Midterm Flashcards
(149 cards)
1
Q
Components of the preop assessment
A
name and DOB, verify site and procedure, labs, med history, anesthetic history, education, informed consent, H&P (airway exam)
2
Q
What herbal meds increase bleeding time and when should the patient discontinue it?
A
garlic, gingko, ginseng- 7 days pre-op
3
Q
Latex allergies are common in?
A
patients with spina bifida and multiple surgeries; common to also have allergy to tropical fruits
4
Q
When should patients stop smoking before surgery and why?
A
4-8 weeks pre-op (decrease carboxyhemoglobin levels and prevent respiratory complications)- minimum 12 hours before
5
Q
What does chronic alcoholism vs acute intoxication do in regards to anesthetics?
A
chronic alcoholism increases resistance to CNS depression, whereas acute intoxication does the opposite
6
Q
components of airway evaluation
A
Mallampati (1 is best), thyromental distance 7 cm, intercisor distance 4 cm, good head and neck range of motion, good dentition, neck size
7
Q
What are the effects of general anesthesia on the respiratory system?
A
decrease FRC (up to 2 weeks), alters V/Q, inhibits ilia, decreases surfactant, increased sensitivity
8
Q
What are the high, intermediate, and low scores of STOP BANG?
A
5-8 high, 3-4 intermediate, 0-2 low
9
Q
In terms of MET scores, what’s good and bad?
A
1- bad, 4- good
10
Q
Cancel surgery if BP is over?
A
180/110
11
Q
What antihypertensives should you continue and which ones should you stop?
A
continue beta blockers, stop ACEI (day of)
12
Q
How long after an MI should you wait to have surgery?
A
60 days
13
Q
What are the considerations of patients with OA, ankylosing spondylitis, and RA?
A
limited neck mobility, may be on steroids (may need stress dose), may be on NSAIDs/ASA- bleeding
14
Q
What is an anesthetic consideration for someone with GERD?
A
may need RSI
15
Q
What lab is the most accurate reflection of renal reserve?
A
creatine clearance
16
Q
When should you delay surgery in regards to hyperkalemia?
A
over 5.5 (not absolute)
17
Q
What labs should you check if someone is in renal failure?
A
K, creat, Hgb
18
Q
Considerations about diabetics
A
stiff joint syndrome, may need Reglan (gastroparesis), may give half insulin the day of, try to do surgery in the AM to minimize fasting
19
Q
What drugs should you use in hyperthyroidism and which ones should you avoid?
A
use beta blockers, avoid anticholinergics
20
Q
What can you have within one hour of surgery?
A
meds with sip of liquid (150 mL for adults, 75 mL kids)
21
Q
What can you have within two hours of surgery?
A
clear liquids
22
Q
What can you have within 4 hours of surgery?
A
breast milk
23
Q
What can you have within 6 hours of surery?
A
infant formula, nonhuman milk, light meal
24
Q
Describe ASA classifications
A
1- normal; 2- disease w/o limitations; 3- disease w/ limitations; 4- severe dz with constant threat to life; 5- moribund, minimal chance of survival w/o surgery; 6- brain dead
25
What does the ASTM do?
makes anesthesia machine regulations about workstation and components
26
What does the FDA do?
anesthesia machine checkout, standards for gases
27
What does the DOT do
compressed gas regulations
28
What does the ICC do?
construction of cylinders
29
What does the CGA do?
sets safe practices for gas cylinders
30
What is the pressure in the breathing circuit limited to?
125 cm H20 or 12.5 kPa
31
What is the psi in each system on the ventilator?
high- 2000 psi; intermediate- 45-55 psi; low- 16 psi
32
What are the 5 tasks of oxygen?
ventilator driving gas, flush valve, O2 pressure failure alarm, O2 pressure sensor shutoff (failsafe), flowmeters
33
Describe a free floating valve
prevents gas leak- moves in direction pushed by gas
34
Describe a ball and spring valve
permits gas flow after concentration made (all or none)
35
Describe a diaphragm valve
decreases pressure (pressure regulator)
36
When should you change an O2 tank?
half full -1000 psi
37
What is the psi and L of an oxygen tank?
2000/ 660 L
38
What is the psi and L of a nitrous tank?
745 psi / 1590 L
39
What is the psi and L of an air tank?
200 psi/ 625 L
40
What is the critical temp of oxygen?
-119 C
41
What is the critical temp of nitrous?
