Dopamine

dopamine

I rank Dopamine 13 out of the 33 drugs I carry.

We use Dopamine for cardiogenic shock or septic shock refractory to fluids.

I have never used a lot of Dopamine over the years. When I started we carried Dopamine in vials and had to mix up our own drips. Working as a single medic, if I had a patient who needed Dopamine, they usually needed too much attention from me for me to break away and mix up a drip (and we had fairly short transports to the hospital). Over the years I have grown more comfortable with mixing drips, while at the same time we now carry a premixed Dopamine. Lately I have started to use Dopamine more with return of spontaneous circulation (ROSC) from cardiac arrest. I have had success to the extent that where before I often lost pulses after regaining them as the epinephrine wore off, I have had many more patients gain and hold a decent pressure once I have the Dopamine hung. Still, most of these patients end up dying in the ICU.

If I am giving someone Dopamine, as I said before, they are pretty bad off. I have only ever given it twice for septic shock after having dumped a liter of fluid into a patient with no change in hypotension, but I don’t know the patients’ final outcomes.

I rate Dopamine where I do because it at least has the potential to be a lifesaver.

We don’t carry med pumps so the drip is pretty much of an eyeball, and then titrate to blood pressure. When you have no pressure, you bump it up. You get a pressure above 90, you ease it down.

Several times at the hospital I have had to warn nurses about shutting the Dopamine off completely. Recently I brought in a cardiac arrest ROSC with a BP of 120-something systolic, the nurse shut off (unhooked) the Dopamine because the pressure was good. I said, you might not want to do that, but she never hooked it back up, and when I came back from writing my run form,they were doing CPR. They eventually got pulses back and ended up putting the patient back on Dopamine. Like so many others, she made it to the ICU only to die within a few days.

I only used Dopamine once last year, but have used it twice so far this year. All three cases were post-rescucitation care.

***

Dopamine (Intropin)

Class: Naturally occurring catecholamine, adrenergic agents

Action: Stimulates ?, ?1 and dopaminergic receptors

Effects: 0.5 to 2 ?g/kg/min – Renal and mesenteric vasodilation.
2 to 10 ?g/kg/min – Renal and mesenteric vasodilation persists and
increased force of contraction (FOC).
10 to 20 ?g/kg/min – Peripheral vasoconstriction and increased FOC (HR may
increase).
20 ?g/kg/min or greater – marked peripheral vasoconstriction (HR may
increase).

Indication: Shock – Cardiogenic
- Septic
- Anaphylactic

Contraindication: Pre-existing tachydysrhythmias or ventricular dysrhythmias.

Precaution: Infuse in large vein only
Use lowest possible dose to achieve desired hemodynamic effects,
because of potential for side effects.
Do not D/C abruptly; effects of dopamine may last up to 10 minutes after drip
is stopped.
Do not mix with NaHCO3 as alkaline solutions will inactivate dopamine.

Side effect: Tachydysrhythmias
Ventricular ectopic complexes
Undesirable degree of vasoconstriction
Hypertension relate to high doses
Nausea and vomiting
Anginal pain

Dose: 2.0 – 20. ?g/kg/min titrated to desired effect

Route: IV drip

Pedi dose: same as adult dose – titrate to effect

7 Comments

  • Foster says:

    Peter,

    A few of us did a lot of prep for the JEMS Games this year in Baltimore, part of which involves setting a dopamine drip within a +/- 5% error range. What I found is that it is extremely easy to over or under dose when trying to “eyeball” a drip as you say. When the drip rates are slow (as is the case with anything under 10 mcg/kg/min for normal sized adults, and even higher for smaller people), a difference of a single drip per minute can mean a 10 or 15 percent over/under dosage. After counting out my “eyeballed” drip rates I found that I was consistently off by 20 percent or more. That is really significant!

    I was wondering what you thought about this being that in the hospital, pressors like this are *NEVER* run off-pump. (nevermind in the back of a bumpy ambulance, which for all intents and purposes basically makes accuracy impossible.) Eyeballing drip rates of potent drugs like dopamine seems kind-of like stone age medicine. I recently wrote a blog entry about this very subject.

    I’m sure you’ve tried it before but if you haven’t, try setting up an eyeballed drip rate on a 60 gtt set and a 250 bag while you’re sitting at the base, then count it out over a full minute or two and see what you’ve actually set. I was surprised to find out for myself.

  • medicscribe says:

    Thanks for the intelligent comments, Foster.

    The bottom line answer is in an ideal world you should never give the drug without a med pump. That said, since we don’t have med pumps, the choice is to give dopamine or withhold dopamine. When I took my nursing practical exam we had to set up a drip and were given 15 minutes to select the proper med, calculate the drip rate, spike the bag, hang it and then get a drip rate within 5 drops. I needed most of the time to get it right, holding my watch up to the drip set and counting. You know we don’t have this kind of time in an ambulance. The other thing is our protocols permit us a wide range of between 5 ug/kg/min up to 20 ug/kg/minute titrated to effect. (This is an enormous drops per minute range). If I am a single medic working a ROSC or critical septic patient, I am not going to spend 15 minutes, much less five minutes holding my watch up to the drip set in full concentration trying to get just the right number of drops to start out at 5 ug/kg/min. Keep in mind I am also ballparking the patient’s weight because we don’t have a scale and the patient being intubated and post arrest can’t tell me his weight not that he would be truthful about it. If I start low, and when I recheck the blood pressure and it is still in the 60′s if he has a pressure at all, I will up the drip. If his pressure is 140, I will ease it down. In other words, I will titrate to effect. Once he is in the hospital, which will be soon, he can be reassessed, and put on a med pump. I think this method is preferable to withholding a potentially life-saving drug. The other point to keep in mind is the hospital is setting rates for a much longer term than we are. Being off by five drops a minute makes little difference over 15 minutes, but makes a larger difference over 24 hours.

