Basic Flashcards
1
Q
C6
A
Chassaignac tubercle
2
Q
C7
A
Vertebra prominens, level of stellate ganglion
3
Q
T1-T4
A
Cardioaccelerator fibers
4
Q
T3
A
Axilla
5
Q
T4
A
Nipple Line
6
Q
T7
A
Xiphoid process
7
Q
T8
A
Inferior border of scapula
8
Q
T9-L2
A
Origin of artery of Adamkiewicz in 85% of patients
9
Q
T10
A
Umbilicus
10
Q
T12-L4
A
Lumbar PLexus
11
Q
L1
A
Level of celiac plexus
12
Q
L2
A
Termination of spinal cord (adults)
13
Q
L3
A
Termination of spinal cord (pediatrics)
14
Q
L4
A
Iliac crest
15
Q
L4-S3
A
Sacral plexus
16
Q
S2
A
PSIS, termination of subarachnoid space (adults)
17
Q
S3
A
Termination of subarachnoid space (pediatrics)
18
Q
Absolute pressure
A
Gauge pressure + atmospheric pressure
19
Q
1 atm =
A
760 mm Hg, 988 cm H2O, 14.7 psi
20
Q
pipe line pressure vs E cylinder
A
55 vs 45
21
Q
Full E cylinder of O2
A
660 L (roughly 2000 psi)
22
Q
Nitrous oxide E cylinder
A
mixture of gas and liquid, Cannot tell amount left based on guage. 20% left when gauge starts to fall. Have to weigh to accurate measurement
23
Q
Flow of fluid in a tube
A
Flow = velocity X radius^2
24
Q
Reynolds number (point at which transition from laminar flow to turbulent flow)
A
= (density X velocity X diameter)/ viscosity
laminar < 2000, mixture 4000 < turbulent
25
Hagen Poiseuille (laminar flow)
```
Q= Delta P X pie X radius^4/ 8 Viscosity X length or
Q = Delta P/ R
R= 8 viscosity X Length/ Pie R ^4
```
26
Venturi effect
When a fluid passes through a tube with constriction the lateral pressure exerted by the fluid drops because of the increase in velocity
27
Coanda effect
Due to high velocity and low pressure and constrictions fluid may adhere to one surface of the constriction causing maldistribution of flow
28
ultrasound frequency
> 20,000Hz
29
Relationship of US frequency
higher the frequency the increased resolution with decreased penetration
30
Local anesthestic absorption rates
intravenous > tracheal > intercostal > caudal > paracervical > epidural > brachial plexus > sciatic/femoral > subcutaneous
31
Daltons law
P total = P1+ P2 +P3 ....
32
Ideal Gas law
PV=nRT
| R= gas constant= 0.82 atm /mol K
33
Charles Law
V1/T1=V2/T2
| King Charles under constant pressure to rule
34
Boyles Law
P1V1= P2V2
| Water Boyles at a constant T
35
Gay Lussac
P1/T1=P2/T2
| Gay Volume
36
alveolar gas equation
PaO2= FiO2 X (Patm-P H20) - (PaCo2/RER)
P H20=47
RER= 0.8
37
Henrys law
C=kP
| concentration = K(solubility) X partial pressure
38
Flow rates in vaporizers
decreased output at very low and very high
low= no turbulence to pick up gas
high= incomplete mixing
39
Desflurane vaporizer
Desflurane boils are room temperature. Specific vaporizer was developed which is heated to 39 C. Not pressure compensated so at high altitude the partial pressure will decrease. Also if carrier gas is not 100% O2 then at low flows will be less than expected.
