Treating Hemodynamic Disturbances and Threats to

Tissue Oxygenation:

A Review of Commonly Used PIC/NIC Medications

Julie Warren RN, MSN, CCRNPediatric CNS

4/2013-Current

Intravenous Infusion GuidelinesIntravenous Infusion Guidelines

• Most hemodynamic drugs have a rapid onset and are almost all given intravenously

• Understand how long it will take for new dose to clear IV tubing containing an old dose: Don’t “treat” the line, treat the patient!

Alteration in the Autonomic Nervous System Responses

• Contractile state = inotropy

• Heart rate = chronotropy

• Speed of conduction = dromotropy

Inotropes• An increased intracellular calcium concentration

is the central cellular event that enhances contractility of the myocardium

• Inotropes work in one of two ways:– Stimulate receptors to increase cAMP (cyclic

adenosine monophosphate) which ultimately increases intracellular calcium

– Inhibit phosphodiesterase (PDE) which then increases cAMP

• Digitalis glycosides also enhance contractility but don’t use the cAMP “route”

Increasing Cardiac Strength

• Use of inotropes and preload reducers

Dopamine: Dopamine: • Dose varies based on intent:

• 0.5-2 mcg/kg/min: renal perfusion/diuresis• 2-5 mcg/kg/min: increased contractility and

C.O. (little HR inc)• 5-6 mcg/kg/min: HR and BP increase plus

increased C.O.• 10-20 mcg/kg/min: increased SVR/BP and

HR

• Primary side effects:• tachycardia• increased myocardial oxygen consumption

(MVO2)

Dobutamine• Improves contractility followed by CVP,

SVR, PVR• Dose:

• 2-5 mcg/kg/min to start• Maximum effects at 10-15 mcg/kg/min• Max dose not known

• Primary side effects:• tachycardia• increased myocardial oxygen consumption

(MVO2)• potential hypotension• arrhythmias

• Dose varies based on intent:– 0.05-0.3 mcg/kg/min: Improves contractility and

C.O. through peripheral vasodilation, HR, SVR, PVR– 0.01-1mcg/kg/min: for asystole or pulseless

arrest– > 0.3 mcg/kg/min: SVR and BP; but

vasoconstricts renal arteries• Primary side effects:

• tachycardia• increased myocardial oxygen consumption (MVO2)• arrhythmias• hypertension• CNS excitation: restlessness/dread/fear

Epinephrine:

Norepinephrine • Its hemodynamic effects limit its use in

pediatrics almost exclusively to treatment of septic shock; used to improve vascular tone after numerous boluses and other inotropes fail

• Dose varies based on intent:• 0.05-0.1 mcg/kg/min: Sharp in SVR;

improves contractility and C.O.if the increase in afterload can be tolerated

• 1-2 mcg/kg/min maximum• Primary side effects:

• profound hypertension• ischemic injury of the extremities• CNS excitation: restlessness/dread/fear

Milrinone (Primacor) • A Bipyridine that works as a

Phosphodiasterase (PDE) inhibitor/ “Inodilator”

• Increases cAMP content for an inotropic effect with reduced O2 demand

CO, SV, SVR, PVR, CVP• Mix in NS or 5% Dextrose• Dose:

– Loading dose of 50 mcg/kg over 10 minutes – 0.275-0.75 mcg/kg/min infusion

• Side Effects: hypotension and arrhythmias

RECEPTOR LOCATIONS PRIMARY ACTION

ALPHA-ADRENERGICAlpha 1

Vascular smooth muscleArterioles and venules

Increases intracellular CA++; Muscle contraction; Constriction; Inhibits

insulin secretion

Alpha 2 Presynaptic nerve terminals Decreases cAMP; Inhibits norepi release;

vasodilation; Negative chronotropy (HR)

BETA ADRENERGICBeta 1

Heart innervation:SA nodeAV node

Increases contractility;Increases heart rate;Increases automaticity;

