TL 1 Flashcards
Where is the median nerve located?
Medial to the brachial artery in the antecubital fossa
Organophopshate poisoning mechanism
Irreversible inhibition of acetylcholinesterase –> too much acetylcholine –> cholinergic crisis –> SLUDGEMI
Tx: Immediate - atropine, second - pralidoxime
5 predictors of hypoxemia during one lung ventilation
1) hypoxemia during two lung ventilation
2) right sided thoracotomy (r lung is bigger)
3) high FEV1 (healthy or restrictive lungs desaturate more than obstructive lung disease with low FEV1)
4) supine position (lateral positioning helps reduce shunt with dependent non operative lung getting more blood flow)
5) high perfusion of operative lung (worse shunt)
pH/paCO2 correction in alpha-stat blood gas
Alpha stat ABG run at 37 C - will appear acidotic and hypercarbic for patients in deep hypothermic circ arrest
To correct for patient hypothermic temp:
pH increases by 0.015 for every 1 C below 37
paCO2 decreases by 2 for every 1 C below 37
pH stat ABG values?
pH is maintained when measuring ABG at patient’s actual temperature by adding CO2 to hypothermic blood
Brain death determination (3)
1) coma or unresponsiveness
2) absence of brainstem reflexes
3) apnea testing
*confirmatory testing not required - clinical diagnosis
Brain death confirmatory testing (4)
1) Angiography (gold standard) - filling up to external carotids but not intracerebrally
2) EEG
3) transcranial doppler
4) Single photon emission CT
*Confirmatory testing not required - brain death is a clinical diagnosis
Pain control options after tonsillectomy?
What to avoid?
First line: acetaminophen/ibuprofen
Second line: morphine/oxycodone
CODEINE CONTRAINDICATED
Heparin dosing in pregnancy?
Dose of UFH increases as pregnancy progresses due to decreased bioavailability caused by increased plasma volume, increased protein binding, enhanced renal clearance, and increased degradation.
Target aPTT 1.5-2.5 times normal
Prophylactic dose: 5-7.5K u q12h in first/second trimesters, 10K u q12h third trimest
Therapeutic dose: 10K u or more q12h
Sevo uptake: infant versus adult
sevo uptake is faster in infants than adults because of higher alveolar ventilation to FRC ratio
Changes in plasma concentrations of various solutes after hemodialysis
1) decreased potassium, calcium, creatinine, mag, phos, free water
2) increased large proteins (unable to pass through semipermeable membrane)
3) may increase or decrease: bicarb, glucose, sodium, chloride
hypocalcemia EKG finding (1)
prolonged QT
hypocalcemia causes decreased Ca in sarcoplasmic reticulum which cases decreased calcium-activated outward flow of potassium current which prolongs phase 3 (repolarization) of cardiac action potential
Diagnosis of acute liver failure (3 criteria)
1) elevated INR
2) encephalopathy
3) elevated aminotransferases
NB: most commonly caused by acetaminophen toxicity, viral infection, ischemia, and autoimmune disease
CAM-ICU score - 4 screening questions
1) acute change in mental status or fluctuating course
2) inattention/easily distracted
3) RASS other than 0
4) disorganized thinking
VACTERL stands for?
Vertebral defects
Anal atresia
Cardiac defects
TEF
Renal anomalies
Limb abnormalities
Should get cardiac echo prior to surgery.
Lumbosacral imaging if planning caudal to r/o neural tube defects.
May be associated with coarctation of aorta
Coronary perfusion pressure equation
CPP = DBP - LVEDP
Law of LaPlace equation
Systolic wall tension = Pressure x radius / wall thickness
T = Pr/h
Blood volume for a premature infant?
90-105 mL/kg
Blood volume for a full term newborn?
80-90 mL/kg
Blood volume for an infant 3-12 months?
70-80 mL/kg
Blood volume for a child 1-12 years?
70-75 mL/kg
Blood volume for adult male?
65-70 mL/kg
Blood volume for adult female?
60-65 mL/kg
Carbamazepine toxicity effects
1) Anticholinergic - hot has a hare, blind as a bat, red as a beet, dry as a bone, mad as a hatter
2) Cardiac - prolonged QT, widened QRS
What does a magnet do to a pacemaker versus an ICD?
1) Pacemaker: converts to asynchronous pacing mode such as VOO
2) ICD: does not affect pacing, but suspends tachyarrhythmia detection and therapy
Doppler ultrasound frequency of blood flow?
