PHYS Flashcards
1
Q
Which cell lacks a nucleus/DNA?
A
RBC
2
Q
What is a combination of two or more variants on a single chromosome delineating a pattern that is inherited together?
A
Haplotype
3
Q
Deficiency in which surfactant protein appears to play a role in ARDS?
A
SP-B
4
Q
What is the process in which a molecule LOSES electrons?
A
Oxidation
5
Q
What is the process in which a molecule GAINS electrons?
A
Reduction
6
Q
What are the 3 stages of cellular respiration?
A
glycolysis, Krebs cycle, oxidative phosphorylation
7
Q
In glycolysis, 1 molecule of glucose is converted into what?
A
2 pyruvate, 2 ATP, 2 NADH
8
Q
Before entering the Krebs cycle, if oxygen present, pyruvate is converted to what/what byproducts?
A
Acetyl-CoA, 1 NADH
9
Q
If oxygen is NOT present, pyruvate is converted into what/what byproducts?
A
Lactate, 2 NAD+ (regenerated so glycolysis can continue)
10
Q
Which cells exclusively use anaerobic glycolysis?
A
RBCs
11
Q
What is the name of the cycle that converts lactate back to glucose (and where does it occur)?
A
Cori cycle (liver)
12
Q
What is the net ATP balance of anaerobic metabolism/the Cori cycle?
A
-4 ATP (2 ATP produced in muscle/tissue, 6 ATP used in liver to convert lactate to glucose)
13
Q
What is the net metabolic production of the Krebs cycle for 1 molecule of glucose?
A
1 glucose > 2 pyruvate > 2 acetyl-coA = 2 ATP, 6 NADH, 2 FADH, 4 CO2
14
Q
What is the net metabolic production of oxidative phosphorylation for 1 molecule of glucose?
A
1 glucose = NAD+/FAD+ (NADH/FADH are oxidized), H2O (oxygen is reduced) and 30-32 ATP (ADP is reduced)
15
Q
The citric acid cycle is also known as what?
A
Krebs cycle
16
Q
What is the primary contributor to metabolic acidosis during tissue hypoxia?
A
Hydrogen ions (because oxygen is not available as final acceptor [H2O]; ie, NOT lactate)
17
Q
What affect does a rapid infusion of sodium bicarbonate have on extracelluar and intracellular acid/base status?
A
Fixes extracellular acidosis, but worsens intracellular acidosis (HCO3- + H+ > H2CO3 > H2O + CO2; CO2 readily diffuses into cell [HCO3- does not], combines with H2O > H2CO3 > H+ and HCO3-)
18
Q
DO2 (units) =
A
DO2 (mL/min) = CO (L/min) x CaO2 (mL/dL) x 10 (dL/L)
19
Q
Which patient’s CaO2 most benefits from increasing PaO2?
A
Patient suffering with severe anemia
20
Q
What is the normal BSA for an average adult, infant, 2yo, and 8yo child?
A
1.7 (average adult)
0.25 (infant), 0.5 (2yo), 1.0 (8yo)
21
Q
What is a normal adult CO (units)?
A
5 L/min
22
Q
What is a normal CI (units)?
A
3.2 mL/m2/min
23
Q
What is a normal CaO2 (units)?
A
20 mL/dL
24
Q
What is a normal CvO2 (units)?
A
16 mL/dL
25
What is a normal avDO2 (units)?
4 mL/dL
26
What is a normal DO2 (units)?
600 mL/m2/min (1000 mL/min)
27
What is a normal VO2 (units)?
120 mL/m2/min (200 mL/min)
28
What is the normal DO2:VO2 ratio?
5:1
29
CaO2 (units) =
CaO2 (mL/dL) = Hgb (g/dL) x 1.36 (mL O2/g Hgb) x SaO2 (%) + PaO2 (mmHg) x 0.003 (mL/mmHg/dL)
30
avDO2 (units) =
avDO2 (mL/dL) = CaO2 (mL/dL) - CvO2 (mL/dL)
31
What is the Fick equation?
VO2 = CO x avDO2
32
VO2 (units) =
VO2 (mL/min) = CO (L/min) x avDO2 (mL/dL) x 10 (dL/L)
33
CO (units) =
CO (L/min) = HR (1/min) x SV (mL) x 1/1000 (L/mL)
34
CI (units) =
CO (L/min)/BSA (m2)
35
What is a normal SV for an infant?
