol
PONV ppx antidopaminergic
Glucagon and cardiac effects
activates adenylyl cyclase -> inc cAMP -> positive ionotropic and chronotropic (inc HR and contractility)
-how glucagon treats beta blocker overdose
-can be used in pt w/ anaphylaxis on beta blockers (resistant to beta of epi)
opioids and seizures
opioids do NOT alter the sz threshold or cause sz
-only exception is in renal failure when toxic metabolites accumulate
In ICU triglyceridemia, lactic acidosis, rhabdo, and acute fatty liver injury
Propofol Infusion Syndrome
-inc in TG 1st
if viral pandemic and running out of sedatives best next step
scheduled PO opioids through an NG/OG tube
when attempting epidural placement, what changes in vitals/EKG show a positive intravascular catheter placement?
HR > 10 bpm
Systolic BP >15-25 mmHg
T wave depression of > 25%
-tinnitus, metallic taste, perioral numbness
hyperthermia, vomiting, rigidity, hyperreflexia and myoclonus w/ antipsychotics and meperidine dx?
serotonin syndrome
-SSRI, SNRI, MAOI w/ meperidine
methylene blue
fent, methadone, tramadol, morphine
maprotiline (antidep)
trazodone
buproprion
mirtazapine
buspirone
treatment for serotonin syndrome
cyproheptadine
Isocarboxazid
MAOi
Tranylcypromine
MAOi
Doxepin, desipramine, Clomipramine
TCA
mental status change, hyperthermia, rigidity and dysautonomia w/ antipsychotics and meperidine, dx?
Neuroleptic Malignant Syndrome
-no hyperreflexia in NMS! how you tell them apart
Drug eluding stent 6 months later wants elective surgery on ticagrelor and ASA, what and when d/c prior to surgery?
hold ticagrelor for 5-7 days prior
continue ASA
-allows for spinal anesthesia and still reducing risk of in-stent thrombosis
what is the epidural test dose
3 cc of 1.5% lidocaine w/ 1:200,000 epi
45mg lidocaine and 15mcg of epi
bronchospasm
FiO2 100% and hand ventilate
deepen anesthetic
albuterol
epi
anti-Ch (glyco, atropine, ipratropium) but take 20-30 minutes
Mg sulfate
steriods (4-6 hrs to work)
How does transcutaneous n stimulation using electricity help pain
stimulates A-beta cutaneous mechanoreceptors -> inhibit A-delta and C pain fiber signaling -> inc levels of endorphins
Gabapentin MOA
VG Ca channels
MOA of tranexamic acid
inhibits conversion of plasminogen to plasmin
-preventing clot breakdown (plasmin essential for breakdown of fibrin clots)
-lysine analog antifibrinolytic
Alteplase MOA
fibrinolytic agent
plasminogen activator that converts plasminogen to plasmin -=> breakdown of clots
FDA approval for TXA
heavy menstrual bleeding and prevention of bleeding in hemophiliacs in tooth extractions
-use otherwise is off label
Measure of liver synthetic function
Factor VII
-1/2 life is four hours
PT and bile acid secretion impairment
PT dpts on Vit K consumption and absorption
-so if bile acid secretion impaired (biliary obstruction) -> PT will be prolonged, but hepatic fxn will be normal
Bilirubin measures what in liver
excretory function
Fibrinogen 1/2 life
4 days
-so measures hepatic synthetic function, but factor VII is faster
16 yo rhinoplasty, mild jaundice post op, t bili 2.5 inc in unconjugated bilirubin, no symptoms.
Dx?
Gilbert Syndrome
Gilbert Syndrome enzyme
Reduction of UDP-glucuronosyltransferase activity
-leads to a dec in conjugated bili -> inc in indirect bili
-indirect bili elevated but < 3
-benign no tx
Ischemic hepatitis
hepatic hypoperfusion usually 2/2 hypoTN -> dec hepatic clearance
-AST and ALT peak 25-250x normal 1-3 days after insult
-takes 3-11 days to return to normal
sudden painless bright red vaginal bleeding after 20 weeks gestation
placenta previa
RF for placenta previa
previous c/s
previous pregnancy termination
previous uterine surgery
smoking
advanced maternal age
multiple gestation
multiparity
cocaine abuse
sudden painful vaginal bleeding >20 weeks, uterus rigid and tender, fetal distress
placental abruption
-premature separation from uterus before delivery
sudden, severe abd pain duringn labor, pause in contractions, fetal distress, hemodynamic instability
uterine rupture
sudden painless vaginal bleeding after rupture of membranes
vasa previa
-fetal blood vessels overlying the internal cervical os
-can cause fetal exsanguination
-different from placenta previa b/c after water breaks
50 year old man hx of obesity BMI 32, inguinal hernia repair, what preop tests?
none indicated
-EKG if cardiac dx, resp dx, type of surgery
-CXR if smoking hx, pulm dx or cardiac dx but routinely not done
-Hg/Hct if liver dx, aneemia, hematologic d/o, type of surgery
What would cause a decreased gradient of O2 partial pressure b/w alveolar gas and serum tension leading to a decreased diffusion capacity? what would inc it?
