Block 3 Flashcards
(177 cards)
1
Q
When there is vessel injury, what do platelets bind to?
What conformational changes exist to the platelets?
A
von Willebrand factor
Change in platelet receptor glycoprotein IIb + IIIa
2
Q
When platelets change shape, they release what?
A
ADP
Thromboxane (TxA2)
Serotonin
3
Q
When ADP is released, where does it bind to?
A
P2Y1 and P2Y12 to induce activation and aggregation of platelets
4
Q
What is the intrinsic pathway hemostasis cascade?
A
12, 11, 9
8 is activated on its own
9a + 8a = activation of 10
5 is activated on its own
10a + 5a = activation of 2 (prothrombin into thrombin [2 to 2a])
2a converts fibrinogen (1) into fibrin (1a) and converts 13 to 13a
5
Q
How does protein C become activated?
A
Protein C + thromobmodulin with the help of Protein S
Activated by thrombin
6
Q
Protein C inhibits what in the hemostasis cascade?
A
Inhibits 8 and 5 from being activated
7
Q
What is the extrinsic pathway hemostasis cascade?
A
Trauma (3) activates 7 alongside with tissue factor = TF-7a
TF-7a can now activate 10
8
Q
What is the fibrinolysis pathway in the blood?
A
Plasminogen converts to plasmin via t-PAand that can be inactivated by alpha-2-antiplasmin
Plasmin breaks down fibrin to fibrin degradation products
9
Q
What is thrombin activatable fibrinolysis inhibitor?
A
Produced by thrombin (2a)
Slows conversion of plasminogen to plasmin
Slows conversion of fibrin to FDP
10
Q
What role does antithrombin have in the hemostasis cascade?
A
Neutralizes thrombin (2a) and inhibits activation of 10 to 10a
Heparin proteoglycans increase rate of neutralization
11
Q
What is Virchow’s Triad?
A
Blood stasis
Hypercoagulable state
Vascular injury
12
Q
What are some risk factors of VTE?
A
≥75 yrs old
Prior occurrence (highest during first 180 days)
Virchow’s Triad
13
Q
Warfarin inhibits what?
A
Factor 2, 7, 10, and 10a
Inhibition of VK epoxide reductase
14
Q
Warfarin crosses the placenta (T/F)
A
True, causes fetal hemorrhage
15
Q
Warfarin’s delayed onset is due to what? What is a work around to this?
A
Half-life of VK-dependent clotting factors 7 and 2
Pt w/ acute thromboembolic disorders can be treated w/ both low molecular weight heparin + warfarin
LMWH can be withdrawn after warfarin becomes effective
16
Q
Warfarin AE and contraindication?
A
AE = bleed from any kind of severity
CI = pregnancy (causes fetal warfarin syndrome; bone deformities due to lack of VK)
17
Q
Which anticoagulant is naturally occuring in the body?
A
Heparin
18
Q
Heparin is the most powerful endogenous inhibitor of________
A
thrombin
19
Q
Heparin AE and interactions?
A
AE = bleed, hyperkalemia, and thrombocytopenia
Interacts with salicylates causing more bleed
20
Q
Fondaparinux is chemically related to what?
A
Heparin
21
Q
What are the indications of use for heparin?
A
Heparin - prevent/Tx acute thromboembolic disorders
LMWH (enoxaparin and dalteparin) - prevent/Tx VTE
Fondaparinux - SubQ to prevent VTE
22
Q
LMWH primarily inactive what?
A
10a
23
Q
Dabigatran etexilate MOA?
A
Direct thrombin inhibitor-2 + oral
24
Q
Dabigatran AE and interaction?
A
AE - bleed; reversed by Praxbind
Interactions - etexilate not its metabolite dabigatran should not be used w/ inducers of p-gp like rifampin
25
Argatroban MOA?
Direct thrombin inhibitor + IV
26
Rivaroxaban MOA and interactions?
Inhibits 10a
Dosage adjustments when taking with 3A4 inhibitors
27
Which Rx is used for preventions and Tx of heparin-induced thrombocytopenia?
