Intensive Care
                             ==============
þ Which pressor for cardiogenic shock?
 - ACLS recommendations are seat of the pants recommendations
 - CT surgeons have more experience with shock, they reocmmend
  1. dobutamine
  2. add norepi if needed
  avoid others
  (ACEP 2010)
  
þ Which pressor for post-arrest hypotension?
 - MAP goal should be 80-100 as most of these people have HTN 
   (usually MAP 65 is the goal). CVP >8, SCVO2 > 65%. 
 - if tachy, pick agent with lower beta
 
þ Which pressor for shock from PE?
 - norepi
 - acute pulm HTN,RV dilitation, septum shifts, LV filling less, low cardiac 
   output.
 - fluid bolus likely won't help
 - animal studies show increased survival with norepi, may add dobutamine
 - consider venous dopplers, and if + for remaining clot, IVC filter acutely

þ Which pressor for septic shock?
 - literature supports all
 - US uses norepi
 - follow SCVO2 and lactate, not just BP
 - if MAP < 65 after fluid resuscitation, needs pressor
 - TANK: check IVC collapse with sniffing, get CVP 8-12 (or better, US with 
   normal IVC caliber; HOSE: MAP 65, norepi, dopamine, or epi; PUMP: improving 
   SCVO2 >70% or dropping lactate
 
þ Which pressor for TCA OD (after fluid)?
 - neuronal blockade of norepi uptake
 - norepi
 
þ Which pressor for neurogenic shock?
 - dopamine based on neurosurgical evidence
 
þ Which pressor for anaphylaxis?
 - epi IV 

þ Weight Based Dosing Recommendations for Vasoactive Agents

On May 1, 2009, UPMC Mercy will begin using weight-based dosing for epinephrine, 
phenylephrine (NeoSynephrine) and norepinephrine (Levophed) when these 
medications are started as infusions. Included are the new weight-based dosage 
ranges for each medication. Staring May 1, all orders for these medications 
MUST be written for in a weight-based dose. (Example: Norepinephrine 
0.02 mcg/kg/min, titrate to MAP>65 mm Hg.) Orders written in terms of mcg/min 
will NOT be acceptable. See policy 3.15 for further details regarding these 
medications.

Epinephrine usual starting dose: 0.01-0.02 mcg/kg/min 
Usual dosage range: 0.01-0.3 mcg/kg/min*

Norepinephrine (Levophed) usual starting dose: 0.01-0.02 mcg/kg/min 
Usual dosage range: 0.01-0.15 mcg/kg/min*

Phenylephrine (NeoSynephrine) usual starting dose: 0.2 mcg/kg/min 
Usual dosage range: 0.2-2 mcg/kg/min*

*There is no true maximum dose for any of these medications. 
Once a patient requires a dosage towards the upper limit of the dosage range, 
continue to titrate the infusion to goal, but alert the prescriber regarding 
the dosage increase.


þ Inotropes and steroids (ACEP 2006)
 - Now known that dopamine mostly works as an inotropic agent and may actually
   decrease SVR.
 - Vasopressin may act synergystically with other agents. Patients may have
   vasopressin deficiency 0.01-0.04. Multicenter trial just reported seems to
   show that people who required 5 mcg/kg NE for 6 hours, organ system failure
   benefited from low dose fo 0.03 mcg/min.

 - Adrenal insufficiency increases mortality in vasopressor dependent septic
   shock. Giving hydrocotisone interferes, so give 5 mg Decadron single dose,
   doesn't interfere with corticotropin stim test.
 - Giving steroids in Corticus study: 50% of patients in septic shock adrenal
   insufficient.
   [Tiffany Osborn, M.D., FACEP, UVA, at ACEP 2006]

þ ScvO2
 - use post-resuscitation hematocrit, if less than 30, transfuse to 33.
 - 15-20% get cardiogenic shock later
 - starting on dobutamine improves ScvO2 but HR may increase, may use Dig.
 - Activated Protein C (Zygris): prevents microthrombi.

þ Afterload/Preload
 - Afterload Reducers:
  + ACE inhibitors (SL Captopril, IV enaliprilat, e.g., IV Vasotec)
  + IV Hydralazine
  + high-dose NTG

 - Preload Reducers:
  + normal-dose NTG (also improves coronary circulation)
  +
 - Mixed Reducers
  + Nipride
  + Phentolamine

 - May want to add beta blocker to blunt reflex tachycardia

þ APACHE/RAPS:  systems for estimating mortality in critical illness.

þ Pressors:

>Texts including AHA ACLS and others make statements such as....Dopamine is
>preferred since providers have more experience with it.....
>
>     Just wonder if this guides our practices?
>
>Harold Cohen

Although I agree with your point, I really do think it is best to start
with dopamine or adrenaline for any severely hypotensive patient for
several reasons:
1. Safe to give through a peripheral vein
2. Invasive monitoring desirable, but not essential as when giving
noradrenaline
3. No sudden crashes in BP,as may be seen if dobutamine is given to a
patient with impaired preload
4. Just one infusion pump and just one dedicated IV line. (If giving
dobutamine to an already hypotensive patient , I really do thing it is
essential to have a vasoconstrictive -dopamine or noradrenaline- standing
by, hooked-up, ready to go)

I am thoroughly familiar with dobutamine and noradrenaline, but in a case
that is severely hypotensive I tend to wait until I have stabilised BP, put
in a few more lines, organised the necessary urgent Ix and Rx, before I
start optimizing inotropic support/cardiac output.

I always go for simplicity initially, and the old maxims:

Predominantly hypotensive (SBP<80)- give dopamine or adrenaline (epi) to
maintain vital organ perfusion pressure initially, then utilize other
therapeutic modalities to maximize cardiac output and tissue perfusion
(dobutamine, norepi, IABP, etc) once BP stabilized.

Predominantly bubbling (APE) or impaired perfusion but reasonable BP (>80)-
give dobutamine cautiously +/- fluid loading as appropriate. Consider
adding a vasoconstrictor, but best done utilizing a PA catheter, especially
when more than just a trickle of vasoconstrictor is required (although I
accept that PA catheters are the subject of some debate at present)

No references: No-one has even proven that inotropes improve mortality-
Talk about empirical!

Cheers

Simon

Simon Brown
[mdsbrown@mailbox.uq.edu.au]