Anemia dec diffusion
polycythemia inc diffusion
Why decreased diffusion capacity of carbon monoxide in pulm hypertension
thicken walls of the alveolar-capillary membrane -> dec gas diffusion
-similar to chronic thromboembolic dx
What causes a decreased surface area that will dec DLCO in lungs?
small lungs
pulm fibrosis
hx of lung resection
emphysema
What you need to maintain your certification by ABA every 10 years
-hold an active, unrestricted medical license in US or Canada
-250 Cat 1 CME credits (125 done by year 5) -> 20 must be ABA-approved for pt safety
-30 MOCA MC questions every quarter -> 120 questions per year
-25 pts in first 5 years and 25 points in 2nd 5 years: given points for clinical practice assessments and systems-based practice such as QI
PFTs diagnostic for COPD
FEV1/FVC < 70% incompletely reversed after bronchodilatory therapy
Severity for COPD based on FEV1
mild: FEV 1 80% or greater of predicted
moderate: FEV1 50-79%
severe: FEV1 30-49%
very severe FEV1 < 30%
*** < 50% means inc risk of postop pulm complications and likely postop ventilation esp after abd and thoracic procedures
Dx of COPD v severity testing
Dx: FEV1/FVC ratio of < 70%
severity is entirely based on FEV1 (<50% severe and at risk for postop complications)
Vapor pressure of des, sevo, iso, nitrous
Des 669 w/ BP at 24 -> so at room temp, already a gas, so has a high vapor prssure
Iso 238 w/ BP at 49 -> why when in a sevo vaporizer gives more gas than it should
Sevo 157 w/ BP at 59 -> why when in an iso vaporizer gives less gas than it should
Nitrous 38,770 w/ BP at -88 -> why gas in a cylinder w/ liquid at room temp
Retrobulbar v peribulbar block: which has a faster analgesia onset?
Retrobulbar < 5 minutes
Retrobulbar v peribulbar block: results in akinesia of the orbicularis oculi?
peribulbar
-b/c larger volume injected, greater distribution
-if doing a retrobulbar block, need a suppl facial n block to get akinesis of orbicularis oculi
Retrobulbar v peribulbar block: more likely to inject into subarachnoid space
retrobulbar: longer needle used
Retrobulbar v peribulbar block: increased risk of conjunctival chemosis
peribulbar: larger amount of local anesthesia accumulating under conjunctiva
Drops v gel local anesthesia for eye surgeries
gels have higher concentrations of local anesthesia and offer superior surface analgesia
Tramadol MOA
mu-opioid agonism
SNRI
Carbamazepine and opioid meds effect
Carbamazepine is a CYP 3A4 inducer
-tramadol is partially metabolised by CYP 3A4 -> would inc efficacy b/c metabolite is active
Dexmedetomidine SE
bradycardia, hypoTN, HTN -> all more likely to occur w/ loading or bolus dose
Bohr effect
-hemoglobin has a lower affinity for O2 w/ inc CO2 and dec pH
-Hg has a higher affinity for O2 in alkalosis
Haldane effect
deoxygenated Hg’s ability to carry more carbon dioxide than oxygenated blood
-oxygenated blood has a decreased ability to carry CO2 and releases it
Vasopressin receptors and actions
V1: systemic, renal, coronary, and splachnic circulations -> vasoconstriction
V2: mobilization of aquaporin channels to collecting duct, and inc vWF release
V3: in pituitary -> release of ACTH
What causes decreased Na reabsorption in CD?
ANP
-also causes renal afferent arteriole dilation and efferent constriction -> enhancing water and Na excretion
EXIT = EFFERENT
larygnospasm reflex afferent, efferent
afferent: SLN
efferent: RCLN
Acute intermittent porphyria
Auto Dom usually women 20-30
mutation in: porphobilinogen deaminase
-accumulation of porphobilinogen and delta-aminolevulinic acid
severe abd pain, numbness, paresthesias, weakness, N/V, psychosis after TMP-S for UTI
dx and tx
Acute Intermittent porphyria
tx: glucose and hemin -> dec activity of delta-aminolevulinate synthase and heme production, IVF, lytes, and painn control
What do you use delta-aminolevulinic acid in urine to dx?
Acute intermittent porphyria
Anesthesia med triggers for Acute intermittent porphyria?
Ketamine
Barbiturates
Ketorolac
Etomidate
Anticonvulsant triggers for Acute intermittent porphyria
Phenytoind
Carbamazepine
Valproic Acide
Acute intermittent porphyria med triggers
CCB
Amiodarone
Estrogens
Fasting
Surgery, Infxn
Barbs
Ketamine
ETomidate
Ketorolac
Acute Intermittent Porphyria
5 P’s
painful abd
polyneuropathy
psych distrubance
port wine-colored urine
precipitated by meds
Platypnea
SOB worse when standing/sitting and improves when laying flat
-sign of hepatopulm syndrome
Hepatopulm Syndrome triad
liver dysfxn
intrapulm vascular shunting/dilation
unexplained hypoxemia
orthodeoxia
hypoxemia in upright position resolves w/ laying down
-sign of hepatopulm syndrome
Alpha-1 antitrypsin def
early-onset emphysema, bronchiectasis and cirrhosis
Portopulm HTN
pulm HTN in pt w/ portal HTN
1. portal HTN w/ or w/o hepatic dx
2. mean pulm artery pressure of 25 at rest or 30 while exercising
3. mean pulm arterial occlusion pressure < 15
4. elevated pulm vasc resistance > 3 wood units
-screen by TTE
-confirm w/ R heart cath
-tx: Diuresis and vasodilators (prostanoids, PDE inh, and endothelin antagonists)
Formal recognition by a regulatory agency or body that a person possesses the qualifications to practice a specific profession in that state is?
