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JACK

Dilution and Concentration of Inotropes

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We are in process of revising our policies on intropes infusion

Can I ask my colleagues to share their practice policies regarding the following:

1 - What dose range do you use for Dopamine, Dobutamine and Adrenaline infusion ?

2 - Do you use combination of Dopamine and Dobutamine routinely ? Do you have a fixed ratio for these two inotropes ?

3 - What dilution do you use for Dopamine, Dobutamine and Adrenaline infusion ?

4 - DO you have fixed concentration for these drugs or do you use different concentration based on weight ?

Edited by JACK

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Dose range - per Neofax - Dopamine 2-20 mcg/kg/min, Dobutamine 2-25 mcg/kg/min, Epinephrine (Adrenaline) 0.1 - 1 mcg/kg/min.

We are not a very large unit, so this is not "routine" at all.

Dopamine & Dobutamine have been used together, variable rates, not fixed.

Dilutions: we used to make 500, 1000 and 2000 mcg/mL infusions of dopamine, now with the increased worry about making errors in diluting meds we just use the pre-mixed bags from Baxter, 800, 1600 and 3200 mcg/mL.

Dobutamine: 500, 1,000, 2,000 mcg/mL

Epinephrine: 40 or 60 mcg/mL

We use "smart pumps" that are programmed with these dilutions and rates, and the RNs use our drip rate charts to double check their mixing and rates.

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Hi Jack, we are a third level nicu. We use a formula to calculate the right dose of dopamine, dobutamine and adrenalin. It's useful when you have to calculate micrograms/kg/min

6 x (micr/kg/min) x kg : ml/hour

this is the amount of dopamine, dobutamine or adrenalin to add to reach 100 ml of infusion like glucose.

example: you have a baby weighing 1200 gr (1.2 Kg) and you want to give 3 micrg/kg/min by pump syringe at a rate of 0,1 ml/hour

calculate: 6x 3 x 1,2 : 0.1 ml/hour

= 216 mg for 100 ml

= 108 mg for 50 ml

= 54 mg for 25 ml

= 21 mg for 10 ml

so if you give at this baby 0,1 ml/hour of this concentration it will be 3 micg/kg/hour

I hope I've helped you...

Which drug ? It depends on what you want to achieve. Usually dopamine works on kidneys at low dosage, on heart at higher ones. Dobutamine increases heart rate. We usually decide at the moment on which the baby needs :)

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1. Doses... dopamine and dobutamine is usually given 2.5-12.5 microgram/kg/min; adrenalin 0.1-0.3 microgram/kg/min

2. Combinations - yes sometimes... if dopamine does not give enough response (whatever that may be...)

3. glucose (50 mg/ml)

4. We have fixed dilutions of inotropes, and change the infusion rate depending on the response: dopamin/dobutamin 0.3, 0.6 or 1.2 mg/ml and adrenalin 10 microgram/ml.

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Hi

There always has been debate going on regarding the best ionotropic agent , their dose and related issues . A fabulous area to discuss

We usually tend to avoid giving combination of ionotropes unless the situation is desperate . The strategy is usually to detect the underlying cause . We normally do a functional bed side echocardiography and look at the cardiac function . If the cardiac function is a factor that is responsible , then dobutamine is the choice . Similarly , is the case with PPHN

However , if the cause is significant hypotension with a normal cardiac function , Dopamine is usually the first choice

We prefer not to go beyond 10 mcg / kg / min . This is usually sufficient . And we have found that doses of dopamine as low at 2 mcg / kg / min works in some cases , especially in preterms . This is usually noted during weaning of ionotropes . What happens sometimes is when we stop dopamine when it reaches 5 mcg , the BP dips .. So , we might persue weaning down to as low as 2 mcg . Its interesting ... but cant explain . Maybe the mechanisms differ in preterms

We prepare dilutions based on the fluid balance . If fluid restriction is a concern , then a very concentrated solution is made , which would be run at 0.3 ml / hr or so ... and this is invariably given through the central line .... I could send you the formula for dilution if you are interested . Its a bit laborious , but works fine . A bit of thinking goes into the concentration of fluid so that the rate of infusion can be optimized

We generally avoid fixed combinations ... So far , I didnt find any error in calculation , the system being very meticulous . The doctor first write the orders which is then verified by 2 other nurses , and a further verification prior to administration .

