OpenAnesthesia Flashcards
pump flow range
1.6-3 L/min/m2
CPB mixed venous goals
SvO2 >65%
CPB glucose
aggressive (80-110 mg/dL) management ass with worse outcomes
meds to avoid with reproductive assistance, why?
droperidol and metoclopramide; both can increase prolactin levels, which can follicle maturation and corpus function
LMWH clearance
renally - prolonged in renal insufficiency, directly proportional to creatinine clearance
how to monitor enoxaparin
PTT is not usually monitored, can test anti-Xa activity (peak at 4 hours), therapeutic for tx 0.6-1.0 U/ml and ppx 0.1-0.3 U/ml
uterine atony risk factors
oxytocin, multiples, polyhydramnios, chorioamnionitis (NSAIDs irreversibly inhibit platelet function but little affect on uterine tone)
TRALI mechanism
GVHD - leukocytes/neutrophils causing flood of neutrophils and inflammatory mediators to lungs causing increased microvasc permeability
Haldane effect
Deoxygenated blood can carry increasing amounts of carbon dioxide
Bohr effect
an increase of carbon dioxide in the blood and a decrease in pH results in a reduction of the affinity of hemoglobin for oxygen
IgA deficiency considerations
blood products need to be washed before administration
cryo contains
VIII (100 IU), vWF, XIII, and fibrinogen (250 mg)
type
patient’s RBCs mixed with serum with known antigens (ABOD)
screen
(indirect) put patients serum with RBCs with known antigens
crossmatch
patient’s serum with donor cells
therapeutic hypothermia
32-34 for 24 hours
emergent therapy for stroke 2/2 air embolism
hyperbaric O2
HBO uses
arterial air embolism, CO poisoning, decompression sickness, severe anemia, hypoperfusion, gas gangrene
HBO MAC effects
decrease in MAC because HBO increases partial pressure of volatiles at higher barometric pressure and gas density increases so rotameter flowmeters will read falsely high (2% sevo at 1 atm produces same as 0.66% sevo at 3 atm)
1 mm Hg CO2 decrease - CBF?
decreases 3-4%, goal 30-35
goal CPP with increased ICP
60-70 mm Hg
prevention of contrast nephropathy
periprocedural continuous hemofiltration, oral N-acetylcysteine, bicarbonate infusion
predisposition to renal damage with contrast
Cr >1.5, GFR < 60, DM nephropathy, hypovolemia, high dose contrast media, multiple myeloma
pierre robin ass syndromes
stickler syndrome, velocardiofacial syndrome, treacher-collins
pierre robin characteristics
micrognathia, glossoptosis (prone position may help), airway obstruction –> can cause cor pulmonale, can also see cleft palate, high incidence of central/obstructive apnea
congenital lobar emphysema management
inhalational induction, spontaneous ventilation preferred, single lung ventilation, nitrous contraindicated
congenital lobar emphysema characteristics
causes hyperinflation of lungs, resp distress in newborn-6 mos, left lung more common, left upper lobe most common,
congenital lobar emphysema physical exam
decreased breath sounds, hyper-resonant, hyperinflation on CXR
CPB roller pump
roller pump flow is predictable and depends on revolutions per minute of the pump, retrograde flow is not possible, but if there is outflow occlusion, pressure can build and cause tubing rupture or separation
CPB centrifugal pump
retrograde flow is possible, flow depends on pressure differential created by the spinning cones –> cause negative pressure that propels fluid forward, flow varies with afterload an preload
roller pump vs centrifugal
roller has predictable speed and cost less
best echo view for ischemia
transgastric mid-papillary short axis
fluconazole active against
candida, Cryptococcus, coccoidioides immitis
needed for nitrogen balance calculations
nitrogen intake, 24 hour urine nitrogen, 24 hour change in BUN (very sick usually have negative nitrogen balance)
PNA diagnosis from BAL
10,000 colonies, 1,000,000 for endotracheal aspirates, 1,000 for protected brush specimen
hyperkalemia treatment
hyperventilation, gluscose/insulin, beta agonist, lasix, dialysis, aldosterone agonist
nitroglycerin
much more potent venodilator than arterial dilator
hydralazine metabolism
metabolized by acetylation in the liver
synchronized cardioversion
shock synchronized with QRS to avoid shock during refractory period (R on T)
smoking cessation 48-72 hours
increased secretion, more reactive airway activity, decreased carboxyhgb, improved oxygentation
smoking cessation 2-4 weeks? 8 weeks?
