New TrueLearn Questions Flashcards
pt on naltrexone, what to do for pre-medication?
ok to give versed and fentanyl
which condition is caused by autoimmune destruction of postsynaptic ACh receptors at the NMJ?
myasthenia gravis
pt on naltrexone, what to do when opioid is required?
opioids still work, but higher dose needed to overcome antagonistic effect of naltrexone
how does the solubility of a gas affect its diffusion?
the more soluble a gas, the more readily it will diffuse. e.g. CO2 much more soluble in water than O2, so CO2 diffuses much faster across the alveolar-capillary membrane
what vent settings to change when there is auto-PEEP?
decrease RR (to slow down breathing) and increase time for expiration compared to inspiration (with I:E ratio)
where is norepinephrine metabolized?
lungs
what changes in potassium and pH would you expect after massive transfusion?
increased potassium (RBC cell membrane degrades, K leaks out)
decreased pH (anaerobic metabolism during storage b/c no oxygen, lactic acidosis)
what percentage of anesthesiologists who had substance abuse eventually relapse and fail long-term abstinence?
40%
which coagulation factors are synthesized in the liver and require vitamin K-dependent gamma carboxylation?
Factors 2, 7, 9, 10, proteins C and S
which coagulation factor is decreased during pregnancy?
anticoagulant factor protein S
how long does emergence delirium last for in pediatric patients?
10-30 minutes, and usually resolves without any treatment
which procedure increases the risk of intraoperative awareness?
C-section
mechanism by which thiazide diuretics increase Ca2+?
enhancing Na+/Ca2+ antiporter exchange
which local anesthetic has the fastest onset of action when used for spinal anesthesia?
lidocaine
what is the most anterior structure on ultrasound in the popliteal fossa?
popliteal artery
which artery is the popliteal artery a continuation of?
superficial femoral artery
where are nicotinic acetylcholine receptors found?
in the ganglia of both the sympathetic and parasympathetic systems
what gastric fluid volume and pH are considered high risk for aspiration lung injury?
volume >25 mL and pH <2.5
MH occurs following exposure to what agents?
volatile anesthetics and succinylcholine
which anti-platelet drugs are prodrugs that require activation by hepatic cytochromes in order to exert their clinical effects?
clopidogrel, prasugrel, and ticlopidine
“Grel needs ‘help’—these drugs need activation to help them work.”
Ticlopidine – P, D – pro drug
which anti-platelet drugs are direct ADP receptor inhibitors that do not require enzymatic activation?
cangrelor and ticagrelor
“Grelor sounds like ‘go’—these drugs are ready to go without activation.”
Vs.
Mnemonic: “Grel needs ‘help’—these drugs need activation to help them work.”
what type of drugs are used in pts with occlusive arterial disease?
antiplatelet drugs that prevent platelet aggregation
how does upregulation of immature (fetal) nicotinic acetylcholine receptors affect its sensitivity to neuromuscular blocking agents?
increased sensitivity to acetylcholine and succinylcholine but decreased sensitivity to nondepolarizing neuromuscular blocking agents
when is there upregulation of immature (fetal) nicotinic acetylcholine receptors?
during times of decreased stimulation at the neuromuscular junction such as in severe burns, infection, sepsis, immobilization, CVAs, and extended use of neuromuscular blocking agents
when is there downregulation of mature nicotinic acetylcholine receptors?
chronic pyridostigmine use in myasthenia gravis, organophosphate poisoning, or exercise conditioning
ASA 2 definition and examples?
mild systemic disease
-obesity (but not morbidly obese)
-well controlled DM or HTN
-mild lung disease
ASA 3 definition and examples?
severe systemic disease
-morbid obesity
-poorly controlled DM, HTN, COPD
-hepatitis
-ESRD on dialysis
-MI, CVA, TIA, or CAD/stents >3 months ago
ASA 4 definition and examples?
severe systemic disease that is a constant threat to life
-MI, CVA, TIA, or CAD/stents <3 months ago
-current cardiac ischemia
-severe valvular dysfunction or reduced EF
-ARDS
-sepsis, shock, DIC
-ESRD NOT on dialysis
ASA 5 definition and examples?
