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. This creates a polar molecule, where 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
applications:
- anesthetic emergence is prolonged in the hypothermic patient
- dissolved oxygen in the oxygen carrying capacity equation (CaO2)
describe Fick’s law of diffusion.
transfer rate of gas through a tissue medium.
rate of transfer increases w/:
- partial pressure difference
- diffusion coefficient
- membrane surface area
rate of transfer decreases w/
- membrane thickness
- molecular weight
list clinical examples of Fick’s law of diffusion.
diffusion hypoxia COPD = reduced alveolar SA - slower rate of inhalation induction CO calculation 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
we can adapt Ohm’s law to understand fluid flow
current = voltage difference/resistance
flow = pressure gradient/resistance
Q = change in pressure/R
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 (x2, x3, x4, adn x5)
altering the radius of the tube exhibits the greatest impact on flow
R = 1^4 = 1 R = 2^4 = 16 R = 3^4 = 81 R = 4^4 = 256
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 there 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 and vice versa
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 teh tube falls below atmospheric pressure, then air is entrained into the tube (venturi effect)
adjusting the diameter of teh 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!
explain teh 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 adn 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?
BP = temp at which a liquids vapor pressure equals atmospheric pressure
increase in P –> increase BP (ex. hyperbaric O2 chamber)
decrease in P –> decrease in BP (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 and enter the 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). For example, a very rapid expansion or compression of a gas where there is no transfer of energy is an example of an adiabatic process.
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: head 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 laser 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) 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
9% head 36% torso 9% each arm 18% each leg 1% peri-area
how is the rule of 9s different for children?
head = 18% of TBSA
- 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 (letahl 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 and treatment 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 determinants of IOP? Whats the normal value?
intraoc perfusion pressure = MAP - IOP
globe is relatively noncompliant, thus the IOP is determined by the choroidal blood voulme, aqueous fluid volume, and extraocular muscle tone
normal = 10-20mmHg
aqueous humor is produced by the ciliary process (posterior chamber) and 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?
glaucoma is d/t chronically elevated IOP that leads to retinal artery compression.
open angle = d/t sclerosis of the trabecular meshwork, impairing humor drainage
closed angle = d/t closure of the anterior chamber creating mechanical outflow obstruction
IOP is decreased by drugs taht 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 (can prolong DOA of sux + ester LA)
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:
- external oblique
- latissimus dorsi
- iliac crest
define allodynia and give an example.
pain d/t a stimulus that doesn’t normally cause pain
ex: fibromyalgia
define dysesthesia and give an example.
abnormal and unpleasant sense of touch
ex: burning sensation from diabetic neuropathy
define neuralgia and give an example.
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 involveent.
Type I: reflex sympathetic dystrophy
Type II: causalgia
i.e. distinction is that type II is always preceded by nerve injury whereas type I is not.
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
if you had to explain “chemo man” to a friend, could you do it? try it now for practice.
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 5 most important GI hormones? What is the key function of each?
gastrin: increases stomach acid and stimulates chief cells to secrete pepsinogen (converted to pepsin) in response to food entering the stomach
secretin: stim pancreas to secrete HCO3- and liver to secrete bile
CCK: pancreas to release digestive enzymes and gallbladder to contract
gastric inhibitory peptide: slows gastric emptying, stim pancreatic enzyme release
somatostatin: universal off switch for digestion.
what is gastric barrier pressure? Why is it important?
barrier pressure = LES pressure - intragastric pressure
the likelihood of GERD is determined by barrier pressure
- higher the barrier pressure = lower likelihood of reflux.
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)
what is the mechanism of action of NK-1 antagonists? Give an example of a drug in this class.
neurokinin-1 antagonists block substance P in the chemoreceptor trigger zone
ex: aprepitant
what are the risk factors for PONV? It helps to divide them into patient, surgical, and anesthetic risk factors.
patient:
- female
- nonsmoker
- hx of motion sickness
- previous PONV
- youth > elderly (loosely)
surgical:
- long procedures
- gyn, breast, plastics
- laparoscopy
- peds: strabismus, orchiopexy, T&A
anesthetic:
- halogenated anesthetics, N2O (>50%)
- opioids
- etomidate
- neostigmine
name 2 antiemetics that prolong the QT interval.
droperidol
ondansetron
list 2 contraindications for metoclopramide.