Argatroban
28
Apixaban vs Edoxaban, which one can cause brain bleed?
Edoxaban; also causes anemia symptoms, allergic rxn, vision problems, slurred speech
29
What is the Homan's sign?
Pain in the back of knee when examiner dorsiflexes the foot; could be a sign for DVT
30
How do you interpret the Wells Clinical Score for DVT?
Score = 0; Low ; 3% of DVT
Score = 1 or 2; Moderate; 17% of DVT
Score = ≥3; High; 75% of DVT
Low or Moderate; test D-dimer
High; go straight to imaging
31
Diagnosing DVT via D-Dimer
Negative result rules out VTE
Positive result does NOT state you have VTE
Threshold for most assays is 500ng/mL; then you would use imaging
32
Diagnosing DVT via Imaging
2 procedures; Venography and Compression Ultrasound
Venography; gold standard, but invasive and expensive with contrast
Compression Ultrasound; more widely used and non-invasive and not so expensive
33
How do you interpret the Wells Clinical Score for PE?
Score = <2; Low ; 3-10% of PE
Score = 2-6; Moderate; 15-35% of PE
Score = ≥7; High; 70-80% of PE
Low or Moderate; test D-dimer
High; go straight to imaging
34
Diagnosis of PE via imaging?
Pulmonary angiography; gold standard, but invasive and expensive with contrast
Computed tomography pulmonary angiography; most commonly used, less invasive, less expensive, BUT still uses contrast
V/Q scan; used in pt w/ renal or allergy issues on contrast
35
How do you interpret the Padua Risk Assessment?
For VTE prophylaxis on general medical pt
<4 = Low; no prophylaxis
≥4 = High; Rx for low bleed risk, compression socks or pneumatic compression machine for high bleed risk
36
What are the VTE prophylaxis doses for general medical pt?
Enoxaparin: 40mg SQ QD
Dalteparin: 5000u SQ QD
Unfractionated heparin: 5000u SQ q8-12hrs
Fondaparinux: 2.5mg SQ QD
All of given during length of hospital stay or until ambulatory
Alternative RX: Betrixaban 160mg PO once then 80mg for 35-42 days
37
How do you interpret the Caprini Risk model?
For VTE prophylaxis on non-orthopedic surgical pt
0 = very low = early ambulation
1-2 = low = average or high bleed risk just use IPC machine
3-4 = moderate = average bleed risk uses RX or IPC, high bleed risk only uses IPC
≥5 = high = average bleed risk use RX AND IPC or compression socks, high bleed risk uses IPC then add heparin when bleed risk goes down
38
What are the oral RX for VTE Tx?
Apixaban 10mg BID for 7 days, then drop it to 5mg
Rivaroxaban 15mg BID for 21 days, then increase it to 20mg ONCE A DAY
39
What is the switch method for VTE Tx?
Start with UFH, LMWH, or fondaparinux for 5-10 days, switch to either:
Dabigatran 150mg PO BID or Edoxaban 60mg (30mg if ≤60kg) PO daily
40
What ist the overlap method for VTE Tx?
Start with UFH, LMWH, or fondaparinux for 5 days
At the same time, start warfarin daily and make sure INR ≥2.0
41
What is the preferred Rx for VTE Tx on non-cancer pt?
Direct oral anticoagulants over warfarin and then heparin
42
What is the preferred Rx for VTE Tx on cancer pt?
LMWH over warfarin or direct oral anticoagulants
43
Unfractionated Heparin MOA?
Inhibits 10a and 2a in 1:1 ratio
44
Low molecular weight heparin MOA?
Inhibits 10a and 2a in 3:1 ratio
45
Fondaparinux MOA?
Inhibits only 10a
46
Unfractionated Heparin, what is used to measure the effect of IV infusion?
aPTT
47
Continuous IV infusion of Unfractionated Heparin
80u/kg (max of 10,000)
Followed by 18u/kg/hr (max of 2,000u/hr)
48
SQ dosing of Unfractionated Heparin
Not preferred due to erratic absorption
333u/kg bolus
Followed by 250u/kg q12hrs
49
Advantages/disadvantages of unfractionated heparin?