5 mL
36
What is a normal SV for an adult?
70 mL
37
What is the shortening fraction (echocardiography)?
The percent change in DIAMETER of the LV; (LV diastole diameter - LV systole diameter) / LV diastole diameter
38
What is a normal shortening fraction (echocardiography)?
30-40%
39
What is the ejection fraction (echocardiography)?
The percent change in VOLUME of the LV; (LV diastole volume - LV systole volume)/LV diastole volume
40
What are the values of normal, mild, moderate and severely reduced EF?
normal >55%, mildly reduced >40%, moderately reduced >30%, severely reduced <30%
41
What is the Law of Laplace?
Principle that states the wall tension of a sphere is proportional to transmural pressure ("LaPlace pressure") and radius (y = P x r)
42
Wall stress (afterload) is an application of which law?
Law of Laplace
43
Wall stress = (is proportional to)
P x r/2T (wall stress = wall tension/2T); P = pressure, r = radius, T = wall thickness
44
If estimating wall stress (P, r, T), at what point in the cardiac cycle should these measurements be taken?
End of LV systole
45
Hypoxemia is detected by what areas of the body?
Chemoreceptors in the aortic and carotid bodies
46
When aortic and carotid bodies detect hypoxemia, what response occurs?
Respiratory area of the medulla is stimulated to increase minute ventilation (increases alveolar PAO2)
47
PAO2 (alveolar gas equation) =
PAO2 = (Pb - Ph20) x FiO2 - PaCO2/RQ
48
What is the normal PB (barometric/atmospheric pressure) at sea level?
760 mmHg
49
What is the normal PH2O (water vapor pressure; at 37C body temperature)?
47 mmHg
50
pRBC: better or worse at releasing oxygen (and why)?
worse; have decreased levels of 2,3 DPG over time, causing left shift of oxyhemoglobin curve
51
What causes a left shift (increased affinity) of the oxyhemoglobin curve?
fetal hemoglobin, alkalosis, decreased 2,3 DPG
52
What causes a right shift (unloading) of the oxyhemoglobin curve?
increased H+, increased CO2, increased temperature, increased 2,3 DPG
53
Chronic hypoxemia causes increase of what hormone?
erythropoietin (increased hemoglobin concentration)
54
Which organs have the highest oxygen extraction ratios?
myocardium (55%), brain (30%)
55
Which organs have the lowest oxygen extraction ratios?
kidney (8%), skin (10%)
56
Which ScvO2 is higher: IVC or SVC?
IVC (brain has high OER, while kidneys have low OER)
57
Where is the lowest venous sat in the body (highest OER)?
coronary sinus (coronary venous blood)
58
OER =
avDO2(CaO2-CvO2)/CaO2
59
What is a normal OER?
0.2
60
The various factors of the coagulation system are what type of enzymes?
serine proteases
61
The factors of the coagulation system are produced where?
Liver
62
What is the final common pathway of the clotting cascade?
Thrombin (factor IIa)
63
What does thrombin do?
Catalyzes formation of fibrinogen into fibrin
64
What does plasmin do?
Lyses fibrin clot
65
What is the most important molecule in the fibrinolytic pathway?
Plasmin
66
What are the basic components of a clot?
platelets (vWF) and fibrin
67
What are the major anticoagulant proteins?
protein C, protein S, TFPI (tissue factor pathway inhibitor), antithrombin III, heparin
68
Protein C is activated by what?
Thrombomodulin
69
What are the 3 steps of clot formation in response to injury caused by trauma?
1 vasoconstriction, 2 platelet aggregation, 3 fibrin deposition
70
Tissue factor complexes with which factor of the clotting cascade?
factor VII
71
PT is reflective of which pathway of the coagulation cascade?
extrinsic pathway (TF pathway)
72
PTT is reflective of which pathway of the coagulation cascade?
intrinsic pathway (contact pathway)
73
What is a normal PT value?
13 seconds
74
What is a normal PTT value?
30-40 seconds
75
What are the 4 phenotypes of TMA?
TTP, DIC, HUS, secondary TMA
76
What is the classic "pentad" of symptoms of TTP?