moribund pt not expected to survive without surgery
-ruptured abdominal or thoracic aneurysm
-massive trauma
-intracranial bleed with mass effect
-ischemic bowel with significant cardiac pathology or multiple organ dysfunction
ASA 6 definition and examples?
brain-dead pt whose organs will be removed for donation
how does the lipid solubility of opioids affect the onset, spread, and duration in the CSF?
highly lipid soluble drugs have rapid onset, less extensive spread, and short duration
order of opioids from least lipophilic to most lipophilic?
hydromorphone
morphine
alfentanil
fentanyl
sufentanil
“Hardly Moving After Fentanyl Shot”
mechanism of action of volatile anesthetics?
potentiates pre-synaptic and post-synaptic GABA release, and glycine
how does immobility from volatile anesthetics occur?
due to inhibitory effects on the spinal cord rather than in the brain
how is the sensory afferent limb of the corneal reflex mediated?
trigeminal nerve (CN 5) ophthalmic branch
how is the motor efferent limb of the corneal reflex mediated?
facial nerve (CN 7)
what happens to the serum concentration of albumin during pregnancy and why?
decreases, not due to a decrease in total albumin but rather an increase in plasma volume
what happens to the serum concentration of fibrinogen during pregnancy and why?
increases
both fibrinogen and factor 7 increase, which create a hypercoagulable state during pregnancy
what happens to the serum concentration of transferrin during pregnancy?
increases
serum iron falls because of hemodilution but transferrin and TIBC increase during pregnancy because of increased iron demand
what is a nonparticulate acid that is used to decrease the risk of pulmonary aspiration?
sodium citrate
which medication prolongs the QT interval?
methadone
what is the name of the law that describes the relationship between resistance of flow through a tube and the radius of that tube?
Poiseuille’s Law
in myotonic dystrophy, what is the risk of malignant hyperthermia and the use of succinylcholine?
no increased risk of MH but succinylcholine should be avoided due the risk of hyperkalemia and diffuse sustained muscle contractions
how is succinylcholine’s action terminated?
by diffusion away from the NMJ
it’s then hydrolyzed in the plasma by pseudocholinesterase
what happens to the heart rate after administration of succinylcholine?
bradycardia, especially in children
how does hyperglycemia occur in times of surgical stress?
reduction in insulin release and increased resistance to insulin
how should a needlestick injury be treated?
wash with soap and water
expressing fluid should NOT occur
pt has laryngospasm after IM ketamine, has no IV access, next step?
administer IM succinylcholine
first steps in management of laryngospasm?
remove offending stimulus, apply 100% oxygen with CPAP, jaw thrust at Larson’s point (pain stimulates the autonomic nervous system and relaxes the vocal cords)
how does MAC change with age?
MAC increases from birth until 1 year, then decreases after
Electrolyte findings in pyloric stenosis?
hyponatremia, hypokalemia, hypochloremia, metabolic alkalosis with compensatory respiratory acidosis
normal serum bicarb level?
22-28 mEq/L
what is an important clinical manifestation of hypophosphatemia from refeeding syndrome?
respiratory failure from diaphragmatic weakness due to ATP depletion
at which postconceptual age do preterm infants have an increased risk of perioperative apnea?
less than 60 wks postconceptual age
what to administer with neostigmine for reversal in order to avoid fetal bradycardia?
atropine, which crosses the placenta more easily than does glycopyrrolate
what is the least stable coagulation factor in FFP?
Factor 8
“Factor 8 can’t wait”
how does terbutaline work?
can cause tocolysis as a b2 agonist, smooth muscle relaxation causes uterine relaxation
metabolic side effects of b-adrenergic receptor agonists?
hypokalemia and hyperglycemia
e.g. terbutaline and ritodrine
zero-order vs. first-order kinetics
zero-order: a constant amount of the drug is eliminated over time. graph shows linear decline in concentration over time
first-order: a constant fraction of the drug is eliminated over time. graph shows exponential decline in concentration over time
normal PaCO2 range?
35-45 mmHg
normal PaO2 range?
75-100 mmHg
nitrous oxide mechanism of action?