Immediate onset of action
Preferred in pt w/ renal dysfunction
HOWEVER; requires hospitalization w/ frequent aPTT monitoring
50
Enoxaparin (Lovenox) dose?
1mg/kg BID or 1.5mg/kg daily
51
Dalteparin (Fragmin) dose?
100units/kg BID or 200units/kg daily
52
Fondaparinux (Arixtra) dose?
<50kg = 5mg daily
50-100kg = 7.5mg daily
>100kg = 10mg daily
Renal dosing; CrCl = 30-50? Reduce dose by 50%
53
What is thrombocytopenia?
PLT count <100
or
>50% reduction of PLT from baseline
54
Using the 4T's of HIT + Low score (<3); what should you do?
HIT is ruled out
Monitor PLT count and continue heparin
55
Using the 4T's of HIT + Medium (4-5) or High (>6); what should you do?
Obtain PLT activation or antigen assay to confirm HIT
Those developing HIT, stop all heparin therapies
Future use of any heparin = no bueno; except w/ Fondaparinux (low cross-reactivity)
56
DOAC safety compared to warfarin
All were non-inferior for VTE
Apixaban had less major bleeding for VTE
Rivaroxaban has less major bleeding for PE
57
Does Rivaroxaban have renal dosing? Contraindications?
Yes; for VTE it is contraindicated <30
Avoid in liver issues
Take w/ food
58
Does Apixaban have renal dosing? Contraindications?
Yes; for VTE it is contraindicated <25
Avoid in liver issues
59
Which oral DOAC has minimal CYP3A4 metabolism?
Edoxaban + Dabigatran (both utilize P-gp)
60
Does Edoxaban have renal dosing? Contraindications?
Yes; contraindicated for >95 and <15; in between = half the dose
Avoid in liver issues
61
Which DOAC does not take liver issues into consideration?
Dabigatran
62
Does Dabigatrann have renal dosing? Contraindications?
Yes contraindicated <30
60 count bottle expires 4 months after opening, dont crush, dyspepsia is a common AE
63
What are some Rx that are P-gp inducers? What happens?
Phenytoin + Rifampin
Less DOAC in body, therefore VTE risk goes up
64
What are some Rx that are P-gp inhibitors? What happens?
Amiodarone + ABx + Fungal Rx + CCBs
More DOAC in body, therefore bleed risk goes up
65
What are some Rx that are CYP3A4 inducers? What happens?
Carbamazepine + Phenytoin + Rifampin
Less DOAC in body, therefore VTE risk goes up
66
What are some Rx that are CYP3A4 inhibitors? What happens?
Amiodarone + ABx + Fungal Rx + HIV meds
More DOAC in body, therefore bleed risk goes up
67
Which DOAC is associated w/ dyspepsia?
Dabigatran
68
Which DOACs are (eventually) given once a day?
Rivaroxaban (starts with BID)
Edoxaban
69
Which DOACs are given twice a day?
Apixaban
Dabigatran
70
What are some contraindications and requirements of DOACs?
CI = Active bleed + prosthetic heart valves
Requirements = stable kidney and hepatic function
71
Prior to surgery + high bleed risk, when should you stop the DOACs?
All = ≥48hrs
Dabigatran extra = CrCl is 15-60 = ≥96hrs
72
Prior to surgery + low bleed risk, when should you stop the DOACs?
All = ≥24hrs + CrCl is 15-30, ≥36hrs (except Dabigatran)
Dabigatran = CrCl 15-60, ≥48hrs
73
When can you resume DOACs after surgery?
High risk = 48-72 hrs
Low risk = 24hrs
74
When initiating warfarin, what must you do?
Overlap it with a parenteral anticoagulant for a min of 5 days and until INR >2 for 24 hrs
75
When is someone initially dosed 5 or 10mg of warfarin?