Required dial setting = desired % x (760* mm Hg / current atmospheric pressure mm Hg)
40
Relationship of solubility within a liquid vs gas partial pressures
Inversely related
41
Factors affecting Aveloar concentration(FA)
1) delivery into the lungs (alveolar ventilation, inspired concentration FI)
2) uptake of agent by the blood (solubility, cardiac output, Aa anesthetic partial pressure gradient)
42
Tissue groups (uptake of volatile)
1) vessel rich: heart, brain, splanchnic, liver; 75% of cardiac output ( near complete saturation in 4-8 minutes)
2) muscle group (and skin): receives 20% cardiac output 2-4 hours for saturation
3) fat group: poorly perfused but great affinity for anesthestics
43
Fa/Fi ratio graph
highest to lowest: nitrous oxide, desflurane, sevoflurane, isoflurane, halothane, methoxyflurane
44
metabolic derangement with diuretics
loop and thiazaide= hyperchloremic hypokalemic metabolic alkalosis
k sparing+ hypochloremic metabolic acidosis
45
Respiratory alkalosis electrolyte derangement
hypocalcemia, hypokalemia, hypophosphtemia
46
Which abx can potentiate neuromuscular blocking
aminoglycosides, polymyxins, tetracyclines, lincomycin, and clindamycin
47
Para vs sympathetic nervous system for bronchoconstriction
parasympathetic
48
relationship of lung volume and PVR
PVR highest at extremes; residual volume and total lung capacity
49
MELD score
serum creatinine, bilirubin, INR, sodium
| MELD: "I Crush Several Beers Daily" for INR, creatinine, sodium, bilirubin, dialysis
50
Child-Pughs
"Pour Another Beer At Eleven" for PT, Ascites, Bilirubin, Albumin, Encephalopathy
51
lab test to monitor enoxaparin
Factor Xa activity
52
signs of PrIS (propofol infusion syndrome)
metabolic lactic acidosis, cardiac failure, renal failure, rhabdomyolysis, hyperkalemia, hypertriglyceridemia, hepatomegaly, and pancreatitis.
53
highest blood product for risk of infection
platelets
54
meperidine can potentiate what?
Seratonin syndrome if other drug on board.
| Libby Zion
55
chronic opioid effect on hormones
increased prolactin levels, and decreased testosterone, estrogen, cortisol, LH, and FSH
56
Succinylcholine effect on esophageal sphincters
decrease upper and increase lower tone.
57
FFP dose for warfarin revesal
typically 10-15 mL/kg which attains a goal factor activity level of 30-40% in most patients
58
side effects of glycopyrrolate
Glycopyrrolate delays gastric emptying, decreases salivary and gastric secretions, increases heart rate, relaxes bronchial smooth muscle, decreases lower esophageal sphincter tone, and causes urinary retention
59
myxedema coma
Myxedema coma is an extreme form of hypothyroidism that generally occurs in patients with chronic, severe, and/or poorly treated hypothyroidism, or hypothyroidism in the setting of a physiologic stressor (infection, trauma, exposure to cold, MI, etc). Key features of myxedema coma are altered mental status (ranging from confusion to coma), non-pitting edema, and hypothermia. Other symptoms that can be present include constipation, dry skin, bradycardia, and hypotension.
60
Concentration effect
Increasing the Fi of an inhalation anesthetic will more rapidly increase the FA of that agent.
80% NO vs 20%; if 50% is absorbed then 40/60 vs 10/90 is a 6 fold increase not the initial 4 fold. Due to increase concentration from the increased Fi. Additionally the amount absorbed is replaced with a high concentration from the original Fi
61
Second gas effect
Addition of NO will increase the rate at which the volatile FA approaches the Fi.
