1 Flashcards
how does acetaminophen differ from salicylates?
no gastric irritation, does not affect plt aggregation, no anti inflam properties
2 prime indications for acetaminophen
-analgesia
-antipyreixa
very little antiinflammatory properties
what are the 2 components of the circle system test on an anesthesia machine? between what 2 machine components does the circle system test?
circle system test evaluates circle breathing system from common gas outlet to y piece
consists of 2 parts: leak test and flow test
most common critical incident in anesthesia
due to breathing circuit disconnections- most commonly happens at y piece!!
an optimal face mask seal will allow for maintence of an airway with no leak at what pressures
at an airway pressure between 20-25
what are the two main factors that determine the resistance to gas flow in an anesthesia circuit?
length of the tube and its diameter
shorter the length and larger diameter- less resistance it offers
what ETT would be best for surgery involving significant flexion of the neck?
armored ETT containing spiral wire in the tube to prevent kinking or bending when neck is flexed
when would high flow nasal warmed humidified oxygen administration be beneficial
high flow nasal warmed humified oxygen administration at flows 30-70 would be beneficial for procedures where rapid oxgen desat is likely such as hypopharyngeal or laryngotracheal procedures
why should be cuff pressure be monitored in pt undergoing long term ventilation via ett
too high-> ischemia of trachea wall. low cuff pressure in the ett increases risk material can pass beside the cuff and into lungs- increased risk of pneumonia in pt on long term ventilation
concerns of 1st generation LMA
does not protect against gastric secretions. ventilation requiring pressures > 20 may result in inflation of stomach.
-can become malpositioned-> inability to ventilate
-c/i in pharyngeal pathology such as tumor or abscess
-pathology at or below level of LMA may make it an ineffective means of ventilation
the plasma half life is inversely proportional to its
rate of clearance
hepatic enzyme induction will result in a reduction in the ___ of a drug
half life
if liver enzymes are exposed to a particular compounds or drugs over a period of time, they will increase their activity, resulting in increased ability to metabolized drugs (hepatic enzyme induction)-> reduces half life of a drug
what plasma proteins bind preferentially to acidic drugs?
albumin
alpha 1 acid glycoprotein and beta globulin bind preferentially to basic drugs
when you bolus a drug IV, what tissue will have an increase in the tissue concentration of the drug first?
liver
vessel rich group: brain, heart, liver, kidneys, lungs, and endocrine
then it goes to muscle, adipose, and bone
plasma half life of a drug is directly proportional to its
volume of distribution
what is ion trapping
when the lipid soluble portion of a basic drug like lidocaine crosses the placenta and enters the acidic enviornment of the fetus, the drugs becomes more ionized and unable to cross back through the placenta.
as a result, a higher concentration of the drug exists in the fetus than in the mother.
at a ph of 7.3 if you administer a drug with a pka of 4.5 how much of the drug would you expect to be ionized
> 50%
at a ph of 7.3 if you administer an acidic drug with a pka of 8.1 how much of the drug would you expect the be ionized
<50%
bases are more ionized below the ph and acids are more ionized above
at a ph of 7.3 if you administer an acidic drug with a pka of 7.3 how much would you expect to be ionized
50%
bases are more ionized below the ph and acids are more ionized above
less ionized=
more non ionized, more lipid soluble, less charged, more likely to cross the cell membrane
Drug A is an acid with a pKa of 9 and Drug B is a base with a pKa of 7.4. When injected into the bloodstream, which will cross the cell membrane most easily?
Drug A is an acid that has a pKa that is below the pH on the mnemonic diagram. This means that it is less ionized (and more non-ionized). The base (Drug B) has a pKa that is the same as the pH of the blood which means it is exactly 50% ionized and 50% non-ionized. Since the acid is more non-ionized, it will be able to cross a cell membrane more easily.
approximately what % of CO goes to adipose tissue group
6
formula for clearance
clearance= blood flow x extraction ratio
what is the LMA size for 35 kg
3
what nerve does the transtracheal block anesthetize?