decreased secretions, decreased airway reactivity; decreased overall post-op morbidity and mortality
MS management
sensitive/insensitive to NMBD, suc may cause hyperkalemia, hyperthermia may cause exacerbations, neuraxial not recommended?, MAC may be reduced
MS
autoimmune disease of inflammation, demyelination, and axonal damage to CNS, tx with corticosteroids, methotrexate, azathioprine, glatiramer acetate, interferon-beta
autonomic hyperreflexia
HTN followed by profound vagal response (brady), may see vasodilation and flushing above injury (2/2 high afterload)
layers for paramedian neuraxial
skin, sub Q fat, paraspinal muscles, ligamentum flavum, dura mater, subdural space, arachnoid mater, subarachnoid space
DMD heart changes
dilated CM from fatty infiltration, prominent Q waves, inverted T waves, cardiac involvement seen in 90% patients, can lead to LV failure and sudden death (ACE-I and bb)
DMD presentation
most severe MD, 3-5 years start, waddling gait, progressive falls, difficulty with stairs, gower (both hands to get up from seated position)
becker’s dystrophy
problem with dystrophin results in leaking muscle membranes and elevation of CPK, pseudohypertrophy of muscles from fibrofatty infiltrates
LA absorption
ICE-BS intercostal, caudal, epidural, brachial, sciatic/femoral
gasserian ganglion
formed from 3 divisions of trigeminal nerve, trigeminal nerve root emerges from here and travels to its nucleus in the pons
trigeminal neuralgia cause
irritation of nerve root by blood vessel (superior cerebellar artery), MS, tumor, trauma
trigeminal neuralgia treatment
carbamezapine (tegretol), oxycarbemezapine (trileptal), phenytoin, baclofen, gabapentin, microvascular decompress, nerve lesions, motor cortex stim
carbamezapine and phenytoin side effects
hyponatremia, agranulocytosis, hepatic toxicity; gingival hyperplasia
WHO analgesic ladder
- non-opioid w/wo adjuvants 2. weak opioids w/wo adj 3. strong opioids w/wo adj
acute hemolytic reaction
can occur 3-21 days after transfusion, elevated unconjugated bili, back pain, fever, SOB, chest pain, pain at sight of infusion, HA, change in vitals, pulm edema, bleeding, renal failure
febrile transfusion reaction
0.5% RBC transfusions, 30% platelet transfusions, see increase > 1 degree C, HA, chills, back pain, may take 2 hours to develop
febrile transfusion reaction treatment
stop transfusion (may be hemolytic), acetaminophen, diphenhydramine, leukoreduced transfusions in the future and premed with acetaminophen
LVAD contraindications
PFO/ASD, AI, MS (tends to improve MR)
acute hemorrhage and resus, which factor is first to reach critical low
fibrinogen
can fibrillating atrium be paced
no
Pacemaker
Paced, Sensed, Response to sensed event, Rate modulation, Multisite pacing
highest risk for abnormal placentation
placenta previa (increased maternal age, C-sections)
bronchial blocker disadvantage
higher cost, not able to add CPAP or suction operative lung
missed musculocutaneous on ax block
maintain biceps motor, elbow flexion and supination, sensation to lateral forearm
tibial nerve stim
innervates gastroc and soleus muscles of calf - controls plantar flexion of toes and ankle
2-chloroprocaine epidural use
associated with decreased efficacy of subsequent epidural opioids because it antagonizes mu and kappa opioid receptors (onset 6-12 min, peak 10-20, duration 30-60 min)
2-chloroprocaine epidural use
associated with decreased efficacy of subsequent epidural opioids
SC stimulator procedure management
can be extensive dissection and awake has lower fail rate; can use spinal, LA with conscious sedation, thoracic epidural (single shot)
spinal cord stim
send pulsed electrical signals to spinal cord to control chronic pain, stim electrodes are placed in epidural space, generator in lower abd or gluteal region, and generator remote
spinal cord stim indications
