UNIT 12 Miscellaneous Topics Flashcards
describe the architecture of an atom
basic building block that makes up all matter. Consists of 3 components
- protons (+ charge)
- neutrons (no charge)
- electrons (- charge)
protons/neutrons at the center of the atom, together forming the nucleus
- number of protons = atomic number
electrons orbit the outer nucleus in the e- cloud
- they are attracted to the positive nucleus, keeping them from flying away
how do you know if an atom carries a charge? what is a charged atom called?
neutral: electrons = protons
positive: protons > electrons
negative: electrons > protons
ion = atom that carries a positive or negative charge.
- charge: cation
- charge: anion
what is an ionic bond?
complete transfer of valence electrons from one atom to another, leaving one atom w/ a negative charge and the other w/ a positive charge
metals tend to form ionic bonds
- also common w/ acids and bases
what is a covalent bond?
equal sharing of electrons. This is the strongest type of bond
- single bond = 1 pair e- is shared
- double bond = 2 pairs
- triple bond = 3 pairs
what is a polar covalent bond?
polar covalent bonds are an “in-between” type of bond
Atoms share electrons but the electrons tend to remain closer to one atom than the other. One area of the molecule is relatively positive and the other is relatively negative
what are van der Waals forces?
very weak intermolecular force that holds molecules of the same type together
electrons are in constant motion, creating a temporary + and - charges at different parts of the molecule at any given time. The net result is that electron rich areas of one molecule will be attracted to electron poor areas of another molecule.
This is the weakest type of molecular attraction
define Dalton’s law. list several examples of how it can be used in the OR.
daltons law of partial pressures says that total pressure is equal to the sum of the partial pressures exerted by each gas in the mixture.
Ptotal = P1 + P2 + P3 + ..
applications:
- calculate partial pressure of unmeasured gas
- calculate total pressure
- convert partial pressure to volumes percent
- convert volumes percent to partial pressure
at sea level, the agent monitor measures the end tidal sevo as 3%. What is the partial pressure of sevo in the exhaled Tv?
application of Dalton’s law of partial pressures
PP = volumes % x total pressure
0.03 x 760mmHg = 22.8mmHg
define Henry’s law. List several examples of how it can be used in the OR.
at constant temp, the amount of gas that dissolves in solution is directly proportional to the partial pressure of the gas over the solution. (the higher the gas pressure, the more that will dissolve into a liquid)
increase temp = decrease solubility
decrease temp = increase solubility
Ex:
- anesthetic emergence is prolonged in the hypothermic patient
- dissolved oxygen in the oxygen carrying capacity equation (CaO2)
- Overpressurizing vapor pressure
- Measuring PaO2
describe Fick’s law of diffusion, what increases it? What decreases it?
transfer rate of gas through a tissue
rate of transfer increases with:
- partial pressure difference
- diffusion coefficient
- membrane surface area
rate of transfer decreases with:
- membrane thickness
- molecular weight
list clinical examples of Fick’s law of diffusion.
1) diffusion hypoxia 2) COPD = reduced alveolar SA 3) slower rate of inhalation induction 4) CO calculation 5) drug transfer across placenta
compare and contrast Boyle’s, Charles, and Gay-Lussac’s laws.
Boyle
P1V1=P2V2
Charles
V1/T1=V2/T2
Gay-Lussac
P1/T1=P2/T2
list several examples of how Boyle’s law can be applied in the OR.
(PV)
- diaphragm contraction increases Tv
- pneumatic bellows
- squeezing an Ambu bag
- using Bourdon pressure gauge to calculate how much O2 is left in a cylinder
list an example of how Charle’s law can be applied in the OR
V/T
- LMA cuff ruptures when placed in an autoclave
list an example of how Gay-Lussac’s law can be applied in the OR.
P/T
- oxygen tank explodes in heated environment
what is the function of the ideal gas law
unifies all 3 gas laws into a single equation
PV= nRT
R = constant 0.0821 Latm/Kmol
define Ohm’s law
the current passing through a conductor is directly proportional to the voltage and inversely proportional to the resistance
Q = change in pressure / resistance
how is Poiseuille’s law related to Ohm’s law?