Blood flow towards probe: frequency of RBCs higher than frequency emitted by probe
Blood flow away from probe: frequency of RBC lower than frequency of probe
4 mechanisms of high aspiration risk in patients with myotonic dystrophy
1) gastric atony
2) delayed gastric emptying
3) intestinal hypomotility
4) pharyngeal muscle weakness
How to calculate shunt fraction (Qs/Qt)?
Qs/Qt = (1-SaO2) / (1-SvO2)
CVP Waveform:
a, c, v, x, y
A - Atrial contraction
C - ventricle Contracts - TV bulges back into RA
X descent - atrial relaXation
V - atrial villing
Y descent - passive RV filling
Indications for CRT (4)
Cardiac resynchronization therapy (ALL 4 must apply)
1) LVEF < 35%
2) Intraventricular conduction delay > 120 ms
3) Clinical HF symptoms
4) sinus rhythm
CVP Waveform: Cannon A wave
AV dissociation
CVP Waveform: Tall A and V waves, minimal Y descent
Tricuspid Stenosis
CVP Waveform: Tall A wave, loss of X descent
Tricuspid Regurgitation
CVP Waveform: Loss of A wave
Atrial fibrillation
CVP Waveform: Dominant X descent, minimal Y descent
Cardiac Tamponade
CVP Waveform: Tall A and V wave; Steep X and Y descent
Constrictive Pericarditis
What is syringomyelia? When is it most often seen? Symptoms?
-Fluid filled cyst at central spinal cord
-Causes loss of pain and temp sensation with retained touch, pressure, propioception
-Assoc with Chiari I malformation and trauma
How can you reverse High spinal?
CSF lavage – remove 20 cc of CSF and replace with NS
How to calculate dead space?
Vd/Vt = (PaCO2 - PEtCO2) / PaCO2
ABG with hyperparathyroidism?
non anion gap metabolic acidosis due to…
PTH inhibits renal reabsorption of bicarb and also sodium-chloride cotransporter leading to low bicarb, high chloride, and low pH
Which patients respond most and least to bronchodilator therapy?
Best response to bronchodilators: Moderate obstructive disease
Minimal response to bronchodilators: mild disease, severe disease, healthy patients
How to treat methemoglobinemia? What if G6PD deficient?
Normally: Methylene blue
G6PD or if taking MAOIs: Ascorbic acid
Obstructive versus central sleep apnea?
OSA: upper airway obstruction - snoring - apneic episodes
CSA: central respiratory drive fails - apneic episodes (no snoring!)
Tx for both: CPAP
PO to IV methadone dose?
PO 2 : IV 1
Botulism: mechanism, dx, tx?
Clostridium botulinum - gram positive anaerobic bacteria - secretes botulinum toxin, which inhibits SNARE proteins and prevents release of ACH at NMJ and autonomic nerves
Dx:
suspicious history like home canning, IVDU, raw honey PLUS bilateral symmetric flaccid descending paralysis
Tx:
infants < 1 yr = human derive immune globulin
anyone > 1 yr = equine serum antitoxin
Coverage of TAP block (4 nerves)?
subcostal, intercostal, ilioinguinal, iliohypogastric
How to treat SVT in a transplanted heart?
Synchronized cardioversion!
Carotid sinus massage and other indirect therapies (including esmolol and phenylephrine) will be blunted due to denervation s/p transplant
What is Klippel-Feil syndrome?
Congenital fusion of the cervical spine - airway difficulties
What is Pierre Robin sequence associated with (3)?
Micrognathia, macroglossia, severe upper airway obstruction
What is Beckwith-Wiedemann associated with (4)?
Macroglossia, organomegaly, hypoglycemia, omphalocele
What is Down syndrome associated with (6)?
endocardial cushion/AV canal defects, macroglossia, subglottic stenosis, atlanto-axial instability, hypotonia, OSA
How to differentiate between pre-renal vs intra-renal AKI?
1) normal patient
2) patient taking diuretics
1) normally… FeNa!
FeNa < 1% - pre-renal
FeNa > 3% - intra-renal
2) if taking diuretics… use FeUrea
FeUrea < 35% - pre-renal
FeUrea > 50% - intra-renal
ABG in pregnant vs non-pregnant patient
Non-pregnant:
7.4 / 100 / 40 / 24
Pregnant:
7.44 / 105 / 30 / 20
TCA overdose: ECG findings (3)
**Hallmark finding: Prolonged QRS
Also may see:
prolonged QT, T wave flattening or inversion
ASIA - American Spinal injury association - Spinal cord injury classification scale A-E:
A =?
E =?
A = complete cord injury with motor and sensory deficit in S4-5
E = no injury with intact motor and sensation
Which blood products have highest risk of TRALI?
FFP followed by Platelets (higher amount of plasma which contains granulocytes which get sequestered in lungs)
Dural sac and conus medullaris is infants vs adults?
