Dobutamine

Aka: Dobutamine

1. Mechanism
   1. Synthetic Sympathomimetic amine
   2. Overall effect similar to Dopamine with Nitroprusside
   3. Selective for Beta Adrenergic Receptors
      1. Beta 1 Adrenergic Receptor
         1. Increased cardiac contractility and Heart Rate
      2. Beta 2 Adrenergic Receptor
         1. Mild increase in vasodilation
         2. Does not directly affect renal or splanchnic flow
   4. Relatively mild Alpha 1 Adrenergic Receptor effect
      1. Vasoconstriction countered by more potent beta effect
   5. Minimal effects on myocardial oxygen demand
      1. Favorable balance between oxygen supply and demand
         1. Preferred in Cardiogenic Shock over Dopamine
         2. Increased perfusion balances inotropic strain
         3. Benefit lost if not titrated to avoid Tachycardia
      2. Does not increase infarct size
      3. Does not elicit arrhythmia
2. Pharmacokinetics
   1. Short half-life
      1. Only effective by infusion
3. Indications
   1. Cardiogenic Shock (Severe Congestive Heart Failure)
      1. Pulmonary congestion or Hypotension
      2. Right ventricular infarction
         1. Use with fluid Resuscitation
      3. Often used in combination with Dopamine
         1. Moderate dosages of each (7.5 ug/kg/min)
         2. Maintains critical organ perfusion
         3. Less pulmonary congestion than with Dopamine alone
         4. Not shown to alter mortality
         5. May alter secondary organ injury outcomes
   2. Septic Shock
      1. May be useful in enhancing left ventricular function
      2. Epinephrine is preferred agent in Septic Shock
   3. Not usually indicated in non-Cardiogenic Shock
      1. Other Catecholamines preferred in other shock types
4. Pediatric Infusion (Same as Dopamine preparation)
   1. Preparation
      1. Draw up "x" mg of Dobutamine
      2. Where "x" = 6 x Weight in Kilograms
      3. Add enough D5W or NS to Dobutamine for 100 ml total
      4. At this dilution
         1. Infusion rate of 1 ml/h provides 1.0 ug/kg/min
   2. Start Dose: 5-10 ug/kg/min or 5-10 ml/hour
   3. Titrate to clinical response (usually <20 ug/kg/min)
5. Adult Infusion
   1. Preparation
      1. Start with 2-4 ampules Dobutamine (250 mg each)
      2. Dissolve 500-1000 mg Dobutamine in 250 ml D5W or NS
      3. Final Concentration: 2000-4000 ug/ml
   2. Start Dose: 0.5 to 2.0 ug/kg/min
   3. Titrate: 2-20 ug/kg/min to clinical response
      1. Perfusion
      2. Urine output
      3. Blood Pressure
      4. Avoid increasing Heart Rate 10% over baseline
6. Adverse Effects
   1. Tachycardia
   2. Arrhythmia
   3. Ectopic beats
   4. Provokes Myocardial Ischemia if Tachycardia occurs
   5. Headache
   6. Nausea
   7. Tremor
   8. Hypokalemia