Healthy or general population
If 10, it is for 2 days then switched to 5
76
When is someone initially dosed 2.5mg of warfarin?
>60yrs, <45kg
Malnourished or NPO for >3 days
Liver issues, HF, High risk of bleed
77
What is the INR goal for VTE?
2 to 3
78
What RX increase warfarin's effect (Increases INR)? **increase % of hemorrhage
Amiodarone, ABx, Antifungals, Analgesics
79
What RX decrease warfarin's effect (decreases INR)? **Increases % of thromboembolism
Rifampin and St. John's Wort
80
What RX increases bleed risk when taking with warfarin?
SSRIs, antiplatelet, NSAIDs, alternative remedies (ginger, cranberry, garlic)
81
Increasing vitamin K will (increase/decrease) INR
Decrease
82
If someone has a low bleed risk and either low or high VTE risk, what should you do with warfarin prior to a procedure?
Nothing
It's only a concern when there is a high bleed risk
Low VTE risk = d/c warfarin 5 days prior but dont bridge with heparin
High VTE risk = d/c warfarin 5 days prior but DO bridge
Both cases, resume warfarin 12-24 hrs after procedure
83
What is considered "high" VTE risk?
Within 3 months
Moderate = 3-12 months
Low = >12 months
84
In obese pt, what should the unfractionated heparin does be? LMWH? DOACs?
7500u every 8hrs (prophylaxis)
Only Enoxaparin is affected
Increase dose to 40mg BID
For DOACs, >120kg or >40BMI = AVOID
85
If someone is severely renal impaired, what anticoagulant could you use?
UFH or Warfarin
Enoxaparin = 30mg daily (prophylaxis) or 1mg/kg/day
Dalteparin + Fondaparinux = AVOID
86
Which anticoagulant should you give for pregnant and lactating women?
UFH + LMWH (+warfarin if they are lactating only)
87
Someone is taking oral anticoagulant and becomes pregnant, what should you do?
Switch to UFH or LMWH
88
What are the symptoms caused by blockage of the anterior cerebral artery?
Legs and feet issues + aphasia
89
What are the symptoms caused by blockage of the middle cerebral artery?
Lower face, arm, hand + aphasia
90
What are the symptoms caused by blockage of the posterior cerebral artery?
Vision issues and memory defect
91
What are some non-modifiable risk factors for ischemic stroke?
Each decade >55yrs doubles the risk
AA have 1.5-2x risk compared to whites
Women have higher mortality and risk
92
What are some modifiable risk factors for ischemic stroke?
HTN is the most common
93
Ischemic stroke pathophysiology?
Blockage of cerebral artery
No oxygen -> ATP depletion
Lactate and sodium accululate -> cytotoxic edema and cell lysis
Influx of calcium which degrades protein
Glutamate and aspartate produce ROS, prostaglandins, and leukotrienes
Cell apoptosis and necrosis
94
What are the stereotyped clinical syndromes of ischemic stroke?
Moto hemiparesis + sensory stroke
95
What kind of stroke is categorized for ppl w/ A.Fib?
Ischemic: Cardioembolic stroke
96
What kind of stroke is categorized for ppl w/ no medical history nor heart disease? Has an unknown origin
Ischemic: Cryptogenic stroke
97
What kind of stroke is categorized for ppl with transient symptoms w/o evidence of infarction?
Ischemic: Transient Ischemic attack
98
What kind of stroke is categorized for ppl who suddenly have headaches and vomit? Also loss of consciousness and/or neck stiffness
Hemorrhagic: Subarachnoid hemorrhage
99
What kind of stroke is categorized for ppl who bleed in the brain parenchyma itself? Comes with uncontrolled HTN, anticoagulation or illicit drug use
Hemorrhagic: Intracerebral hemorrhage
100
Hemorrhagic stroke pathophysiology?
2 mechanisms; primary + secondary
Primary: blood in parenchyma, compression of tissue, and activation of inflammation and neurotoxins
Secondary: inflammatory response, cerebral edema, damage from blood product degradation
101
On a CT, what does a white or dark picture mean?