Conus medullaris: Infants L3, adults L1
Dural sac: Infants S3, adults S2
Omphalocele vs gastroschisis:
O: more common, associated w/ phys/chromosomal abnormalities (BW, trisomy 13, etc), covered by membrane
G: less common, isolated lesion, exposed bowel without covering, higher inc of dehydration, infection, heat loss
Neuraxial analgesia for IICH/pseudotumor cerebri?
Intrathecal catheter w/ intermittent physician administered boluses and CSF withdrawal
Midazolam bioavailability??
IV > SubQ > IM > SL/Buccal > IN > Rectal > PO
*Extensive first pass metabolism, <50% bioavailability when dosed PO
Why does heparin resistance occur? How do you correct it?
Likely due to Anti-thrombin III deficiency if receiving repeated doses of heparin. Give 2-3 units of FFP, this contains AT III and will allow heparin to exert its full effect
Infraorbital nerve block: anatomy and distribution of analgesia? indication?
Infraorbital nerve is terminal branch of maxillary division (V2) of trigeminal nerve (CN V)
sensation to: Lower eyelid, lateral nose, cheek, upper lip
Good for cleft lip surgery!
Risk factors for placenta accreta? (5)
-multiparity
-prior c section/uterine surgery
-placenta previa
-smoking
-advanced maternal age
Risk factors for post-op ventilation in myasthenia gravis (4)
-Pyridostigmine dose > 750 mg/day
-Disease duration > 6 years
-Vital capacity < 2.9 L
-chronic respiratory illness
TEG values: definition, problem, and treatment
R time
R = initial clot formation time
if prolonged, clotting factors low
Tx: FFP or coag factor concentrate
TEG values: definition, problem, and treatment
K time
K = time to achieve full clot strength
if prolonged, fibrinogen or clotting factors low (mostly fibrinogen)
Tx: FFP, factor concentrate, cryo, or fibrinogen
TEG values: definition, problem, and treatment
Alpha angle
A = speed of clot formation
if decreased, mostly low on fibrinogen
Tx: FFP, factor concentrate, cryo, or fibrinogen
TEG values: definition, problem, and treatment
MA
Max amplitude = strength of clot
if decreased, platelet problem
Tx: Platelets
TEG values: definition, problem, and treatment
LY30
LY30 = fibrinolysis (breaking up clot)
if low, problem with plasmin
Tx: TXA or ACA
von willebrand disease mechanism and treatment intra-op?
VWF is a plasma protein that stabilizes Factor VIII and platelets
VWD leads to poor clotting and low Factor VIII levels
Tx: desmopressin, recombinant factor VIII, cryoprecipitate, ACA/TXA
What is cryoprecipitate composed of? (4)
-Factor VIII
-Factor XIII
-Fibrinogen
-VWF
Complications of interscalene block (5)
-intra-arterial injection (carotid or vert)
-spinal or epidural injection
-stellate ganglion block leading to Horner’s
-phrenic nerve block leading to diaphragmatic paralysis
-ulnar nerve sparing
Hyper vs hypo kalemic periodic paralysis - ion channel affected
HYPER - voltage gated sodium channel
HYPO - voltage gated calcium channel (Type 1) or voltage gated sodium channel (Tye 2)
What abnormality is myelomeningocele associated with?
Arnold Chiari malformation and hydrocephalus
Cerebral salt wasting vs SIADH —- euvolemic vs hypovolemic?
SIADH - euvolemic/hypervolemic
CSW - hypovolemic
*Both have dilute blood and concentrated urine
Features of drugs that cross the placenta (4)
-high lipid solubility
-low molecular weight
-low ionized fraction
-non-protein-bound
Drugs that DON’T cross the placenta
He Is Going Nowhere Soon
Heparin
Insulin
Glycopyrrolate
NDNMB
Succinylcholine
Congenital diaphragmatic hernia: 4 anesthetic considerations
Allow permissive hypercapnia
Avoid hypothermia
Avoid venous access in lower extremities
Avoid nitrous (need high FiO2)
Mechanism of hepatic encephalopathy
hyperammonemia - ammonia binds with glutamate to form glutamine
glutamine osmotically causes brain astrocytes to swell – cerebral edema
Mechanism of lactulose in treating hyperammonemia
converts ammonia to ammonium ion and prevents it from crossing into cells keeping it GI tract
qSOFA criteria (3)
RR > 22
SBP < 100
Altered mentation
APGAR criteria
APGAR:
Appearance
Pulse
Grimace
Activity
Respirations
2 points each total of 10
Glasgow coma scale criteria