RLN
penetrate cricothyroid membrane into the trachea
3-5 mL of 2% lidocaine
inject on end expiration-> cough-> spread anesthetic throughout airway
what nerve provides sensation to the anterior 2/3 of the tongue
lingual nerve (branch of trigeminal)
what kind of block is injection of 3 mL of 2% lidocaine bilat 1 cm below each greater cornu of the hyoid
SLN block- anesthetizes airway below the epiglottis and portion of epiglottis itself
how big should thyromental distance be for an adult
6-9 cm (3 fingers)
measure with mouth closed and head extended
what scoring system is used to objectively describe difficulty of laryngoscopy?
cormack and lehane
what complication of an esophogeal intubation is associated with highest mortality rate
mediatinitis - 50% mortality
what 2 rbanches of glossopharyngeal n will be anesthetizes by injecting 2 mL of local at the base of the palatoglossl arch
pharyngeal and lingual
what is the first step for tx laryngospasm
remove offending stimulus
following a difficult intubation, you suspect the patient may have obstructin of the submandubular duct due to trauma establishing the airway. this condition would present as
swelling of the tongue
what method can help prevent lens fogging when using a flexible fiberoptic laryngoscope
soak the scope in warm water
fogging is more common if scope is cold
in pacu, a peds pt exhibits a barking cough and a stridorous sound during respirations. what would be the most appropriate innital treatment?
racemic epi and humidified oxygen
what are the advantages of a lighted stylet over traditional laryngoscopy
-less affected by anterior airway
-associated with lower incidence of sore throat
-less stimulating than traditional laryngoscopy
what nerve provides sensation to the larynx below the vocal cords?
external laryngeal nerve
a cricothyrotomy is performed by inserting a cannula into
the membrane between thyroid and cricoid cartilage
what is the largest size ett the LMA fasttrach (intubating LMA) will accomidate?
8.5
you are administering a LA intranasally to block the anterior ethmodial and sphenopalatine nerves. you know these nerves are braches of the
trigeminal nerve
nose is innervated by opthalmic division of trigeminal nerve (V1) anterior and maxillary division of the trigeminal nerve (v2) posteriorly
under what structure does the R recurrent laryngeal nerve pass?
R RLN branches off the vagus nerve and passes under the innominate artery
L RLN branches off the vagus nerve and passes under the aorta
what muscles lenghen and increase the tension of the vocal cords?
cricothyroids
how long does croup usually take to appear after extubation
within 3 hours
laryngotracheobronchitis= croup
how do you properly perform the sellick maneuver?
-10-20 newtons of force prior to LOC
-increse to 30-40 newtons once pt LOC
-about the amount of pressure that would cause discomfort if a pplied to bridge of nose
endobronchial intubation is most common in
small children/ infants- b/c length between glottis and carina is shorter
what mallampati score involves visualization of only uvula, fauces and soft palate?
class II
Class I: The soft palate, fauces, uvula, and tonsillar pillars are visible
Class II: The soft palate, fauces, and uvula are visible
Class III: The soft palate and base of the uvula are visible
Class IV: Only the hard palate is visible.