Poiseuille’s law is a modification of Ohms law that incorporates vessel diameter, viscosity, and tube length.
Q = blood flow R = radius deltaP = arteriovenous pressure gradient "n" = viscosity L = length of the tube
Q = (piR^4deltaP)/(8”n”L)
how do changes in radius affect laminar flow (x1, x2, x3, x4, and 5)
altering the radius of the tube exhibits the greatest impact on flow
R = 1^4 = 1 R = 2^4 = 2x2x2x2= 16 R = 3^4 = 3x3x3x3 = 81 R = 4^4 = 4x4x4x4 = 256 R = 5^4 = 5x5x5x5 = 625
how can we apply Poiseuille’s law to the administration of a unit of PRBCs?
we can deliver PRBCs faster if we:
- increase the radius w/ a large bore IV
- increase the pressure gradient w/ a pressure bag or increasing IV pole height
- decrease viscosity by diluting blood w/ NS or running it through a fluid warmer
- decrease the length by not using longer tubing than you really need.
What does Reynold’s number tell you?
There are three types of flow: laminar, turbulent, and transitional
Reynolds number allows us to predict the type of flow that will occur in a given situation
Re <2000 = laminar flow is dependent on gas viscosity (Poiseuille’s Law)
Re 2000-4000 = transitional flow
Re >4000 = turbulent flow is dependent on gas density (Graham’s law)
Re = (densitydiametervelocity)/viscosity
explain how understanding Reynold’s number helps you treat status asthmaticus.
increased airway resistance, and this increases flow turbulence and the work of breathing.
- bc turbulent flow is primarily dependent on gas density, we can improve flow by having the patient inhale a lower density gas
- an oxygen/helium mixture (Heliox) improves Reynold’s number by reducing density
- the key here is that we are converting turbulent flow to laminar flow. Helium doesn’t improve flow if it’s already laminar.
Explain Bernoulli’s principal, and discuss it in the context of a river.
- describes the relationship b/n the pressure and velocity of a moving fluid (or gas)
- if the fluid’s velocity is high, then the pressure exerted on the walls of the tube will be low
explain the Venturi effect, and give some examples.
an application of the Bernoulli principal.
As air flow in a tube moves past the point of constriction, the pressure at the constriction DECREASES and if the pressure inside the tube falls below atmospheric pressure, then air is entrained into the tube (venturi effect)
adjusting the diameter of the constriction allows for control of the pressure drop and the amount of air that is sucked into the tube. The key here is air entrainment!
Example is jet ventilator
explain the Coanda effect and give some examples.
describes how a jet flow attaches itself to a nearby surface and continues to flow along that surface even when the surface curves away from the initial jet direction
ex: wall hugging jet of mitral regurg and the water that follows the curve of a glass.
how do you calculate the law of Laplace for a sphere? for a cylinder?
sphere:
T = PR/2
ex: alveolus, ventricle, saccular aneurysm
cylinder
T = PR
ex: blood vessels, aortic aneurysm
what is the yearly maximum for radiation exposure? How does this change if someone is pregnant?
nonpregnant:
- 5rem max
- eye, thyroid = most susceptible
pregnant
- 0.5rem max for fetus or 0.05rem/month
- fetus = most susceptible
list 3 ways to protect yourself from radiation exposure
distance
duration
shielding
how can we apply the inverse square law to radiation exposure?
intensity of exposure
1/distance ^2
minimum safe distance from radiation source is 6ft
what is boiling point and how is it affected by atmospheric pressure?
Temp at which a liquid vapor pressure = atmospheric pressure
increase in atmospheric pressure –> increase BP (ex. hyperbaric O2 chamber)
decrease in atmospheric pressure–> decrease in boiling point (ex high altitude)
define specific heat
amount of heat required to increase the temperature of 1g of a substance by 1C
define vapor pressure
in a closed container, molecules from a volatile liquid escape the liquid phase = gas phase.