Parkinson’s (it’s a dopamine antagonist)
bowel obstruction (it’s a prokinetic agent)
where is the P6 acupressure point, and why is it important?
nonpharmacologic method of reducing PONV
3 fingers across the inner wrist
how long must the tourniquet remain inflated after a Bier block? Why?
300mmHg or 2x SBP for at least 20mins after LA injection
premature release can increase risk of seizure and/or cardiac arrest
what physiologic changes accompany tourniquet deflation?
release stresses the body in 2 ways:
- restoring blood flow to extremity produces relative decrease in circulating blood volume
- products of cellular hypoxia enter systemic circulation
- increased EtCO2
- decreased core temp
- decreased BP
- decreased SvO2
- metabolic acidosis
discuss the role of the cyclooxygenase enzyme in the arachidonic acid cascade.
COX1 is always present, maintains normal physiologic function
- inhibition impairs platelet function, causes gastric irritation, and decreases RBF
- NSAIDs, aspirin
COX2 is not always present, just during inflammation
- inhibition produces analgesia (ceiling occurs), anti-inflammation, antipyretic effects
- COX 2 inhibitors AND NSAIDs, aspirin
compare the equianalgesic dose of ketorolac and morphine.
toradol 30mg IV
morphien 10mg IV
what is Samter’s triad? Why is it important?
aspirin exacerbated respiratory distress (Samter’s triad) refers to the combination of asthma, allergic rhinitis, and nasal polyps. These patients can develop life threatening bronchospasm after aspirin administration.
list 4 herbal supplements that increase bleeding risk.
garlic
ginger
gingko
saw palmetto
list 2 herbal supplements that reduce MAC
kava kava
valerian
chronic ingestion of which herbal medication can mimic Conn’s syndrome?
licorice
describe the modified Aldrete scoring system.
used to assess readiness for PACU discharge. score of 0-2 is awarded in 5 areas, where a score of 9 or more is generally accepted as discharge ready.
activity (moving) respiration (breathing) circulation (BP) consciousness O2 sats (on RA)
compare and contrast android and gynecoid obesity.
android
- more common in men
- central/abdominal visceral fat accumulation
- increased risk of ischemic heart disease, HTN, HLD, insulin resistance, death
gynecoid
- more common in women
- gluteal and femoral fat accumulation
- metabolically inactive, primarily used for energy storage
- increased risk of join disease, varicose veins
- associated w/ reduced incidence of non-insulin dependent diabetes
what are the diagnostic indicators for metabolic syndrome?
metabolic syndrome (syndrome X) = various disease states that coincide w/ obesity. CV risk is 50-60% greater than the gen pop.
must have at least 3 of:
- waist circumf >40in men, >35in women
- triglycerides > 150
- HDL <40 men, <50 women
- BP >130/85
- fasting BS >100
how can you use BMI to classify obesity?
underweight BMI <18.5 normal 18.5-24.9 overweight 25-29.9 obese class I 30-34.9 obese class II 35-39.9 obese class III >40 (morbid)
how can you classify obesity in children?
overweight: 85-94th weight percentile
obese: 95-98th
severely obese: 99th
what is the formula for BMI?
weight (kg)/height (m^2)
how can you calculate ideal body weight for a man? For a woman?
IBW describes the BMI associated w/ the lowest risk of body-weight related comorbidities.
men (kg) = cm -100
women (kg) = cm - 105
describe how obesity creates a restrictive ventilatory defect.
lung inflation is inhibited d/t:
- chest fat compressing rib cage and hindering outward expansion
- abdominal fat shifting diaphragm cephalad, compressing lungs
- kyphosis/lordosis develop over time and alter ribcage geometry
extra weight on the chest increases WOB. Rapid, shallow breathing pattern provides the most energy efficient way to achieve this goal
how does obesity affect respiratory gas tensions?
fat is metabolically active, thus pts have increased oxygen consumption and CO2 production –> MV must be increased
while pt may have hypoxemia, PaCO2 is usually normal. This is d/t high diffusing capacity of CO2. High PaCO2 signals impending respiratory failure.
how does obesity affect FRC? How about the other lung volumes and capacities?
FRC is inversely proportional to BMI.