62
Nitrous Oxide
- second gas effect
-0.47 blood partition coefficient= fast on fast off
sympathomimetic = increased CO and SVR
-does not inhibit hypoxic pulm vasoconstriction
- does not cause uterine relaxation or muscle relaxation
-mild analgesic
-megaloblastic anemia ( oxidize cobalt atom in VitB12 stopping b12 dependent enzymes)
-expands gases
-PONV
63
Nitrous expansion
NO is about 30 times more soluble in blood than nitrogen
- highly blood soluble NO is brought to the space faster than the poorly soluble N2 can be carried away from the space
- volume of expansion depends on time and Fi
Contraindicated: intestinal obstruction, Pneumo, VAE, COPD (bleps), laparoscopy, intraocular air, tympanoplasty/middle ear surgeries, penumocephalus,
Check your ETT cuff
64
Intraocular air
- sulfur hexafluoride (SF6) ; expands 2.5 times in eye, stays 10-14 days
- perfluoropropane (C3F8); expands 4 times stays 60 days
- should be cleared by ophtho after bubble is gone
65
Absorbers
Allow for a closed system
- H20 and heat are a byproduct = benefit
- smaller granules can absorb more but have increased resistance
- dry granules can cause CO and high temp = fire risk
- Sevo compound A
- Amsorb is calcium hydroxide lime which minimized compound A and CO
66
Fresh gas entry
between absorber and inspiratory valve
67
pressure fail safe
detects if O2 pressure falls too low ( usually 30 psi) and alarms
68
Rotameters/ flometers
- measure flow; glass tube with increasing diameter
- bobbin or ball rides the gas jet, which stabilizes at correct height due to the annulus (space around the item)
- bobbins have grooves to rotate
- tube is calibrated for specific gas
- viscocity is important in low flow/ density in high
- affects by temp (minimally) and altitude (higher the altitude the more falsely low the reading will be)
69
O2 and N2O proportioning devices
Connection between the two to prevent hypoxic gas flow.
| - 14 tooth gear (N2O) connected to 29 teeth gear (O2) to maintain 25% or higher
70
Acoustic Impedance
product of the density of the medium and the propagation speed of sound through that medium
71
Chloroprocaines rapid onset time due to
concentration
72
EMLA cream contraindications
- Allergy to amide anesthetics
- Concomitant class III anti-arrhythmic drugs
- Congenital or idiopathic methemoglobinemia or G6PD deficiency
- Infants (< 12 months) receiving treatment with methemoglobin-inducing agents
73
Hemophilia A vs B vs C
Factor VIII, Factor IX, Factor XI
74
Metaclopramide
- derives its anti-nausea effect from antagonizing dopamine in the chemoreceptor trigger zone in the CNS
- accelerated gastric emptying, reduced gastric fluid volume, increased tone and amplitude of gastric contractions, and enhanced peristalsis of the duodenum and jejunum.
- It causes relaxation of the pyloric sphincter, however increases lower esophageal sphincter tone. It has no effect on gastric pH.
75
Eccrine sweat gland innervation
synpathetic preganglion-> nicotonic recepter ->sympathetic post ganglion -> muscarinic
76
BBB
- small lipophilic molecules diffuse through, <500 Da
| - glucose through transporter
77
Clonidine
Clonidine is a selective alpha-2 adrenergic agonist with an affinity ratio of 220:1 for the alpha-2 receptor compared to the alpha-1 receptor
- rebound HTN in 12-60 hours
- decreased MAC
- decrease PONV and shivering post op
78
Soda Lime
-silica added to make granules more hard
-NaOH is what absorbs O2
-
79
Ambsorb
- less capacity than Soda Lime
| - No alkali agents like NaOH and KOH = less risk of compound A or CO
80
Baralyme
withdrawn due to risk of fires
81
Absorbent granules
balance of size ( smaller = better absorber but increased resistance)
- Channeling can occur (path of least resistance)
82
absorbed dessication
- gets dried out
- increase risk of CO and heat production (Des > Enflurane > iso>> halthothan =sevo)
- more likely in absorbers with strong base
- Monday morning CO poisoning
83
Fire in absorber (risks)
Sevo
baralyme
granule dessication
84
Nasal Cannula
- 1-6 L/min (anything above doesnt do anything)
- FiO2 increased 4% each L
- FiO2 varies with minute ventilation
- HFNC: warms and humidifies: can go above 6
85
Face Masks
- flow of at least 5L/min
- Simple 35-60%
- non rebreather 60-90%
- Partial non rebreather 60-80%
86
Venturi Mask
