Vasopressors- Critical Care RN's please help!

loopingrace,
He was crumping the minute paramedics brought into the department. Had a BP 84/52 and a HR 125. He was breathing 40/min and our ER MD decided to intubate. We started giving him IV fluids (NS X 2 liters). He didn't have any signs of CHF- despite the SOB his lung sounds were ok and he had no JVD/ pedal edema. His initial complaint was rapid onset of left sided paralysis. He had a history of left sided weakness from a prior CVA, but this paralysis was new. Anyway, after we started fluids on him, we took him to CT to R/O bleed. When we came back, his blood pressure hovered in the 80's systolic. At this point, his 2nd liter was halfway done.
At this point, he may have been treated like a stroke patient. New onset of paralysis on a previous L sided weakness screams...reestablish blood flow with thrombolytics. But with changing diagnosis...it's hard to sort through.

I received an order to give Cardizem 10 mg IVP, to "Stimulate his atrial kick" according to the physician. Cardizem is a CCB, which I am sure you know. It is used to selectively reduce tachycardias that involve the AV node. It also slows ventricular rate in patients with rapid ventricular response during afib/aflutter. My guess is that if the patient went into afib, she wanted to slow the conduction to allow for an atrial kick, which would increase CO and BP. However, cardizem will cause hypotension and cause bradycardia or complete heartblock. So to combat this...you give in combination with a pressor i.e. Dopamine and plasma expanders and IV calcium gluconate/Calcium Chloride. This is asssuming patient isn't overloaded, CHF, in which case you want an inotrope.
I guess she was suspecting cardiogenic shock? My question however is "Why dump fluids into somebody if you're suspecting cardiogenic shock?"
There are two types of cardiogenic shock, systolic dysfunction and diastolic dysfunction. Basically systolic dysfunction is the decreased ability of the heart to pump blood forward and it effects the left ventricle. Diastolic dysfunction is an impaired ablility of the the ventricles to fill during diastole. So if the patient is having an increase heart rate with a low BP, the inital quick fix is volume. I advised the MD that the BP was low (In some way you questioned the order), she intructed to give it slow IVP and watch his BP, which I did. I slowly gave 5 mg of Cardizem and watched his BP go down to 64, then 54. I held the rest of the medication and notified the MD. She instructed to give more fluids.
I ask "Any pressors?" (Great suggestion!!!) My thinking is that, this should have been done sooner. I received an order to start the patient on Dopamine. I start the patient on Dopamine and titrate up. I started at 25 mcg, then titrated up to 50 mcg. (This is the maximum amount of Dopamine, at this does it is time to consider another pressor, like levophed.) Or why not try Epinephrine dose 0.01mcg/kg/min-0.1mcg/kg/min. This is a potent vasoconstrictor. It is used for cardiogenic shock. It can be used as inital treatment, it isn't only resevered for a code situation. Epi, increases heart rate, contractility, cardiac output, systolic BP, and cvp. This drug decreases SVR to some extent. This is benefical for patients in cardiogenic shock because an increase in SVR (afterload) increases the workload of the heart, which is detrimental for a shock patient because increased workload will cause more myocardial damage. This drug would have been the first choice among the surgeons we work with. Actually, one time we were coding this man. He eventually had a BP like 50's on Dopamine at max dose. The surgeon saw the drug and sharply said that Dopamine isn't going to help, get EPI. Which helped. This did nothing for his blood pressure and the MD wanted to then give dobutamine. At this point my patient brady'd down into the 40's and the physician stated to cancel dobutamine and start Levophed. While I'm preparing meds, the MD walks into the room and says she doesn't feel pulses and starts CPR.

Anyway, we code this guy. Initially he was in a PEA brady at 44. Then after rounds of medications and CPR, back and forth from Vfib to asystole, etc, pacing the guy, defibrillating, etc. The MD pronounces. Sounds like a rough night. Sounds like you did all that you knew to do. You questioned what the doc and made suggestions.
Not having any ICU experience besides the 13 week internship I had in school, my question is: Which vasopressor is chosen to be used at what time? If his pressures were low, he was probably tachy to compensate. If he was in afib..in theory correcting the afib with or without ventricular response would correct the low BP. Cardiazem, however, I would have been weary of giving, which you were since it decrease BP. Rather, which vasopressor is better for what patient? Dopamine, dobutamine, levophed? All of these drugs are indicated for patient in cardiogenic shock. Are they the same as far as effect on BP/HR? Or are some more for HR vs. BP?
Dopamine: Increases HR, BP, CO
Levophed: Increases BP, MAP, not sure about HR
Epi: Increases HR, BP, widened pulse pressure, contractility
Neo: Increases HR, BP, SVR, CO

Dobutamine is a beta1 selective adrenergic stimulant, vasopressor, and inotrope. It will increase CO and SV without increasing SVR (it actually decreases SVR), which increases the workload of the heart. Therefore, you have a combination of effects working together to increase tissure perfusion without overworking the heart.
By the way, after my patient coded, we saw his labwork where his BNP was 120 and his troponin was negative. CT was negative for bleed. Do you think this guy was a PE?