croup is edema of the
airway below the vocal cords
for every 1 degree celcius that the core body temp decreases, the cerebral metabolic rate of oxygen consumption
decreases by 8%
hypothermia between 12-20 degrees c has been shown to protect against ischemia for
30-60 mins
during a crainotomy, a pt blood pressure decreases from 120/80 to 60/30. what would happen with cerebral vessels
cerebral vessels would dilate and cbf would decrease
in response to decreased MAP, cerebral vessels dilate. between maps of 60-160 this increases cbf. out of the range it is pressure dependent. since map in this case is 40, cbf would decrease despite compensatory mechanisms
a resting nerve is less sensitive to LA because
LA enters active cells more easily
LA can only enter cell when NA channel is in activated or open state. the more the nerve is firing and the more frequently the channel opens, the more opportunities lidocaine has to enter the cell and bind to na receptor
you did a bier block with 50 mL of lido 0.5% for a pt with closed reduction of distal radius and ulnar fracture. when procedure is complete, tourniquet time is 20 mins. what do you do
deflate tourniquet and immediately reinflate for 60 sec then release again
goal: avoid rapid bolus of LA
min inflation time: 20 mins
if 40 mins has elapsed tourniquet can be deflated in single maneuver
if 20-40 mins, tourniquet should be deflated, reinflated then deflated 1 min later to prevent rapid absorption of LA
a femoral nerve block will typically provide anesthesia for
tka
works for anterior thigh, knee and medial aspect of foot
most common complication from a thoracic paravertebral block
pneumothorax
sympathetic blockade from subarachnoid block can produce
urinary retention
block of sympathetic fibers to urethral structures -> increased tone of urethral sphincter-> urine retention.
how to calculate ideal body weight
ht in cm - 100 for men
ht in cm - 105 for women
why is there pain on injection with diazepam and lorazepam
preservative propylene glycol
pain during the first stage of labor is usually confined to what dermatomes?
t10-L1 (primarily from uterine contractions and cervical dilation)
progresses to 2nd stage: s2-s4
what is the most common diagnosis for pt needing a renal transplant
type 2 DM
what is the earliest sign of graft function after liver transplant surgery?
base deficit normalizes with rapid fresh frozen plasma administration
liver transplant is associated with admin of lg volumes of FFP to maintain euvolemia and correct bleeding due to hypofibrinogenemia. admin of plasma is associated with citrate binding of ca and will require iv ca.
if graft is functioning normally, base deficit should resolve within 30 mins despite continued ffp admin as the new liver begins metabolizing the citrate
which lab change is the most specific for hepatobiliary obstruction?
5 nucleotidase elevation
a form of alkaline phosphatase that is present in most tissues but elevated serum levels are always hepatobiliary in origin and markedely elevated in intrahepatic or extrahepatic obstruction
which lab result is consistent with glycogen storage disease?
metabolic acidosis
glycogen storage disease results in lack of enzyme g6p. as a result glycogen cannot be hydrolyzed in hepatocytes and other cells and becomes inappropriately stored in intracell space.
hypoglycemia can be severe and met acidosis develops as a consequence
symptoms of acromegaly
increased incidence of: OA, systemic HTN, ischemic ht disease, ventilation perfusion mismatching, glucose intolerance, neuropathy, skeletal muscle weakness, thick/ oily skin
what happens to k levels with hyperaldosteronism
hypokalemia
MS exacerbation occurs with
increases in body temp
it is from demyelination in CNS (not peripheral nerves!!!)
what happens with ach receptors in MG
decreased number of functional ach receptors
antibodies attack ach receptors-> decrease in 70-80% of number of functioning receptors. muscle weakness predominates and pt are prone to rapid exhaustion of skeletal muscles
all of the following regarding admin of analgesics to a laboring patient are true except:
A. ketamine 0.2-0.4 mg/kg iv does not produce neonatal depression
B. fentanyl may be given safely to a laboring pt
C. meperidine produces greater resp depression in neonates than morphine
D. narcan can be administered IM to newborns
C. meperidine produces less resp depression in neonates than = dose of morphine
-fentanyl 1 mcg/kg iv can be administered without producing severe resp depression in newborn
-narcan may be administered iv directly into newborn at dose of 10 mcg/kg
which provides greatest deggree of neuro protection against global ischemia?