failed back surgery syndrome, refractory angina pectoris, PVD, CRPS I
failed back surgery syndrome
40% of patients s/p spinal surgery
refractory angina pectoris
angina caused by CAD not controlled with meds, surgery, etc –> treat with SCS decrease chest pain, hospital admission, increase exercise duration, less morbidity than other open procedures for pain
SCS for PVD
when PVD is inoperable –> improves quality of life, limb mobility, pain relief
AMS differential diagnosis post craniotomy
hemorrhage, tension pneumocephalus, venous/arterial stroke, hydrocephalus, infection, seizures, metabolic, retraction/surgical injury
CBF, slowing, flat EEG
50ml/100g/min (15% CO), 20, 12
CMRO2
3ml/100g/min
PaCO2 and CBF/CBV
decrease CBF 1-1.5 and CBV 0.05
cerebral vasospasm treatment
hypertensive euvolemia (HTN, hypervolemia, hemodilution), nimodipine, balloon angioplasty, papaverine/verapamil intraterial injection (vasodilators)
cerebral vasospasm presentation and detection
3-10 s/p SAH (think hydrocephalus, seizure, hyponatremia, rebleed), use cerebral angiography, transcranial Doppler (increased arterial velocity
vasospasm prevention
nimodipine, remove subarachnoid blood ASAP, instill thrombolytics (urokinase), antinflam (NSAIDs/steroids)
AAA repair renal problems
see ATN, decrease chance with good intravascular volume and heart function
AAA crossclamp complications (increase)
increased wall motion abn, increased wedge and CVP, increased coronary blood flow, increased mixed venous, increased epi/norepi, renal vasc resistance
AAA crossclamp complications (decrease)
decreased CO, EF, RBF, CO2 production, renal cortical blood flow, GFR
intralipid dose
1.5ml/kg bolus and 0.25 ml/kg/min infusion
bupi cardiac toxicity
binds more strongly to resting/inactive Na channels and dissociates from channels during diastole more slowly
methgb with LA
prilocaine (o-toluidine), benzocaine
most common arrhythmia with bupi
wide complex ventricular rhythm (vtach)
MS and pregnancy
20-30% experience exacerbation post partum 2/2 loss of immune-tolerant pregnancy state
most important crossclamp factor
level of clamp - infrarenal least hemodynamic changes
CEA neuromonitoring
awake, EEG, SSEP, transcranial Doppler, cerebral oximetry stump pressure
hypernatremia and MAC
increases MAC
ADH site of action
distal and collecting tubules
avoid with HOCM
increasing velocity of blood across LVOT - decreasing SVR, decreasing preload, increasing contractility, increasing HR
HOCM treatment
beta blockers, CCB, amiodarone (for afib), diuretics (with caution for diastolic dysfunction)
pHTN diagnosis
resting PAP >25, PCWP/LAP 15, PVR >3 (RVH is not required)
morphine neonate vs adult differences
increased half life (6-9 hr) until 2-3 months (2-4 hr), more protein bound in adults
methadone CV
prolongs QT
prostaglandin E1
used for interrupted aortic arch and hypoplastic left heart syndrome (0.1 mcg/kg/min) - maintains ductal patency
prostaglandin E2
ductus arteriosus patent in utero
prostaglandin E1 se
hypotension, fever, apnea, myoclonus, irritability
beta thal minor
microcytic red cells
beta thal major (cooleys)
fine at birth because of hgbF, then hemolysis causes severe anemia - pale, jaundice, hepatosplenomegaly, growth retard, skeletal abn
beta thal major treatment
regular transfusions of bone marrow transplant
CV changes pregnancy
may see cardiomegaly, S3, regurg murmurs (TR-systolic), dilation can cause RAD and RBBB - S4 is pathologic so get it checked
coagulation changes pregnancy
hypercoagulable state with increase in factors, decrease in protein S (anticoagulant) and resistance to protein C (anticoagulant), platelet turnover increases
pregnancy EKG
heart moved cephalad and laterally - sinus tach, other dysrhythmias, ST depression, T wave flattening, LVH, LAD
HAART drug interactions