I hope this helps to a certain extend .... I just included these so that these aspects could be looked into while formulating a policy .. Its entirely upto the unit to decide on the formulation based on the comfort level and availability of resources . Please reply if you wanted more information

Bye

Gopakumar

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Good to see so many informative responses.

We have been computing Inotrope (Dopamine, Dobutamine, Adrenaline) Dilutions based on weight.....E.g., Dopamine: For a baby weighing x kgs, we used to add 3 times x of Dopamine (mg) to Dex 5 to make a total of 25 mL and then the infusion was 0.1 to 1 ml/hr ( corresponds to 2 to 20 mcg/kg/min)...SO if weight is 1 kg , we add 30 mg Dopamine to Dex 5 to make total of 25 mL and so on. There were similar formulas for DObutamine and Adrenaline.

All preparation is being made in the central IV Room. All dilutions are made by a Microsoft Excel based formula depending upon the weight. Majority of the time a baby getting inotropes will have a central line.

The doses we use are 2-20, 4-40, 0.1-1 mcg/kg/min of Dopamine, Dobutamine, Adrenaline. We rarely use adrenaline except in the unresponsive shock cases. We always try hydrocortisone prior to using adrenaline infusion. We frequently use Dopamine plus Dobutamine co-infusion.

There are now dissenting voices in the unit who feel that changing dilution based on weight may lead to errors in calculation though that has not happened so far. Also some feel that in babies of good weight ( eg 4 kg plus ), our existing calculations will give rise to a very concentrated final solutions, and would prefer not to exceed the upper levels as stated in neofax.

This is the current debate in our unit. Should we just continue the existing system, which has worked so nicely and which everyone is used to? Is there any danger of infusing concentrated inotrope solutions or should there be an upper limit of concentration ? Will using pre-mixed bags, make it difficult to control fluid intake ?

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We follow a very simple formula. Most of the time it works especially in micropremies.Here's it.please do opine.

Dopamine

1 ml in 49 ml NS /5% dextrose depending on babies electrolyte and sugar status ;this is taken in 50 ml syringe;given using syringe pump

weight of baby x microgram/kg/min= ml/hr

13.3

Dobutamine

1ml in 49 ml NS or 5% dextrose ;

weight x mcg/kg/min= ml/hr

16.6

We follow the babies clinically-STOPS criteria;sensorium,temperature,oxygenation,perfusion,sugar.ABG too helps.Besides the BP values either NIBP or IBP.Tachycardia and prolonged CRT are critical findings.

We try and keep the MBP for premies above 30 atleast and as per their weight and gestation.If BP is low after a bolus of 10 ml/kg slowly over 30 min ,(unlike 20 ml/kg over 5-10 min in larger ones),is followed by inotropes-dopamine.IF tachycardia is prominent we opt FOR dobutamine.If baby is septic our choice would be adrenaline .In many a situation we have started dopa and doby as co-infusion.

Our policy is to follow the neofax dose, begin at 10 mcg /kg/min and escalate or stepdown as per response which is again assessed clinically.Meanwhile we perform echo too which can reveal the flow and presence of PPHN.These assessments are done in 5-10 min and rquired dose changes are done .We follow the GOLDEN HOUR principle,whereby if required all 4 drugs are added(dopa,dobut,adren,nor adren) one after the other.If still no improvement we consider steroids after necessary blood tests.

Baby might be ventilated as well.

Edited by dr hazeena
formula with underline not coming properly

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