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