Increases cAMP;Enhances renin secretion

Beta 2 Vascular smooth muscleArterioles and venules

Pulmonary smooth muscle

Dilation; RelaxationIncreases cAMP; Bronchodilation;

Enhanced glucagon secretion

DOPAMINERGIC Vascular smooth muscle:renal, coronary, mesenteric

Dilation

Review of Receptor Sites

Agent Dose

(mcg/kg/min)

Peripheral Vascular Effects

Alpha(+) = ConstrictingBeta 2 (-) = Dilating

Cardiac Effects

Beta 1 (+) = ↑contractilityBeta 2 (+) = ↑contractility

Alpha (+)

Beta 2 (-) DA Beta 1 Beta 2

Dopamine 2-5 0 0 2+ 0 0

5-10 0 2+ 2+ 1-2+ 2+

> 10 2-3+ 0 0 1-2+ 2+

Dobutamine 2-10 1+ 2+ 0 3+ 1-2+

Epinephrine 0.05-0.1 1-2+ 1-2+ 0 2-3+ 2+

Norepinephrine 0.05-0.5 3+ 0 0 2+ 0

Effects of Commonly Used Inotropes

DiureticsDiuretics

• Furosemide– Dose 1-2 mg/kg q 6-12 hrs, given at max rate of 0.5

mg/kg/min; If larger doses required (>120 mg), the infusion rate should not exceed 4 mg/min

• Can dilute to 1-2 mg/ml and give over 10-15 mins

– Continuous IV infusion:• 0.05 mg/kg/hr titrated for clinical effectiveness

• Side Effects:– Hypovolemia/hypotension– Hypokalemia/hyponatremia/hypochloremia– Ototoxicity– Metabolic alkalosis

Other DiureticsOther Diuretics

Spirinolactone 1-3 mg/kg/day PO

Ethacrinic Acid 1 mg/kg/dose diluted to concentration of 1 mg/ml infused over 20-30 mins

Bumetanide (Bumex)

Neonates:0.01-0.05 mg/kg/dose q 24-48 hrs Infants/kids: 0.015-0.1 mg/kg/dose q 6-24 hrs (max 10 mg/day)

Metolazone (Zaroxolyn)

0.2-0.4 mg/kg/day PO

Chlorothiazide

20 mg/kg/day po in two divided doses; Infants up to 6 mos: 40mg/kg/day PO

Cautions with DiureticsCautions with Diuretics

• Used cautiously in patients who are hypotensive– due to potential to further reduce BP

• Can cause fluid and electrolyte abnormalities– altered potassium and magnesium– dehydration/hypovolemia

• Urine output is not always a reliable method of estimating preload reduction

Afterload Reducers

Nitroprusside (Nipride)Nitroprusside (Nipride)• Balanced vasodilator: equal effects on venous and arterial

circulation– If SVR is not elevated, SV and CO/CI decline and BP is reduced; HR

increases as result– When SVR is high and contractility is depressed, the reduction in preload

and afterload result in increased SV and CO/CI; the increase in SV is proportional to the decrease in SVR; HR declines and BP is unchanged

• Dose: Given in 5% Dextrose- bag and tubing must be opaque or covered

• 0.5 mcg/kg/min starting dose• 1.5-2 mcg/kg/min usually reduce SVR; highest dose is 10 mcg/kg/min• very rapid onset of action; effects stop 3 mins after infusion d/c’d

• Side Effects:– byproduct of breakdown is NO and cyanide (toxic)

• use only for short periods (< 72 hrs)• measure cyanide levels by measuring lactate levels• hypotension

Afterload Reducers• The other key afterload reducer is

Milrinone• Nitroglycerine is rarely used in children• Calcium channel blockers rarely used:

– Nifedipine has been tried in hypertensive emergencies and to treat patients with hypertrophic cardiomyopathy (BP lowering effect in kids is not predictable however)

