Meds

Question 1

What are the functions of Ca++?

Answer 1

1) Cardiac action potential
2) Increase FOC, smooth muscle contraction
3) Blood clotting factor in coag cascade
4) Bone density

Question 2

What is calcium gluconate indicated for, and how is it given?

Answer 2

For electrolyte replacement.

1-2g IV in 100cc D5W over 1 hr

Question 3

What is the corrected calcium calculation and why is it used?

Answer 3

50% of calcium is ionized but 45% bound to albumin and 5% to other elements

Corrected Ca++ = Ca(m) + [0.02 x (40-alb) ]

Question 4

What is calcium chloride used for, and how is it given?

Answer 4

For severe hypocalcemia, hyperkalemia, Ca++ channel blocker OD, cardiac arrest, CRRT protocol

1g in 100cc D5W CVC over 1 hr or push

Must administer centrally, pre loaded syringe available

Question 5

How is calcium gluconate and calcium chloride different?

Answer 5

Calcium chloride has 3x the elemental / ionized calcium, used for emergencies, centrally administered, can be pushed via pre-filled syringe

Question 6

What class of drug is dopamine?

Answer 6

Sympathomimetic, inotrope, vasopressor

Question 7

What are the doses of dopamine and effects?

Answer 7

1) Low / Dopaminergic / Renal ( < 3 mcg/kg/min) mild renal vasodilation, increase U/O
2) Moderate / Intermediate / Beta (3 - 10 mcg/kg/min) Beta-1 selective, cardiac inotrope cronotrope dromotrope

3) High / alpha / pressor (10 - 20 mcg/kg/min)
Alpha selective, vasoconstriction

Question 8

When is dopamine indicated and how is it given?

Answer 8

Acute severe hypotension, sepsis (4th line), symptomatic bradycardia (but dobutamine and milrinone are better)

400mg in 250cc –> 5mg/kg/min titrate (start at beta dose)

Give centrally

Question 9

What must be considered when given inotropes?

Answer 9

Inotropes increase FOC. Hypovolemia must be resolved first so that the heart has something to pump

Question 10

What is dobutamine’s drug class?

Answer 10

Sympathomimetic inotrope, beta 1 selective mild beta 2

Question 11

What is the effect of dobutamine?

Answer 11

Inotropic, mild vasodilation

Increase FOC, CO, decrease afterload and preload

Question 12

Does dobutamine affect renal vessels?

Answer 12

No. Any increase in U/O is related to increase GFR and CO

Question 13

When is dobutamine indicated and how is it given?

Answer 13

Reversible heart failure / post op, shock, CHF, pharmacologic stress testing

5 - 15mcg/kg/min given centrally

Question 14

What are nursing considerations for dobutamine and milrinone?

Answer 14

Little change to HR so good med for cardiac patients, but high doses will cause tachycardia and arrhythmias from enhanced AV conduction. Fix hypovolemia

Question 15

What is milrinone’s drug class? What is its mechanism of action?

Answer 15

Cardiac inotrope, vasodilator

Inhibits phosphodiesterase type III which is an enzyme that destroys cAMP (regulates Ca++ passage to heart). Inhibition therefore overall raises the level of Ca++ in the cardiac cells and increases FOC as well as allows mild vasodilation in vasculature resulting in increased SV

Question 16

When is milrinone indicated and how is it given?

Answer 16

Reversible heart failure / post op, shock, CHF, weaning off cardiopulmonary bypass

Loading: 50mcg / kg over 10-15 mins
Continuous: 0.25 - 0.75 mcg/kg/min

Mix 20mg in 80mls D5W/NS to give 100 mls
Give centrally

Question 17

What are the similarities and differences between dobutamine and milrinone?

Answer 17

Similarities: 
Increase FOC, CO, SV
Decrease afterload, preload 
Use central line
Titratable 
Good for cardiac patients (not chronotropic) but can cause tachycardia at high doses 
Similar indications 

Differences:
Sympathomimetic vs Cardiac inotrope
Beta 1 selective vs enzymic inhibition
Milrinone has loading dose and LONG half life (2-4hrs)

Question 18

Why should we monitor pts after stopping milrinone?

Answer 18

Long half life 2-4 hrs, med is bound to plasma proteins and continue to release. Monitor pts > 4hrs to ensure hemodynamics remain stable