- FRC < CC = small airway collapse during tidal breathing
- -> V/Q mismatch, shunt, hypoxemia
GA causes FRC to decrease by 50% (nonobese = 20%)
- + higher O2 consumption = decreased safe apnea time.
decreased VC, TLC, ERV, FRC
normal RV
how you can you reduce atelectasis in the morbidly obese patient who is mechanically ventilated?
keep FiO2 <80% to prevent absorption atelectasis.
to recruit alveoli:
- reopen collapsed alveoli w/ recruitment maneuvers (40cmH2O x10sec)
- hold open the re-expanded alveoli w/ PEEP or CPAP
both maneuvers may cause decreased venous return and cause hypotension
what is the optimal tidal volume for a morbidly obese patient who is mechanically ventilated?
6-8mL/kg of IBW
higher Tv may only minimally increase PaO2 and may cause sheer stress to the lungs
does a morbidly obese patient require RSI? Why or why not?
obesity alone doesn’t mandate a RSI
- consider other risk factors though.
conflicting evidence re: effects of obesity on gastric pH, residual volume, and emptying time. No data supports an increased aspiration risk in obesity.
how does obesity impact the cardiovascular system?
- increased intravascular blood volume
- high CO
- adipocytes require vascular growth to support their growth, requiring increased blood volume and CO
- increased CO is d/t increased SV (normal HR)
- increased CV workload –> thick, dilated heart –> decreased ventricular compliance –> diastolic, systolic dysfunction
HTN is d/t hyperinsulinemia, SNS and RAAS acitvation, and elevated plasma [cytokine]
describe the EKG changes that can accompany obesity.
low voltage L axis deviation (mass effect) R axis deviation (hypertrophy) QT prolongation ischemia dysrhythmias (fatty infiltrates, etc. )
what valvular defect is highly suggestive of pulmonary HTN in the obese patient?
tricuspid regurg
what factors affect the volume of distribution in the obese patient?
increased blood volume
increased CO
altered protein binding
larger mass for lipid solubilty
–> increased Vd for both lipophilic and hydrophilic drugs (lipophilic more tho)
how does obesity impact your selection of inhaled anesthetic agents?
MAC doesn’t change
IA are lipophilic, so use agents w/ lowest blood:gas coefficients
sevo or des = faster emergence than iso, propofol
N2O is generally avoided b/c it restricts the max FiO2 that can be delivered.
how does obesity affect the dosing of propofol?
loading dose is based on LBW b/c redistribution limits it’s effects, not clearance
maintenance dosing based on TBW
how does obesity affect the dosing of succinylcholine?
TBW
this is a clear exception to the rule for water soluble drugs. although there is increased Vd, there is also increased pseudocholinesterase activity that offsets the Vd
how does obesity affect the dosing of nondepolarizing neuromuscular blockers?
roc and vec = LBW
cis and atra = TBW
how does obesity affect the dosing of opioids?
fent, sufenta (fat soluble, large Vd) expect prolonged E1/2t:
- loading TBW
- maintenance: LBW
remi always LBW (behaves like a low Vd drug d/t it’s clearance)
how does obesity affect the dosing of an epidural?
engorgement of the epidural veins and an increased epidural fat content will cause a greater spread of LA in the epidural space
dose should be reduced to 75% of the normal dose
name the key muscles that control the diameter of the upper airway and describe their functions.
pharynx = collapsible tube
airway patency is maintained by the balance b/n pharyngeal muscles that dilate the airway and negative pressure of inspiration that collapses it.
tensor palantine - opens nasopharynx genioglossus - opens oropharynx hyoid muscles - opens the hypopharynx
define hypopnea.
a 50% reduction in airflow for 10 seconds, 15x or more per hour, and is linked to snoring and decreased O2 saturation
discuss the pathophysiology of OSA.
cessation of airflow for at least 10 seconds (apnea) with 5 or more unsuccessful efforts to breathe (obstruction) and >4% reduction in SaO2
leads to hypoxemia, hypercarbia, and arousal from sleep
- -> ANS stimulation, daytime somnelence
- -> systemic HTN, dysrhythmias, MI, pHTN, HF
what is the definitive test for OSA? What does it measure? how do you interpret the findings?
polysomnography
AHI (apnea-hypopnea index) = # apnea/hypopnea episodes/hr
mild = 5-15
mod = 15-30
severe >30
what is the best bedside tool to identify undiagnosed OSA? How do you interpret the findings?