The molecules in the gas phase exert a pressure on the walls of the container = this is vapor pressure
define vaporization
the process by which a liquid is converted to a gas (requires energy (heat))
define the heat of vaporization
the number of calories required to vaporize 1mL of liquid
explain latent heat of vaporization, and apply this to anesthetic vapor inside of a vaporizer
the number of calories required to convert 1g of liquid WITHOUT a temperature change in the liquid
applied to anesthetic vaporizer:
- gas exerts vapor pressure inside chamber
- FGF over liquid, carrying away some of the agent that exists in the gas phase
- this cools the remaining liquid –> reduction in VP of that liquid –> less molecules in the gas phase
NET RESULT: decrease in vaporizer output
However, modern vaporizers compensate for this temperature change
explain the Joule Thompson effect in the context of gas cylinders
gas stored at high pressure that is suddenly released escapes from its container into a vacuum. It quickly loses speed as well as kinetic energy –> decrease in temp
This explains why an oxygen cylinder that is opened quickly feels cool to the touch. Conversely, rapid compression of a gas intensifies its KE, causing temp to rise
REMEMBER: JOULE IS COOL
what is an adiabatic process?
process that occurs w/out gain or loss of energy (heat). It does not use or lose energy
For example, rapid expansion or compression of a gas where there is no transfer of energy
What is critical temperature, and how does this apply to gas cylinders?
critical temp = highest temp where a gas can exist as a liquid (i.e. it cannot be liquified regardless of pressure)
critical temp for N2O = 36.5, which explains why it’s primarily a liquid inside the cylinder.
critical temp for O2 = -119, so it exists as a gas inside the cylinder
of the gases used in the OR, only CO2 and O2 have critical temps below room temp
what is critical pressure?
the minimum pressure required to convert a gas to a liquid at its critical temperature
know the temperature conversion formulas.
C = K - 273.15 K = C + 273.15
C = (F-32) x 5/9 F = (C*1.8) + 32
define pressure
pressure = force/area
increased area = decreased pressure and vice versa
know the pressure conversion factors
1 atm = 760mmHg = 760 torr = 1 bar = 1033 cmH2O = 14.7lb/in^2
1mmHg = 1.36cmH2O
1cmH2O = 0.74mmHg
what is avogadro’s number
says that 1 mole of any gas is made up of 6.023x10^23 atoms
- a mole of gas is equal to the molecular weight of that gas in grams
- if a molecule is diatomic (O2), you must account for both atoms
what are the 4 mechanisms of heat transfer? rank them from most to least important.
radiation - infrared (60%)
convection - air (15-30%)
evaporation - water (20%)
conduction - contact (<5%)
explain the 3 stages of intraoperative heat transfer
when no attempts are made to maintain normothermia, heat transfer follows a triphasic curve:
phase 1: heat redistribution from core to periphery
phase 2: heat transfer > heat production
phase 3: heat transfer = heat production
what are the consequences of perioperative hypothermia?
CV:
- SNS stimulation (MI, dysrhythmias)
- O2Hgb curve L shift (decreased O2 delivery)
- vasoconstriction, decreased tissue pO2 (SSI)
- coagulopathy, platelet dysfunction (increased EBL)
- sickling of HgbS (crisis risk)
pharm:
- slowed drug metabolism (prolonged effects of anesthetic agents)
- increased solubility of IA (prolonged emergence)
name 3 drugs that can be used to treat postoperative shivering.
shivering increases o2 consumption up to 400-500%. This increases the risk of MI and ischemia
- meperidine (kappa)
- clonidine (alpha2)
- precedex (alpha2)
when is hypothermia a good thing?
all are based on the fact that O2 consumption is reduced by 5-7% for every 1C decrease in body temperature:
- cerebral ischemia
- cerebral aneurysm clipping
- TBI
- CPB
- cardiac arrest
- aortic cross clamping
- carotid endarterectomy
in which region of the esophagus should an esophageal temp probe be placed? How does misplacement affect the reading?