NMDA antagonist
Nitrous Oxide → NMDA Off
“Nitrous (N2O) turns NMDA Off” can help cement the idea that it blocks NMDA-mediated excitation.
next step when pt has refractory ventricular fibrillation despite rounds of defibrillation and epinephrine?
amiodarone
proper placement and orientation of axillary roll?
oriented A-P and placed caudal to the axilla
excessive fasciculations from succinylcholine would be most expected in which disorder and why?
myotonic dystrophy because it’s a disease of impaired muscle relaxation
which additive increases duration of action for local anesthetics?
alpha-2 adrenergic agonists like clonidine
dexamethasone addition effect on local anesthetic?
increases duration of analgesia for both ropivacaine and bupivacaine
epinephrine increases the duration of local anesthetics except for which ones?
ropivacaine and bupivacaine
effect of adding bicarbonate to local anesthetics, especially bupivacaine?
alkalization will cause precipitation and will not increase the speed of onset or duration of action
what is the primary efferent pathway for the hippocampus?
fornix
which structure in the brain is involved in memory formation?
hippocampus
what is associated with a higher risk of AKI during surgery?
overly restrictive IV fluid management
which medication is contraindicated for treatment of uterine atony in pts with HTN and preeclampsia?
methergine
which medication is contraindicated for treatment of uterine atony in pts with asthma?
prostaglandin
what is magnesium sulfate used for in pregnancy and what is a side effect?
seizure prophylaxis in preeclampsia
causes uterine relaxation which can contribute to uterine atony
on a radiograph, how to identify T1?
the first rib arises from T1
what level is vertebra prominens?
C7
C se-VEN = promi-NENs
which nerve is largely unaffected by the lithotomy position?
posterior femoral cutaneous nerve, which is not a branch of the sciatic nerve but rather originates directly from the sacral plexus
which nerves are affected by the lithotomy position?
obturator nerve and lateral femoral cutaneous nerve (both pass beneath the inguinal ligament and is compressed with hip flexion)
sciatic nerve and its branches (stretched with hip flexion)
carotid sinus vs. carotid body?
sinus monitors blood pressure, regulates HR and BP. think “sinus pressure”
body is a chemoreceptor, monitors blood gas levels, regulates respiratory activity.
think “body” for “blood gas”
how does increased afterload affect the velocity of fiber shortening during contraction in a normal functioning heart?
when afterload increases, the fibers must generate more force to overcome the resistance. this increased demand for force slows down the speed at which the fibers can shorten
Imagine pushing a door open. If the door is light, you can push it quickly (low “afterload”). If the door is very heavy (high “afterload”), it will open much more slowly even though you are using more force.
what effect can ketamine have on a patient who has been critically ill?
ketamine normally causes a sympathetic stimulation by inhibiting reuptake of catecholamines. When a pt is depleted of catecholamines, ketamine is unable to cause this and blood pressure may fall.
which artery supplies the AV node?
right coronary artery
how does ingestion of a carbohydrate beverage two hours before surgery decrease insulin resistance?
surgery and fasting before surgery increases the stress response, which leads to the release of hormones like catecholamines and cortisol, which promote insulin resistance
in order to obtain additional anesthetic coverage of the medial upper arm from torniquet pain, which nerve is blocked?
intercostobrachial nerve
what does the axillary block have a lower risk of compared to other upper extremity blocks?
pneumothorax
in order to obtain additional anesthetic coverage of the lateral surface of the forearm, which nerve is blocked?
musculocutaneous nerve
which nerves does the axillary block target?
M, U, R
Does NOT include the axillary nerve despite its name
which supplemental nerve is included in an axillary nerve block and which area does it cover?
musculocutaneous nerve
Lateral aspect of forearm
what is the most common complication of an autologous blood transfusion?
infection
how does the celiac plexus block affect the autonomic nervous system?
the celiac plexus provides sympathetic outflow to the internal organs in the abdomen. blockade of the celiac plexus results in a loss of sympathetic innervation.