STOP BANG
high risk 3+ yes
low risk <3 yes
Snoring Tiredness Observed apnea Pressure BMI Age Neck circumference Male gender
what is obesity hypoventilation syndrome? How do you identify a patient w/ this condition?
(aka Pickwickian syndrome)
long term consequence of untreated OSA = failure of resp center in medulla to respond to increased PaCO2 appropriately –> apnea during sleep w/out resp effort
diagnostic:
- BMI >30
- awake PaCO2 >45
- dysfunctional breathing asleep
signs
- obesity
- daytime hypersomnelence
- hypoxemia, hypercarbia
- resp acidosis w/ comp
- polycythemia
- pHTN
what are the most common signs of an anastomotic leak following gastric bypass?
(2% incidence)
unexplained tachycardia is the most sensitive sign (>120)
others: fever, abdominal pain
toradol increases the incidence of this complication, so avoid.
what is Ma huang? what are the complications of its use?
natural source of ephedrine
any drug interactions that would occur w/ ephedrine will apply here as well
complications of adrenergic overstim, HTN, CVA, sz, death have occurred
what is Orlistat? what are the complications of its use?
lipase inhibitor
reversibly binds lipase and hinders the absorption and digestion of consumed fats
decreased fat, vitD, vitA, vitK, vitE absorption (requires supplementation)
- decrease in vitK dependent clotting factors
How does the Trendelenburg position affect the distribution of blood volume, MAP, and venous pressure?
increased venous return = increased position on Frank-Starling (caution w/ HF)
MAP + or no change
- since vasodilation and HR decrease follows increased venous return
venous pressure increases
can lead to edema of the face, eye, and airway, and intracranial HTN
how do position changes affect respiratory function?
trendelenburg
- compressed lungs, decreased pulmonary compliance
- increased PIP
- decreased TLC, FRC
reverse T
- expanded lungs, increased pulmonary compliance
- decreased PIP
- increased TLC, FRC
how do position changes affect the position of the ETT?
neck position:
- flexion = ETT toward the carina
- extension = ETT toward VC
“tube goes where nose goes”
carina position
- T burg = carina toward ETT
which positions increase the risk of post op airway edema, and how can you assess the severity of this complication?
edema of the face, tongue, pharynx can affect airway patency
- prone, Tburg = increased hydrostatic pressure
- sitting = neck flexion impairs venous drainage
if you are concerned about airway patency pre-exutbation, then you can perform a leak test and/or visually inspect w/ DL
discuss how the brachial plexus is susceptible to stretch and compression injury.
stretch injury since it’s anatomically fixed at the cervical vertebrae and the axillary fascia
- risk is highest w/ abducted arms >90degrees and/or head rotated to the side
compression injury b/n clavicle and first rib or by an external force (shoulder brace, bean bag)
should shoulder braces be used for the patient in Tburg position? Why or why not?
No - a non-sliding mattress is a better option
if used, they should be placed over the acromion
- avoid placement near base of neck or midway along the clavicle to decrease risk of compression injury
how do you assess a patient for thoracic outlet syndrome? Which surgical position increases the likelihood of this complication?
clasp hands behind head - if pt complains of pain, this may suggest an increased risk of TOS
most likely to occur in any position where the arms are over the head (i.e. prone)
where should an axillary roll be placed for the patient in the lateral decubitus position?
distal to the axilla
a roll placed inside the axilla can cause neurovascular compression
- a poor SpO2 signal in the dependent arm is a good monitor for this.
describe the anatomy of the cubital tunnel.
boundaries:
- medial epicondyl of humerus
- olecranon process of ulna
- cubital tunnel retinaculum
ulnar nerve emerges from the cubital tunnel b/n the humeral and ulnar heads of the flexor carpi ulnaris.
who is at risk for ulnar nerve injury?
*most commonly injured peripheral nerve
male gender (esp >50yrs)
preexisting ulnar neuropathy
extremes of body habitus
prolonged LOS/bedrest
describe the presentation of ulnar nerve injury.
impaired sensation of the 4th and 5th digits
inability to abduct (oppose) the pinky finger
chronic injury presents w/ claw hand (muscular atrophy)
which type of nerve injury provides a greater risk for long term injury (sensory or motor)?
sensory are more common, less serious, and tend to resolve on their own (usually <5 days)
motor deficits are less common and more serious
what are the causes of median nerve injury?