in the distal 1/3-1/4th of the esophagus (38-42cm past the incisors)
temp is increased if placed in stomach d/t heat created by liver metabolism
temp is decreased if placed proximally d/t cool inspiratory gas.
compare and contrast the various sites of temp measurement.
esophagus: best in distal 1/3-1/4th of esophagus
nasopharynx: less reliable than esophageal
rectum: risk of bowel perforation
bladder: risk of UTI, decreased reading if inadequate UOP
pulmonary artery: temp decreased if open chest procedure
tympanic membrane: risk of tympanic membrane injury
skin: doesn’t correlate w/ core temp
what are the 3 ingredients required to produce a fire? Give examples of each
fuel (ETT, drapes, surgical supplies)
oxider (O2, N2O)
ignition source (electrosurgical cautery, laser)
details the steps you would take during an airway fire.
stop ventilation, remove ETT stop all FGF remove other inflammable materials pour water/saline in airway \+/- CO2 fire extinguisher
after fire is controlled:
- BMV, avoid supp O2 or N2O
- check ETT for damage (fragments in airway)
- bronch to inspect for a/w injury
DO NOT squeeze the reservoir bag as you extubate the patient (blow torch effect!)
what does l.a.s.e.r stand for? how is it different from ordinary light?
light amplification by stimulated emission of radiation.
differs from ordinary light because it is:
- monochromatic (single wavelength)
- coherent (oscillates in the same phase)
- collimated (exists as a narrow parallel beam)
what is the difference b/n a long and short wavelength laser? What are the clinical consequences of this?
long wavelength: absorb more water and don’t penetrate deep into tissue
- cornea is at risk
short wavelength: absorb less water and penetrate deeper tissues
- retina is at risk
what color googles must be worn for each type of laser: CO2, Nd:YAG, Ruby, and Argon?
CO2 = Clear Ruby = Red Argon = Amber Nd:YAG = Green
discuss the flammability of ETT in the context of laser surgery on the airway.
- most ETT are flammable
- laser reflective tape no longer advised (use laser resistance ETT)
- laser resistant ETT are NOT laser proof
- cuff is most vulnerable part
- laser resistant tubes do NOT have laser resistant cuffs
- fill cuff w/ saline/dye
- many laser resistant ETT have 2 cuffs to allow for continued PPV in the event of perforation by the laser
- laser resistant ETT doesn’t prevent fire w/ electrocautery
describe the 4 degrees of burns. Which require a skin graft?
1st = epidermis (spont healing) 2nd = superficial dermis (spont healing) to deep dermis (skin graft for deep dermis) 3rd = subQ (skin graft) 4th = muscle/bone (skin graft)
describe the rule of 9s. How does this apply to the adult?
TBSA of a burn
10% head 36% torso 9% each arm 18% each leg 1% peri-area
how is the rule of 9s different for children?
head = 19% of TBSA
Torso = 16% top and bottom
Arms front and back = 9.5%
legs are 15% each instead
describe the consequences of the capillary leak that occurs after a burn.
immediately after a burn, microvascular permeability increases –> capillary leak
- edema
- protein loss = decreased plasma oncotic pressure = edema
- hypovolemia, shock
- hemoconcentration
fluid shifts/edema are greatest in first 12hrs, begin to stabilize by 24hrs
- avoid albumin in first 24hrs
- hemolysis common but hypovolemia –> hemoconcentration (rise in Hgb in first few days = inadequate volume resuscitation)
Describe the parkland formula for resuscitation in burn patients.