39.5 C
42
F to C
5/9(F-32)
43
C to F
(9/5 x C) + 32
44
How often do medical cylinders need to be tested, and who sets that regulation?
every 5 years; ICC
45
Describe the Joule Thompson effect
compressed gas escapes- process is adiabatic and cooling occurs (if cylinder is opened rapidly, temperature increases rapidly- why we "crack" cylinder)
46
What are the PISS configurations of all 3 cylinders?
air- 1,5
oxygen- 2,5
nitrous- 3,5
47
What does the free floating valve of the hanger yoke do?
prevents full cylinder or pipeline from emptying into empty cylinder
48
Do the Bourdon pressure gauges measure absolute or relative pressure?
relative
49
What does the oxygen pressure failure device do, and what are its limitations?
if PRESSURE drops below 30 psi, 2nd gas turns off- only senses pressure, only prevents problems upstream
50
What does the oxygen failure alarm do?
alerts to loss of oxygen pressure (<20 psi)- audible whistle
51
What should you do if you suspect a pipeline crossover?
disconnect pipeline, turn on cylinder, use low flows, conserve O2, manually ventilate, use TIVA
52
Describe the O2 flush valve
bypasses the vaporizers, delivers 35-75 L/min of oxygen- should use only on expiration
53
Describe the design of the flowmeters
Thorpe tube- has variable orifice- specific for each gas
54
Describe laminar flow
parallel, orderly; dependent on viscosity and Pouisueille's law; Reynolds <2000
55
Describe turbulent flow
nonorderly; dependent on density and Graham's law; Reynolds <4000
56
What changes flow from laminar to turbulent?
change in direction >20 degrees, corrugated tubing, increased velocity
57
What does the hypoxic mixture prevention device do?
keeps mandatory O2 flow 50-250 ml; limits nitrous to 3x that of O2
58
what kind of breathing system is the anesthesia machine?
semi-closed
59
What is the order of efficiency from best to worst of Mapleson circuits for spontaneous ventilation?
ADCB
60
What is the order of efficiency from best to worst of Mapleson circuits for mechanical ventilation?
DBCA
61
What is the purpose of the reservoir bag and what is the characteristics of its connector?
prevents excessive pressure from getting to the patient- 22 mm female connector
62
If you turn the APL clockwise, what are you doing?
increasing limiting pressure
63
CO2 absorbers are a ? neutralizing a ?
base; acid
64
How much CO2 is absorbed with NaOH?
26 L per 100 g
65
What is the product of the first absorber reaction?
carbonic anhydrase
66
Is the second absorber reaction fast or slow? And what are its products?
fast- water and heat
67
Is the third absorber reaction fast or slow?
slow
68
Compare soda lime to calcium hydroxide
soda lime absorbs more CO2 and forms more compound A and CO; whereas CaOH produces less but absorbs less CO2 (only 10.6 L perr 100 g)
69
What is the mesh size of CO2 absorber granules?
4-8
70
What is compound A formed from, and what is it toxic to?
sevo; kidneys
71
What is carbon monoxide formed from?
des, iso, enflurane
72
How do you reduce the amount of Compound A made?
use at least 2 L/min FGF, lower concentrations of sevo, fresh CO2 absorber
73
What are some signs of CO2 absorber exhaustion?
hypercarbia, acidosis, inreased RR, SNS discharge, dysrhythmias
74
What does vapor pressure depend on?
temperature- if you add heat, more molecules enter vapor phase
75
Difference between flow over and draw over vaporization methods?
flowover- stream passes over liquid; draw over uses patient breath
76
How do the variable bypass vaporizers compensate for changes in temperature?
bimetallic strip (opens more when cold, closes more when hot)
77
Which way do the vaporizer knobs turn?
counter clockwise
78
What prevents using more than 1 agent at a time?
interlock system
79
What is the Tec 6 heated and pressurized at?
39 degrees and 2 atm/1300 psi
80
What did we add to the machine that minimizes the risk of incorrect concentrations of gases?
gas analyzer
81
What would happen if you put sevo in an iso vaporizer?
lower output (and vice versa)
82
What would happen if you put iso in a halothane vaporizer?
nothing- similar VP
83
Does the Tec 6 compensate for changes in altitude?
no
84
What bellows is better?
ascending- shows disconnect
85
What happens with a leak in the bellows?
increased FiO2, barotrauma
86
Which drive mechanism is more likely to have FGF decoupling?
piston
87
How do you calculate TV if your ventilator does not have decoupling and does not compensate for compliance?
(TV+FGF) - compliance
88
How do you calculate compliance?
compliance x PIP
89
How do you calculate FGF per breath?
FGF divided by I:E ratio divided by RR
90
Should you use a cylinder for your driving gas?
no
91
Describe volume control
delivers preset TV, time initiated
92
In VC, what do plateau pressure and PIP reflect?
plateau pressure- compliance; PIP- resistance
93
Describe pressure control
Delivers programmed pressure- TV variable- may need to alter I:E ratio
94
What ventilation method is good for emergence?
SIMV
95
What are advantages and disadvantages of the non-diverting gas monitor?
advantages- fast, no scavenging needed; disadvantages- circuit weight, increased DS, needed cleaning, only measured O2 and CO2
96
Describe diverting gas analyzers
siphons 50-250 ml/min of gas up to main unit- requires zero calibration, but needs scavenging and has a greater difference between PaCO2 and EtCO2
97
Does infrared analysis measure O2?
no- measures CO, nitrous, and halogenated agents
98
What part of the machine uses paramagnetic O2 analysis?