Licensing
Process by which an employer confirms that a practitioner has the required education, training and experience to practice w/i their system
Credentialing
If you have the particular ability to perform a specific procedure within an institute
Privileging
Recognition of the successful completion of requirements for recognition as a specialist w/i a specific specialty of medicine
Certification
Serum osmolality
(Na*2) + (glucose/18) + (BUN/2.8)
BBB is diff from endothelial cells w/ osmolality changes
BBB has tight junctions and aquaporins to limit changes in brain size w/ osmotic changes and do not allow entry of Na, Ca, and Cl into tissues require a channel -> endothelial thinsg move easier
Fluid shifts across intracranial capillaries depend on what pressure
hydrostatic and mostly determined by Na
Fluid movement in brain
Cerebral capillary fluid shift fxn of hydrostatic and total osmotic forces
-osmolar gradient plays a large role -> primarily determined by Na -> rapid inc or dec in Na -> cerebral desiccation or edema
which neonatal defect is ETT most likely required
congenital diaphragmatic hernia
-improves gas exchange and prevent bowel insuff
Assoc w/ congenital diaphgramatic hernia
adrenal insuff
congenital heart disease
spina bifida
type I error
null hypothesis incorrectly rejected when ther eis no difference
alpha error
aka type I error
null hypothesis incorrectly rejected when ther eis no difference
accepting the null hypothesis when it is false
beta or type II error
What level should neuraxial go to for TURP?
T10 level
spinal levels required for postpartum tubal ligation
higher than T8
spinal level required for c/s
higher than T6
spinal level for cervical cerclage
higher than T10
spinal leel for hip fx, knee replacement, knee arthroscopy, ankle surgery
higher than T12
spinal level for inguinal hernia repair, or open appendectomy
Higher than T8
Postherpetic neuralgia
Pain for a duration of greater than or equal to 3 months at local of herpes zoster eruption
-as many as 34%
RF for postherpetic neuralgia
> 60 years of age
greater severity of pain during acute herpes zoster eruption
greater severity of skin lesions
greater severity of prodromal pain
location of eruption (worse on ophthalmic V1 and brachial plexus distribution)
immunosuppresion
Tx of postherptic neuralgia
1st line: gapapentin and pregabalin
TCAs
2nd line: opiates
topical tx
Increased R time on TEG
problem and tx?
initial clot formation
prob w/ clotting factors
given FFP or coag factor concentrate
Highest risk of seroconversion after a needlestick from pt
Hepatitis B
what to do after you get stuck w/ possible HIV
- post-exposure ppx immediately and continued for 4 weeks
- immediately determine the HIV status of pt
- PEP should have >3 antiretrovial drugs
- F/u includes counseling, HIV testing and monitoring for PEP toxicity
- If 4th gen HIV p24 Antigen-HIV antibody test used -> HIV testing can cease after 4 months of exposure if negative, if older test 6 motnhs
Drainage of superior sagittal sinus in brain
superior sagital sinus -> confluence of sinuses -> transferse sinuses -> sigmoid sinus -> internal jugular vein
Drainage of inferior sagittal sinus
inferior sagittal sinus or cerebral veins -> straight sinus -> confluence of sinuses -> transverse sinus -> sigmoid sinus -> internal jugular vein
Unfractionated heparin ppx dose
time b/w last dose and before catheter placement
4-6 hours
Unfractionated heparin ppx dose
time after catheter placement to drug start
immediately
UFH ppx dose
time b/w last dose and catheter removal
4-6 hours
UFH ppx dose
time after catheter removal to drug start
immediately
High dose UFH
time b/w last dose and catheter placement
12 hours
High dose UFH
time after catheter placement to drug start
1 hour
High dose UFH
time b/w last dose and catheter removal
12 hours
High dose UFH
time after catheter removal to drug start
1hour
AC and caatheter dosing/time
How long to wait before restarting LMWH after neuraxial catheter removed?
4 hours
How long after the last dose of LMWH for ppx would be the time in which catheter placement or removal can occur
12 hours
Transcutaneous electrical nerve stimulation therapy
low freq stimulates mu opiods receptors
high freq stimulates delt receptors
**chronic opioid use may get less relief
hepatopulm syndrome TTE
contrast or bubbles w/i LA in 3-6 beats
-due to intrapulm shunting
Diagnostic criteria for hepatopulm syndrome
PaO2 < 80 or Alveolar-arterial O2 gradient of at least 15
pulm vascular dilation: TTE contrast or saline
liver dx
hyperthermia, rigidity, dysautonomia
Neuroleptic malignant syndrome
muscle rigidity, hyperthermia, tachycardia, hyperreflexia
serotonin syndrome
What does lactate in LR get metabolized into?