US cylinder color code for oxygen
green
“plants are green and produce oxygen”
US cylinder color code for carbon dioxide
gray
“gray clouds and gray smoke carry carbon dioxide”
US cylinder color code for nitrous oxide
blue
“feeling blue? nitrous oxide brings the giggles”
nitrous oxide is known as laughing gas
US cylinder color code for nitrogen
black
nitrogen sounds like “night” which is black
-or-
“nitrogen gives black stout beers their smooth finish”
nitrogen is used to pressurize stout beers like Guinness, which are dark or black in color
US cylinder color code for helium
brown
“helium makes you sound like a brown chipmunk”
Inhaling helium changes your voice to a high-pitched squeak, much like a chipmunk’s voice. Since chipmunks are brown, this connection can help you link helium with the color brown.
Think of H for helium and H for “hazel,” a shade of brown.
US cylinder color code for air
yellow
“yellow sun warms the air”
Connect the color yellow with the sun, which heats the air. This imagery can help you remember that air cylinders are color-coded yellow.
EKG findings of a pt taking digoxin?
downsloping (scooping) ST segment depression
which conditions promote digoxin toxicity?
electrolyte disturbances and renal insufficiency (most of digoxin is excreted unchanged via the kidneys)
how should IV crystalloid be administered after a burn injury?
first half in the first 8 hours
second half in the next 16 hours
how to calculate how much fluids should be given after a burn injury?
4 mL x total body weight (kg) x percentage of burned total body surface area
what is the first line treatment for trigeminal neuralgia?
carbamazepine
IV extravasation of a vasoconstrictor, how to manage?
inject phentolamine into the affected area
succinylcholine side effects are seen in which conditions?
pt with MS and hyperreflexia
MS is autoimmune destruction of axons and myelin
this denervation and misuse myopathy leads to a higher risk for hyperkalemia
where are the scalene muscles located in relation to the brachial plexus roots in an interscalene block?
anterior scalene muscle located immediately medial to the brachial plexus roots
middle scalene muscle located immediately lateral to the brachial plexus roots
what is the onset of action time after a standard intubation dose of rocuronium?
1-2 minutes
what is the standard intubation dose of rocuronium?
0.6 mg/kg
which structure in the brain is responsible for voluntary motor control?
basal ganglia
how does morphine improve coronary perfusion?
morphine reduces preload and afterload. this reduces myocardial oxygen demand and improves coronary perfusion pressures by reducing ventricular end-diastolic pressures
which hormones increase hepatic blood flow?
glucagon receptors
dopaminergic D1 receptors
adrenergic beta-2 receptors
what is the equation for left ventricle coronary perfusion pressure?
aortic diastolic pressure - left ventricle end-diastolic pressure
what causes post-operative hoarseness after endotracheal intubation?
arytenoid subluxation
acetazolamide mechanism of action?
inhibits carbonic anyhdrase. normally, carbonic anhydrase results in the reabsorption of bicarb, but blocking carbonic anhydrase prevents reabsoprtion of bicarb along with water
what blood gas changes will be seen with acetazolamide?
azetazolamide inhibits carbonic anhydrase, preventing the reabsorption of bicarb, which results in metabolic acidosis with a decrease in partial pressure of CO2 as respiratory compensation
pH decreases
bicarb decreases
PaCO2 decreases
what cardiovascular effects are seen with methohexital?
methohexital is a barbiturate that decreases cardiac output, decreases systemic vascular resistance, and causes reflex tachycardia, which are harmful to patients with CAD
which nerve innervates the medial arm and is NOT anesthetized during a brachial plexus block?
intercostobrachial nerve
which nerve does transtracheal injection through the cricothyroid membrane block?
recurrent laryngeal nerve
used to anesthetize the vocal cord and trachea during awake intubation
which branch of which nerve provides sensory innervation to the glottis ABOVE the vocal cords?
internal branch of the superior laryngeal nerve
what are the absolute contraindications to MAC?
there are no absolute contraindications to MAC
what are the relative contraindications to MAC?
inability to cooperate, communicate, or lie still
what does the modified Aldrete scoring system look at?
activity
respiration
consciousness
circulation (bp)
o2 sat
“A Really Cool Cat Observes”
do loop and thiazide diuretics cause metabolic acidosis or alkalosis and why?
alkalosis, caused by increased excretion of hydrogen ions
pt in the OR begins to vomit and there is concern for possible aspiration. next step?
place in T-berg
how is static compliance of the respiratory system calculated?
compliance = dV / dP
= tidal volume / (plateau pressure - PEEP)
how is dynamic compliance of the respiratory system calculated?
compliance = dV / dP
= tidal volume / (peak pressure - PEEP)
what is the equation for standard error?
standard deviation / square root N
which diuretics cause hyperkalemia?