    Peter

  • Foster says:

    Peter,

    Yeah, I spoke with some nurses about this a few weeks ago when I found how difficult it was to set the drip rates within a reasonable amount of time. They all had the same story as you: it takes a good amount of time watching that drip chamber to get even close, and even then often times nurses would do 10 minute check backs and “tape counts” to verify they had set the wheel correctly. Often times, even after spending a lengthy period setting the rate, they found they hadn’t and had to readjust.

    I think you’re right about the reduced potential for damage given our short transport times, and the inherent inaccuracy due to a “made up” patient weight, but even still the whole process strikes me as a a little rougher than it should be. For the JEMS Games, I ended up buying a small musician’s electronic metronome, which I could set to beep at a given rate. That helped a lot with setting drip rates on the fly. People will probably make fun of me, but I packed it in my backpack that I bring to work. The guidelines may say “titrate to effect,” but I still think it is reasonable and professional to know more concretely what dose you are giving your patient. I do sometimes wonder if the inaccuracy of our drips often has a lot to do with why nurses lock them off or pull them down so quickly: they can’t chart an unknown titrated rate, so I bet it is easier for them to simply stop the bag and think about restarting it themselves (on a pump) later on.

    At that same conference, I dropped by one of the vendor’s booths that sells those mini med pumps and inquired about cost. They’re about four grand each. Heh. I’m not holding out any hope that those will be sitting on our ambulances any time soon.

  • Just a medic says:

    Like medicscribe, I’ve experienced my share of cardiac arrest patients who go RoSC only to crump again a couple minutes later once the epi wears off. A couple years ago a newly minted paramedic taught me something new. He pointed out how long it takes to find the dobutamine (or dopamine), spike the bag, guesstimate a weight, and calculate a drip rate. He suggested I could avoid the crump phase entirely by starting a vasopressor drip “soon enough,” i.e. before the patient *needed* it. The justification was that, by definition, patients in cardiac arrest were experiencing cardiogenic shock. We know cardiogenic shock doesn’t — can’t — resolve instantaneously. I think he was on to something. For the past several dozen codes I’ve been preparing my vasopressor during CPR, going so far as to start an extra peripheral IV and hook up the dobutamine bag (without turning it on). If/when we get RoSC, step 2 is to activate the vasopressor drip with a flick of the thumb. (Step 1 is to activate the transcutaneous pacer and step 3 is to measure a blood pressure.) Since I changed I’ve been seeing less hypotension in my RoSC patients, often avoiding it entirely. That lets me move on to other things like the ventilator, hypothermia, sedation, 12-leads, etc. Let’s face it, when one works as a solo medic every little bit helps. Has anyone else tried this?

  • Chris says:

    You must be getting a whole lot more ROSC than we are here. If we set up our pressor drip before getting pulses back, we would never start 12 of every 13 or so of those drips. That’s a lot of wasted effort, and a whole lot of wasted drug.

  • medicscribe says:

    I think there is some merit in getting the dopamine ready. You would of course have to guage your odds of ROSC. If someone is asystole and unwitnessed, you are obviously less likely to need it, but witnessed arrests, arrests with high ETCO2 after intubation are all much more likely to be resucitated.

    Where I have thought of giving Dopamine before ROSC is in those patients who show a jump in their ETCO2, but you still can’t feel pulses. These are the psuedo PEA patients. You have a rhythm, and in all likleihood they have a blood pressure, it is just to low for you to feel a pulse. Maybe with a doppler, you could hear one. I think these patients might benefit from Dopamine. I haven’t used it in this situation yet, but I am thinking of discussing it wen we readdress our regional guidelines.

  • Just a medic says:

    To Chris: Lately I’ve been seeing RoSC every 3rd or 4th code, thanks probably to quick defibrillation by volunteer firefighters. On an unsuccessful code with field termination my agency expends about $130 worth of supplies. On a code with RoSC and transport my agency expends about $250 in supplies. A bag of dobutamine (or alternately dopamine) costs about $6.

    To Medicscribe: You’re on the right track with “pseudo PEA.” I like that term. I agree about an organized ECG rhythm plus an increasing EtCO2 strongly suggesting RoSC even if you can’t measure a blood pressure or feel a pulse. Often I have time to set up central venous pressure monitoring while CPR is underway, and this adds a third indicator. The triad of A-waves on CVP plus organized ECG plus rising EtCO2 is unmistakable evidence of RoSC. Vasopressors and standby pacing seem to work well. I’d encourage you to pursue supporting protocols if you don’t have them already.

    One of these days I hope to get arterial pressure monitoring going in time to capture the transition to RoSC on the memory card. I concur with your hypothesis: we’d see pressures probably in the 40′s or 50′s at first, well beneath the sensitivity of noninvasive cuffs. This area may be ripe for research. I wonder how much time elapses after true RoSC before we the intubating gorillas take notice?

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