White = hyperintensity = hemorrhage
Dark = hypointensity = infarction (take up to 24hrs to reveal)
102
In hemophilic patients, what are they missing?
Factors 8 and 9
103
What is the pharmacophore in warfarin?
The two benzene rings with 2 oxygens
104
What is the active metabolite in warfarin?
What can inactive R-warfarin?
Active - 2'-Hydroxywarfarin through reductase
CYP 1A2, 2C19, and 3A4 inactive R warfarin
CYP 2C9 can inactive S warfarin
105
Conformationally, what does fondaparinux do that heparin doesnt do?
Fondaparinux changes antithrombin III to bind to factor X only
Heparin is a bigger sugar molecule with lots of negative charges and is able to bind to both factor X and thrombin
106
Which RX is an IRREVERSIBLE thrombin inhibitor?
Hirudin
Argatroban, Dabigatran, and Bivalirudin are REVERSIBLE
107
What happens if there is no redox recycling of Vit. K?
No prothrombin
108
Fondaparinux vs Heparin, which one has a more consistent PK parameter?
Fondaparinux; due to its composition not changing unlike heparin
109
What is an advantage of argatroban and dabigatran over the other thrombin inhibitors?
They are peptidomimetic not peptide-based
They mimic peptide, but are not peptide. Longer shelf-life
110
Aspirin MOA?
Irreversibly inhibits COX1 and further blocks TXA2 production
111
What do phosphodiesterase inhibitors do?
EX: Dipyridamole and Cilostazol
Inhibit conversion of cAMP to AMP; coronary vasodilator
High levels of cAMP = reduced activation of platelets
112
What Rx are P2Y purinergic receptor inhibitors?
Clopidogrel
Ticlopidine
Prasugrel
All of which are prodrugs (needs CYP3A4) + are work irreversibly
113
What is an important group that P2Y purinergic receptor inhibitors have prior to their active metabolites?
Thiolactone group (5-ringed structure with sulfur and oxygen)
114
What are your Glycoprotein IIb/IIIa receptor antagonist RX?
Abciximab
Eptifibatide
Tirofiban
All utilize carboxyl and amine groups
115
What are your PAR-1 inhibitors?
Vorapaxar
116
Urokinase
Reteplase
Tenecteplase
Which one has longer half life in human body due to reduced hepatic elimination vs alteplase?
Reteplase
117
Urokinase
Alteplase
Reteplase
Tenecteplase
Fibrin-bound plasminogen specific, low reactivity with free plasminogen
Alteplase
118
What three AA are replaced in Tenectaplase?
TNK are replaced
Threonine to Asparagine
Asparagine to Glutamine
Lysine to 4x Alanines
119
Urokinase
Alteplase
Reteplase
Tenecteplase
Non-selectively digest free plasminogen and plasminogen bound to fibrin
Urokinase
120
What is the relation between cAMP and platelet adhesion?
Increased cAMP inhibits adhesion
121
Aspirin dose + its effect on TXA2?
Low dose = inhibits only TXA2
High dose = inhibits both TXA2 + prostacyclin
122
Aspirin AE?
GI bleed
123
Clopidogrel AE?
Bleed, diarrhea, epgastric pain, rash
124
Ticlopidine AE?
Bleed, diarrhea, Ab pain, rash, neutropenia, and thromocytopenia
125
Abciximab AE?
Bleed, thrombocytopenia, hypotension, bradycardia
126
Abciximab
Eptifibatide
Tirofiban
Which one is a reversible inhibitor of fibrinogen of GP IIb/IIIa?
Eptifibatide
| Tirofiban
127
Eptifibatide
Tirofiban
AE?
Intracranial, GI, and genitourinary bleed
128
Streptokinase AE?
Bleed, hypotension, allergic rxn, arrhythmias, fever
Urokinase rarely causes hypotension
129
Alteplase AE?