1st 24hrs:
- crystalloid = 4mL LR/% TBSA/kg
- 1/2 in 1st 8hrs, 1/4 in 2nd 8hrs, 1/4 in 3rd 8hrs
- no colloid
2nd 24hrs:
- cystalloid = D5W at normal maintenance rate
- colloid = 0.5mL/%TBSA/kg
describe the Modified Brooke formula for resuscitation in burn patients.
same as parkland except w/ 2mL LR/% TBSA/kg in first 24hrs
what is an acceptable UOP in a burned patient? Is this different in children or patients who’ve suffered a high voltage electrical injury?
adult > 0.5mL/kg/hr
child > 1mL/kg/hr
high voltage electrical > 1-1.5mL/kg/hr
- increased UOP d/t myoglobinemia from muscle damage after high voltage electrical injury (nephrotoxic)
why is the burn patient at risk for abdominal compartment syndrome? What is the diagnosis and treatment of this complication?
may be d/t aggressive fluid resuscitation
- intra-abdominal HTN: IAP > 20mmH2O or >12mmHg AND evidence of organ dsyfunction
- tx: NMB, sedation, diuresis, abdominal decompression via laparotomy
discuss the clinical considerations for the patient w/ CO poisoning.
CO binds Hgb 200x affinity of O2
COHgb = L shift OxyHgb curve
impairs oxidative phosphorylation
–> inadequate o2 delivery and utilization = metabolic acidosis
blood = cherry red
pulse ox = not accurate (may be falsely elevated)
tx: 100% FiO2, hyperbaric O2
discuss the use of NMB in burn patients.
upregulation of extrajunctional receptors begins after 24hrs
- sux ok w/in first 24hrs post-burn
- avoid sux after 24hrs (lethal hyperK+)
- dose of NDMR should be increased 2-3x (there are more receptors)
describe the physiologic changes that accompany electroconvulsive therapy.
seizure caused by ECT causes profound physiologic changes:
- initial: increased PNS during tonic phase (15sec) –> brady, hypotension, increased secretions
- secondary: increased SNS during clonic phase (several mins) –> tachy, HTN, increased intragastric pressure, increased CBF, ICP, IOP
discuss the absolute and relative contraindications to ECT.
typically r/t increased SNS response or increased ICP.
absolute:
- recent MI
- recent intracranial surgery
- recent CVA
- brain tumor
- unstable C-spine
- pheo
relative
- pregnancy
- pacemaker/ICD
- CHF
- glaucoma, retinal detach
- severe pulm disease
compare and contrast neuroleptic malignant syndrome w/ malignant hyperthermia.
NMS is d/t dopamine depletion in the basal ganglia and hypothalamus
- causes: dopamine antagonists or withdraw from dopamine agonists
- tx: bromocriptine, dantrolene, supportive care, ECT
compare/contrasting the two:
- NMS no genetic link
- NMS doesn’t develop acutely
- NMS is associated w/ psych meds
- both cause muscle rigidity, hyperthermia, tachycardia, acidosis
- both can be treated w/ dantrolene
- NMB cause paralysis in NMS but doesn’t in MH
what is the etiology of serotonin syndrome?
occurs when there is excess 5-HT activity in the CNS and PNS. Key drug interactions that increase the risk are:
SSRIs and:
- meperidine
- fentanyl
- methylene blue
MAOI and:
- meperidine
- ephedrine.
What are the 3 determinants of IOP?
What is the intraocular perfusion pressure formula?
Whats the normal value?
Where is aqueous humor produced and reabsorbed?
IOP is determined by the
1) choroidal blood volume
2) aqueous fluid volume
3) extraocular muscle tone
intraoc perfusion pressure = MAP - IOP
normal = 10-20mmHg
Aqueous humor is produced by ciliary process (posterior chamber)
Reabsorbed by the canal of Schlemm (anterior chamber)
what factors reduce IOP? which increase it?
decreases:
- hypocarbia
- decreased CVP, BP
- IA, N2O, NDMR, propofol, opioids, benzos
- hypothermia
increases:
- hypercarbia
- increased CVP, BP
- hypoxemia
- DL/intubation, straining/coughing
- succ, N2O if SF6 bubble
- trendelenburg, prone
- external compression by mask
LMA placement/removal = minimal effect on IOP
- ketamine +/- increases IOP, but causes nystagmus + blepharospasm (avoid in eye surgery)
what is the difference b/n open and closed angle glaucoma?
elevated IOP that leads to retinal artery compression.
