Vasopressors: Difference between revisions
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===Indication=== | ===Indication=== | ||
*Septic shock | *Septic shock | ||
*Cardiogenic shock: | |||
**If marked hypotension (SBP <70) | |||
**If used with dobutamine | |||
===Primary Receptor=== | ===Primary Receptor=== | ||
*α1 >> β1 | *α1 >> β1 | ||
Revision as of 00:54, 10 January 2014
Norepinephrine
Indication
- Septic shock
- Cardiogenic shock:
- If marked hypotension (SBP <70)
- If used with dobutamine
Primary Receptor
- α1 >> β1
Relative Effects
- ↑↑↑SVR
- ↑HR
- ↑SV
Dosing
- Start 2mcg/min
- Incr by 1-2mcg/min
- Max dose is 40mcg/min
- Replace volume before starting
Rate of Titration
- Q2-5 min
Adverse Effects
- If extravasates use phentolamine 5-10mg into affected area
Notes
More potent vasoconstrictor than dopamine and phenylephrine.
Dopamine
Indication
- Hypotension caused by:
- Septic shock
- MI
- Trauma/spinal shock
- Heart failure
Primary Receptor
- Low dose: DA, β1
- High dose: DA, α1 >> β1
Relative Effects
- Low dose: Natriuresis, ↑↑HR, ↑↑SV
- High dose: ↑SVR and ↑SV
Contraindication
- Tachyarrhythmias
Dosing
- Low dose:
- 1-5 mcg/kg/min - Vasodilation (renal, mesenteric, coronary)
- 5-10 mcg/kg/min - predominant β1
- High dose: 10-20 mcg/kg/min - predominant α1
- Titrate to clinical effect
- Use lowest dose possible (prevent tachyphylaxis)
- May use in peripheral IV temporarily
- Avoid using in same line as alkaline infusions
Rate of Titration
- Q2-5 min
Adverse Effects
- Low doses:
- Hypotension
- High doses:
- Hypertension, ectopic beats
- Tissue necrosis (if extravasates)
- If occurs use phentolamine 5-10mg in affected area
Dobutamine
Indication
- Cardiogenic shock
- Low-output heart failure
- Tricyclic overdose
Primary Receptor
- β1
- β2
Relative Effects
- ↑↑↑SV
- ↑↑HR
- ↓SVR (transient, from β2 agonism)
Dosing
- 2-20mcg/kg/min
- 10mcg works for most
- May use in peripheral IV
Rate of Titration
- Q2-5 min
Adverse Effects
- Tachyarrhythmias
- Myocardial ischemia
- Hypotension as β2 effect may result in vasodilation
- Caution if SBP <90
Phenylephrine
Indication
- Neurogenic Shock
Primary Receptor
- α1
Relative Effects
- ↑SVR
- ↓HR (reflex bradycardia)
Dosing
- Start 100-200mcg/min then taper down
- 40-60mcg/min works for most
Adverse Effects
- Baroreceptor-mediated reflex bradycardia
- If extravasates use phentolamine
Notes
- Use with caution in pts with spinal cord injury-related bradycardia
- Useful for treatment of vasodilatory shock when norepinephrine or dopamine have precipitated tachyarrhythmias
- In pts with ↓LV function, unopposed α1 may lead to decreased CO or myocardial ischemia
- However clinical trials do not support these effects when used in clinically appropriate dose range
Vasopressin
Indication
- Adjunct for septic shock
Primary Receptor
- V1
Relative Effects
- ↑SVR
- ↓HR
Dosing
- 0.04 units/min
Rate of Titration
- Fixed dose (do not titrate)
Adverse Effects
- Bradycardia
- Limb ischemia
- Myocardial ischemia
- Splanchnic ischemia
Notes
- Adverse effects are dose-dependent
- Acts on V1 receptors leading to ↑vasoconstriction and
↑sensitivity to catecholamines in pts with shock
Epinephrine
Indication
- Anaphylaxis
Primary Receptor
- β1
- α1
- β2
Relative Effects
- ↑↑↑HR
- ↑↑↑SV
- ↑↑↑SVR
- Bronchodilation (β2)
Dosing
- Dose-dependent effects:
- 1-10 mcg/min - increase HR and SV
- 10-20 mcg/min - increase SVR
Rate of Titration
- Q2-5 min
Adverse Effects
- Tachyarrhythmias
- Myocardial ischemia
- ↑Serum lactate
- Splanchnic ischemia
Notes
- ↑lactate occurs primarily from ↑glycolysis/glycogenolysis within skeletal muscles not tissue hypoperfusion
- Use with caution in pts with CAD
- However clinical trials have not demonstrated worsened outcomes
Milrinone
Indication
Primary Receptor
- PDE-3 inhibitor
Relative Effects
- ↑HR
- ↑↑↑SV
- ↓SVR
Dosing
- Normal renal function:
0.25 - 0.75 mcg/kg/min
- Creatinine clearance < 50mL/min, reduce infusion rate
Rate of Titration
- Q2H; slower titration rate if renal insufficiency
Adverse Effects
- Tachyarrhythmias
- Hypotension
- Myocardial ischemia
Notes
- Can use as alternative to dobutamine in pts with cardiogenic shock and on b-blockers
- Causes pulmonary vasodilation, may be good choice in pts with RV failure
- ↑cAMP in cardiac myocytes and vascular smooth muscle, thereby ↑HR and ↑SV while decreasing ↓SVR
- Use with caution in pt with renal failure and hypovolemia
Push Dose Pressors
- Use when need temporary BP or CO boost
- Post-intubation hypotension
- Propofol-induced hypotension
- A-fib w/ hypotension
- Easier to convert well-perfused heart
Epinephrine
- Mix 9mL of NS with 1mL of 1:10,000 epi
- Now have 10mL of 10mcg/mL
- Use 0.5-2mL q2-5min (similar to epi drip)
- Same as 2% lido with epi
- Ok to give peripherally
- Now have 10mL of 10mcg/mL
- Onset - 1min
- Duration - 5-10min
Phenylephrine
- Pure alpha (no effect on heart)
- Place 1mL of 10mg/mL in 100mL NS
- Draw up 10mL
- Now have 100mcg/mL
- Use 0.5-2mL q2-5min
- Draw up 10mL
- Onset - 1min
- Duration - 20min
Source
- EBmedicine.net
- Tintinalli
- EmCrit Podcast 6