ANY ADVICE/ETC WOULD BE GREATLY APPRECIATED!![/quote]

I would not have given the diltiazem. You mention that he was in A-Fib and was hypotensive....this is unstable a-fib and he should have had synchronized cardioversion.


As far as what is used when: 1)Patient situation 2)Physician preference 3)Past medical history.


Epi--Stimulates Alpha and Beta

Dopamine--Stimulates Alpha and Beta (had different affinities and different dosage ranges)

Norepi---More alpha stimulation than beta

Dobutamine--Major Beta 1 stimulation, arrythmogenic

NeoSynephrine--Alpha

Beta 1 is in the heart, beta 2 is in the lungs (1 heart and 2 lungs is the easy way to remember). Alpha receptors are vascular

If you stimulate beta 1 you are going to increase contractility and your rate which results in an increased CO/CI. Stimulating Alpha is going to cause vascular constriction= increased systemic vascular resistance=increased BP.

You must fill the tank (being the intravascular space) before you can press it (with pressors).


Renal dosing of dopamine is very controversial and is believed to be a figment of our imaginations. We start dopamine and UOP increases. Well of COURSE it's going to increase when you increase renal perfusion!

Epi is typically not a first line therapy for cardiogenic shock. While epi does increase MAp by increasing cardiac index, stroke volume, and heart rate, epi does not cause a decrease in SVR as it stimulates Alpha to cause vasoconstriction. Epi can help enhance tissue oxygenation it can also increase myocardial O2 demand which would result in further ischemia. The cons of epi in the cardiogenic patient is: increase in lactate, potential for myocardial ischemia (read: further cardiac insufficiency), and a reduction in splanchnic blood flow.

Treatmnent modalities for cardiogenic shock typically include: dobutamine, phosphodiesterase inhibitors, and IABP.



Dislcamer: All physicians are different. Just pointing out the physiology and how these drugs work.

At the end it's all about physican preference.

I havent worked in patient care now for years so I am really rusty. This is a tough one, I am wondering if you guys just didnt catch him on the tail end of him compensating and finally his body gave out. We never gave more Dopamine than 20 mcg then started on Dobutamine however from what I have been told Dopamine around here is really on its way out. Levophed used a lot more. I see there is a difference between Dopamine and Levophed but I was under the impression your body coverted Dopamine to norepinephrine.

If his pressure was going lower and his heart rate was only in the low 100s I would have probably been hesitant to give Cardizem however per his admission vital signs I think it could have been reasonable. With a rate of less than 150 do the ACLS guidelines state to cardiovert immediately instead of giving meds?

Again I am rusty and this thread is more of a learning thing for me. I don't think I would have agreed with cardioversion with a rate in the low 100s either. Ultimately I just don't think a fib with ventricular rate of 125 would normally cause such significant symptoms, I could be wrong.

I would question if he did not have some type of aortic rupture or aneurysm that burst. Really tough with a patient like that with no history.

Not being there and seeing the rhythm I can't say beyond doubt that the process you described was as questionable as it sounds but : tachycardia if it is sinus is a symptom not an arrythmia-treat the cause-low volume sounds OK - after that I have no idea what the doc was thinking. Dopamine is out with tachycardia, dobutamine- can't imagine using with tachycardia, cardizem-is he nuts with the BP that low and sinus rhythm?? levo is OK with the HR up and low SBP but you still haven't treated the cause of the hypotension/tachycardia-? sepsis, MI, bleed, pneumonia, pneumo??? L side neuro defict is suspicious of CVA even with Hx cva but you wouldn't give that much fluid if you suspected a brain injury- even if it was ischemic (not a head bleed). I would have expected:eval systems for cause-CBC, ABG, CXR, chem panel, enzymes. Then IV&O2, give .5 to 1 L ns while awaiting labs. Start levophed, vasopressin, phenelepherine, or epi and titrate to MAP >60. After that you refine your Tx based on causes. I wasn't there but I can't help think I must be missing something based on your description of the series of events. Still- I'm not a doc- just an old RN.

http://secure2.acep.org/BookStore/p-...inotropes.aspx is the site where you can get a dosing card that would help........I know every pt/situation is different, however this is a good place to start.

Wow! Will I ever be as smart as you old pros?

I'd be willing to bet you will! So much of our learning is involuntary and unconscious. It astounds me sometimes when I think about the things I just know.