O2 analyzer- O2 is the only paramagnetic gas
99
What should you be able to do with the suction catheter?
occlude and hold at waist height
100
What are some hazards of suctioning?
hypoxemia (avoid during stage 2), trauma, infection, increased ICP, negative pressure pulmonary edema
101
Electrical currents usually not perceived if less than...
1 mA
102
What is the threshold for electrical current with and without skin?
skin- 100 mA; without- 100 microA
103
Why are ORs ungrounded?
does not allow for completed circuit through which equipment may be grounded
104
When does the line isolation monitor alarm?
2-5 mA
105
What could be some causes of hypoxia?
short gas supply, O2 leak, air entrapment
106
What could be some causes of hypoventilation?
disconnection, supply issues, leaks, increased scavenger suction
107
What could be some causes of hypercarbia?
absorbent failure, unidirectional valve problem, coaxial leak, increased dead space
108
What could be some causes of high airway pressure?
spill valve or APL malfunction, plastic left on, O2 flush valve
109
What could be some causes of anesthetic agent overdose?
tipped vaporizer, transfilled, overfilled, failed interlock
110
What could be some causes of inadequate anesthetic delivery?
entrapment, faulty vaporizer, empty vaporizer
111
What is the most important part of the scavenging system?
interface- protects patient from positive or negative pressure from scavenging
112
In a closed scavenging system, when do the positive and negative P valves open?
positive- 5 cmH2O
| negative- -0.25 cmH2O
113
What should your reservoir bag look like in the scavenging system?
partially filled
114
What are the allowable trace gas levels?
nitrous- 25 ppm
halogenated agents- 2 ppm
both- nitrous 25/halogenated 0.5
115
Oxyhemoglobin absorbs more ? light and deoxygenated Hgb absorbs more ?
infrared; red
116
What is the "law" of pulse oximetry?
Beer Lambert
117
Is pulse oximetry in real time?
no- 15 second delay
118
What are some things that could cause a false higher SpO2 reading?
carboxyhemoglobin and methemoglobin
119
What can cause methemoglobin?
congenital issues or acquired (nitrobenzenes)
120
What is the treatment of methemoglobinemia?
methylene blue
121
Hgb has ? x affinity for CO than O2
200
122
What population has a normal 5-6% level of carboxyhemoglobin?
smokers
123
What drugs cause a transient decrease in SpO2?
methylene blue, indigo carmine
124
What is oxygraphy used for?
measure preoxygenation efficiency
125
What is the normal FiO2 and FeO2
21% and 16%
126
Describe phases of capnography
1- inspiratory baseline
2- expiratory upstroke
3- expiratory plateau- uneven emptying
4- inspiration
127
normal alpha and beta angle
100-110; 90
128
What is the dividing point between the upper and lower airway?
cricoid cartilage
129
At what cervical levels are the hyoid, thyroid, and cricoid cartilages?
C3; C4-5; C6
130
What nerves innervate the muscles of the larynx, pharynx, and soft palate?
vagus, glossopharyngeal, and spinal accessory
131
What innervates all muscles that move the VC, (except for the cricothyroid muscle)?
RLN
132
What innervates the motor function of the cricothyroid muscle?
external branch of SLN
133
What innervates the sensory portion of the larynx above the vocal cords?
internal laryngeal nerve (branch of the SLN)
134
What innervates the sensory portion of the larynx below the vocal cords?
RLN
135
What are the RLN and SLN branches of?
vagus nerve
136
What does the R RLN wrap around?
brachiocephalic artery
137
What does the L RLN wrap around
aorta
138
Describe RLN and SLN injury
SLN and unilateral RLN damage causes hoarsness, whereas bilateral RLN damage causes stridor
139
What does the only motor branch of the glossopharyngeal nerve innervate?
stylopharyngeus
140
What arteries supply blood to larynx?
SLN- branch of superior thyroid artery; RLN- branch of inferior thyroid artery
141
Which muscles pull the pharynx down?
omohyoid, sternohyoid, sternothyroid
142
How many cartilagenous rings make up the trachea?
16-20
143
What are the "false" vocal cords?
vestibular folds
144
What abducts the vocal cords?
posterior criocoarytenoids
145
What adducts the vocal cords?
lateral thyroarytenoids
146
What is the only intrinsic muscle not innervated by the RLN, and what is it innervated by?
cricothyroid- external laryngeal branch of X
147
What innervates the diaphragm
C3-5- phrenic nerves
148
What are some signs of correct ETT placement?
bilateral breath sounds and chest rise, positive end tidal CO2, O2 sat, tube condensation, CXR, blood gas
149
What are some techniques for airway management?
head tilt (leave pillow), jaw thrust, Sellicks (cricoid pressure), RSI