ACE inhibitors, ARBs, aldosterone antagonists
how does precedex affect ventilation?
preserves ventilation and the ventilatory response to hypercarbia
what muscles are the last to be recruited at maximal work of breathing and impending respiratory failure
back and paravertebral muscles
which agents can cause rhabdomyolysis?
succinylcholine and HALOGENATED volatile anesthetics
what is the half-life of IV labetalol?
6 hours
what is the duration of IV labetalol?
16-18 hours
what is cromolyn not used for?
it has no bronchodilatory effects and should not be used for bronchospasm or acute asthma attacks
it is a mast cell stabilizer and inhibits the release of inflammatory mediators from mast cells
how does chronic carbamazepine affect neuromuscular blocking effects?
carbamazepine induces CP450, which is responsible for metabolizing vecuronium, leading to a reduced neuromuscular blocking effect
blood-gas partition coefficients from smallest to largest?
“Do Not Stop Inhaling”
D - Desflurane (Smallest coefficient)
N - Nitrous Oxide
S - Sevoflurane
I - Isoflurane (Largest coefficient)
context-sensitive half-time from highest to lowest?
“Fat Anaesthetists Prefer Recess”
Fat → Fentanyl (Longest half-time)
Anaesthetists → Alfentanil
Prefer → Propofol
Recess → Remifentanil (Shortest half-time)
effect of propofol on cerebral blood flow and cerebral metabolic consumption of oxygen?
decreases both
halogenated volatile anesthetics effect on cerebral blood flow and cerebral metabolic consumption of oxygen?
reduce cerebral metabolic consumption of oxygen but increase cerebral blood flow
during pregnancy, what happens to GFR and renal plasma flow and why?
both are increased due to a larger cardiac output
how does septic shock affect cardiac output?
Vasodilation reduces systemic vascular resistance (SVR), which triggers a compensatory increase in heart rate (HR) and stroke volume (SV) to maintain blood pressure.
how does septic shock affect pulmonary capillary wedge pressure?
decreases, due to peripheral vasodilation
how does septic shock affect mixed venous oxygen saturation?
increases, due to increased cardiac output and decreased oxygen use
Cardiac output increases bc heart rate increases and contractility increases
what vertebral level is associated with the line drawn in the horizontal plane at the upper margin of the iliac crests?
L4-L5
what are the physiological effects of stellate ganglion block on skin temp and skin resistance?
stellate ganglion is part of the sympathetic trunk, so this sympathetic blockade leads to vasodilation of blood vessels in the skin (which leads to increased skin temperature) and reduced sweating (which leads to high skin resistance because sweat contains electrolytes that conduct electricity)
cortisol effects on immune system?
Leukocytosis in Cushing syndrome does not reflect improved immune function. It’s a redistribution effect of neutrophils into the bloodstream, while the overall immune response is weakened.
cushing syndrome effects on electrolytes?
hypokalemia and metabolic alkalosis
cortisol mimics aldosterone, leading to increased absorption of sodium and excretion of potassium and hydrogen ions
amount of rebreathing in Mapleson circuits from greatest to least during spontaneous ventilation?
A > D > C > B
“All Dogs Can Breathe”
amount of rebreathing in Mapleson circuits from greatest to least during controlled ventilation?
D > B > C > A
“Dead Bodies Can’t Assist”
which coagulation factor is increased in liver disease?
factor 8
in order for pulse pressure variation (PPV) to most accurately predict volume response, should PEEP be used or not?