protease inhibitors inhibit cytochrome p450 metabolism - CCB, macrolide antibiotics, barbs, alprazolam, midazolam, carbamazepine, azole antifungals, phenytoin, rifampin
large v waves
MR
mitral stenosis
increase preload, decrease HR, maintain SVR, giant a waves, pressure gradient >10 across valve, PCWP reflects LA not LV
CMRO2 reduction with anesthetics
barbs and others decrease by 50% (amount responsible for electrical activity)
central retinal artery occlusion
associated with external pressure on globe, unilateral most of the time, no improvement in visual acuity over time, see pale retina and cherry red spot on macula
morphine peak
1 hour 2/2 very hydrophobic
student’s t test
compare means of 2 normally distributed populations
mann-whitney
compare two populations that are not normally distributed
coronary perfusion pressure
aortic diastolic pressure minus LVEDP
coronary blood flow
(aortic diastolic pressure - LVEDP)/coronary vascular resistance
chattering/fluttering and treatment
of venous cannula when compliant arterial/venous walls collapse against intake cannula opening; treat by increasing blood volume or decreasing siphon pressure
mild preeclampsia
BP 140/90, 24 hour urine >300mg (+1 dipstick x 2), after 20 weeks
severe preeclampsia
SBP>160 or DBP>110 x 2 (6 hr), 24 hr urine >5g (+3 dipstick x 2), pulm edema/cyanosis, oliguria <400 ml in 24 hr, HA, epigastric pain and/or impaired liver function, thrombocytopenia, oligohydramnios/decreased fetal growth/placental abruption
poiseuille’s law
Q=(pixPxr^4)/(8xviscosityxlength)
preeclampsia increases risk of
postpartum venous thromboembolism, chronic HTN, CV disease; risk of adverse outcomes worse if onset <34 weeks
sodium citrate
non-particulate antacid rapidly decreases acidity of gastric contents, duration 1 hour
alpha-stat
d/n add bicarb, associated with less post op cognitive dysfunction
pH-stat
temperature corrects for pH and pCO2
etomidate and ECT
increases seizure duration
bicuspid aortic valve significance
increased risk for aortic aneurysm and dissection
normal pulm vascular resistance
0.25-1.6 wood units or 20-130 dyne-sec-cm-5 (when equation multiplied by 80)
normal SVR
9-20 wood units or 700-1600 dyne-sec-cm-5
normal PA SBP
1/8-1/10 systemic SBP
transpulmonary gradient
mPAP - PCWP, >14 increased pressure and >16 with elevated right atrial pressure (>20) predictive value for RV failure
pulmonary HTN
> 1/4 systemic SBP
PABA allergy
ester LA
AR management goals
“fast and loose” relative tachy (reduces time in diastole for regurg), maintain preload, reduce afterload, maintain contractility
decreased lvad effectiveness
Ai will decrease output the most, TR and MS also decrease; PFO increases chance of hypoxemia and paradoxical embolus
pyloric stenosis lab abnormality
hypochloremic, hypokalemic metabolic alkalosis with possible aciduria (normalization of chloride signifies resolution of alkalosis)
true ventricular aneurysm
at apex, dilated and dyskinetic area with all layers, 90 days after MI (abn remodeling), smooth transition with orifice 0.9-1.0
pseudo ventricular aneurysm
saccular/globular at site of chronic ventricular rupture lined with only pericardium after MI, trauma, surgery, infection, abrupt transition with small orifice <0.5, bi-directional flow on doppler
affect oxygenation during one lung
degree of HPV (volatiles, hypocapnea, vasodilators), high airway pressures (PEEP, hypervent, high PIP)
abd compartment syndrome bladder pressure
> 20-25; 25-35 need eventual decompression, >35 immediate decompression
abd compartment syndrome bladder pressure
> 20-25
abd compartment syndrome presentation
sudden intra-ab pressure increase, increased PIP, decreased UOP, hypoxia, hypercarbia, hypotension
afib treatment
rate control w/ beta blocker, CCB; cardioversion w/ amiodarone, sotalol, procainamide, synchronized DC (stable/unstable)
underestimate LV preload