A. mech ventilation with 100% o2
b. barbituate coma
c. profound hypothermia
d. iso 2%
c. profound hypothermia
< 20 degrees C circ arrest can be tolerated for 30 min
medial and lateral cricoarytenoids are innervated by
RLN
what part of cvp waveform would be absent in pt with a fib
a wave (atrial contraction)
c wave- elevation of tricuspid valve during vent contraction
v wave- venous return against closed tricuspid valve
x and y descents- downward displacement of ventricle during systole and opening of tricuspid during diastole
you are performing GA and notice sustained high circuit pressures. you switch to bag and manually vent the pt. circuit pressures go back to normal. you switch back to vent mode and they rise again. pt is relaxed. whats wrong?
ventilator relief valve is malfunctioning
the circuit is having high pressures only on vent mode. if it was an issue with the scavenging or kinked / obstructed tube it would be an issue with mannual mode also
if nitrous oxide is also used, the max exposure to halogenated agents allowed by osha is
0.5
is nitrous is not used it is 2
max exposure to nitrous alone is 25
at birth the spinal cord extends to about
L3
by adulthood the spinal cord extends to about
L1
during a carotid endartectomy, which of the following techniques for management of ventilation would be the most appropriate?
maintain normocarbia to mild hypocarbia
hypocapnea can theoretically constrict cerebral blood vessels and potentially reduce blood flow-> reverse steal effect
a patient is undergoing GA for strabismus surgery. which of the following is not true regarding anesthesia during this procedure?
A. it is associated with an increased risk for eliciting the oculocardiac reflex
B. it is associated with a higher than normal risk of MH
C. postop n/v occurs in the majority of pt undergoing this procedure
D. hypervent increases risk for sudden bradycardia
D. hypervent increases risk for sudden bradycardia
hypoventilation resulting in hypercapnia increases risk of bradycardia due to oculocardiac reflex which occurs due to traction on ocular muscles
what may happen with the use of intraop blood salvage (cell saver)
nonimmunogenic hemolysis, fever or contamination from substances such as bacteria, anticoags or amniotic fluid
which of the following is true regarding fentnayl?
A. it has a half life of 4 hours
B. termination of its effects are primarily via hepatic metabolism
C. IV fentanyl has an onset of 2-5 mins
D. it undergoes significant first pass metabolism when admin orally
C. iv fentanyl has an onset of 2-5 mins
D. it undergoes significant first pass metabolism when admin orally
-orally is usually not enough for admin due to first pass metabolism.
-half life is 8 hours due to high lipid solubility and slow rate of re entry into central compartment
-peak effect of 3-5 mins
which of the following would you expect to see in a patien changing from erect position to supine?
A. increase in HR
B. decrease in PVR
C. increase in CO
D. increase in MAP
B. decrease in PVR
C. increase in CO
there will be an increase in central blood volume
-resulting in sretch of barpreceptors-> decrease in MAP, HR, PVR
-CO and SVR increase
which of the following changes are expected to occur in the elderly as part of the normal aging process?
A. hepatic microsomal activity is decreased
B. pulmonary collagen content increases
C. renal blood flow decreases
D. alveolar arterial difference for oxygen decreases
B. pulmonary collagen content increases
C. renal blood flow decreases
-hepatic and renal blood flow both decrease
-hepatic microsomal enzyme activity is generally preserved
-decrease in elastic tissue and increase in amount of collagen -> 15% reduction in functional alveolar surface area
-A-A difference INCREASES
symptoms of chronic bronchitis
frequent cough, copious sputum, elevated hct, increased markings (not hyperinflation) on chest xray, elevated paco2, normal elastic recoil, increased airwayb resistance
symptoms of pt with emphysema
min sputum production, less frequent cough, normal hct and paco2, decreased elastic recoil, hyperinflation on chest xray, normal- slighty increased airway resistance
principal cells in the cortical collecting duct are primarily responsible for?