open angle = sclerosis, impairing humor drainage
closed angle = closure, mechanical outflow obstruction
IOP is decreased by drugs that decrease aqueous humor production or facilitate drainage (cause miosis)
which drugs reduce aqueous humor production? which increase aqueous humor drainage?
aqueous humor is produced by ciliary process (posterior chamber) and reabsorbed by canal of Schlemm (anterior chamber)
decrease production:
- acetazolamide
- timolol (nonselective)
facilitate drainage:
- echothiophate but it can prolong DOA of sux
What is strabismus correction? What unique considerations apply to the anesthetic management of these patients?
corrects the misalignment of the extraocular muscles and re-establishes the visual axis. Three key considerations:
- increased risk of MH
- increased risk of PONV
- increased risk of activating the oculocardiac reflex (afferent CN V, efferent CN X)**
which patient populations benefit from a TAP block?
TAP = transverse abdominal plane block
- unilateral peripheral nerve block that targets the nerves of the anterior and lateral abdominal wall
best for abdominal procedures (general, GYN, urologic) that involve T9 to L1
- bilateral TAP required for midline incision or laparoscopic surgery
describe the anatomy and landmarks required to perform a TAP block
superficial to deep:
- subQ
- external oblique m.
- internal oblique m.
- transverse abdominis m.
- peritoneum
landmarks of the TAP form the triangle of Petit. These include: “Eli”
- external oblique
- latissimus dorsi
- iliac crest
define allodynia and give an example.
AlloDyNia- pain stimulus that Doesn’t Normally cause pain
ex: fibromyalgia
define dysesthesia and give an example.
“dys-” meaning “bad” or “difficult,” and “-esthesia” meaning “sensation.” So, it’s a “bad sensation.”
abnormal and unpleasant sense of touch
ex: burning sensation from diabetic neuropathy
define neuralgia and give an example.
Think of “neuralgia” as “neuro” (referring to nerves) + “algia” (meaning pain). This can help you associate it directly with nerve pain.
pain localized to a dermatome
ex: herpes zoster (shingles)
what is the defining characteristic between type I and type II complex regional pain syndrome?
CRPS is characterized by neuropathic pain w/ autonomic involvement.
Type I: reflex sympathetic dystrophy (mild pain like needle stick and ankle pain)
Type II: causalgia from large nerve
distinction is that type II is always preceded by nerve injury
discuss the use of a thoracic paravertebral block.
LA injected into the paravertebral space (potential space) targets the ventral ramus of the spinal nerve as it exits the vertebral foramen
- creates unilateral sensory and sympathetic block for that dermatome
- “single shot, unilateral epidural block”
best for breast surgery, thoracotomy, and rib fractures
what structures are anesthetized by a celiac plexus block? How about a superior hypogastric block?
celiac plexus
- upper abdominal viscera (except L colon)
- NOT the pelvic organs
- useful for pain from upper abdominal organs but not pelvic organs
superior hypogastric plexus block
- pelvic organs
- useful in those involving pelvic organs
both useful in cancer patients
aside from an epidural blood patch, which regional technique is used to release post dural puncture headache?
sphenopalatine block
what is post-retrobulbar block apnea syndrome?
the optic nerve is unique b/c it is the only CN that is part of the CNS (enveloped by the meningeal sheath and bathed in CSF)
- thus LA injected into the optic sheath can enter the brain directly –> subarach block
discuss the use of cephalosporins in the PCN allergic patient.
previous literature suggested high cross-reactivity (up to 10%), but these numbers are grossly overstated.
if PCN allergy, pt may receive a cephalosporin if the reaction:
- was NOT IgE mediated (anaphylaxis, bronchospasm, urticaria)
- did NOT produce exfoliative dermatitis (Stevens Johnson syndrome)
otherwise, use vanco or clinda
what is the antibiotic of choice to treat MRSA? What are the special considerations for the administration of this antibiotic?
vanco
to reduce histamine release and hypotension, administer at a rate of 10-15mg/kg over 1hr
histamine response can be minimized by benadryl 1mg/kg + cimetidine 4mg/kg 1hr pre-anesthesia
discuss the different levels of infection control precautions. Give examples w/ specific pathogens.
contact precautions
- transmitted by direct contact
- gown, gloves
- MRSA, VRE, C.diff
droplet precautions
- transmitted by droplets
- gown, gloves, mask
- influenza, resp synctyial virus
airborne precautions
- transmitted airborne
- gown, gloves, N95, negative pressure room
- TB
what is the rate of seroconversion following exposure to HIV infected blood?
most common cause of occupational HIV exposure = needle stick injury w/ a hollow bore needle
rates:
- needle stick = 0.3%
- mucus membrane exposure = 0.09%
what are the functions of the 5 types of WBC?
