Dobutamine (Dobutrex)

Primary use in anesthesia - dobutamine is used intraoperatively and perioperatively to augment cardiac output in patients with low cardiac output states, cardiogenic shock, or decompensated heart failure with preserved blood pressure. dobutamine is preferred when inotropy is needed without vasoconstriction;

Dobutamine vs. dopamine - dobutamine is preferred when inotropy is needed without vasoconstriction; dopamine may be preferred when both vasopressor and inotropic support are needed at higher doses.

Dobutamine vs. milrinone - milrinone (PDE-3 inhibitor) provides similar inotropy and afterload reduction but has a much longer half-life (~2 hours) — dobutamine is preferred when rapid titration and short offset are needed; milrinone may be preferred for RV failure and pulmonary hypertension.

Increases Cardiac output - dobutamine reliably increases CO and stroke volume through β1-mediated positive inotropy; expect a 25–50% increase in CO at therapeutic doses.

Heart rate - mild to moderate chronotropy occurs at standard doses (5–10 mcg/kg/min); significant tachycardia becomes more common above 10 mcg/kg/min and limits its use in tachycardia-prone patients.

Tachycardia Treatment - Reduce or stop infusion; β-blocker (e.g., metoprolol or esmolol) may be used to manage refractory tachycardia — recognize this will also blunt inotropy.

Blood pressure - BP effects are variable — the net result of increased CO and reduced SVR (β2 effect) often causes little change or a mild drop in MAP; it is not a vasopressor and will not reliably correct hypotension due to low SVR.

SVR reduction - β2-mediated peripheral vasodilation lowers afterload, which benefits the failing heart but may worsen hypotension if volume is inadequate — ensure euvolemia before initiating.

Arterial line placement - Strongly recommended for continuous blood pressure monitoring when running dobutamine for the above-mentioned hemodynamic effects.

Pulmonary vascular effects - may mildly reduce pulmonary vascular resistance via β2 activity — potentially beneficial in right heart failure and pulmonary hypertension, though vasodilators like milrinone are often preferred for isolated RV failure.

Tachycardia and arrhythmias - dose-dependent tachycardia is the most common side effect; can precipitate atrial fibrillation, PVCs, or VT — monitor continuously and reduce dose if HR rises significantly or ectopy develops.

Myocardial ischemia - increased oxygen demand from tachycardia and inotropy can worsen ischemia in patients with CAD — use with caution and have nitrates or beta-blockers available.

Hypotension - paradoxical hypotension can occur if SVR drops without a proportional rise in CO, particularly in hypovolemic patients.

Renal and mesenteric effect - does not cause significant renal or mesenteric vasodilation as seen with dopamine.

Drug Interactions - non-selective beta-blockers (e.g., propranolol) blunt dobutamine's β1 effects and can allow unopposed α1 activity, potentially increasing SVR — avoid concurrent use or expect an attenuated response. Halogenated agents sensitize the myocardium to catecholamines and may increase arrhythmia risk; monitor closely when running dobutamine alongside sevoflurane or desflurane. Concurrent use of MAOIs is contraindicated due to risk of severe hypertensive crisis and cardiovascular instability. There's an additive risk of arrhythmias when used together with digoxin; monitor rhythm closely if both are running.

OB - Dobutamine crosses the placenta; fetal tachycardia and potential ischemia should warrant applying fetal monitoring. Research is limited in parturients; dobutamine may be used in hemodynamically unstable obstetric patients (e.g., peripartum cardiomyopathy with cardiogenic shock) when the benefit outweighs the risk.

Absolute - Idiopathic hypertrophic subaortic stenosis (IHSS) / hypertrophic obstructive cardiomyopathy (HOCM); known hypersensitivity to sulfites (any formulation that contains sodium bisulfite).

Relative - Uncorrected hypovolemia (volume-resuscitate first); atrial fibrillation with rapid ventricular response (dobutamine may accelerate AV conduction); severe aortic stenosis (fixed outflow obstruction limits ability to augment CO)

Caution - Known CAD or active myocardial ischemia (increased O2 demand); significant tachycardia at baseline; ventricular arrhythmias; post-MI patients in the acute phase; patients on MAOIs

Not used — continuous infusion only

Start at 2.5–5 mcg/kg/min and titrate every 10–15 minutes to hemodynamic response; reassess continuously

Low Dose: 2.5–5 mcg/kg/min

Standard Dose: 5.0 - 10 mcg/kg/min: balanced inotropy and chronotropy, reduced SVR

High Dose: 10.0-20.0 mcg/kg/min: significant tachycardia risk

Maximum Dose - 40.0 mcg/kg/min: clinical benefit over 20 mcg/kg/min is limited and arrhythmia risk rises substantially

Typically prepared as a 250 mg/250 mL (1 mg/mL) or 250 mg/500 mL (0.5 mg/mL) admixture in D5W or NS

β1-adrenergic receptors (cardiac); mild β2-adrenergic (peripheral vasodilation), minimal α1-adrenergic activity. Directly stimulates β1 receptors on myocardial cells, activating adenylyl cyclase → increased cAMP → enhanced Ca²⁺ influx → increased contractile force (inotropy) and mild increase in HR (chronotropy). Net hemodynamic effect is increased CO and SV, decreased SVR and PVR, variable blood pressure effect

Hepatic and peripheral tissues. Active metabolite is 3-O-methyldobutamine (minimal clinical significance). Hepatic impairment does not significantly prolong effects given the very short half-life and predominance of rapid peripheral metabolism

Renal (primary), Feces (secondary)

None