PEEP should not be used
in order for pulse pressure variation (PPV) to most accurately predict volume response, what ventilation mode should be used?
controlled, positive pressure ventilation like volume control
in order for pulse pressure variation (PPV) to most accurately predict volume response, what tidal volume should be used?
high tidal volume
>7-8 mL/kg
when can you restart LMWH after removal of an epidural?
can restart 4 hours after catheter removal
what can you restart 4 hours after removal of epidural catheter?
LMWH, both prophylactic and therapeutic, all dosages
total body surface area (TBSA) % of head and neck?
9% total
(4.5% front, 4.5% back)
total body surface area (TBSA) % of each arm?
9% total
(4.5% front, 4.5% back)
total body surface area (TBSA) % of each leg?
18% total
(9% front, 9% back)
total body surface area (TBSA) % of anterior trunk (front of the chest and abdomen)?
18%
total body surface area (TBSA) % of posterior trunk?
18%
total body surface area (TBSA) % of perineum?
1%
maintenance fluid regimen for 1-week-old full term infant?
120 mL/kg/day
intravascular injection of epidural test dose of lidocaine + epi, what would happen?
tachycardia
intravascular injection of epidural test dose of lidocaine + epi, in a pt taking beta blocker, what would happen?
HTN
what kind of cells does the trachea contain and why?
ciliated pseudostratified columnar cells
to aid in the clearance of respiratory debris
what kind of cells do bronchioles contain?
simple ciliated columnar cells
the trachea contains how many hyaline cartilages and what shape are they?
15-20 U-shaped hyaline cartilages
the larynx contains how many cartilages?
nine
three unpaired and three paired
stimulation of what causes reflex bronchoconstriction?
parasympathetic stimulation through the vagus nerve
how does an epidural infusion of local anesthetic affect GI function return?
the sympathectomy decreases the time to return of GI function
how do single dose neuraxial opioids affect GI function?
no effect because it does not affect the sympathetic component that causes decreased bowel motility
what is the formula for pH?
pH = -log[H+]
what concentration of [H+] does a pH of -1 correspond to?
10 M
what concentration of [H+] does a pH of 0 correspond to?
1 M
what concentration of [H+] does a pH of 1 correspond to?
10^-1 M = 0.1 M
what concentration of [H+] does a pH of 10 correspond to?
10^-10 M = 0.0000000001 M
when do most medication errors occur?
within 20 minutes of induction of anesthesia
vapor pressures from lowest to highest for gases?
sevoflurane < isoflurane < desflurane < nitrous oxide
“Sevo Is Dainty, Nitrous is Nuclear”
carotid sinus vs. carotid body?
sinus detects stretch (baroreceptor for blood pressure)
body detects breathing (chemoreceptor for oxygen and CO2)
monomorphic ventricular tachycardia, pt is hemodynamically unstable, next step?
cardioversion
monomorphic ventricular tachycardia, pt is hemodynamically stable, next step?
Antiarrhythmic drugs (amiodarone, lidocaine, procainamide)
what medications are contraindicated in Wolff-Parkinson-White syndrome and why?
AV nodal blockers like adenosine, CCBs, beta-blockers because they prevent normal physiologic conduction through the AV node, leading to preferential conduction down the accessory or preexcitation pathway that can lead to a fatal arrhythmia
which nerves does the celiac plexus block?
T5 to L2
“T5 to L2: Take 5 for Less Pain Too.”
which region does the celiac plexus block?
from distal esophagus to transverse colon
includes kidneys and adrenal glands
what hemodynamic effect does a celiac plexus block have?
orthostatic hypotension, due to decreased postural hemodynamic reflexes
The splanchnic circulation accounts for a significant portion of blood volume (~25%). Loss of sympathetic tone in this region can cause blood pooling in the abdominal vasculature, reducing the amount of blood returning to the heart (venous return).
what GI effects does blockade of the celiac plexus have?
sympathectomy causes increased GI motility and diarrhea
beneficial in counteracting constipation caused by opioids
normal PaCO2?