CO2, water, and bicarb
Abdominal compartment syndrome
Intraabd pressure > 20 w/ evidence of organ dysfxn, typically renal
-dx: indirect measurement of intra-abd pressures using intravesicular (bladder) P
NSAIDs and pregnancy
CI after 32 weeks gestation b/c inc risk of premature closure of ductus arteriosus in fetus
Methotrexate MOA
folate analog, suppresses nucleotide synthesis to inhibit cell division
Methotrexate SE
myelosuppression
megaloblastic anemia
mucositis
GI inflammation
hepatotoxicity
acute/subacute interstitial pneumonitis
Motor neurons
fast-conducting, large diameter myelinated neurons that lose their myelin sheaths as they branch into terminal fibers
-each fiber supplying a muscle fiber
-motor neuron + m fiber it innervates = motor unit
-cell body in ventral horn
What CYP metabolized tramadol into active metabolite
CYP 2D6
What CYP metabolizes methadone
CYP 2C9 and 2C19
CYP 2D6 inhibitors and inducers
inh: SSRIs (so tramadol won’t work)
inducers: rifampin and dexamethasone -> tramadol overdose
Pilocarpine and eyes
M3 agonist -> pupillary constriction (miosis)
Phenylephrine eyes
pupillary dilation
Corneal reflex afferent, efferent
afferent: V1: opthalmic branch of trigeminal nerve
efferent: VII temporal branch of facial n
pupillary light reflex, afferent efferent
afferent: CN II optic n
efferent: CN III oculomotor -> ciliary sphincter contraction
Healthy nonobese pt preoxygenated w/ FiO2 of 100% for 5.5 minutes, how long is the apneic period
~8 minutes before desat to < 90%
Healthier obese pts safe apneic time w/ adequate preoxygenation
~2-3 minutes
Which opioid would have reduced analgesia if also taking SSRIs?
SSRIs are a CYP 2D6 inhibitors -> codeine and tramadol wouldn’t become an active prodrug
-same thing w/ oxycodone, hydrocodone
papilledema is assoc w/ which electrolyte
severe hypoCa
Which IV anesthetic inc hepatic blood flow
Propofol
Which lung volumtes increase in pregnancy
TV
inspiratory capacity
Nalbuphine
mixed opioid agonist/antagonist
-reverses opioid-infuced pruritis w/o affecting analgesia of ipioids
It’s now FINE because i’m no longer itchy and i’m still not in pain
Recovery of muscles from NMB order
diaphragm > laryngeal muscles > corrugator supercilii > rectus abominis > orbicularis oculi > adductor pollicis
-diaphragm also 1st muscle to be blocked b/c i’ts a central muscle so more blood flow also higher conc of nicotinic Ach receptors
When arm tucked in surgery, what to monitor for NMB?
corrugator supercilii at eyebrow correlates w/ recovery of diaphragm and laryngeal muscles
orbicularis oculi correlates w/ adductor pollicis
Baby born to mom w/ myasthenia gravis
20% change of showing symptoms: poor feeding, generalized hypotonia, feeble cry, resp distress
-monitor clinical course w/ repeat n stimulation testing and measuring ACh receptor antibodies
-tx supporting AChE therapy can be given if needed
-no sym once Ab clear, usually w/i 2-4 weeks
Where does an axillary roll go
below the axilla on the chest to precent brachial plexus injury in lateral position
How does metochlopramide inc gastric emptying
stimulation GI motility
inc tone of GES
relaxing pyloric sphincter and duodenal bulb
Which antacid given to pregnant pts
Sodium citrate
-neutralize the contents in the stomach
When doing an interscalene block what is posterolateral to the nerves
middle scalene
-you enter from the lateral direction, penetrating middle scalene before entering interscalene groove
interscalene n block whats superficial and meidal
SCM
Dermatome for medial knee
L3
Dermatome for anterior knee and medial malleolus
L4
Dermatome for dorsal surface of the foot, 1st 2nd and 3rd toes
L5
Dermatome for lateral malleolus
S1
PPV inspiration effect on preload and afterload
preload decreases
afterload decreases (compression on LV reducing force required to eject blood from the LV) and inc in return to LA -> inc in SV
Alveolar gas equation
PAO2 = FiO2 x (Patm - PH2O) - PaCO2/R
Prolonged hypoxia w/ altitude causes longer term changes
- inc in 23DPG prod to favor O2 offloading
- hyperventilation (chemorec stimulation)
- inc in mitochondria to inc aerobic eff
- inc in RBC mass via EPO
- inc in renal elimination of bicarb
Dexmedetomidine alpha 2 agonist effects and where it binds on body
analgesia: a2 receptors in dorsal horn of spinal cord
sedation and anxiolysis: locus coeruleus of the brainstem
hypoTN and bradycardia: brainstem vasomotor center
suppress shivering: hypothalamus
Which carbon dioxide absorbent most likely to result in higher levels of carbon monoxide production
KOH > NaOH»_space; Ba(OH)2 and CaOH2
KOH: baralyme
sodalime: less KOH and NaOH
BaOH and Ca are both weak bases -> no real carbon monoxide
Innervation of cricothyroid muscle
SLN external branch
-if injury loss of VC tension -> higher risk for aspiration
Innervation of the stylopharyngeus muscle
glossopharyngeal n
-aids in elevation of pharynx for special fxns such as speech and swallowing
What is an anechoic space b/w parietal and visceral pleura on lung u/s?
pleural effusion
Chassaignac tubercle
C6 transverse process
-landmark for deep cervical plexus block
goal C2-4
where is the posterior tibial nerve blocked
injxn behind medial malleolus
-sural n is lateral malleolus
where to block the supraorbital nerve
palpating the supraorbital notch
Dabigatran reversal
Idarucizumab
No posttenaic twitches present, what dose of sugammadex?