AC PIV
carpal tunnel syndrome
elbow hyperextension
- including forced extension during position after NMB
describe the presentation of median nerve injury.
reduced sensation over palmar surface of thumb, index finger, middle finger, and lateral aspect of the ring finger
inability to oppose the thumb (chronic injury can lead to the ape hand deformity)
what are the causes of radial nerve injury?
radial nerve passes along the spiral groove at the lateral aspect of the humerus (3 FB above the lateral epicondyle)
etiology:
- external compression (i.e. IV pole)
- excessive NIBP cycling
- UE tourniquet
- too tight of tucking w/ sheets
describe the presentation of radial nerve injury.
wrist drop (inability to extend the hand at the wrist)
discuss the etiology, presentation, and prevention of obturator nerve injury.
etiology: excessive flexion of thigh toward groin, excessive traction during lower abdominal surgery, or forceps delivery
presentation: inability to adduct the leg, reduced sensation over medial thigh
prevention: minimize hip flexion
discuss the etiology, presentation, and prevention of femoral nerve injury.
etiology: excessive traction during lower abdominal surgery
presentation: impaired knee extension, hip flexion, reduced anterior thigh/anteromedial leg sensation
prevention: avoid excessive traction
discuss the etiology, presentation, and prevention of saphenous nerve injury.
etiology: medial aspect of leg leans against supporting cradle in lithotomy position
presentation: reduced sensation over anteromedial aspect of leg
prevention: padding b/n leg and stirrup
discuss the etiology, presentation, and prevention of common peroneal nerve injury.
etiology: stirrups (highly susceptible here when lateral aspect of the leg leans against the stirrup bar)
presentation: foot drop, inability to evert foot or extend toes
prevention: padding, knees flexed w/ minimal rotation
discuss the etiology, presentation, and prevention of sciatic nerve injury.
etiology: lithotomy w/ extreme hip flexion and/or external rotation; sitting w/ straight legs
prevention: ample padding under buttocks, avoid excessive external hip rotation, flex table at the knees
presentation: foot drop
which position is most likely to cause compartment syndrome?
lithotomy
- increased leg compartment pressure
- raising legs above heart reduces LE perfusion pressure
- together –> leg ischemia –> edema –> more ischemia –> more edema, etc.
- this can progress to rhabdomyolysis and/or reperfusion injury
compartment syndrome is treated w/ fasciotomy
which position is most likely to cause a venous air embolism?
sitting
but this complication can occur in any position that produces a pressure gradient b/n the atmosphere and the veins at the surgical site
VAE –> R heart –> pulm vasculature –> increased dead space, RV workload
which position is most likely to cause midcervical tetraplegia?
associated w/ hyperflexion of the neck (chin to chest). Ischemia results d/t stretching and/or compression of the midcervical SC (usually C%)
most common in sitting position
should be able to place 2 FB b/n chin and chest
what is the purpose of a positioning device for a patient in the prone position?
(chest rolls, wilson frame, jackson table (best))
distribute the patient’s weight to the thoracic cage and bony pelvis, allowing the abdomen to hang freely , which promotes normal diaphragmatic excursion throughout the respiratory cycle
which position provides the most optimal VQ matching in the patient w/ ARDS?
prone
list 3 factors that worsen tracheobronchial compression in the patient w/ an anterior mediastinal mass.
supine position
GA induction
PPV
what is the best induction technique for a patient w/ an anterior mediastinal mass?
sitting and maintenance of SV
what are your options if you lose the airway during induction in the patient w/ an anterior mediastinal mass?
may be impossible to advance the ETT beyond the mass.
try repositioning lateral or prone, using rigid bronchoscope
if unable to ventilate, emergent fem-fem CPB may be required
what is the AANA code of ethics?
dictates the principles of conduct and professional integrity that guide the decision making and behavior of CRNAs
speaks to responsibilities as a professional, which hods the CRNA accountable for their own actions/judgements regardless of institutional policy or physician orders.
what are practice guidelines?
systematically developed statements to assist providers in clinical decision making that are commonly accepted w/in the anesthesia community.
