Ex 3

Question 1

Nitroglycerin MOA

Answer 1

Primarily a venous dilator
Relaxes peripheral vascular smooth muscle by donating an NO group
Reduces cardiac O2 demand by decreasing preload
Dilates coronary arteries & improves collateral flow to ischemic regions
DOC: HTN emergencies with coronary ischemia

Question 2

Nitroglycerin Dosage

Answer 2

Concentration: 25 mg/250 mL (100 mcg/mL)
Bolus: 10-25 mcg
Infusion: 0.2-1.5 mcg/kg/min OR 5-200 mcg/min

Question 3

Nitroprusside MOA

Answer 3

Arterial & venous vasodilator via NO group donor

Causes afterload reduction

Question 4

Nitroprusside Preparation

Answer 4

50 mg in 250 mL (200 mcg/mL)
100 mg in 250 mL (400 mcg/mL)
May dilute one mL in 10 mL (20 or 40 mcg/mL)

Question 5

Nitroprusside Dosage

Answer 5

0.25 – 5 mcg/kg/min

20 – 40 mcg PRN

Question 6

Nitroprusside Elimination

Answer 6

Metabolized to cyanide and then thiocyanate, then excreted by kidney
Need to monitor cyanide levels, especially in renal failure

Question 7

Nitroprusside Induced Cyanide Toxicity Tx

Answer 7

100% O2

• Administer sodium thiosulfate
  Enhances conversion of cyanide to thiocyanate
• Administer hydroxocobalamin
  Combines with cyanide to form cyanocobalamin (vitamin B-12)

Question 8

Nicardipine MOA

Answer 8

Blocks calcium influx into smooth & cardiac muscle by binding to voltage-gated ion channels
Decreases arterial BP
May have modest increase in HR due to decrease in SVR

Question 9

Nicardipine Dosage

Answer 9

Concentration: 25 mg/250 mL
Dose
5 – 15 mg/hour
Start at 5 mg/hr
Increase Q15 minutes by 2.5 mg/hr

Question 10

Aminocaproic Acid (Amicar)
MOA

Answer 10

Antifibrinolytic
Inhibits conversion of plasminogen to plasmin
Prevents the breakdown of fibrin clots

Question 11

Aminocaproic Acid (Amicar) Dose

Answer 11

Loading dose
50 – 75 mg/kg

Infusion rate
20 – 25 mg/kg/hr

Non weight-specific dosing: 5-10 g load followed by 1 g/hr

Question 12

TXA Dosing

Answer 12

10 mg/kg followed by 1 mg/kg/hr infusion

Question 13

Protamine MOA

Answer 13

Protamine inactivates heparin by binding to it to form an inert salt

Question 14

Protamine Dosage

Answer 14

Test dose of 1 mg given over 10 minutes
Actual Dose
~ 1 mg of protamine for every 100 u of heparin administered
May also be dosed per kilogram (3 – 4 mg/kg)

Question 15

Protamine adequacy

Answer 15

Assessing ACT q3-5 minutes after completion of infusion

Question 16

Risk factors for adverse CV response to protamine

Answer 16

mitral valve disease	
pHTN 
infusion rates > 5 mg/minute 
diabetes with previous exposure to NPH insulin 
Vasectomy

Question 17

SVR

Answer 17

= (MAP – CVP) / CO
Normal is 800 to 1,600 dynes-sec/cm5/m2
Important component of the resistance to ejection (afterload)

Question 18

PVR

Answer 18

= (PA mean – wedge) / CO
Normal is < 150 dynes-sec/cm5/m2
Defined as pressure difference across the pulmonary vascular bed