mixes room air and O2 to assure FiO2
| 24-50%
87
Meperidine
- works on kappa (and mu) opioid recepter
- metabolite normeperidine is a proconvulsant
- structure is similar to atropine = increased heart rate
88
Uremia
causes platelet dysfunction
89
Factors that decrease Ach release
1) Antibiotics (clindamycin, polymyxin)
2) Magnesium: antagonizes calcium
3) Hypocalcemia
4) Anticonvulsants
5) Diuretics (furosemide)
6) Eaton-Lambert syndrome: inhibits P-type calcium channels
7) Botulinum toxin: inhibits SNARE proteins
90
Apneic window calculations
Oxygen consumption in an adult is 3-4 mL/kg/min and functional residual capacity (FRC) is 30 mL/kg
-Minutes until hypoxemia = [FRC (ml) ÷ O2 consumption (mL/min)] * %O2 in FRC
91
Side effects of zofran
```
QTc prolongation (20%)
Headache (11%)
Transient increases in AST and ALT (5%)
Constipation (4%)
Rash (1%)
Flushing / warmth (< 1%)
Dizziness (< 1%)
```
92
Radiation exposure
I = S / (4 * π * r^2)
or
I ∝ 1 / r^2
Where: I = intensity, S = source strength, r = radius (distance from source)
93
time constant
- time constant (t) is calculated by dividing the volume or capacity of the circuit (Vc) by the fresh gas flow (FGF).
- 63%, 84%, 95%, and 99% of equilibrium will be reached after 1, 2, 3, and 4 time constants, respectively
94
Flumazenil
benzo reversal. Shorter duration of action than all clinically used benzos (will have to redose to prevent recrudescence)
95
Which opioid doesn't cause sphincter of Oddi spams
Butorphanol, unlike most opioids, does not cause biliary spasm as it does not cause sufficient sphincter of Oddi contraction to increase pressure in the common bile duct.
96
Post op delerium treatment secondary to scopolamine
Physostigmine: penetrates CNS
97
Modified Cormack lehane
Grade 1 Full view of the glottis
Grade 2a Partial view of the glottis
Grade 2b Only the posterior arytenoids and the epiglottis are visible
Grade 3 Only epiglottis is visible
Grade 4 Neither the glottis nor the epiglottis are visible
98
SVR
SVR = 80 * (MAP - RAP) / CO
99
Train of 4
- 4 stimuli at 2 Hz .5 seconds apart
- 75% fade when 80% of receptors blocked
- No TOF4 = 80% blocked
- No TOF3 = 85%
- No TOF2= 90%
- .9 ratio means adequate reversal
- can't detect fade greater than 0.4
100
Sustained tetnus
indicates TOF greater than 0.7
101
Double burst
- better tactile feel
- two burst fired 750 ms apart
- can detect fade up to 0.6
102
Dynamic PV curve vs static
Dynamic is constructed during gas flow while static is not
103
Dynamic effective compliance
= (Ppeak-PEEP)/delivered TV
| -takes airway and circuit resistance into account
104
Static effective compliance
=(Pplateau-PEEP)/delivered TV
| -influenced by chest wall and alveolar elastic recoil
105
Elastic pressure
P plateau- PEEP
106
Heat loss in OR
- mainly due to redistribution initially then;
1) radiation
convection, conduction and evaporation
- typical loss is 0.5-1.5 C 30 minutes from induction
107
4 core T sites
- pulmonary artery
- distal esophagus
- nasopharyngeal
- tympanic membrane
108
Calculate pulse ox
Ratio of red (660 nm) to infrared (940 nm)
- uses pulsatile portions to zero out none flowing times; acts as own zero
Ratio of 1 = 85% (.4 = 100% and 3.4 = 0%)
109
Erroneous pulse ox
- MetHb = absorbed at same rate = ratio of 1 = 85%
- CoHb = falsely high
- low readings= hypothermia, vasoconstriction, ambient light, red or dark nail polish, methelyne blue > indocyanine green > indigo carmine, anemia < 10
- doesn't effect; flourecien, hyperbilirubinemia, fetal hemoglobin,
110
NMB not to use with renal failure
pancuronium
111
Respiratory failure 2/2 to hypermagnesium
15-20 mg/dL
112
Blood Gas value calculated
bicarb
113
Blood gas
pH: 7.35-7.45
Partial pressure of oxygen (PaO2): 75 to 100 mmHg
Partial pressure of carbon dioxide (PaCO2): 35-45 mmHg
Bicarbonate (HCO3): 22-26 mEq/L
Oxygen saturation (O2 Sat): 94-100%
114
pH stat
During pH-stat acid-base management, the patient’s pH is maintained at a constant level by managing pH at the patient’s temperature. pH-stat pH management is temperature-corrected. Compared to alpha-stat, pH stat (which aims for a pCO2 of 40 and pH of 7.40 at the patient’s actual temperature) leads to higher pCO2 (respiratory acidosis), and increased cerebral blood flow. Often CO2 is deliberately added to maintain a pCO2 of 40 mm Hg during hypothermia.