MS, noncompliant LV, AI, AS
nitrous cylinder pressure drops
about 400 L remain
temp and CO2 and pH
low temp - low arterial CO2 - high pH
pH stat
cooled blood will have high pH, to correct will add CO2, which will cause acidosis which will increase CBF
idiopathic Thrombotic Thrombocytopenic Purpura treatment
medical emergency treated urgently with plasma exchange - FFP
TRALI diagnosis
new onset acute lung injury symptoms (PaO2/FiO2 300, pulm artery pressure < 19 mm Hg, Edema Fluid/Plasma Protein Ratio >0.75), <0.65 differentiates between a transudate (pulmonary edema) and an exudate (TRALI), greater amount of protein in the edema fluid (larger ratio), more likely exudate
stewart approach to acid base
bicarb is not a mathematically independent determinant of pH - pH independent variables are total weak acid concentration, strong ion difference, and pCO2
DI lab values
sodium >145, urine osm 310, urine spec gravity <1.005(polyuria, polydipsia)
fire triad
oxidizer (O2, nitrous), ignition source (lasers, burrs, drills, fiberoptic scopes, electrosurgical devices), fuel (ETT, sponges/gauzes, drapes, masks) *metal ETT are combustion resistant
vit K
IM/oral take 6-8 hours to decrease INR, IV vit k associated with anaphalactoid reaction - hypotension, seizures, death
argatroban
reversible direct thrombin inhibitor - does not directly affect platelet function
airway fire management
stop the procedure, remove ETT, stop gases, remove flammable material, pour saline into airway, reestablish ventilation, examine ETT, consider bronchoscopy, assess patient status and decide what’s next step in patient care
finding with epidural >6 hrs
fever
disadvantages of stress ulcer prophylaxis
increased incidence of PNA, C. dif, and thrombocytopenia
positive intravascular test dose under anesthesia peds
T wave amplitude increase >25%, >10 bpm elevation, increase in SBP >15
pHTN definition
resting PAP >25
WHO pHTN classifications
class 1 - arterial HTN (includes idiopathic aka primary), class 2 - venous HTN, class 3 - pHTN ass with hypoxemia, class 4 - chronic thromboembolic pHTN, class 5 - miscellaneous
severe HF managment
difficulty with increased/reduced preload, d/n tolerate pHTN, increased SVR will decrease SV, brady/tachy poorly tolerated, keep 80-90 bpm
prolongs QT
sevo, iso, thiopental
PONV children
rare, 3 yo risk is 40% and increases until puberty, increased with T&A, strabismus, hernia, orchipexy, penile surgery
Eberhart’s PONV classification in children
personal/family history of PONV, duration of anesthesia >30 min, age >3 yo, strabismus surgery (10, 30, 55, 70% risk)
ASDs
40% of all CHD, 2-3 x more common in women, ostium secundum 70%, ostium primum 20%, sinous VSD 10%
Ostium secundum
70%, ass with mitral valve prolapse
ostium primum (endocardial cushion defect/AV septal defect)
20%, ass with cleft of anterior leaflet of mitral valve that causes MR (downs)
sinous vsd
10%, ass with anomalous venous return
lmwh 2x daily dose
not recommended with epidural no matter the dose
lmwh and epidural
placement 12 hours after prophylaxis, placement 24 hours after treatment, removal 10-12 hours after last dose, after removal next dose should be delayed at least 2 hours
ECG and mechanics of heart
end of PR mitral closes, R wave starts isovolumic contraction, S wave aortic valve opens, near end of ST aortic valve closes - isovolumic relaxation, end of T wave mitral opens and diastole starts
liver blood supply
1/3 hepatic artery - 50% O2, 2/3 portal vein - 50% O2
bicuspid AV
most common congen CV anom, more men, ass with coarctation of aorta, often leads to AS, also at risk for AI and endocarditis
independent stress ulcer risks
coagulopathy and mechanical ventilation for 48 hrs
TEF cause and ass
failure of foregut to separate from larynx, ass with VACTERL (veterbral anom, anal atresia, CV anom, TEF, esophageal atresia, renal/radial anom, limb defects)