secreting potassium
the physiologic characteristics of HPV include
A. the onset and resolution are relatively slow
B. it is trigggered by arterial hypoxemia
C. it may be inhibited by verapamil
D. it is a diffuse effect throughout the entire pulm vasculature
C. it may be inhibited by verapamil
HPV is localized - happens quick
-happens due to ALVEOLAR hypoxia (not arterial hypoxemia)
-may be inhibited by CCB, nitrates and inhaled anesthetics
how many L of oxygen does an E cylinder contain
660
the phenomenon of channeling in a carbon dioxide absorber cannister can be minimized by
A. shaking the co2 cannister prior to use
B. running high flows at the end of an anesthetic
C. decreasing amount of nitrous oxide used during anesthetic
D. allowing pt to breathe spontaneously
A. shaking co2 cannister prior to use
channeling: occurs when gases flow through passages of lower resistance in the co2 cannister. when this occurs, most of the co2 absorbent granules are bypassed and the efficiacy of the absorber decreases. can be minimzed by gently shaking the cannister prior to use.
why is it recommended to disconnect the oxygen pipeline supply from the wall in the event of loss of pipeline pressure?
A. decrease risk of fire
B/ otherwise backup oxygen cylinder will not work
C. b/c pipeline will need to be connected to a backup oxygen cylinder
D. prevent contamination of the inhaled gas
D. prevent contamination of the inhaled gas
in the event of loss of pipeline pressure, it is recommended to disconnect the oxygen pipeline supply from the wall in case of cross connection or contamination of the oxygen due to a breach in the line
what is the most common anesthetic for c section
spinal
what min level of block is eneded for cystoscopy to block obturator reflex
t9-t10
what anesthetic agent is metabolized by the liver to the greatest degree?
sevo! 8%
what opioid causes mydriasis
meperidine
atropine like qualities- causes increase in HR rather than bradycardia- causes mydriasis rather than miosis
-lack of cough suppressant effects, not as useful as a sedative for procedures involving the airway like bronch
how many L of nitrous oxide does an e cylinder hold
1590
what type of visual evoked potentials is performed on an awake patient?
patterned veps
what bmi is considered class III (morbid obesity)
40
what does it mean if a structure is anechoic on US
black
the nucleolus of a cell is responsible for synthesizing
ribosomes
at what age would you expect a peds pt to start to have seperation anxiety
8-10 months
failure to block what nerve would result in difficulty tolerating pain of ankle tournique
saphenous n. (medial side of malleolus and medial aspect of lower leg)
administration of a large dose of which of the following drugs would be most likely to produce seizures in a peds patient?
flumazenil- can be used to antagonize benzos in peds patients.
should be noted short half life of flumazenil as been associated with re sedation in children ages 1-5
larger doses-> seizures in peds pt
in the neonate, calcium delivery to the cardiac myocyte is primarily reliant upon
diffusion through the sarcolemma
-heart of the neonate is developmentally immature
-saroplasmic reticulum and t tubule network is incomplete
-so the cardiac myocytes rely primarily on the diffusion of ca through sarcolemma
what form of hepatitis does not convert into chronic hepatitis?
A
what is the normal mitral valve area?
4-6
the central termination of visceral afferent fibers synapse spinal neurons in laminae
A. I, II, III, IV
B. II, V, VII, X
C. I, II, V, X
D. III, IV, V, VI
I, II, v, X
the central termination of visceral afferent fibers synapse spinal neurons in laminae i, ii, v, x and deliver visceral sensation info to supraspinal sites through the contralateral spinothalamic tract or the ipsilateral dorsal column
you are doing an epidural. when you aspirate fluid flows back easily. how do yoou know this is saline and not CSF?
csf will be warm, and test pos for glucose
so you should test fluid for presence of glucose
which of the following will increase risk of globe injury during a retrobulbar block?
A. hyperopia
B. expothalmus
C. previous scleral buckle surgery
D. retinal detachment
C. previous scleral buckle surgery
myopia or hx of prev of “ “ increase risk of globe penertration by needle- both are associated with inc anteroposterior length of the globe.
conditions required to justify the use of recombinant factor VIIa
only recommended when acidosis has been corrected to at least pH of 7.25, hypothermia has been corrected to a temp of at least 33 degrees C and plt and fibrinogen levels are adequate
