Vasopressors
(Redirected from Push dose pressors)
Background
- Goal is to reach critical organ perfusion pressure
- IV Vasopressor have not been shown to be unsafe when used peripherally[3] If running peripherally perform frequent site check via institutional protocol. [4]
- Ideally use proximal (antecubital fossa) large-bore IV (at least 18-gauge)
Types
Vasopressors
Vasopressors may be initiated peripherally while central access is being obtained — do not delay for central line placement (SSC 2021).[5]
| Pressor | Initial Dose | Max Dose | Cardiac Effect | BP Effect | Arrhythmias | Special Notes |
|---|---|---|---|---|---|---|
| Dobutamine | 2-5 mcg/kg/min | 20 mcg/kg/min (up to 40 in refractory cases)[6] | Strong β₁ agonist (+inotrope, +chronotrope); weak β₂ agonist (+vasodilation) | Minimal α effect; may decrease BP due to β₂ vasodilation | Variable HR effects; can cause tachycardia | Indicated in decompensated systolic CHF and cardiogenic shock with adequate BP. Not a vasopressor — it is an inotrope. Must be used with a vasopressor if hypotensive. |
| Dopamine | 2-5 mcg/kg/min | 20 mcg/kg/min | β₁ and endogenous norepinephrine release | Mixed α and β effects at all doses; α effects predominate at higher doses | Arrhythmogenic from β₁ effects | More adverse events (especially arrhythmia) when used in shock compared to norepinephrine[7]. SSC 2021 suggests against dopamine as first-line except in select patients with bradycardia and low risk of tachyarrhythmia. |
| Epinephrine | 1-10 mcg/min (0.01-0.1 mcg/kg/min) | 0.5 mcg/kg/min | +Inotropy, +chronotropy (β₁) | Low dose: β₂ vasodilation may predominate; high dose: α₁ vasoconstriction predominates | Significant — tachycardia, SVT, VT. Increases myocardial O₂ demand. | 2nd or 3rd line for septic shock (SSC 2021: add after norepinephrine ± vasopressin). 1st line for anaphylaxis (0.3-0.5 mg IM) and cardiac arrest. May cause splanchnic vasoconstriction, lactic acidosis, and hyperglycemia. |
| Norepinephrine | 2-5 mcg/min (0.01-0.03 mcg/kg/min) | 0.5-1 mcg/kg/min (some sources up to 3.3 mcg/kg/min)[8] | Mild β₁ direct effect (+inotropy) | Strong α₁ and α₂ vasoconstriction; β₁ effect | Less arrhythmogenic than dopamine[7] | 1st line for septic shock (SSC 2021)[5]. Increases MAP primarily via vasoconstriction. Increases coronary perfusion pressure. Minimal β₂ effect. |
| Milrinone | 50 mcg/kg IV over 10 min (loading dose often omitted in acute illness due to hypotension risk) | 0.375-0.75 mcg/kg/min | PDE-3 inhibitor → ↑intracellular cAMP → ↑Ca²⁺ influx → +inotropy | Arteriolar and venous vasodilator (reduces preload AND afterload) | Less arrhythmogenic than dobutamine | Inodilator — useful in decompensated HF with elevated afterload, RV failure, or pulmonary hypertension. Causes hypotension — not a vasopressor; use with a vasopressor if MAP is low. Renally cleared — dose-reduce in CKD. |
| Phenylephrine | 100-180 mcg/min, then 40-60 mcg/min | 0.4-9.1 mcg/kg/min | No direct cardiac effect | Pure α₁ agonist → vasoconstriction | May cause reflex bradycardia | Short duration of action (5-20 min IV). Use in septic shock only if: NE causes arrhythmias, cardiac output is high with persistent hypotension, or as salvage when NE + vasopressin have failed.[5] |
| Vasopressin | 0.03 U/min (fixed dose) | 0.04 U/min | No direct inotropic or chronotropic effect; possible reflex bradycardia | V₁ receptor agonist → vascular smooth muscle constriction | Minimal | 2nd line in septic shock — add to NE rather than escalating NE (SSC 2021 suggests adding before epinephrine)[5]. Fixed dose — generally not titrated. May reduce the risk of atrial fibrillation vs. catecholamine-only regimens.[9] Avoid dose >0.04 U/min → risk of cardiac and mesenteric ischemia. |
