Another heparin protocol...

brithoover · Dec 22, 2013

Don't you have a smart pump where you can actually program in units/hr?

nyteshade, BSN · Dec 22, 2013

Yes, but the question is regarding what is in the patient's MAR: "If aPTT is 35-45 sec increase rate by 150 units/hr (2 units/kg/hr)" if you simply increase by 150 units/hr the result is 11.5 ml (1150 units/hr) or if you use 2 units/kg/hr it is 12 ml/hr (1200 units/hr). If you're supposed to increase by 150 units, then the weight-based answer of 1200 units/hr is 200 units more over the initial 1000...it's a difference of 50 ml/hr something doesn't compute...

The pump will not help in this case.

I'm not sure if my facility is using weight-based and non-weight based calculations. I've seen literature that states some hospitals use both or just weight-based.

psu_213, BSN, RN · Dec 22, 2013

This seems like a pretty standard protocol for heparin (in most cases, exactly which protocol is followed is based on the pt's medical dx--NSTEMI, PE, DVT, etc.--that is determined by the doctor).

Our pumps, under our "Guardrail infusions" (Alaris) allow us to enter a weight in kg (technically, for you physics folks, that is their mass, but I digress big time). The you under the dose...for example 12 units/kg/hour. The pump then calculates the drip rate and delivers that. The nomogram then has the drip changes for each aPTT result--i.e. for aPTT 35-45, increase by 2 units/kg/hr (another example could be "for aPTT>150, hold drip for one hour and then decrease rate by 2 units/kg/hour when drip resumes). Going back to your example, if the drip is 12 units/kg/hour and the aPTT comes back at 40, then the pump dose could be set at 14 units/kg/hour. Again, the pump does all of the math and sets/delivers the drip rate. Some facilities require a rate change to be witnessed by a second RN.

If you don't have that type of pump...you were running at 1000 units/hour. Based on the nomogram, you are increasing the dose by 150 units/hour. Which comes out to 1150 units/hour for a drip rate of 11.5 ml/hour.

If possible, heparin drips should be set based on units/hour or units/kg/hour...not based on the drip rate.

psu_213, BSN, RN · Dec 22, 2013

Yes, but the question is regarding what is in the patient's MAR: "If aPTT is 35-45 sec increase rate by 150 units/hr (2 units/kg/hr)" if you simply increase by 150 units/hr the result is 11.5 ml (1150 units/hr) or if you use 2 units/kg/hr it is 12 ml/hr (1200 units/hr). A difference of 50 units/hr. The pump will not help in this case.
I'm not sure if my facility is using weight-based and non-weight based calculations. I've seen literature that states some hospitals use both or just weight-based.

What is your facility using for the pt's weight? At one hospital for which I worked, pt weights were rounded off to the nearest 5 kg. Not sure why, since the pump can handle an "odd" weight. Are they using an actual, measured weight, or are they going based on the estimated weight that was entered into the chart when they were in the ER?

nyteshade, BSN · Dec 22, 2013

The math:

12 units/kg/hr + 2 units/hr is 14 units/kg/hr

14 units x 86.4 kg is 1209.6 units/hr

1209.6 units/ hr x 250 ml is 302,400 divided by 25000 units equals

12.096 or 12 ml/hr

nyteshade, BSN · Dec 22, 2013

The weight used was 86.4 kg by pharm

nyteshade, BSN · Dec 22, 2013

"If possible, heparin drips should be set based on units/hour or units/kg/hour...not based on the drip rate"

I totally agree with you there psu.

If pharmacy is putting "increase by 150 units/hr (2 units/kg/hr) isn't the 2 units/kg/hr supposed to result in the same answer? The parenthesis comes across as if the two were equal to each other. This is where I feel something isn't right. If they are supposed to be equal then it should read:

Increase by 200 units/hr (2 units/kg/hr).

This is where I'm lost.

psu_213, BSN, RN · Dec 22, 2013

If pharmacy is putting "increase by 150 units/hr (2 units/kg/hr) isn't the 2 units/kg/hr supposed to result in the same answer? The parenthesis comes across as if the two were equal to each other. This is where I feel something isn't right. If they are supposed to be equal then it should read:
Increase by 200 units/hr (2 units/kg/hr).

This sounds like a med error waiting to happen. They should be giving you either a weight based dose (i.e. 12 units/kg/hr to 14 units/kg/hr) or an increase based on just units (i.e. 1000 units/hour to be increased by 150 units/hour). To give both, just makes it more confusing--especially when they don't jive. What is the original doctor's order? Weight based or units/hr?

nyteshade, BSN · Dec 22, 2013

Well, the doc ordered a cardiac (ACS) protocol, and pharmacy started it at max rate of 1000 units/hr or 12 units/kg/hr (arbitrary for the protocol). Both figures were listed on MAR for the initial start. Pharmacy also noted the pt weight to be used.

I agree it should be either or, and that this is an error waiting to happen.

I just needed fresh eyes to tell me if I am overthinking this or it really does look screwy.

Altra, BSN, RN · Dec 23, 2013

Are you sure you're supposed to factor in the patient's baseline PTT into the initial infusion rate? Everywhere that I have worked, the nomogram order has listed an initial rate, with further instructions to adjust the rate and/or give boluses based on PTT results q 6 hours.

nyteshade, BSN · Dec 23, 2013

I wasn't trying to calculate the initial rate, pharmacy already set that. This is for a rate change based on aPTT 6 hours after.