16 mg/kg
If posttetanic twitches present w/ TOR <1 sugammadex dose
4 mg/kg
Crouzon syndrome
genetic dx that causes premature closure of cranial sutures
hypoplastic midface
bulging eyes
beaked nose
C’s: closure of cranial sutures
Klippel-Feil syndrome
lack of segmentation of cervical spine -> presents w/ fused cervical spine
-rotation is more reduced than flexion and extension
Klipped and fell, now his cervical spine is together
Pierre Robin sequence
micrognathia
glossoptosis *tongue falls back into throat)
cleft palate
-easier to intubate w/ age
Treacher Collins
zygoma and mandibular hypoplasia
ear defomrity
deafness
mental retardation
harder to intubate w/ age
-teacher: mental retardation
When you have a pt w/ pyloric stenosis, how do you know their fluid status is okay for surgery?
Normalization of Cl is best indicator, greater than 106
-pH and K are not helpful w/ fluid status
-bicarb < 30
Tumescent anesthesia
Injecting very dilute solution of local anesthesia combined w/ epi and sodium bicarb into tissues until it becomes firm and tense
Liposuction concerns
-total aspirated content should be to less than 5 liters due to risk of hypervolemia
-don’t use GA -> may mask trauma b/c pt unresponsive, and may require larger volumes of fluid exposing to hypervolemia
Complications from Tumescent anesthesia
Periop: cannula injuries, hypothermia, volume overload
early postop: infxn, DVT, pulm embolism
Late postop: paresthesias, edema, seroma formation, ecchymosis
What causes emergence delirium MC?
volatile anes, MC sevo
How to diagnose hemolysis in OR
low haptoglobin
elevated bili
hematuria
positve Coombs test
Hg P50
pressure at which Hg is 50% saturated
-so it increases w/ rightward shift and dec w/ L shift
Anemia compensation
inc cardiac output (inc SV)
redistribution of blood to heart and brain
inc O2 release in tissues (inc 23DPG)
Schedule I drug by DEA
high abuse potential, cannot be prescribed, no medical use
-cannabis, MDMA, LSD
Schedule II meds DEA
high abuse potential, only up to 30 day supply
-cocaine topical, morphine, oxycodone, hydrocodone
Schedule III meds
low to mod physical dpt, telephone orders acceptable, give refills
ketamine, buprenorphine, thiopental, codeine
Schedule III meds
low to mod physical dpt, telephone orders acceptable, give refills
ketamine, buprenorphine, thiopental, codeine
Schedule IV meds, mult refills, telephone ok
limited abuse, mult refills, telephone ok
benzos, phenobarbital, tramadol, methohexial
Schedule V meds
limited psych dpt
prescription not necessary
couhg syrup w/ low dose opioid (codeine)
Peds pt w/ moderate sedation how frequently must vitals be checked? minimum
10 minutes
peds deep sedation and GA minimum requirements
every 5 minutes
continual v continuous
continnual: BP cuff
continuous: pulse ox
Transvalvular pressure equation
4 x (peak velocity ^2)
Auto PEEP
occurs w/ PPV if exhalation time inadequate
-MC in COPD pts who require prolonged exhalation
-can lead to dec perfusion of alevoli and worse V/Q mismatch
Brain-dead pts for organ transplant tend to have what issues?
pulm edema
hyperglycemia
hyperNa (early graft loss)
polyuria (DI)
myocardial dyxfxn
catecholamine storm -> hemodynamic instability, hypovolemia
normal cardiac output at rest
5-6 L/min for adult men
Myedema coma
hypoTN, bradycarida, hypothermia, delirium
-if suspect, start treament immediately and do not wait for lab confirmation -> give IVF, inotropic/vasopressor support, thyroid hormone replacement, steroids
**careful high dose T3 can precipitate angina or HF du to high cardiac stimulation
Severe aortic stenosis
valve area less than 0,8 and transvalvular P > 50
Initial tx of trigeminal neuralgia
carbamazepine
NSAIDS and pain
block PG, a sensitizing substance at peripheral nociceptors, and decrease transduction of pain
Nociceptive pathway
transduction, transmission, modulation, and perception
Nociceptive transduction
conversion of noxious stimuli to electrical action potential
-what blocks: NSAIDs, antihistamines, opioids
pain path: transduction -> transmission -> modulation -> perception
Transmission
conduction of action potential through neurons
-blocked by local anesthetic blocks
pain path: transduction -> transmission -> modulation -> perception
Modulation
alteration of afferent pain transmission along the neural pathway
-NMDA receptors, glutamate, epidural opioids
-responsible for neuroplasticity hyperalgesia
pain path: transduction -> transmission -> modulation -> perception
Perception
final part of common pain pathway to produce pain perception
inhibited w/ opioids, alpha 2 agonists, and GA
pain path: transduction -> transmission -> modulation -> perception
source of heat gloss: electromagnetic ray emission from the skin
radiation
** most significant source of heat loss
Most significant sources of heat loss
- Radiation: electromagnetic waves emanating from the body 60%
- Evaporation: energy consumption as it vaporizes water cooling the body 20%
St Johns Wort effect on intraop awareness
it is a cytochrome P450 inducer, metbolizing inhalation agents, opioid sand benzos -> inc risk of intraop awareness
oliguira
production of abnormally small amount of urine
0.5 cc/kg/hr
Whats added to blood sorage
Citrate: anticoagulant
Phosphate: cellular fxn and ATP production
Dextrose: nutrition source for glycolysis
Adenine: incorporated for ATP production
Pulmonary surfactant changes w/ alveoli size
surfactant more effectively red surface tension when concentrated
-so as alveoli shrink, surfactant conc inc -> more effectively red surface tension
What gas issue is most likely to cause lasting neurocognitive changes
Hypoxia
Contraindications to extracorporeal shock wave lithotripsy
Untreated bleeding disorders
Active UTI (displacement of bacteria when stone broken)
Pregnancy
What type of block has diarrhea as s SE?
celiac plexus block (T5-12) -> supplies innervation to intraabd organs
Memantine
NMDA antagonist that can be used in CRPS
w/ turbulent flow what matters for resistance?