“should” be adhered to
what are practice standards?
authoritative statements that describe minimum rules and responsibilities for which anesthetiists are held accountable
“must” be adhered to.
what are position statements?
express the AANA official positions or beliefs on practice related topics; they may also define the knowledge, skills, and abilities considered necessary for a nurse anesthetist.
define autonomy.
pt’s ability to choose w/out controlling interference by others, and w/out limitations that prevent meaninful choices.
define nonmaleficence
asserts that a provider has an obligation not to inflict hurt and harm - in other words, the Hippocratic oath primum non nocere (first do no harm)
define beneficence.
the principle that providers should take action for the benefit of others, including both preventing harm adn actively helping their patients.
underpins to the fundamental guiding principle of evidence based interventions - the benefits of treatment should be demonstrable and must clearly outweigh the risks.
list the 6 elements of informed consent.
competence decision making capacity disclosure of information understanding of information voluntary consent documentation
what is informed refusal? list one example of this concept in a specific patient population.
pt has a right to refuse medical treatment or therapy
common example is refusal of blood products by Jehovah’s Witness.
what is an advanced directive?
legally binding document that delineates the pt’s wishes regarding healthcare interventions in the case of incapacity and/or delegates the authority to another party
often include specific provisions that modify aspects of anesthesia management (intubation, abx, transfusions, etc.)
list the 4 things that must be proven in a lawsuit asserting malpractice.
duty
breach of duty
causation
damages
what is res ipsa loquitur?
“the thing speaks for itself” can shift the burden of proof from the plaintiff to the defendant. This can occur if 4 conditions can be established:
- injury wouldn’t have occurred w/out negligence
- injury was caused by something under complete control of the provider
- pt didn’t contribute in any way to the injury
- evidence for the explanation of events is solely under control of the provider.
what is the difference b/n libel and slander?
libel is defamation in the written form
slander is defamation in the verbal form
what is the difference b/n assault and battery?
assault is the attempt to touch another person
battery is touching another person w/out either expressed or implied consent
what is vicarious libaility? What is another name for this concept?
one person (or entity) may be liable for the actions of another. For example, a physician may be held liable for actions of a PA. The concept doesn’t typically apply to CRNAs working under a physician.
other name: Respondeat superior
what is the patient care and affordable care act?
ACA mandated that all individuals carry health insurance, established standards and requirements for health insurance policies, and launched health care clearinghouses or exchanges to assist people in finding medical insurance.
in addition, insurers are no longer permitted to charge more for pre-existing conditions
what is emergency in medical treatment and active labor act?
> 30yrs ago, this was enacted (EMTALA) to ensure public access to emergency services regardless of ability to pay. “anti-patient dumping” act.
specific obligations on medicare-participating hospitals that offer emergency services: provide a medical screening examination when request is made for an emergency medical condition regardless of ability to pay.
what is the health insurance portability and accountability act?
federal law that prohibits the disclosure of individually identifiable health information. PHI includes past and present health conditions, treatments, and payments for healthcare.
disclosure can occur in any form: orally, written, or electronically
what is the controlled substances act?
federal gvt regulation of the manufacture, importation, possession, and distribution of drugs deemed “controlled substances” by the gvt.
what schedule I drugs are used to provide anesthesia?
schedule I drugs have no currently acceptable medical use, therefore we don’t use any.
as an aside, the legalization of marijuana at the state level challenges it’s schedule I designation at the federal level
what is a schedule II drug? list some examples.
high potential for abuse potentially leading to dependence
opioid agonists
cocaine
methamphetamine
phencyclidine
what is the health information technology for economic and clinical health act (HITECH)?
intended to create a healthcare information technology infrastructure in order to improve care quality and coordination b/n providers
amendment to HIPAA, and applies to the same covered entities including providers, health plans, and healthcare clearinghouses. widened the scope of privacy and security protections available under HIPAA
detail the steps involved w/ responding to a lawsuit.