115
Alpha stat
During alpha-stat acid-base management, the ionization state of histidine is maintained by managing a standardized pH (measured at 37C). Alpha-stat pH management is not temperature-corrected – as the patient’s temperature falls, the partial pressure of CO2 decreases (and solubility increases), thus a hypothermic patient with a pH of 7.40 and a pCO2 of 40 (measured at 37C) will, in reality, have a lower pCO2 (because partial pressure of CO2 is lower), and this will manifest as a relative respiratory alkalosis coupled with decreased cerebral blood flow. During alpha-stat management you have no idea what the patient’s pCO2 is, your goal is to maintain a constant dissociation state of histidine.
116
change in temp vs pH
every 1 degree celcius drop the pH will increase by 0.015
117
Polarographic O2 analyzer (clark electrode)
gold or platinum cathode with silver anode
| -needs small voltage applied to two electrodes
118
Galvanic O2 analyzer
lead anode and gold cathode bathed in KCl
| -expose to RA when not in use
119
Paramagnetic O2 analyzer
plots O2 concentrations continuously
120
O2, CO2 and pH measurement
pO2 is measured via the Clark electrode (as per above)
pCO2 is measured via the Severinghouse electrode
pH is measured via the Sanz electrode
121
Raman scattering
- intense beam of laser light into gas sample
- this cause unstable vibrational and rational energy states which causes photons to change and emerge at various wavelengths
- light is collected through monochromator and the Rayleigh scattering is filtered out and the rest is dispersed on a detector.
122
Piezoelectric gas analysis
- uses oscillating quartz crystals, one of which is covered in a lipid
- volatile anesthetics dissolve in the lipid layer and change frequency of oscillations
123
Damage to the preoptic anterior hypothalamus
can impair thermoregulation and temperature homeostasis
124
pre renal oliguria
A urine-to-plasma osmolar ratio (UOSM : POSM) >1.5
125
epidural with morphine
increased risk of nausea and vomitting compared to more lipophilic opioids (fentanyl)
126
endobronchial intubation vs speed of induction
One-lung ventilation (OLV) creates a right to left pulmonary shunt, which has the greatest effect on the less soluble inhalational anesthetics, such as desflurane
127
highest infection rate with blood transfusions
CMV
128
amnesia with versed
anterograde
129
Aspirin MOA
- Aspirin inhibits the enzyme cyclooxygenase (COX). COX mediates the biotransformation of arachidonic acid into three eicosanoid compounds: prostaglandin, prostacyclin, and thromboxane.