Resistance increases w/ increasing gas density
-so w/ subglottic stenosis -> heli/ox b/c helium has decreased gas density
w/ laminar flow, what determines resistance?
Gas viscosity
pulm HTN and pregnancy
assoc w/ high mobidity and mortality -> pulm HTN is a CI for pregnancy (mortality 30-55%) most deaths early postpartum w/ R heart failure
nitrous oxide and pulm vascular resistance
inc PVR -> avoid in pts w/ pulm HTN
Confusion Assessment Method of ICU screening of delirium
- Acute mental status changes or fluctuating?
- inattentive or easily distracted?
if yes: - altered LOC or RASS other than 2
- Disorganized thinking?
Lung protective ventilation in ARDS
TV 6 cc/kg predicted body weight
plateau pressures < 30
minimum PEEP of 5
ARDS severity
PAO2: FiO2 ratio
Mild < 300
mod <200
severe < 100
Why is a patient hypoxemic and hypercapneic post opioids and volatiles anesthesia?
Impaired carotid body chemoreceptors due to dec in glossopharyngeal afferent n activity
-carotid bodies very sensitive to inhibition by anesthetics
-similar phenomenon in b/l carotid endarterectomy
Carotid body
chemoreceptors inc ventilation when PaO2 dec
-does this through afferent impulses via glossopharyngeal n to CNS ventilation centers
***impaired by opioids, benzos, volatiles, and b/l carotid endarterectomy
What arm should the a line be in for CPB
right upper extremity
-incase a surgeon places a L axillary art cannula, would display only that pressure
RF for GERD in prengnacy
gestationl age
GERD sym prior to pregnancy
multiparity
BMI not a RF
following transsphenoidal surgery, hyperNa to 155, osm of 320, 2.4L of UOP dx? tx?
central DI
give free water
SE of Hetastarch
inhibits expression of glycoprotein IIb-IIIa on plts -> plts cant achieve appropriate conformation to bind fibrinogen -> prob w/ plt aggregation
SACRAL SPINAL NERVE PHYSIOLOGIC FUNCTIONS
sacral = parasympathetic
-internal urethral sphincter relaxation
-internal anal sphincter relaxation
-detrusor muscle contraction
-sigmoid contraction -> promote bowel transit
Changes intraop w/ dec temp
coag impairment
inc blood loss
inc transfusion req
dec drug metabolism
inc wound infxn
potentiation of NMB
3x inc in morbid myocardial outcomes
** O2 consumption in by shivering and symp activity -> morbid myocardial outcomes*
risk of airway fire higher in GA or mAC?
MAC
-O2 collects near face, not contained
EtCO2 and MAC
EtCO2 monitoring is not mandatory -> but must ensure adequate ventilation w/ visualization or end-tidal monitoring
Dexmedetomidine effect on CBF
Causes a dec in cerebral metabolic rate -> dec in CBF
Hydralazine, nicardipine, and NG effect on CBF
cause direct cerebral vasodilation w/o dec CMR -> inc CBF and inc in cerebral blood volume
propofol and CBF
dec CMR -> dec CBF
Labetalol and CBF
DOES NOT EFFECT CMR or CBF -> useful in neurosurgical pts
Combitube
esophageal obturator airways = cuffed pharyngeal sealed w/ esophageal cuff
-double-lumen, double-cuff designed for emergency airway
-placed blindly
-ventilation through perforations of pharyngeal lumen
-*ETT annot be placed through it
Laryngeal tube
single-lumen supraglottic airway
-distal cuff seals the esophagus
-blindly inserted
esophageal obturator airway = cuffed pharyngeal sealer w/ esophageal cuff
-if the correct model, can be intubated through**
Which morphine metabolite causes analgesia and which causes adverse effects?
