Confused about dobutamine. Help!

Specialties CCU

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Hi, everyone. I've on my second week of off orientation in a CCU. The other day I had a patient who had multiple issues: pleural effeusion w/ chest tube ( the effeusion was resolving however), improving septic shock, AKI, moderate valvular disease. Initially on admission, he was on dobutamine, levophed, and vasopression- the dobutamine because he was in cardiogenic shock, levo and vaso for the sepsis. They first managed to get him off the levo and vaso and then I see that the dobutamine was weaned off to "keep SBP >90 or MAP >60"- this is according to an order I saw.

During my night with him, I noticed that his SBP was over the 90's, but his DBP was consitantly in the 20's. This made is MAP in the 40's-50's. I looked at his trends and it seemed that his DBP has been mainly in the 30's-40's during prior shifts. I got concerned and noticed that the dobutamine drip was still on standby on the pump and this order was still active, so I started him on 2 mcg. I contacted the cardiology group and they mentioned to start Levo at 8 mcg. I didn't notice a significant difference in his pressure until I went to 7.5 of the dobutamine and stayed at 8 of the levo. And by the morning, his DBP returned back to the 20's unless I went up on the levo. And his MAP stayed around the high 50s but struggled to hit 60. I was confused on how to titrate between these two gtt's and what would most benefit this patient.

I think I am most confused about the role of dobutamine. I know its a positive inotrope but does it really increase blood pressure or decrease it because I know it will decrease SVR. I have heard one RN tell me it decreases BP while another says it increases BP. With a cardiac patient whose blood pressure is tanking does it really help them in the short term or should I just placed him first on the Levo instead? His EF came back at 55% which is why (according to the notes I read) they wanted to wean the dobutamine gtt.

BTW, I was told he had received dialysis the day I got assigned to him, so perhaps he really needed some fluid instead? The oncoming RN also mentioned that perhaps he needed to get re-cultured again. Maybe he was still septic?

I'm just thinking there was another way I could have handled it. It's been difficult to adjust to feeling comfortable with what to do as far as making critical thinking judgments.

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Specializes in Critical Care.

Are there no nurses on your unit who could have helped you in the moment? Sounds like you were flying solo here?

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There were other nurses who advised me to talk to the doctor. The patient looked stable but his bp was low so that was my primary concern.

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Diastolic is very often a measure of fluid status. You can tighten the vasculature all you want with pressors but with no volume you're not going to get anywhere.

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Did this patient have significant aortic insufficiency? That can cause low diastolics. They should have told you what they wanted to prioritize in terms of blood pressure control - titrating to SBP or titration to MAP. Were they aware that you had restarted the dobutamine?

Dobutamine can actually cause some vasodilation (especially at low doses) and lower the SVR, but if the BP is low because your CO/CI is in the toilet, it will actually raise BP as the CO/CI improves. Milrinone does the same thing, although the mechanism of action is different from dobutamine. In my CCU, milrinone is by far the preferred agent. I rarely see dobutamine.

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Did this patient have significant aortic insufficiency? That can cause low diastolics. They should have told you what they wanted to prioritize in terms of blood pressure control - titrating to SBP or titration to MAP. Were they aware that you had restarted the dobutamine?

Dobutamine can actually cause some vasodilation (especially at low doses) and lower the SVR, but if the BP is low because your CO/CI is in the toilet, it will actually raise BP as the CO/CI improves. Milrinone does the same thing, although the mechanism of action is different from dobutamine. In my CCU, milrinone is by far the preferred agent. I rarely see dobutamine.

Thanks everyone for their response. When I returned to work, I was told that because the patient had severe valvular disease (particularly the mitral/triscupid valve), his DBP would be low. This was considered his baseline. They didn't focus on his MAP as much as his SBP. They took off the dobutamine and used levophed instead.

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Interesting, complex case. Dobutamine isn't as common as it used to be. It sounds like it was added precisely because of the mitral insufficiency. Vasopressin and the NE would make the mitral resurge worsen because of the afterloading effect on the LV.

More blood would go through thru the diseased valve.

The dobutamine would help the heart overcome the after load effect of those pressors, thus decreasing the amount of backward flow thru the mitral valve on systole.

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Specializes in Cardiac/Transplant ICU, Critical Care.

When dobutamine is started you have a stimulation on your B1 and mild B2 andrenergic agonist receptors. The B1 stimulation causes a + inotropic and + chornotropic effect. With dobutamine being an inodilator it will also decrease your SVR via vasodilation of the peripheral vasculature.

So when dobutamine is started one of two things will happen. You will have an increase in index/output and increase in blood pressure (MAP) because the + inotropic + chronotropic effects will supercede the vasodilatory effects. On the flip side the vasodilatory effects can supercede the + inotropic and + chronotropic effects of dobutamine in which case we will see an increase in index/output decrease in blood pressure necessitating levo and vaso as well.

I actually made a video on the finer aspects of Vasoressors and Vasopressor like medications in the ICU setting for Critical Care Nurses, if you check it out, I think it will definitely help step your nursing game up. :yes:

[video=youtube;hiI-8GV-kBk]

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Thanks a lot for the video. That really helped!

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Specializes in Cath/EP lab, CCU, Cardiac stepdown.
When dobutamine is started you have a stimulation on your B1 and mild B2 andrenergic agonist receptors. The B1 stimulation causes a + inotropic and + chornotropic effect. With dobutamine being an inodilator it will also decrease your SVR via vasodilation of the peripheral vasculature.

So when dobutamine is started one of two things will happen. You will have an increase in index/output and increase in blood pressure (MAP) because the + inotropic + chronotropic effects will supercede the vasodilatory effects. On the flip side the vasodilatory effects can supercede the + inotropic and + chronotropic effects of dobutamine in which case we will see an increase in index/output decrease in blood pressure necessitating levo and vaso as well.

I actually made a video on the finer aspects of Vasoressors and Vasopressor like medications in the ICU setting for Critical Care Nurses, if you check it out, I think it will definitely help step your nursing game up. :yes:

[video=youtube;hiI-8GV-kBk]

You just got yourself a subscriber. Now go make more videos

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Specializes in Cardiac/Transplant ICU, Critical Care.
Thanks a lot for the video. That really helped!

My pleasure, im happy I was able to help!

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Specializes in Cardiac/Transplant ICU, Critical Care.
You just got yourself a subscriber. Now go make more videos

Done and Done! After my first video I was planning to do a video every week, but all of a sudden it was 4 weeks later and finally got around to it. :yes:

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