– Diltiazem-has emerged as an effective agent for SVT and atrial fib/flutter

• ACE inhibitors: Captopril/Enalopril – Also reduce preload

Other Key Drugs• Digoxin (increases contractility and has antiarrhythmic

properties)

• Antiarryhthmics– Adenosine (SVT)– Procainamide (SVT/JET/atrial ectopic tachycardia)– Lidocaine (Vtach/Vfib)– Amiodorone (Vtach/Vfib)– Esmolol (tachyarrhythmias)– Sotalol (refractory SVT/VT)

• Triiodothyronine (T3) -increases CO/decreases SVR

• Ca++ (increases contractility)

• Nesiritide /Natrecor (diuretic/natriuretic/vasodilator)

Other Key Drugs• Pulmonary Bed Vasodilators:

– Oxygen– Prostaglandins (also dilates PDA)– iNO – Prostacyclins:

• Epoprostenol (Flolan)– Endothelin Receptor Antagonists:

• Bosentan (Tracleer)– Phosphodiesterase Inhibitors:

• Sildenafil (Viagra) - oral

• Pulmonary Bed Vasoconstrictors: – Nitrogen– CO2

Miscellaneous Drugs

• Insulin Infusions for DKA: Refer to DKA Protocol

• Heparin infusions: Refer to Heparin Protocol (pilot)

• Propofol/Diprivan: Short term use only!!!!

Nursing Responsibilities in Checking Drips

• At the start of each shift, you must check each pump for the correct infusion rate and medication - calculate the rate, don’t trust the pump!

• For each new medication infusion order or rate change, you must manually calculate the drip rate and have it independently double-checked by a second nurse

Let’s Shift Gears:

Drip Calculations

Calculating Drips

• Two methods can be used:

– Use / memorize formulas and plug in your numbers

– Use conversion ratios: extremely useful if you forget formulas! Plus, there isn’t a formula for everything we calculate

Calculating Drips• Try to remember that there is more than one

step. With either method, start with what you know– You will need to know the patient’s weight in

kilograms (# lbs divided by 2.2)– You will need the # milligrams of medication in the

solution– You will need the amount of solution in milliliters

(ml’s)– You will need to know the infusion rate ordered

(mcg/kg/min)

Calculation: Example #1

• Epi drip is ordered at .05 mcg/kg/min

• Pt weighs 4.1 kg

• Your epi syringe comes labeled .064 mg/ml

• How fast do you run the pump (ml/hr)?

Calculation: Example #1• Use/ memorize the formula:

cc/hr = (mcg/kg/min) x (60 mins) x (wt in kg) syringe/drip concentration in mcg

• Fill in the “knowns” and do the math:

cc/hr = (.05) x (60) x (4.1) = 12.3 = .19 cc/hr

64 64

Calculation: Example #2

• Dopamine drip ordered at 5 mcg/kg/min

• Pt weighs 11 kg• Your dopamine syringe comes

labeled 80 mg/ 50ml• How fast do you run the pump

(ml/hr)?

Calculation: Example #2A• Use/memorize the formula:

cc/hr = (mcg/kg/min) x (60 mins) x (wt in kg)syringe/drip concentration in mcg

• Fill in the “knowns” and do the math:

cc/hr= (5) x (60) x (11) = 3300 = 2.1 cc/hr

1600 1600

Calculation: Example #2BUse the formula but place the syringe med

concentration in the denominator; if it’s already in mcg you are all set; if it’s in mg, do the math and then move the decimals after you get your answer

cc/hr = (mcg/kg/min) x (60 mins) x (wt in kg)_________________________________________________________________________________________________________________________

syringe/drip concentration in mg

Calculation: Example #2BThe easiest way??

Med concentration: 80 mg/50 mls= 1.6 mg/ml

cc/hr= (5) x (60) x (11) = 3300 = 2062______________________________________________________________ _____________

1.6 1.6

Now move the decimal because the denominator was in mg not mcg

Answer: 2.062 or 2.1 cc/hr

What if you know the infusion rate but don’t know the mcg/kg/min?