morphine-6-glucuronide: causes analGesia (6 is an upside down G) but resp depression, upside down lunG (only in pts w/ renal failure)
morphine 3-glucuronide: looks like brain -> excitability when builds up
Celecoxib MOA
selective COX-2 inhibitors
1st line for cancer pain w/ nonopioids
What temperature measuring device requires a battery
Thermistors
Thermistors
-temp sensitive resistors
-requires a power source to create a current
Infrared thermometers
devices that collect heat and use calculations to covert to temperature
-non-invasive, used in ear or along forehead
Thermocouples
junction b/w 2 metal types -> when temp different b/w current produced -> measure current
-do not require power source, inexpensive and accurate
Charcot-Marie-Tooth def and effect on NMB
hereditary denervation of peripheral NM system -> m weakness and neuropathy
-avoid succ and effects of NDNMB prolonged
Friedreich Ataxia
auto rec ataxia -> progressive limb ataxia and m weakness
**death from HF from myocardial degeneration
-avoid succ b/c denervation -> negative inotropes avoided b/c cardiac
Duchenne Muscular Dystrophy def and NMB
X linked rc, MC dystrophy
-m replaced w/ fibrous tissue -> inc intracellular Ca
-avoid succ and inh anesthetics -> rhabdo due to extrajunctional ACh (similar to MH)
-inc risk for blood loss (plt dysfxn)
-avoid hypovolemia b/c relatively fixed cardiac output from noncompliant ventricles
-if NDNMB needed, low dose
Becker muscular dystrophy def and NMB
-milder version of Duchenne -> rep and cardiac failure seen later
NO INC risk of MH! will have rhabdo and hyperK w/ succ and volatiles so still use TIIVA
-if NDNMB needed, low dose
Myotonic Dystrophy
-m wasting and weakness -> due to prolonged m contraction after stimulation
-cardiac conduction defects and cardiomyopathy
-restrictive lung dx, OSA, endocrine issues, intellectual impairment
-TRIGGERS: hypothermia, shivering, mechanival and electrical stimulation AVOIOD
-avoid succ, NDNMB should be reversed judiciously, as ACh can precipiate contractions
-NMB do NOT tx myotonic reactions
Myotonia Congenita
Auto Dom -> dyxfxn Cl channel -> global m hypertrophy and severe contractions
-NO weakness
-NO succ b/c intractable myotnias
-TRIGGERS: hypothermia, shivering, physical manipulation AVOID
-NDNMB unable to relax
-topical local anesthesia and Na channel blockers can break contracturs
HyperK periodic paralysis
Auto Dom d/o of Na channel -> hyperexcitability followed by inactive wakness
-TRIGGERS: inc serum K, cold, hunger, stresss
-can use lasix preop
-minimize fasting time, and use gluoce containing solutions
HypoK periodic paralysis
Auto Dom of Ca channel -> muscle parlysis in low K
-LINKED TO MH avoid succ and use NDNMB of short duration
-avoid glucose containg solutions, and alkalosis
Congenital diapghramatic hernia
peak insp P < 25
permissive hypercapnia
SaO2 b/w 85-95%
spontaneous respirations
delayed surgical repair until stable and NEVER laparoscopic
LP in pseudotumor cerebri
Reduce ICP and improve assoc neuros ymp incl vision
-risks: PDPH, back pain, bleeding, infxn, n damageq
What causes inc in peak insp pressure but plateua pressure unchanged
bronchospasm
kinked ETT
airway secretions
mucus plug
**only airway resistance
inc in peak pressure and plateau pressure
situations w/ inc elastic resistance (or dec compliance)
intrisnic pulm dx, ascites, abd insufflation, PX, trendelenberg
-when you do plateua perssure, theres no lung/air movmeent, so its a function of LUNGS
Normal CBF
50 cc/100g/min
EEG changes based on CBF
20 cc/100g/min -> EEG slowly
10-15/100g/min -> isoelectric EEG
6-10: neuronal injury will be temorarily reversible, but death if BF not resored
Focal ischemia v global ischemia
-focal: BF restricted parts of the brain insuff
-global: hypoTN wide area of brain
-focal more well tolerated b/c some BF through collaterals
-both can have EEEG changes -> just depends on if local area of EEG cahnges v global
-both attenuated by hypothermia
-both have ischemia -> depolar -> influx of extracellular Na -> neuronal edema
low grade fever post pRBC transfusioncaused by what?
recipient antibodies to donor leukocytes
-1 C inc w/i 4 hours, can last 48 hours
When are you more likely to get bactweial contaminationn of blood products
higher risk in plts b/c stored at room temp
-fever chills, tachycardia, dyspnea, emesis, shock
-possibility for DIC and acute resp failure
Why hyperglycemic in stress
inc glucose production (cortisol)
peripheral insulin resistance
insulin released reduced (inh by cortisol, to prevent glucose from being stored, and having it readily available instead)
Strong ion difference equation
(NA + K + Ca + Mg) - (Cl + lactate)
What’s not considered in strong ion difference
Total weak acid concentration: do not fully dissociate
-mainly albumin and phosphate
-so if alubmin dec -> metabolic alkalosis
Balance of all ions in body
Strong ion difference plus total weak acid concentration
-metabolic acidosis: due to inc weak acids (hyperphos in renal failure)
-met alkalosis: due to dec weak acids (hypoalbumin)
-met acidosis (decreased SID, large amount of NS)
-met alk: increased SID (vomiting pt, losing chloride)
SID: (Na + Ca + K + Mg) - 9Cl + lactate)
pH and strong ion difference
decreased SID = decreased pH (acidosis)
PPx for infective endocarditis
-prosthetic cardiac valves, prev infective endocarditis, congenital heart dx unrepaired, CHD w/ prosthesis w/i first 6 months of valve issues
PLUS
-dental procedure w/ gingival manipulation, perforation of oral or resp tract (incision, biopsy)
-GI or GU w/ active infxn
Where is oxytocin synthesized
supraoptic nuclei of hypothalamus
-transported to posterior pituitary gland through infundibular stalk
-released by post pituitary gland
whre is vasopressin synthesized
paraventricular nuclei of hypothalamus
-transported to posterior pituitary gland through infundibular stalk
-released by post pituitary gland
which opioid metabolite causes myoclonus
hydromorphone -> it’s metabolite hydromorphone-3-glucuronide (accumulates in renal failure)
meperidine -> metabolite normeperidine -> sz, agitation, and myoclonus (again builds in renal faiilure)
which opioid metabolite causes myoclonus
hydromorphone -> it’s metabolite hydromorphone-3-glucuronide (accumulates in renal failure)
meperidine -> metabolite normeperidine -> sz, agitation, and myoclonus (again builds in renal failure)
sympathetic nervous system cell bodies span which SC levels?