(FATRN) fever, anemia (microangiopathic hemolysis), thrombocytopenia, renal dysfunction, neurologic dysfunction
77
What is the pathophysiology of TTP?
acquired ADAMTS-13 deficiency (inhibitors and inactivators)
78
What are the 5 abnormal lab values of DIC?
thrombocytopenia, decreased factor V and VIII, decreased fibrinogen, increased D-dimers (increased PT/PTT from decreased factors and fibrinogen)
79
DIC: is the anticoagulation (protein C, S, ATIII) system increased or reduced?
anticoagulant system is significantly reduced in patients with DIC
80
DIC: hyperfibrinolysis or hypofibrinolysis?
hypofibrinolysis after 12-24H
81
What parts of the coagulation system are in plasma/FFP?
procoagulant factors, anticoagulant factors (protein C, ATIII, TFPI), prostacyclin, tPA, ADAMTS13, vWF
82
What is the classic "triad" of HUS?
("ATR" of FATRN) anemia (hemolytic), thrombocytopenia, renal dysfunction
83
What is the underlying pathophysiology of HUS?
uncontrolled complement activation
84
What is the most common trigger for infection-induced HUS?
Shiga toxin-producing E coli (STEC)
85
Which factor of the coagulation cascade is NOT made by the liver?
factor VIII (endothelium)
86
At what platelet count are patients with ITP at increased risk of brain bleed?
<10K
87
Increased levels of F1.2 are indicative of what?
Systemic thrombosis (F1.2 is a prothrombin activation fragment)
88
Increased levels of plasmin alpha2-antiplasmin (PAP) are associated with what?
Hypofibrinolysis (clotting; decreased levels associated with fibrinolysis and bleeding)
89
What are the two first-line treatments for TTP?
Steroids and plasma exchange
90
What is the first line treatment for atypical HUS?
Eculizumab (anti-C5)
91
What is the first line treatment for infectious HUS?
PLEX
92
Which factors are decreased in liver failure?
II, VII, IX
93
What is the first line treatment for liver failure-associated bleeding?
Vitamin K
94
Which factors are in FFP and not in cryoprecipitate?
factor VII (both have factor VIII, XIII, fibrinogen, vWF)
95
What is the treatment for DIC?
FFP (to replenish factors) and low-dose heparin (to prevent clotting)
96
How is SIRS defined?
at least 2: abnormal temperature, tachycardia, tachypnea, abnormal WBC
97
What are the 4 major effector cells of the innate immune system?
monocytes, neutrophils, dendritic cells, natural killer cells
98
What are the pathogen triggers for NK cells?
pathogens withOUT MHC class 1
99
NK cells express what receptors?
Lectins
100
What part of immunoglobulin is detected by opsonizing cells?
Fc portion
101
Antigen presenting cells load small pathogen peptides onto what?
MHC class II molecules
102
HLA-DR is what kind of molecule?
MHC class II molecule
103
Antigen presenting cells present pathogen peptides to what cells?
T cells
104
NK cell lectins binding to host cells are inhibited by simultaneous ligation of what?
Host MHC class I molecules
105
HLH pathogenesis is due to reduction in the activity of what cell type?
NK cell activity
106
What are the two types of T cells?
CD4 (Th1, Th2, Treg) and CD8
107
What do CD8 T cells do?
release lytic granules (cytotoxic)
108
What are the 4 main types of CD4 T cells?
Th1, Th2, Treg, Th17
109
What do Th1 cells do?
produce pro-inflammatory mediators and induce B cell antibody production
110
What do Th2 cells do?
produce anti-inflammatory mediators
111
GM-CSF: pro- or antiinflammatory?
pro
112
INFy: pro- or antiinflammatory?
pro
113
IL-10: pro- or antiinflammatory?
anti
114
TGFbeta: pro- or antiinflammatory?
anti
115
Th17: pro- or antiinflammatory?
pro
116
Which cytokine, when elevated, is highly correlated with adverse clinical outcomes during proinflammatory insults?
IL-6
117
CC and CXC are groups of what molecules?
chemokines (C stands for the arrangement of the cysteine residue)
118
What is the primary chemokine for neutrophil migration?
IL-8
119
Where are the proteins of the complement system made?
liver
120
What is a zymogen?
precursor enzyme that requires proteolytic cleavage for activation
121
The classical pathway of complement starts with what?
C1 binding to PAMPs or antibody complexes
122
What is the convergence point for the three pathways of complement activation?
C3 convertase
123
Which complement pathway is constitutively active?
alternative pathway (spontaneous C3 cleavage)
124
The mannose binding lectin pathway of complement activation starts with what?
MBL binding to carbohydrates on pathogens
125
Which is the chief opsonizing molecule of the complement system?