Mild hypotension, nausea, fever
130
Vorapaxar AE?
Bleed and anemia
131
Which fibrinolytic RX is given as an infusion vs bolus?
Streptokinase and alteplase = infusion
Reteplase and tenecteplase = bolus
132
Which fibrinolytic RX is the most specific to fibrin?
Tenecteplase
133
What should the door to CT time be? Door to drug?
Door to CT ≤20min
Door to Drug ≤60min
134
How is alteplase dosed?
Max of 90mg
0.9mg/kg
10% IV over 1 min
90%IV over 60min
135
tPA candidates?
<3hrs of symptom onset (<4.5 for some..?)
Warfarin: INR ≤1.7
PT ≤15 seconds
BP <185/110
≥18 yrs old
CT negative for ICH
136
What are some exclusion criteria for tPA on the head?
Head trauma or stroke within 3 months
History of intracranial hemorrhage, neoplasms, aneurysms
Recent intracranial or intraspinal surgery
CT showing multilobar infarction (hypodensity >1/3 cerebral hemisphere)
137
What are some exclusion criteria for tPA + blood?
Arterial puncture in noncompressible site within 7 days
Active internal bleed
PLT <100,000
>185/110 BP
Blood glucose <50
138
What are some exclusion criteria for tPA + medications?
Heparin within 48hrs with elevated aPTT
Current anticoagulants with INR >1.7 or PT >15 seconds
Current use of DOACs with elevated lab tests
139
What are some exclusion criteria for tPA in the 3-4.5hr range?
>80 yrs old
Taking oral anticoagulants w/o regard of INR
History of BOTH diabetes and prior ischemic stroke
140
What are the BP goals with regards to tPA, no tPA, and thrombectomy?
No tPA ≤220/120
No tPA but planned thrombectomy <185/110
Prior to tPA <185/110
After tPA <180/105
141
Prior to giving tPA and pt BP >185/110, what can you do?
4 drugs can be given
1. Labetalol 10-20mg IV
2. Clevidipine 1-2mg/hr IV (max 21/hr)
or
3. Nicardipine 5mg/hr IV (max 15/hr)
4. Last = hydralazine or enalaprilat
If not under goal, do NOT give tPA
If they are under goal, give the same drugs listed above and monitor BP closely; may consider sodium nitroprusside if DBP is >140
142
If someone has an unknown BP goal, what is a reasonable one after stroke ro TIA?
<140/90 unless they had MI, ADHF, aortic dissection. Lowering it by 15% is safer
143
What HTN meds should you give after stroke or TIA?
ACEi +/- thiazides
144
Hypotension after stroke or TIA?
30ml/kg/day
Give NS or LR
145
Aspirin after stroke or TIA?
Aspirin 160-325mg daily for 4 wks
146
BG after stroke or TIA?
* rare* If <60, give 25mls of 50% dextrose
| * common* Hyperglycemia - usually insulin
147
How long should you wait to give DOAC after stroke or TIA?
24hrs
148
ASCVD should be used in (primary/secondary) prevetion
Only primary
149
Primary prevention of stroke + Diet?
Reduce sodium
Increase potassium
DASH and Mediterranean diet
150
Primary prevention of stroke + physical activity / weight loss?
90-150 min/week
1kg lost = 1mmHg SBP reduction
151
Primary prevention of stroke + BP goal?
<130/80
First line = ACE,ARB,CCB,thiazides
AA= thiazides,CCB
152
Primary prevention of stroke + Dyslipidemia?
LDL≥190 = high intensity statin +/- ezetimibe +/- PCSK9-l
LDL 70-189 AND DM; no risk enhancer = moderate statin, with risk = high statin
LDL 70-189 with NO DM 5-20% ASCVD = moderate, >20 = high
153
Primary prevention of stroke + Aspirn?
Only for ppl aged 40-70 w/ 10-year ASCVD risk >10% w/o bleed risk
Not beneficial for low-risk or aged >70
154
Primary prevention of stroke + A.Fib?