T1-L2
Parasympathetic NS which spinal n?
CN III, VII, IX, X
pelvic: S2-4
when is epi used as a NT?
postganglinic cell sof SNS at adrenal medulla
where does Symp NS use ACh as a NT?
b/c pre and post ganglionic cells and ACh terminally at sweat glands
When do you need to monitor temp intraop?
-GA longer than 30 minutes
-neuraxial longer than 30 minutes
do NOT need for sedation and peripheral n blocks
Transfusion-related immunomodulation
transient immunosuppression in recipients after blood transfusion -> b/c substances released by donor leukocytes -> immune resp
-inc risk of bacterial infxn, cancer, mortality
**reduced by leukocyte reduction
When do you leukocyte reduce blood?
to prevent transfusion-related immunomodulation
When do you irradiate blood
reduce risk of graft v host disease
When do you wash blood
reduce risk of allergic rxn
-pts w/ IgA def
-and red extracellular K -> useful in HD pts
Acute v chronic resp acidosis CO2 and bicarb compensation
Acute: inc in HCO3 of 0.2 for each 1 inc in PaCO2 above 40
Chronic: .4 inc in HCO3 for each 1 inc in PaCo2 above 40
Normal bicarb: 24
Normal bicarb level
24
How to calculate GCS
EYES: 4
VOCALS: 5
MOTORS: 6
Acute epiglottitis, best way to proceed
get to OR, maintain spontaneous ventilation (inhalational induction)
avoid muscle relaxation
Cardiac output in labor
Latent labor inc 15%
active labor inc 30%
expulsive labor inc 45%
-uterine contractions additional inc cardiac output by 10-25%
Nociceptive afferent neurons
A-delta and C fibers
C fibers unmyelinated
A-delta: medium sized, thinly myelinated
-high-threshold neurons
Normal TV and RR, whats the normal minute ventilation
~5L/min
Normal PFT whas the normal vital capacity
~5L
When does rebreathing on circuit occur
When MV exceeds FGF -> rebreathing -> lower FiO2
CRPS I v II
CRPS I: occurs in absence of prior n injury
II: occurs after nerve injury (trauma, surgery, ischemia)
palpable taut band, exquisite tenderness on palpation, painful limitation to passive full ROM
myofascial pain syndrome
HypoCa symp
paresthesias, tetany
severe cases: sz, laryngospasm
Best way to prevent heat loss during first phase of hypothermia in OR
forced air warming blanket for 1/2 hour prior to surgery
Commingling of forced air warming device
connecting one manufacturer’s device (warming hose) to another manufacturer’s warming blanket
-considered a type of MISUSE
Type 1 diabetes and airway
difficult laryngoscopy can occur
-freq hyperglycemia -> glycosylation of joints and limited mobility
-affects atlantio occipital joint and compromises adequate neck extension
What chromosomal issue predisposes to subglottic stenosis
Trisomy 21 (Down Syndrome)
-atlantoaxial occipital joint instability, macroglossia, floppy soft palate
-enlarged tonsils/adenoids
Pain tx of choice for ankylosing spondylitis
Indomethain and other NSAIDs
Ankylosing spondylitis
chronic inflammation of spin (esp cervical and lumbar), hip joints and shoulders
-progressive ossification -> fusion of the spine
-assoc w/ reactive arthritis, UC, Crohns, and psoriasis
**give NSAIDs (Indomethacin)
Hypothyroidism and airway
hypothyroid -> myxedema -> swelling in oral cavity, hypopharynx and total body (inappropriate ADH)
Sensitivity of a class III or IV mallampati for predicting difficult laryngoscopy or intubation
35%
Specificity lass III or IV mallampati for predicting difficult laryngoscopy or intubation
91%
Strongest predictor of difficult intubation
prior hx of diff intubation
SSEPs v MEPs: which is more favorable in detecting SC ischemia
MEPs
SSEPs v MEPs: which responses more rapidly to ischemic conditions?
MEPs
SSEPs v MEPs: which does volatile anesethetics suppress more
MEPs
What nerve is MC monitored when lookingn for anterior and posterior SC ischemia during aortic surgery?
tibial nerve
Hemodynamic goals during cardiopulmonary bypass
Pump flow 1.6-3 L/min/m^2
arterial BP 50-90
O2 sat in venous cannula of greater than 65%
Type 1 diabetes, destruction of what cell
pancreatic beta cells
How does RhoGAM work
destroys fetal erythrocytes before they evoke a maternal immune response
Emergency transfusion
PRBCs: type O Rh neg
FFP: Type AB (lack of anti-A or anti-B)
plts: type O
anesthetic concerns for myotonic disorders
NMB do not treat myotonic reactions
TRIGGERS: cold, stress, pain, succ, AChEinh
Guillain Barre and MH
NO iincreased risk
-but still don’t u se succ -> hyperK
Neuromuscular disease w/ inc risk of MH
Duchenne and Becker muscular dystrophy
King-Denborough disease
Central core and multiminicore Dx
Nemaline rod myopathy