40 mmHg
what to give to prevent delayed cerebral ischemia caused by cerebral vasospasm after SAH?
oral nimodipine
which pathway is thiamine needed for?
citric acid cycle
goal for heart rate in aortic insufficiency?
avoid bradycardia because lower HR means more time spent in diastole, which is when aortic regurgitation occurs
goal for afterload in aortic insufficiency?
avoid increased afterload (and reflex bradycardia) which can worsen regurgitation
what to use for induction in aortic insufficiency?
opioids and benzodiazepines to reduce sympathetic stimulation during DL. sympathetic stimulation increases afterload which leads to increased regurgitation
what should not be given during neonatal resuscitation?
naloxone and sodium bicarbonate
-Bicarbonate can lead to paradoxical intracellular acidosis, as bicarbonate combines with carbon dioxide and increases CO₂, which diffuses into cells more rapidly.
-Neonates born to mothers who have used opioids during pregnancy may develop acute withdrawal (neonatal abstinence syndrome) if naloxone is administered.
which metabolic imbalance does NS lead to?
hyperchloremic metabolic acidosis due to its high chloride concentration
when is it safe to use LR?
it’s safe to use in CKD. the rise in potassium levels is negligible
what electrolyte imbalances does diarrhea cause?
metabolic acidosis
how to decrease incidence of postoperative sore throat with LMAs?
maintain cuff pressure at <40 mmHg
what ekg findings does hypercalcemia cause?
Shortened QT interval (due to faster ventricular repolarization, shortened ST segment).
Elevated calcium enhances L-type calcium channel activity, speeding up repolarization.
what ekg findings does hypocalcemia cause?
prolonged QT interval due to prolonged ST segment
what ekg findings does hypokalemia cause?
flattened/inverted T waves
dorsal column spinal tract carries signals for which senses?
fine touch/pressure
vibration
propioception
spinothalamic tract carries signals for which senses?
crude touch/pressure
pain & temperature
when is “E” emergency surgery added to ASA?
when there could be loss of limb or life
after how long can you give repeat dose of ondansetron?
six hours
at term, the uterus receives what percentage of maternal cardiac output?
20%
uterine arteries supply which percentage of uterine blood flow?
85%
ovarian arteries supply which percentage of uterine blood flow?
15%
cushing syndrome effects on immune system?
increased leukocyte count but causes immunosuppression
cushing syndrome electrolyte findings?
hypokalemic metabolic alkalosis
cortisol mimics aldosterone
what is the main source of occupational exposure to radiation?
radiation scattered from the patient’s body
what is the annual limit for occupational exposure to radiation?
5 rem
which factors are increased in liver disease?
factor 8 and vWF
sodium nitroprusside mechanism of action?
causes both arterial and venous dilation
at what MAP is cerebral blood flow relatively constant?
60 - 150 mmHg
at which PaO2 is cerebral blood flow relatively constant?
60 - 200 mmHg
below which level of PaO2 does cerebral blood flow increase rapidly?
60 mmHg
how are peripheral nerve stimulators connected?
negative pole to the needle and positive pole to the patient’s skin
what is normal mixed venous oxygen saturation?
70%
how does cyanide toxicity affect SpO2 and PaO2?
misleadingly elevated
oxygen is present in the serum but not used at the tissue level
congenital prolonged QT syndrome treatment?
beta blockers
congenital prolonged QT syndrome with cardiac arrest - treatment?
ICD placement
how to calculate physiologic (total) dead space?
tidal volume x (PaCO2 - ETCO2)/PaCO2
what muscles are recruited during forced expiration?
abdominal muscles (rectus abdominis, transversus abdominis, external oblique, latissimus dorsi)
what muscles are recruited during forced inspiration?
SCM, scalene (elevate the clavicle and upper ribs)
which ingested material for fasting period of 6 hours?
-infant formula
-nonhuman milk
-light meal of toast and clear liquids
which ingested material for fasting period of 2 hours?
clear liquids - water, fruit juices without pulp, carbonated beverages, clear tea, black coffee, carbohydrate-containing drinks
which ingested material for fasting period of 4 hours?
breast milk
which ingested material for fasting period of 8 hours?
heavy meals - fried or fatty foods
what is the first step in managing bronchospasm intraoperatively?
raise the FiO2 to 100% and begin hand ventilation
what is the second step in managing bronchospasm intraoperatively?
deepen the anesthetic with an IV bolus of propofol or ketamine or increase the inhaled anesthetic
what is the third step in managing bronchospasm intraoperatively?
administer a short-acting b2 agonist such as nebulized albuterol into the breathing circuit
Position 1 of pacemaker?