• This calculation is used when you need to work the other way: you’ve been titrating or weaning your drip (turning the rate up/down) or a patient comes to you from the O.R. or from outside transport

• Use the following formula and plug in pump rate, pt wt, and drip concentration:

mcg/kg/min= (rate) x (*drip concentration) (pt wt) x (60)

* in mcg/ml

Using Conversion Ratios When All Else Fails

• Set up equivalent formulas from what you know such as:– 1 lb = 2.2 kg– 1 mg = 1000 mcg– 1 hour= 60 mins

• Set up your equation so that numerators cancel out with denominators and what you want to find out is set up correctly (cc/hr not hr/cc).

A Conversion Ratio Example

• 1 gorp = 2.2 burps• 1 dweeb = 1000 mini dweebs• 1 jerp = 60 flibs• 10 burps = 1000 mini dweebs• 6 dweebs= 5 flibs

• How many jerps would you have if you had 20 gorps?

Start with what you have and what you want

• Have 20 gorps ? Jerps• Set up your conversion ratios so that units cancel

out correctly:

Let’s Try An Easy One

• Ativan ordered to be given: 1.25 mg

• It comes as 2 mg /ml

• Another nurse has drawn up 0.75 ml and asks you to check his/her math

• Did he/she draw up the correct amount?

Using Conversion Ratios

Let’s try using Conversion Ratios with our Epi example

from earlier• Epi drip ordered at .05 mcg/kg/min• Pt weighs 4.1 kg• Epi syringe comes labeled .064

mg/ml• How fast should you set you pump?

Start with what you have and what you want

Let’s try Milrinone

• Ordered dose is .5 mcg/kg/min• Pharmacy sends you 50 cc of

Milrinone in a 60 cc syringe labeled 20 mg/100 ml

• Your patient weighs 14 kg• What rate do you set your

pump???

Using Conversion Ratios

Let’s see if our Milrinone rate is correct using the “formula”

cc/hr = (mcg/kg/min) x (60 mins) x (wt in kg)*syringe/drip concentration in mcg

• Convert the syringe/drip concentration to mcg/ml:

* 20 mg/100 ml = .2 mg/ml= 200 mcg/ml

• Fill in the “knowns” and do the math:

cc/hr= (.5) x (60) x (14) = 420 = 2.1 cc/hr

200 200

Now You Try!!

• Your patient is receiving Fentanyl at 1.3 ml/hr

• The syringe is mixed 500 mcg in 50 cc

• How many mcg/hr is your patient receiving?

Another One!• You’ve just come on duty to find your

patient is on a dobutamine drip at 10cc/hr. You want to check the dose/rate against the original order.

• Your pt weighs 20 kg

• The dobutamine syringe reads “50 mg in 50 cc D5W”

• How many mcg/kg/min is the dobutamine currently infusing at?

Propofol

• Ordered mcg/kg/min as an infusion

• Ordered mg/kg as incremental doses

Precedex (mcg/kg/hr)

• Use the following formula:

cc/hr = (dose ordered in mcg/kg/hr) x (wt in kg)

syringe/drip concentration: mcg/ml

Precedex

• Dose ordered: 0.2mcg/kg/hr • Pt weight: 12 kg• Syringe concentration is: 4 mcg/ml

• How fast would you run the pump?• If you needed to titrate the drip- What

would the rate be for 0.3mcg/kg/hr?• 0.4mcg/kg/hr?

Almost Done!!• A new “experimental drug” has just been

approved for use on your patient following approval by the IRB

• Drug “x” is mixed as 20 units in a 50 cc syringe

• You are to infuse this new drug at a rate of 3 units/kg/hr

• Your pt weighs 5 kg

• How fast do you set your pump???

Last One!!!!!!

• You’ve just received an order to begin dopamine at 10 mcg/kg/min

• Your pt weighs 22 lbs

• Pharmacy sends you a syringe labeled “40 mg in 50cc”

• What rate do you set your pump at???