physiology Flashcards
how do hypoxia, hypercapnia, and acidosis effect pulmonary vasculature
pulm vasocontriction
urine to plasma osmolar ratio > 1.5 indicates what
oliguria 2/2 prerenal hypovolemia
how does sodium bicarb administration effect LV contractility, preload, intracranial, lactate
- bicarb increases calcium so increases LV contractility
- its hypertonic so increases preload due to increase intravascular volume
- increases lactate
- can cause intracranai hemmorhage (due to number 2 )
what properties of gas determine flow rate through annular space at low fresh gas flow vs high
at low –> viscosity
high –> density
think low cost
high demand
what type of cells are have the most insulin dependent transporter for glucose uptake
cardiac myocytes
think u have to give insulin with hyper K to stabilize that shit or whatever
when is pulmonary vascular resistance at its lowest
at FRC
how does uremia interefere w platlet activation and aggregation (4 places)
- vWF
- gp IIb-IIIa
- increases prostacylcin
- increased NO
how does hetastarch inhibit platelet aggregation
will cause decreases in gp IIa-bIII
how do u interpret increased platuea pressure vs increased peak pressure
increased platuea pressure = decreased pulm compliance (TRALI, pulm edema etc.)
increased peak pressure = increased airway resistance (kinked tube, asthma, bronchospasm etc)
define lithotripsy and. how the pressure volume loop would change for increased lithotripsy
increased compliance
will have a rightward downward shift of end diastolic pressure volume curve to show more volume at decreased LV pressure
large volumes of licorice will create more of what hormone
aldosterone so you will have HTN, metabolic alk, hypo K, hypernatremia
how can u diagnose abdominal compartment sydrome w bladder and what effect does it have on ICP
the pressure will be greater > 20 ish
increased ICP
patients with 3 or more risk factors for CAD are recommended to take what medication perioperatively?
what is the risk factors
beta blocker
risk factors: hx of ischemic heart dz, stroke, DM, CHF, CKD
which nerve carries afferent signals from carotid bodies
CN 9 or glossopharyngeal nerve
3 ways in which volatile anesthetics potentiate NMBA
- decreasing sensitivity of the post junctional membrane to depolarization
- increasing skeletal muscle blood flow which augments NMBA
- depression of upper motor neurons
when minute ventilation exceeds fresh gas flow how will that affect fio2
fio2 will be lower because u are rebreathing exhaled gases and therefore less O2
normal umbilical artery blood gas sample?
pH 7.2-7.3
pco2. 50s
pao2 20s
bicarb 22 ish
how do you trouble shoot o2 pipeline failure
disconnect o2 pipeline from wall
open emergency oxygen cylinder
ventilate by hand
what would u see etco2 do with co2 embolism
etco2 will usually decrease with CV collapse but may increase as well
if you decrease paco2 by 1 how much does that decreased CBF
decreases 1-2 cc
what 2 lab tests are low in DIC
factor 8
fibrinogen
d dimer is high af
whats the benefit of stopping smoking the day before surgery
shifts hemeglobin O2 dissociation curve to the right
whats the primary cause of low serum bicarb in patients w high AG metabolic acidosis
low bicarb is bc they are used to buffer H+ ions
if you have paraplegic patient how will the TOF differ between hand and foot nerve stims (if the foot is paralyzed)
the foot will have a increased TOF ratio due to ach receptor build up in the muscle of the paralyzed limb
during forced exhalaiton where does emptying occur first and where does airway closure occur first
emptying of the apex first
forced airway closure of the base of the lungs first
when ABG are corrected for colder temperatures how does that affecr pao2 paco2 and pH
paco2 and pao2 will be lower, pH will be higher
why do barbituates have higher concentrations of of free active moleculres in renal failure
less barbituate bound to protein
how long is the half life of albumin
half life is 2-3 weeks
which is why PT is a better measure of liver synthetic function as factor 7 has a short half life.