- Aspirin inhibits platelet aggregation by blocking thromboxane
130
Transducer
any device that converts energy from one for to another
131
Wheatstone bridge
several strain gauges (electrical resistance of a wire increased as it extends)
-movement of the diaphragm stretches or compresses several wires and alters the resistance
132
Resonance vs Dampening
Resonance is amplification of the signal
-dampening is a decrease of signal amplitude (2 way stop cocks, clots, arterial vasospasm, large catheter size, narrow long of compliant tubing)
133
pressure vs height
7.4 mm Hg for every 10 cm
134
dexmedetomidine
Alpha 2 adrenergic agonist
- reduce incidence of perioperative myocardial ischemia
- provides sedation, anxiolysis, hypnosis, analgesia, and sympatholysis. Dexmedetomidine decreases heart rate (HR) and systemic vascular resistance (SVR) and indirectly decreases cardiac output (CO), systemic blood pressure (SBP), and myocardial contractility.
- minimal respiratory depression
135
precedex vs clonidine alpha ratio
dexmedetomidine (α2:α1 = 1600:1) than clonidine (α2:α1 = 200:1)
136
PaCO2 vs CBF
CBF changes 1-2 mL/100 g/min per every 1 mmHg change in PaCO2
137
Power
1- type 2 error
| Type II or β error = incorrectly accepting Ho (false negative)
138
Increase MAC
Hyperthermia, hypernatremia, chronic ethanol abuse, and increased central neurotransmitter levels (e.g. MAOIs, amphetamine, cocaine, ephedrine, and levodopa use)
-gingers
139
abx ppx for dental
- prosthetic cardiac valves
- history of infective endocarditis
- unrepaired cyanotic congenital heart disease (CHD),
- completely repaired congenital heart defect during the first 6 months after the procedure,
- repaired CHD with residual defects at or adjacent to the site of prosthetic material,
- cardiac transplantation recipients with cardiac valvular disease
140
single best choice for hepatic protein synthesis function
coag factors
141
cushing triad
HTN, bradycardia, respiratory changes
142
Perioperative blood salvage
- contraindicated if pus, feces, amniotic fluid contamination or certain types of malignant cell exposure
- complication is incomplete blood filtration
- coagulopathy can occur because only RBC are transfused back (platelets and clotting factor is removed)
143
1L of room temp crystalloid decreases temp by
.25 C
144
Standard error of mean
SEM = σ/√n
145
Depth of MAC
Minimal: Normal response to verbal stimulation
Mod: Purposeful response to verbal or tactile stimulation Deep: Purposeful response after repeated or painful stimulation
GA: Unarousable with painful stimulus
146
adverse outcome related to anesthesia equipment
misuse of equipment
147
Addition of bicard to LA
- can cause precipitation with bupic and ropiv
148
MOA of LA
act on the cytoplasmic side of voltage-gated sodium channels in nerves. Therefore, the local anesthetic must pass through the cellular membrane to reach its target. To travel through the nerve membrane the local anesthetic needs to be in the unionized form. When the pH of a solution is less than the pKa the molecule will be ionized. When the pH of a solution is equal to the pKa, 50% of the molecules will be ionized and 50% will be unionized.
149
extrapyramidal symptoms in PACU
- most likely from antidopimenergic drugs for PONV - droperidol, metaclopramide, prochlorperazine
- treat with anticholinergics (benztropine) or diphenhydramine
150
Hoffman elimination
- atracurium
| - pH- and temperature-dependent reaction that proceeds more readily when pH and temperature are increased
151
thiopental termination
- bolus from redistribution
| - infusion ; become dependent on hepatic metabolism (side chain oxidation)
152
work up for non cardiac surgery ( concern fro major adverse cardiac event MACE)
if > 4 mets and asymptomatic then no additional workup is needed
153
nail polish pulse ox
Blue, green, and to a lesser extent, black nail polish cause falsely low oxygen saturations to be displayed by standard two-wave pulse oximeters by interfering with the differential absorption of 660 and 940 nm light
- red nail polish does not interfere as much
154
hypercalcemia vs paralytics
-antaganize the effects of NDMB; need a higher dose
155
repeat dose of sux
-After a second dose of succinylcholine the patient is likely to develop bradycardia Bradycardia often occurs in children after they receive succinylcholine because of the activation of muscarinic receptors at the sinoatrial node, along with a high baseline vagal tone
156
Functional Residual Capacity (FRC)
- increases with height and age
- decreased with obesity, short, female,
- decreased PANGOS: Pregnancy, Ascites, Neonatal, General anesthesia, Obesity, Supine position.
