Vasopressors

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Background

  • Goal is to reach critical organ perfusion pressure
    • Brain: MAP of 50 mmHg [1]
    • Heart: MAP of 65 mmHg
    • Kidneys: MAP 65-75 mmHg[2]
  • IV Vasopressor have not been shown to be unsafe when used peripherally[3] If running peripherally perform frequent site check via institutional protocol. [4]

Types

Vasopressors

Pressor Initial Dose Max Dose Cardiac Effect BP Effect Arrhythmias Special Notes
Dobutamine 3-5 mcg/kg/min 5-15 mcg/kg/min (as high as 200) [5] Strong ß1 agonist +inotrope +chronotrope, Weak ß2 agonist +weak vasodilatation ) alpha effect minimal HR variable effects [6]. Also Increase SA and AV node fx indicated in decompensated systolic HF, Debut Research 1979[7] Isoproterenol has most Β2 vasodilatory and Β1 HR effects
Dopamine 2 mcg/kg/min 20-50 mcg/kg/min β1 and NorEpi release α effects if > 20mcg/kg/min Arrhythmogenic from β1 effects More adverse events when used in shock compared to Norepi[8]
Epinepherine 0.1-1 mcg/kg/min
Norepinephrine 0.2 mcg/kg/min 0.2-1.3 mcg/kg/min (5mcg/kg/min) [9] mild β1 direct effect β1 and strong α1,2 effects Less arrhythmias than Dopamine[8] Increases MAP with vasoconstriction, increasescoronary perfusion pressure, little β2 effects.
Milrinone 50 mcg/kg x 10 min 0.375-75 mcg/kg/min Direct influx of Ca2+ channels Smooth muscle vasodilator PDE Inhibitor which increases Ca2+ uptake by sarcolemma. No venodilatory activity
Phenylephrine 100-180 mcg/min then 40-60 mcg/min 0.4-9 mcg/kg/min Alpha agonist Long half life
Vasopressin Fixed Dose 0.4 U/min unknown increases via ADH peptide should not be titrated due to ischemic effects
Methylene blue[10] IV bolus 2 mg/kg over 15 min 1-2 mg/kg/hour Possible increased inotropy, cardiac use of ATP Inhibits NO mediated peripheral vasodilation Don't use in G6PD deficiency, ARDS, pulmonary hypertension
Medication IV Dose (mcg/kg/min) Concentration
Norepinephrine (Levophed) 0.1-2 mcg/kg/min 8mg in 500mL D5W
Dopamine 2-20 mcg/kg/min 400mg in 250 D5W
Dobutamine 2-20 mcg/kg/min 250mg in 250 mg D5W
Epinephrine 0.1-1 mcg/kg/min 1mg in 250 D5W

Push Dose Pressors

  • Use for temporary BP or CO boost
    • Post-intubation hypotension
    • Propofol-induced hypotension
    • A-fib with hypotension
      • Easier to convert well-perfused heart

Epinephrine

  • α1, α2, β1, β2 effects
  • Inopressor
  • Increases heart rate and inotropy and vasoconstricts
  • 10 cc syringe with 9 cc of NS and draw up 1 mL of 1:10,000 epi (cardiac epinephrine with 10mL of 100 mcg/mL which is 1 mg of epinephrine)
    • Now have 10mL of 10mcg/mL (1:100,000)
      • Use 0.5-2mL (5-20 mcg) every 1-5min (similar to epinephrine drip)
      • Can give peripherally since similar concentrations are give subcutaneously with lidocaine with epinephrine (1:100,000)
  • Onset - 1min
  • Duration - 10min
  • Effects are usually gone within 5 minutes

Phenylephrine

  • Pure α (no effect on heart) potent vasoconstrictor
  • Useful in tachycardic patient since no effect on HR and might even decrease from reflex parasympathetic response
  • Increase in heart perfusion can improve cardiac output
  • Place 1mL of 10mg/mL vial in 100mL NS
    • Now have 100mcg/mL with total bag containing 10 mg of phenylephrine
    • Draw up 10mL from bag with syringe
    • Use 0.5-2mL (50-200mcg) every 1-5 minutes
      • Can give peripherally since drug is approved for IM or SQ use
  • Onset - 1min
  • Duration - 20min
  • Effects are usually gone within 5 minutes

Extravasation Injury

  • Classically norepinephrine drips
  • Avoid hand/wrist and ensure peripheral IV quality before starting vasopressors
  • May occur with IO placements as well
  • Push dose epinephrine and phenylephrine have low chance of causing extravasation injury
  • Dermal necrosis[11]:
    • Prevention - phentolamine mesylate 10mg into each liter of norepinephrine solution (pressor effect is not changed)
    • Treatment - 5mg phentolamine in 10 cc of NS injected into area of extravasation

See Also

External Links

blood pressure control]

References

  1. Plöchl, W, D J Cook, T A Orszulak, and R C Daly. 1998. Critical cerebral perfusion pressure during tepid heart operations in dogs. The Annals of thoracic surgery, no. 1. http://www.ncbi.nlm.nih.gov/pubmed/9692450
  2. Bellomo, Rinaldo, Li Wan, and Clive May. 2008. Vasoactive drugs and acute kidney injury. Critical care medicine, no. 4 Suppl. doi:10.1097/CCM.0b013e318169167f. http://www.ncbi.nlm.nih.gov/pubmed/18382191.
  3. Ricard JD. et al. Central or peripheral catheters for initial venous access of ICU patients: a randomized controlled trial. Crit Care Med. 2013 Sep;41(9):2108-15
  4. Chen J. et al. Extravasation injury associated with low-dose dopamine. Ann Pharmacother. 1998 May;32(5):545-8
  5. https://www.ncbi.nlm.nih.gov/pubmed/8449087
  6. Edmund H. Sonnenblick, M.D., William H. Frishman, M.D., and Thierry H. LeJemtel, M.D. Dobutamine: A New Synthetic Cardioactive Sympathetic Amine
  7. 8.0 8.1 De Backer Daniel et al. Comparison of Dopamine and Norepinephrine in the Treatment of Shock. NEJM 363(9). 779-789
  8. https://www.ncbi.nlm.nih.gov/pubmed/15542956
  9. Pasin L et al. Methylene blue as a vasopressor: a meta-analysis of randomised trials. Crit Care Resusc. 2013 Mar;15(1):42-8.
  10. Phentolamine Mysylate for Injection - Dosage and Administration. http://www.rxlist.com/phentolamine-mesylate-for-injection-drug/indications-dosage.htm.