during fasting what organ uses ketone for energy
brain uses ketones
other parts of the body uses fatty acids
switching from spontaneous ventilation to mechanical ventilation does what in obese patients
reduces oxygen consumption
bezoid- jarisch reflex is what
essentially bradyardia, hypotention, apnea
why do you have hypocalcemia in esrd
kidney cant convert to active form of vitamin D so u have low calcium
hematologic effects of hyperthyroidism
thrombocytopenis and anemia
think CHF is possible and so u have dilution
what acid base derrangement will u see with cyanide poisoning
AG acidosis
why is the mivacurium dose only slightly increased in burn patients
burn patients usually require higher dose of paralytis because have upregulaton of acH receptors
but mivacurium is metabolized by pseudocholinesterase which is decreased in burn patients
how does FRC change with heigh and age
greater the high greater the FRC
older patients have greater FRC due to loss of elasticity
fastest uptake IO sites of insertion
manubrium > humerus > tibia
benefits of acute normovolemic hemodilution
- decreased blood viscosity —> 2. decreased vasicular resistance
- increased CO
- increased regional blood flow
what electrolyte abnormalities does hyperventilation cause
tink ur blowing shit off
hypocalcemia
hypokalemia
hypophosphatemia
what explains why NO has a more rapid onset than desflurane despite NO being more soluble
the concentration affect of NO
what is the hering nerve
branch of glossopharyngeal nerve that transmits info from carotid body (chemoreceptors) and carotid sinus (baroreceptors)
**carotid body baroreceptors increase ventilation when paO2 is low, this reflex is impaired with opioids, benzos, volatile anesthetics + b/l carotid endardectomy
what are the 3 ways co2 is transported in the blood
dissolved co2
bicarb
carbonic compounds
in lumbar / low thoracic epidurals what 2 respiratory factors are DECREASED
peak expiratory pressure
cough strength
how is roc excreted
30% renally excreted and then the rest is through hepatic uptake
fresh frozen plasma does NOT have what two factors
factor VII
factor II
if patient with hemophilia A has antibodies formed against factor 8 how do u treat hemorrheage or surgery
porcine factor VIII
Factor VII
or Factor II
which drug has the lowest pka and highest fraction of nonionized drug at physiologic pH
alfentanil
what phase of diastole delivers the highest volume of blood
early rapid filling
most common complication following autologous blood transfusion
infection from improper storage
why will FFP help with heparin resistance
heparin binds to anti thrombin 3, people that have a deficiency will have resistance to heparin
FFP contains antithrombin 3
why NOT use ffp for hemophilia A
ffp does contain factor 8 but very little levels, other blood products have a a greater concentration of factor 8
most common complication of jet ventilation
hypercarbia because u ont have controlled exhalation?
other complications include: hypoxia, loss of airway, impaired cilliary function –> necrotizing tracheobronchitis
how does solubility of gases and partial pressure of gases differ between warmed and cooled blood
partial pressure of paO2 and paco2 is higher I warmed blood, so that means that dissolved gas is lower in warm blood because its more soluble in cold blood
how does low flow anesthesia increase risk of PONV
rebreathing of CO and acetone aka noxious gases
how does burn injury cause increased platelet aggregation
increased fibrinogen which is an acute phase reactant
eccrine vs apocrine sweat glands pathway
eccrine glands
symthatetic pre ganglioninc > nicotinic receptor > sympaththetic post gang > muscarinic receptor
apocrine is found I perineal area and armpits:
symthatetic pre ganglioninc > nicotinic receptor > sympaththetic post gang > adrenal gland
how can can hypothermia lead to metabolic acidosis in neonates
they have hella brown fat, non shivering thermoregulation leads to metabolism of brown fat and metabolic acidosis
decribe how bicarb changes in aucte vs crhonic respiratoy acidosis
assuming norma paco2 is 40 and normal bicarb is 24
in acute every 10 paco2 causes a change of bicarb by 2
in chronic bicarb changes by 4
what is the most reliable sign of uterine rupture
non reassuring fetal heart rate patterns
mechanism by which tetany leads to twitches
accumulation of calcium in the presynaptic membrane that will lead to a slightly higher acH release
what class of drugs can cause increase gastric pH withn an hour
H2 blockers
ranitidine has shortest onset, and longer duration of action
famotidine has the longest half life
H2 blockers increase gastric pH and decrease gastric volume
what leads are the best for monitoring atra
- lead II
2. lead V1
what substances will reflect US beams the least
substances with most water content will be blakcer and reflect the beams the least
is thyroid hormone binding ratio increased or decreased in primary hyperthyroidism
increased
only TSH is decreaed in primary hyperthyroid
wandering baseline artifact on EKG is due to waht
moving patient, lose electrodes, poor skin contact
what class of drugs is most commonly associated wtih PERIOPERATIVE anaphylaxsis
neuromuscular blocking agents
how and why do u adjust dose of benzos and opioid in severe burn patients
severe burn patients will have hypoalbumin
whihc increases the free fraction of benzos and opioids so u should reduce the dose
what is the pathiophysiology behind delayed hemolytic transfusion reaction
recipient antibodies to donor minor RBC antigens like rhesus, kidd, or kell
Bayes theorum
helps determine preop testing algoriths ike people who have ___ need TTE beforehand type of thing
conditional probability
what will cause a larger degree of overlap between IJ and carotid when placing central line
over rotation of patient heads beyond 45 degrees
if someone has polycystic kidney disease what vessel issue do u have to be cautious for
can have aneurysms, esp for cerebral berry aneurysms. which can be an issue if patient is positioned in steep Tberg