157
Termination of action potential
Termination of the action potential occurs primarily via two mechanisms. First, the voltage-gated sodium channels terminate their positive feedback by self-inactivation within milliseconds of opening. Inactivated sodium channels do not allow further sodium ion influx despite a still depolarized membrane. Second, both voltage-gated and voltage-independent potassium channels open in response to depolarization and allow potassium efflux out the cell. Combined, these effects result in neuron membrane repolarization back towards the resting potential. During this time, the sodium channels transition from an inactivated state (unable to potentiate an action potential) to a closed state (ready to open upon threshold stimulation). However, the potassium channels are slower to close than the sodium channels and overshoot the repolarization, causing a brief period of hyperpolarization. The cell membrane returns to its resting potential due to numerous other ion channels/pumps, namely the sodium-potassium-ATPase
158
Ventilation and K
Hypoventilation causes hyperkalemia
159
Increases EtCO2
```
Malignant hyperthermia
Hyperthermia
Hyperthyroidism
Hypoventilation
Rebreathing
Sepsis
Shivering
```
160
Decreases EtCO2
```
Disconnect from or loose sampling line
Malpositioned endotracheal tube
Hyperventilation
Hypoperfusion (hypotension, cardiac arrest)
Hypothermia
Hypothyroidism
Pulmonary embolism
```
161
Fluid in body
```
Total body water = 60% body weight
Intracellular = 40% body weight
Extra cellular = 20% body weight
- Interstitial fluid volume 75-80% of extracellular
- PLamsa 20-25% of extracellular
```
162
largest concentration for flouride ions upon metabolism
methoxyflurane (off market)
methoxyflurane > sevoflurane > enflurane > isoflurane > desflurane
- flouride induced nephrotoxicity
163
Efficacy vs potency
Efficacy is the maximum effect of a drug. It does not depend on dose. Potency is the relative dose required to achieve a given effect and is related to receptor affinity.
164
BEta blocks vs asthmsa
Beta blockers can potentiat bronchospasm in pt with asthma
165
EKG leads that are sensative
2: arrythmia
V5: ischemia
166
OR fire
1) oxidizer: O2, N2O
2) Ingition source: cautery, lazers, argon beams, fiber optic cables, defibrillators
3) fuel source: drapes, laps, etoh swabs, caps gowns, tubes
167
Line Isolation Monitor
- ungrounded
- protects from electrocution by power isolation and continuous monitoring of the isolated power sytem
- alarm at 2-5 mA (does not protect against microshock)
168
Air exchange in OR
2 ppm for halogenated gas
| or 0.5 halogenated gas with 25 ppm N20
169
Sucessfull defibrilation
when ventricular fibrilation has terminated for at least 5 seconds. Even if postshock rhythm is nonperfusing or hemodynamically unstable
170
unshockable rhythms
PEA, asystole
171
monophasic charge vs biphasic
360 vs 120 for biphasic retiliniar, 150-200 for biphasic truncated exponential (200 if unknown)
172
Ohms Law
Voltage =Current X Resistance
| V= I X R
173
Maximum allowable blood loss
```
ABL= [EBV x (Hi-Hf)]/Hi
EBV =Premature Neonates 95 mL/kg
Full Term Neonates 85 mL/kg
Infants 80 mL/kg
Adult Men 75 mL/kg
Adult Women 65 mL/kg
```
174
Variables
catagorical: values that functions as labels rather than as numbers
Continuous: numeric values where the relative magnitude is significant
175
Incidence
incidence= number of new cases/ population at risk
176
Prevalence
prevalence= number of cases at a given time/population at risk at a given time
177
Cohort
- prospective
- identifies patients based on the presence or absence of risk factors and follows them through time
- expensive, time consuming, need many patients
- less susceptible to bias= true incidence
178
Case control
- retrospective
| - compares the proportions of patients with various exposures in a group pf patients with a disease to a group without
179
2 X 2 stats box
Diesase on top, Test on Left
A B
C D
180
Relative risk
measure of the association between exposure and outcome in a cohort study
= {A/(A+B)} / {C/(C+D)}
181
odds ratio
=AD/BC
182
Sensitive
-ability of test to give a positive result when the patient actually has the disease
= A / (A+C)
183
Specificity
ability to give a negative finding when the patient does not have the disease
= D / (D+B)
184
Errors
type 1 = False positive, rejecting the null hypothesis when it is true
type 2= False negative, accepting the null when it is false
185
Chi squared
- categorical variables
| - compares distribution of test results with normal distribution to evaluate independence
186
T-test
- continuous variables
- compares the means of two populations
- useful with small samples
187
ANOVA
- continuous variables
| - compares the means of multiple groups
188
Glucagon
- causes glucose to mobilize to blood stream
- increase gluconeogensesis, glyucogenolysis, and fatty acid break down
- Glucagon activates adenylyl cyclase to increase cyclic AMP levels, leading to a positive inotropic and chronotropic cardiac response.