C3b
126
Which complement protein is a potent inflammatory cytokine?
C5a
127
Which complement protein triggers the assembly of the MAC?
C5b
128
Congenital abnormalities in complement proteins result in increased susceptibility to which infection?
Neisseria
129
What does CRP do?
opsonizes pathogens and activates complement via C1
130
Eicosanoids are what type of molecules?
lipids
131
What are the 3 major types of eicosanoids?
prostaglandins (PG), thromboxane (TX), and leukotrienes (LT)
132
Eicosanoids are generated from what molecule?
arachidonic acid
133
Arachidonic acid is converted to PGH2 by what enzymes?
COX-1 or COX-2
134
NSAIDs inhibit which enzymes?
COX-1 and COX-2
135
PGE2: pro- or antiinflammatory?
anti
136
TXA2: pro- or antiinflammatory?
pro
137
COX1/2 inhibition is antiinflammatory due to reduction in what molecule?
TXA2
138
LTA4: pro- or antiinflammatory?
pro
139
Glucocorticoids inhibit the proinflammatory response through inactivation of what?
NFkB
140
What is the relative potency of dexamethasone: glucocorticoid vs mineralocorticoid?
30 to 0 glucocorticoid
141
What is the relative potency of methylprednisolone: glucocorticoid vs mineralocorticoid?
5 to 1 glucocorticoid
142
What is the relative potency of hydrocortisone: glucocorticoid vs mineralocorticoid?
1 to 5 mineralocorticoid
143
Immunoparalysis syndrome is characterized by what two findings?
Reduced expression of HLA-DR on monocytes and reduced production of TNFa by whole blood stimulated with LPS
144
What two laboratory findings are found in HLH?
elevated ferritin and soluble CD25
145
Insulin: pro- or antiinflammatory?
anti (directly inhibits NFkB)
146
Benzodiazpines and opioids: pro- or antiinflammamatory?
anti
147
Lasix: pro- or antiinflammatory?
anti
148
Alpha receptors: pro- or antiinflammatory?
pro
149
Beta receptors: pro- or antiinflammatory?
anti
150
Epinephrine: pro- or antiinflammatory?
anti (Beta effect predominates)
151
Which body cells require glucose for energy?
RBCs, WBCs, and the myocardium
152
RQ =
VCO2/VO2
153
What are the two methods currently available to estimate caloric needs of children?
WHO equations and Schofield equations
154
What is the minimum recommended protein requirement?
1.5g/kg of lean body mas
155
What is the waste product of protein and were is it made?
urea, liver
156
What is a normal nitrogen balance?
0
157
Which vitamin is important to the biosynthesis of bile and catecholamines?
Vitamin C
158
Which vitamin is important to collagen formation?
Vitamin C
159
Which vitamin is important to maintaining cell membrane integrity?
Vitamin E
160
Which mineral is important to wound healing?
Zinc
161
Supplementation of which mineral is associated with improved lymphocyte counts?
Zinc
162
What are the 3 most commonly measured "visceral proteins"?
albumin, prealbumin, retinol-binding protein (RBP)
163
Why is prealbumin named "prealbumin"?
Because it is close to albumin on an electrophoretic strip
164
What does prealbumin do?
transports thyroxine (T4)
165
MCTs are useful supplements for which patients?
those with pancreatic insufficiency, chylorthorax
166
Which lipid supplement bypasses biliary/pancreatic fat absorption?
MCTs
167
Glucose delivery should not exceed what rate in infants and children?
6 mg/kg/min in infants, 4 mg/kg/min in children
168
Avoid which IV fat emulsion formula in systemic inflammation?
soy-based
169
What is the study of movement of a pharmacologic substance through the body?
Pharmacokinetics
170
What is the study of what the body does to a drug?
Pharmacodynamics
171
What is the study of drug preparation and dosage forms?
Pharmaceutics
172
What are the 4 processes of pharmacokinetics?
absorption, distribution, metabolism, elimination (ADME)
173
What is the fraction of an administered drug dose that reaches the systemic circulation (central compartment)?
Bioavailability
174
What is the bioavailability of an IV administered drug?
100%
175
Which enteral routes bypass the portal circulation (and hepatic first-pass metabolism) partly or completely?
intranasal, sublingual or rectal
176
Which cross the blood brain barrier more easily: lipophilic or hydrophilic drugs?