GRANULOCYTES:
- neutrophils (60%): fight bacterial, fungal infection
- basophils: hypersensitivity rxns (degranulate as mast cells)
- eosinophils: defend against parasites
AGRANULOCYTES
- monocytes: phagocytosis, release cytokines, present pathogens to T-lymphocytes
- lymphocytes: B-type (humoral immunity, Ab production), T-type (cell-mediated, no Ab production)
describe the presentation of anaphylaxis
CV = hypotension, tachycardia, arrhythmias, cardiac arrest
resp = bronchospasm, laryngeal edema, mucus production
skin = flushing, urticaria, erythema, pruritus
GI = cramping, N/V, diarrhea
what is the function of the H1 and H2 receptor?
H1
- vasodilation
- increased vascular permeability
- smooth m. contraction (not vascular)
H2
- cardiac stim (inc HR)
- HCl secretion
describe the patho of the 4 types of hypersensitivity reactions. List examples of each.
Type I: immediate hypersensitivity
- Ag + Ab interaction
- previous sensitization
- ex: anaphylaxis, asthma
Type II: Ab-mediated
- IgG, IgM Ab bind to cell surfaces
- ex: ABO incompat, HIT
Type III: Immune complex mediated
- immune complex is formed and deposited into tissues
- ex: snake venom rxn, protamine-vasoconstriction
Type IV: delayed
- allergic rxn delayed at least 12hrs after exposure
- ex: contact dermatitis, graft-v-host disease, tissue rejection
What is the treatment for intraoperative anaphylaxis?
- d/c offending agent
- a/w support: FiO2, ETT
- epi (5-10mcg IVP for hypotension, up to 0.1-1mg for CV collapse)
- liberal IVF (cryst 10-25mL/kg or colloid 10mL/kg)
- H1, H2 blockers: benadryl 0.5-1mg/kg, ranitidine 50mg/pepcid 20mg IVP
- hydrocortisone 250mg IV
- albuterol for bronchospasm
- vasopressin for refractory hypotension (0.01U/min start)
what are the 3 most common causes of intraoperative anaphylaxis?
1 = NMB (sux most common) 2 = latex 3 = antibiotics
which patients are at the highest risk of a latex allergy?
spina bifida/myelomeningocele atopy health care workers food allergy to: - banana - kiwi - mango - papaya - pineapple - tomato
Explain “Chemo man” know everything about this! Matching question on the SEE
picture of the man
C: cisplatin (alkylating agent)
- acoustic n. injury, nephrotoxicity
V: vincristine, vinblastine (tubulin-binding drug)
- peripheral neuropathy
B: bleomycine (antitumor abx)
- pulmonary fibrosis (FiO2 <30%)
D: doxorubicin (antitumor abx)
- cardiotoxic
5, M: 5-fluorouracil, methotrexate (antimetabolite)
- bone marrow suppression
what are the 3 most important inputs to the vomiting center? What receptors are involved in each one?
vomiting center is in the nucleus tractus solitarius (medulla)
sensory input via:
- chemoreceptor trigger zone (5-HT3, NK-1, DA-2, noxious chemicals)
- GI tract (5-HT3, NK-1)
- vestibular system (H1, M1)
where is the P6 acupressure point, and why is it important?
nonpharmacologic method of reducing PONV
3 fingers across the inner wrist
what are the OSHA limits for noise exposure?
for an 8hr span = 90dB
single noise level <115dB
Pic is from google