- single-chain peptide hormone, synthesized and secreted by the alpha cells of the pancreas
- Glucagon activates G-protein coupled receptors, which stimulates adenylyl cyclase production leading to increased cAMP
189
predictor of difficult intubation
1) Relatively long incisors
2) Prominent “overbite”
3) Patient cannot bring mandibular incisors anterior to maxillary incisors
4) Less than 3 cm interincisor distance
5) Uvula is not visible when tongue is protruded with patient in sitting position
6) Highly arched or very narrow palate
7) Mandibular space that is stiff, indurated or occupied by a mass
8) Less than three ordinary finger breadth thyromental distance
9) Short neck length
10) Thick neck circumference
11) Decreased extension or flexion of the neck
190
Fresh frozen plasma indication
Correction of excessive microvascular bleeding (PT >1.5 times normal, PTT >2 times normal, or INR >2)
Correction of coagulation factor deficiencies if the patient has been transfused with more than one blood volume (approximately 70 ml/kg)
Urgent reversal of warfarin therapy (prothrombin complex concentrate is another option)
Correction of coagulation factor deficiencies for which there are no specific replacements
Heparin resistance (antithrombin III deficiency) in a patient requiring heparin
191
fospropol
- propofol pro drug
- paresthesia > 50%
- burning, tingling, and/or stinging sensations and usually occur in the perianal or genital regions
192
Volatile concentration equations
- Saturated vapor pressure/ total pressure (usually atmospheric) = agent vapor volume / carrier gas volume + agent vapor volume
- Va= SVP X Vc / Ptotal - SVP
- % volatile = Va / FGF +Va X 100
193
Single lung transplant and COPD
double peaked appearance on capnography
194
Cyclopentolate
topical anticholinergic drug used to induce mydriasis (i.e. mydriatic drug) for ocular procedures. Systemic absorption can occur and lead to central nervous system signs and symptoms of anticholinergic toxicity.
195
Increase power
Power= ability to detect a difference
1) Increase alpha: the smaller the alpha, the greater the chance of a false-negative conclusion (risky, as this increases type I error).
2) Decrease population variability (difficult to control).
3) Increase the sample size.
4) Make the difference between the conditions greater (most important factor in decreasing a type II error but difficult to control/manipulate)
196
Zero order medications
any drug can reach this when they overwhelm max amount of enzymes
- set amount is eliminated per unit of time
- not dependent on liver blood flow
- THE PAW: theophylline, heparin, ethanol, phenytoin, aspirin, warfarin.
197
natural licorice
hyperaldosterone-like effects including: hypokalemia, hypertension, hypernatremia, fluid overload, and metabolic alkalosis.
198
thyroid hormone binding ratio
increased in hyperthyroidism, decreased in hypo
199
Meyer Overton rule
direct correlation between olive oil solubility and anesthetic gas potency