TEF cardiac anom
35% ASD, VSD, AV canal, TOF, coarctation of aorta
altitude effects
higher sea level/higher altitude - decreased partial pressure of gas = lighter anesthetic depth
Desflurane vaporizer
heated vaporizer (not variable bypass) so at different altitudes % set is % produced
first line for delirium
haloperidol D2 agonist with warning for fatal ventricular arrhythmias
TEF renal anom
renal agenesis, reflux, renal failure
diffusion constant of gas
directly proportional to solubility and inversely proportional to square root of molecular weight
classic vs modified classic sciatic nerve block
PSIS and greater trochanter vs PSIS, greater trochanter, and line from sacral hiatus to greater trochanter (Labat vs Winnie)
pKa lido, bupi, ropi, tetra, chorpro
7.8, 8.1, 8.2, 8.5, 9
IABP inflation and deflation
inflate after AV closes (dicrotic notch), deflate fully before AV opens
bactericidal
cephalosporins, vancomycin, aminoglycosides, FQs, daptomycin, metronidazole
bacteriostatic
macrolides, tetracycline, trimethoprim, sulfonamides
neuraxial block drugs to avoid
avoid with thrombolytics - even though half-life is a few hours, fibrinogen and plasminogen are decreased for 27 hours
ascending aortic aneurysm ass
hoarseness from compression of L RLN, dyspnea from compression of trachea, left mainstem bronchus or pulmonary artery, SVC syndrome, venous HTN
increased AFE risk
multiparity, placenta previa, placental abruption, cervical lacerations, uterine rupture, operative vaginal delivery
SIRS criteria
T >38/90, RR >22 or pCO2 12,000 or >10% bands
renal failure with immunosuppression
calcineurin inhibitors, tacrolimus, and cyclosporine
immune suppression stages
induction, maintenance, and anti-rejection if needed
chemo stages
induction, consolidation, maintenance (then CNS prophylaxis for ALL)
types of shock
distributive (neurogenic, sepsis), hypovolemic, cardiogenic, obstructive (tamponade, PE, pneumo)
papillary muscle blood supply
posterior pap - post descending artery (most vulnerable to ischemia), anterior pap - LAD and circumflex coronary artery
ECT contraindications
pheo (absolute); Relative = increased ICP/brain tumor with no mass effect, recent stoke CV conduction defects, high risk pregnancy, aortic/cerebral aneurysms, asthma/COPD (theophylline can cause status epilepticus)
dural sac termination
birth to 1 year S3, by 1 yo S2
ANOVA
simultaneously compares the differences among population means of more than two independent groups for a one-factor experiment
chi-square
test for categorical variables determines whether there is a difference in the population proportions between two or more groups.
unpaired t-test
compares the population means between two independent (and normally distributed) groups
paired t-test
examines repeated measurements obtained from the same set of individuals
PABA
metabolite of esters
Dipyridamole
phosphodiesterase inhibitor, increases cyclic AMP which blocks the uptake of adenosine, reducing adenosine at the platelet vascular interface or via direct stimulation of prostacyclin release from the endothelium
HCTZ electrolytes
Low Na, low K, low Mag, increase Ca and cholesterol labs
Only abductor of vocal cords? Innervated by?
posterior cricoarytenoid muscle innervated by RLN
Risk factors for post herpetic neuralgia
Age >60, female, severe acute pain
Neurotransmitter preganglionic
sympathetic and parasympathetic PREganglionic neurons are cholinergic (release acetylcholine)
Neurotransmitter postganglionic sympathetic
POSTganglionic sympathetic neurons are adrenergic and release norepinephrine
Neurotransmitter postganglionic parasympathetic
POSTganglionic parasympathetic neurons are and thus release acetylcholine
Anterolateral pap muscle
LAD and left circumflex
Posteromedial pap muscle
Right coronary - at risk with inferior MI (see MR)