P = Chamber Paced (A = Atrium, V = Ventricle, D = Dual)
“Please Send Roses Right Meow!”
Position 2 of pacemaker?
S = Chamber Sensed (A, V, D)
“Please Send Roses Right Meow!”
Position 3 of pacemaker?
R = Response to sensing (I = Inhibited, T = Triggered, D = Dual)
“Please Send Roses Right Meow!”
Position 4 of pacemaker?
R = Rate modulation (R = Sensor-driven rate modulation)
“Please Send Roses Right Meow!”
Position 5 of pacemaker?
M = Multisite pacing (A, V, D, or 0 = none)
“Please Send Roses Right Meow!”
what is responsible for transporting cholesterol from the peripheral tissues to the liver?
HDL as “Healthy” transports excess cholesterol back to the liver, helping clear it from peripheral tissues.
Think of HDL as a “Housekeeping” shuttle, picking up cholesterol from the body and bringing it back to the liver for processing.
what is the chloride content of albumin 5% and what is it most similar to?
~145 mEq/L
Normal saline (154 mEq/L)
what is a common complication of jet ventilation?
hypercarbia
what should be avoided in pts with hematologic cancers and why?
While dexamethasone is effective PONV prophylaxis, this drug should be avoided in patients with hematologic cancers because it may trigger tumor lysis syndrome.
what to avoid in pts with open angle glaucoma?
succinylcholine, which can cause a rapid increase in intraocular pressure, precipitating an acute closed (narrow) angle glaucoma
what is the closing capacity largely determined by?
the elasticity of the lung parenchyma rather than by extrinsic compression
what is type I hypersensitivity?
Type I is Immediate” (both start with “I”)
IgE-mediated; mast cells and basophils release histamine and other mediators
“A” for Allergic, Anaphylaxis, and Asthma
what is type II hypersensitivity?
Antibody-mediated (IgG or IgM); antibodies target antigens on cell surfaces.
“Type II is Two things: Antibodies and Antigen.”
“Type II: cyTWOtoxic” (sounds like “two”).
what is type III hypersensitivity?
Antigen-antibody (IgG) complexes deposit in tissues, triggering inflammation.
“Type III = 3 things: Antigen, Antibody, and Complexes.”
what is type IV hypersensitivity?
T-cell-mediated (no antibodies); cytokines and macrophages cause tissue damage.
“Type IV = Four = Fourth and Last = Delayed.”
what is the treatment for anthrax?
cipro or doxy
what tidal volumes to use in ARDS?
low 4–6 mL/kg (predicted body weight)
normal is 6-8
what plateau pressures to use in ARDS?
low
≤ 30 cm H₂O
loop diuretic electrolyte effects?
hypo-
K
Mag
Na
Ca
thiazide diuretic electrolyte effects?
Hypercalcemia
Hyperglycemia
Hyperuricemia
low KMN
Why should care be taken with patient positioning in cases of anterior mediastinal mass?
Supine positioning can worsen respiratory and cardiac compression.
which neuomuscular blocker is most dependent on renal elimination?
pancuronium
what is the most common complication of TURP?
hypothermia
what is the treatment for inhalational exposure to anthrax?
cipro or doxy
which tidal volume to use for ARDS?
4-6 mL/kg of predicted body weight
what does not cross placenta?
H → Heparin
I → Insulin
G → Glycopyrrolate
N → Neuromuscular blockers (Paralytics)
“He Is Going Nowhere”
which inhaled anesthetic is associated with megaloblastic hematologic changes?
Nitrous Oxide
atropine onset of action
1 min
atropine duration of action
15-30 min
glycopyrrolate onset of action
1 min
glycopyrrolate duration of action
2-4 hr
neostigmine onset of action
1 min
neostigmine duration of action
20-30 min
pyridostigmine onset of action
> 15-20 min
pyridostigmine duration of action
6 hr