- notify insurance carrier
- do not alter records or discuss the case
- gather all records of the case
- make notes re: all aspects
- cooperate w/ insurers attorney
work w/ attorney to write an initial response to the summons
discovery: gathering of facts
written interrogatory: request for factual info and document exchange
deposition: questioning
what is an emancipated minor?
pts <18yrs old who are legally given the rights of an adult by a state court. although variable by state law, criteria for emancipating a minor may include the fact that they are:
- marrier
- a parent, or currently pregnant
- in the military
- economically independent
discuss the ethical dilemma of surgery for a child of Jehovah’s Witness.
families should be informed that, despite all reasonable efforts to eliminate need for transfusion, if emergency occurs, a court order for transfusion will be sought.
when likelihood is high, court order should be sought pre-op. in life-threatening crisis, emergency transfusion should be given prior to obtaining a court order
as these children approach maturity, they should be involved in the decision making
what is anesthesia crisis resource management?
in an anesthetic crisis, effective response and management is dependent upon non-technical skills. crisis resource management uses a simple model in which effective communication is the glue that holds all teh other components together.
resources available include all the personnel involved and their inherent knowledge, skills, and abilities. resources also include supplies, pharmaceuticals, technology, and information
list 5 complications of fatigue.
- decreased reaction time
- impaired decision making
- decreased situational awareness
- impaired concentration/memory
- periods of microsleep
what is microsleep?
an actual sleep episode that lasts seconds to minutes; it is insidious in a fatigued provider and cannot be predicted. performance b/n microsleep episodes is impaired, and errors of omission increase
what is the relationship b/n 24hrs of wakefulness and alcohol consumption?
24hrs wakefulness = 0.1% BAC
when is sleep-related behavior most common?
after 16+ hrs of continuous work
night shift
list 6 countermeasures for fatigue
napping caffeine exercise consistent sleep/wake medications recovery b/n shifts
what is the OSHA limit for occupational exposure to ionizing radiation?
annual = 5 rem
lifetime = (N-18) x5rem
- N= age in years
what are the physiologic effects of MRI exposure?
lower frequency electromagnetic fields from MRI can cause transient symptoms of nausea, dizziness, vertigo, or light flashes
what are the OSHA limits for noise exposure?
for an 8hr span = 90dB
single noise level <115dB
who is the “second victim”?
the provider
- the provider’s subsequent patients are possible “third victims”
being involved w/ a case w/ a bad outcome is one of the most significant acute stressors for an anesthesia provider
define addiction.
need (psychological or compulsive) for a substance.
there is often a loss of self-control, where the user continues using a drug despite the desire to stop drug use. This represents a severe stage of chronic substance abuse disorder.
define impairment
inability to safely participate in life (or professional) activities
define tolerance.
more drug is needed to achieve a given effect (intoxication) - or - a lesser effect is produced by a given dose of drug.
define withdrawal
characteristic syndrome that is the direct result of stopping or reducing the use of a drug
list the risk factors for developing substance use disorder.
psychological:
- anxiety/depression
- low self esteem
- low tolerance for stress
behavioral/social
- risk seeking behavior
- poor coping skills
- personal/family hx addiction
- hx trauma, abuse, stress
physical
- acute/chronic pain
workplace specific:
- production pressure
- fatigue/burnout
- irregular work hours
- poor work/life balance
anesthesia specific:
- access/availability
- access to unregulated drugs
- sensitization to the effects of drugs
what are some typical behaviors of the impaired provider?
- frequent/unexplained tardiness, absence, etc.
- poor performance
- confusion, memory loss
- mood swings, personality changes
- visibly intoxicated
- refusal of drug testing
- track marks, bloodshot eyes, significant weight loss or gain
what are the key issues regarding re-entry to clinical practice following a substance abuse disorder?
safe return is determined on an individual basis
readiness is a collaborative decision of the monitoring program, counselor, and employer. 1 full year of recovery is recommended
d/t high risk of relapse, abstinence based recovery and refraining from substitute treatments is also recommended.
of the ten criteria that should be met prior to considering re-entry, the most salient point is participation in a monitoring program at least 5yrs in length w/ random drug testing.
what should you do if you suspect a fellow anesthesia provider is impaired?
- don’t let them out of your sight
- don’t let them drive
- have a bed in a tx facility available
- don’t let the impaired person decide their treatment
- only when all else fails, threaten to call the police
what are the 6 elements of high-quality care?
patient centered safe effective timely efficient equitable
discuss cultural competence in the context of anesthesia delivery
strategy to reduce health care disparities and improve equity.
requires the anesthesia provider to:
- know and apply current standards of care
- offer and use evidence based interventions
- have a keen awareness of their own biases and assumptions
- be sensitive to the presence of health disparities and discrimination