CHADSVASc
Congestive Heart failure
HTN
Age ≥75 **2 points**
Diabetes
Stroke **2 points**
Vascular disease
Age 65-74
Sex (female)
Anticoagulation for males ≥1 point or females ≥2 points
155
Primary prevention of stroke + A. Fib. RX
No mitral stenosis or valve = DOAC
W/ stenosis or valve = Vitamin K antagonist
156
A. Fib dosing + Rivaroxaban?
20mg PO daily
Avoid in CrCl <15
157
A. Fib dosing + Apixaban?
5mg PO BID
Reduce to 2.5 if 2 of the following:
Wt ≤60kg
SCr ≥1.5
Age ≥80
Avoid in CrCl <15
158
A. Fib dosing + Edoxaban?
60mg PO daily
Avoid in CrCl <15
159
A. Fib dosing + Dabigatran?
150mg PO BID
160
Secondary prevention of stroke + HTN?
In pt not previously diagnosed with HTN
BP >140/90 = non pharm and pharm
<140/90 = non pharm
161
Secondary prevention of stroke + Antiplatelets?
For non-cardioembolic stroke, antiplatelets are recommended
Aspirin + clopidogrel for 21 days, after 21 days, d/c clopidogrel only
162
What are the main clinical presentations of peripheral arterial disease?
Intermittent: fatigue, cramp, numbness in the leg or butt (>50% occlusion)
Critical limb ischemia: resting pain, pain in feet while in bed (>80% occlusion)
Asymptomatic
163
What is the fontaine classicification system?
Stage 1: reduced pulse
Stage 2: intermittent claudication
Stage 3: resting pain
Stage 4: Ulcers in feet
164
Who should be tested using ankle-brachial index?
≥65 yrs old
Age 50-64 with risk factors (DM,HTN, smoking)
Age≤50 if they have DM + one other factor
165
What are the ABI scores for peripheral arterial disease?
1-1.4 = normal
0. 91-0.99 = borderline
0. 41-0.90 = mild to moderate PAD
≤0.4 = severe PAD
>1.4 = noncompressible and requires further diagnostics
166
What is the exercise ABI test?
Used to establish PAD in those with normal-borderline aBI scores
Measure after 5 min on treadmill or 30-50 repetitions of heel raises
Usually ABI will drop
167
What is the toe-brachial index?
Used to establish PAD with ABI >1.4
168
Vancomycin class and MOA?
Glycopeptide
Binds to D-ala-D-ala end of peptidoglycan precursors to prevent transglycosylation and ultimately inhibit cell wall synthesis
169
Vancomycin parameters vs Aminoglycosides?
Vanco - AUC (goal 400 to 600)
Aminoglycosides - Peak
170
Aminoglycosides Vs Vanco, which one is bacteriacidal?
Both
Typically -cidal ABx disrupts the cell wall
Vanco is a slow cidal ABx
171
Vanco infusion time?
Do not exceed 10-15mg/min or 1g/hr
172
Vanco AE?
Red man's syndrome - double the infusion time and pre-treat with diphenhydramine 30min prior
Nephrotoxicity
Ototoxicity
173
Vanco induced nephrotoxicity risk factors?
AUC >600
Increased body weight
Pre-exisitng renal issues, critical illness, or concomitant nephrotoxic agents (ABx, amphotericin, contrast, loop diuretics, vasopressor)
Duration of therapy ≥3-5 days
174
Vanco + Monitoring?
SCr
BUN
UOP (goal of 0.5ml/kg/hr in RRT)
175
What are the indications for hemodialysis?
**Acute**
Acidemia
Electrolyte abnormalities
Intoxication
Overload
Uremia
**Chronic**
GFR <30
176
Vanco + renal replacement therapy?
Pre-dialysis concentration 15-20
Consider a random level
Level to be obtained on the day of dialysis prior to HD
Vanco is preferred to be given after HD
177
Vanco/Aminoglycosides and dosing in RRT?
Vanco is weight based on TBW
Aminoglycosides is based on IBW