Lipophilic
177
What is the theoretical value indicating the volume that would be required to contain the total amount of drug in the body at the same concentration as measured in the plasma?
Volume of distribution
178
Lipid soluble drug: small or large Vd?
large
179
Hydrophilic drug: small or large Vd?
small
180
Vd (volume of distribution) =
total amount of drug in body/plasma concentration of drug
181
Loading dose =
Loading dose = Vd x desired plasma concentration
182
Neonates: small or large Vd?
large due to higher percentage of body water
183
Highly protein bound drug: small or large Vd?
small
184
Low molecular weight drug: small or large Vd?
large
185
What is the main site of metabolism for most drugs?
liver
186
What are phase I reactions?
modification reactions (oxidation, reduction, hydrolysis, cyclization)
187
What are phase II reactions?
conjugation reactions (attached to polar or charged substrates)
188
Phase I reactions serve to do what (metabolically)?
increase polarity, water solubility, and excretion
189
Voriconazole effect on CYP enzymes?
Inhibits (will increase the concentration of other drugs)
190
What is Hoffman elimination?
Metabolism by exhaustive methylation
191
How is succinylcholine metabolized?
degraded by plasma cholinesterases
192
How is remifentanil metabolized?
degraded by nonspecific plasma esterases
193
Which neuromuscular blocking agents undergo Hoffman elimination?
atracurium and cisatracurium
194
Alkalization of the urine can enhance elimination of what common drug?
aspirin (salicylic acid, a weak acid, gets trapped by alkaline urine)
195
Alkalization of the urine can enhance elimination of what common chemotherapy?
methotrexate
196
What type of elimination involves drug removal from the body as a fixed percentage?
First-order elimination
197
What type of elimination involves drug removal from the body as a fixed quantity?
Zero-order elimination
198
First-order elimination implies: saturated or not saturated enzymes?
NOT saturated
199
First-order elimination: shape of decay?
exponential
200
Zero-order elimination: shape of decay?
linear
201
"Saturable kinetics" is described by what term?
Michaelis-Menten kinetics
202
Michaelis-Menten kinetics involve what type of elimination at lower serum drug levels, and what type of elimination at higher serum drug levels?
First-order elimination at lower serum levels, reach a Vmax (saturated), then zero-order elimination at higher levels
203
What is the amount of time required for the concentration of a drug in the body to decrease by 50%?
Half-life
204
Steady-state concentration is usually achieved after how many half lives?
4-5
205
(Half life) t =
t = 0.693/Ke (Ke = drug's elimination constant)
206
What is the volume of plasma from which a substance is completely removed per unit time?
Clearance
207
How does Vd effect half life?
Drugs with a larger Vd have longer half-lives
208
Clearance (CL) =
CL = ke x Vd
209
Equation relating half-life and clearance; t =
t = 0.693 x Vd / CL
210
Morphine should be dose reduced or avoided in what clinical situation?
Renal failure (morphine metabolized by liver to active metabolite, which is renally excreted)
211
ECMO oxygenator/PVC tubing absorbs which drugs?
fentanyl and midazolam (lipophilic)
212
Above what osmolarity should be avoided peripherally?
>1000 mOsm/L
213
Consider treatment with what drug if vasoconstrictive agent (phenylephrine, norepinephrine) extravasates?
phentolamine (vasodilator)
214
Propylene glycol is found in formulations of which drugs?
pentobarbital, diazepam, lorazepam
215
Propylene glycol toxicity is heralded by elevated levels of what?
lactic acid
216
What reaction do most CYP enzymes perform?
Oxidation (phase I)
217
Which beta blocker is metabolized by RBC esterases?
Esmolol
218
How do you calculate maintenance calories?
100 kcal/kg for first 10 kg + 50 kcal/kg for second 10 kg + 20 kcal/kg for subsequent kgs
219
What is the calorie content of carbohydrates?
4 kcal/g
220
What is the calorie content of protein?
4 kcal/g
221
What is the calorie content of fat?
9 kcal/g
222
What is the calorie content of 10% dextrose?
0.34 kcal/mL (for 15% dextrose, multiply by 1.5)
223
What is the calorie content of 10% lipid?
1.1 kcal/mL
224
Anion gap =
AG = (Na + K) - (Cl + HCO3)
225
Normal anion gap?
~10
226
Calculated Osmolality =
Osmolality = Na x 2 + Glucose/18 + BUN/2.8
227
Normal osmolar gap?
10-15