| Methylene blue[10] | IV bolus 1-2 mg/kg over 15 min | 1-2 mg/kg/hour (limited data on max duration) | Possible increased inotropy; improves cardiac ATP utilization | Inhibits NO-mediated peripheral vasodilation → increases SVR | Minimal reported | Salvage therapy for refractory vasodilatory shock unresponsive to catecholamines. Contraindicated in G6PD deficiency (hemolytic anemia), ARDS, severe pulmonary hypertension. Interferes with pulse oximetry readings (falsely low SpO₂). Avoid with serotonergic drugs (risk of serotonin syndrome). |
| Angiotensin II (Giapreza) | 20 ng/kg/min | 40-80 ng/kg/min (max 200 ng/kg/min per label) | No direct cardiac effect | AT₁ receptor agonist → potent arteriolar vasoconstriction; also stimulates aldosterone secretion | Minimal | Salvage therapy for refractory vasodilatory shock (ATHOS-3 trial)[11]. May be particularly useful in patients on ACEi/ARB or with high renin states. Monitor for thrombosis (increased risk reported). |
| Medication | IV Dose (mcg/kg/min) | Standard Concentration | Final Concentration |
| Norepinephrine (Levophed) | 0.01-2 mcg/kg/min | 8 mg in 500 mL D5W | 16 mcg/mL |
| Dopamine | 2-20 mcg/kg/min | 400 mg in 250 mL D5W | 1,600 mcg/mL |
| Dobutamine | 2-20 mcg/kg/min | 250 mg in 250 mL D5W | 1,000 mcg/mL |
| Epinephrine | 0.01-1 mcg/kg/min | 1 mg in 250 mL D5W | 4 mcg/mL |
Causes of non-response to vasopressors[12]
- Acidosis
- Dx: Blood gas, BMP
- Tx: treat underlying cause, consider bicarbonate gtt
- Note: Vasopressin (in contrast to catecholamine vasopressors) does not show decreased efficacy in setting of acidosis
- Hypothyroidism
- Dx: Clinical, TSH
- Tx: levothyroxine
- Anaphylaxis
- Dx: History
- Tx: Epinephrine, methylene blue, ECMO
- Adrenal insufficiency
- Dx: Clinical, cortisol level, hyperkalemia + hyponatremia
- Tx: Hydrocortisone 100-200mg
- Hypocalcemia
- Dx: ionized calcium, prolonged QTc
- Tx: Calcium chloride or calcium gluconate
- Occult bleeding
- Dx: Clinical (consider GI bleed and retroperitoneal hematoma)
- Tx: Transfusion, treat coagulopathy, surgery/IR interventions
- Toxicologic
- Dx: Clinical (consider beta blocker toxicity, calcium channel blocker toxicity, TCA overdose, etc)
- Tx: Depends on etiology (glucagon, hyperinsulin euglycemia therapy, sodium bicarbonate, ECMO, etc)
- 2nd cause of shock
- Dx: Clinical, consider RUSH exam
- Tx: Address underlying cause
Push (Bolus) Dose Pressors
- Use for temporary BP or CO boost with no evidence for improved patient outcome
- Post-intubation hypotension
- Propofol-induced hypotension
- A-fib with hypotension
- Easier to convert well-perfused heart
- Retrospective review of push-dose phenylephrine showed improved early hemodynamic stability but increased ICU mortality[13]
- While epinephrine and phenylephrine are most commonly used, push dose vasopressin [14] and norepinephrine [15] are reasonable alternatives
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)
- Now have 10mL of 10mcg/mL (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[16]:
- Prevention - phentolamine mesylate 10mg into each liter of norepinephrine solution (pressor effect is not changed)
- Treatment ([17])
- If the pt is relying on the agent for their hemodynamics, switch the pressor to another IV or place an immediate IO or central line
- Do not discontinue the IV
- Aspirate as much residual as you can
- Administer subcutaneous phentolamine mesylate (Regitine) using 25 G or smaller needle
- Place 5 mg (1 ml) in 9 ml of NS
- A dose of 0.1 to 0.2 mg/kg (up to a maximum of 10 mg) should then be injected through the catheter and subcutaneously around the site
- Administered as soon as the extravasation is detected, even if the area initially looks just a little white or OK
- Should see near-immediate effects; otherwise consider an additional dose
- Discontinue the IV/catheter
- May cause systemic hypotension (but they should be on pressors at another site)
- Consult plastic surgery
Medication Dosing
See Also
External Links
- EMCrit Podcast - Vasopressor Basics
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5052865/pdf/ceem-15-010.pdf
- EMCrit Podcast - Push Dose Pressors
References
- ↑ 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
- ↑ 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.
- ↑ 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
- ↑ Chen J. et al. Extravasation injury associated with low-dose dopamine. Ann Pharmacother. 1998 May;32(5):545-8
- ↑ 5.0 5.1 5.2 5.3 Evans L, Rhodes A, Alhazzani W, et al. Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock 2021. Crit Care Med. 2021;49(11):e1063-e1143.
- ↑ Unverferth DV, Blanford M, Kates RE, Leier CV. Tolerance to dobutamine after a 72 hour continuous infusion. Am J Med. 1980;69(2):262-6.
- ↑ 7.0 7.1 De Backer D, et al. Comparison of Dopamine and Norepinephrine in the Treatment of Shock. NEJM. 2010;363(9):779-789.
- ↑ Martin C, Papazian L, Perrin G, et al. Norepinephrine or dopamine for the treatment of hyperdynamic septic shock? Chest. 1993;103(6):1826-31.
- ↑ McIntyre WF, et al. Association of Vasopressin Plus Catecholamine Vasopressors vs Catecholamines Alone With Atrial Fibrillation in Patients With Distributive Shock. JAMA. 2018;319(18):1889.
- ↑ Pasin L, et al. Methylene blue as a vasopressor: a meta-analysis of randomised trials. Crit Care Resusc. 2013;15(1):42-8.
- ↑ Khanna A, et al. Angiotensin II for the Treatment of Vasodilatory Shock. N Engl J Med. 2017;377(5):419-430.
- ↑ Anand Swaminathan, "Occult Causes of Non-Response to Vasopressors", REBEL EM blog, July 13, 2017. Available at: https://rebelem.com/occult-causes-of-non-response-to-vasopressors/.
- ↑ Hawn JM, Bauer SR, Yerke J, et al. Effect of phenylephrine push prior to continuous infusion norepinephrine in patients with septic shock [published online ahead of print, 2020 Dec 11]. Chest. 2020;S0012-3692(20)35353-8. doi:10.1016/j.chest.2020.11.051
- ↑ Nowadly CD, Catlin JR, Fontenette RW. Push-Dose Vasopressin for Hypotension in Septic Shock. J Emerg Med. 2020;58(2):313-316. doi:10.1016/j.jemermed.2019.12.026
- ↑ Onwochei, Desire N. MBBS BSc (Hons), FRCA*; Ngan Kee, Warwick D. MBChB, MD, FANZCA, FHKCA†; Fung, Lillia MD, FRCPC*; Downey, Kristi MSc*; Ye, Xiang Y. MSc‡; Carvalho, Jose C. A. MD, PhD, FANZCA, FRCPC*. Norepinephrine Intermittent Intravenous Boluses to Prevent Hypotension During Spinal Anesthesia for Cesarean Delivery: A Sequential Allocation Dose-Finding Study. Anesthesia & Analgesia: July 2017 - Volume 125 - Issue 1 - p 212-218 doi: 10.1213/ANE.0000000000001846
- ↑ Phentolamine Mysylate for Injection - Dosage and Administration. http://www.rxlist.com/phentolamine-mesylate-for-injection-drug/indications-dosage.htm.
- ↑ Scott Weingart. Podcast 107 – Peripheral Vasopressor Infusions and Extravasation. EMCrit Blog. Published on September 16, 2013. Accessed on February 16th 2020. Available at https://emcrit.org/emcrit/peripheral-vasopressors-extravasation/
