Manage Cardiogenic Shock Pharmacotherapy: A Guide for ICU Pharmacists
As a clinical pharmacist, you may frequently be consulted on the medications used in managing cardiogenic shock. Understanding the pharmacological approach is crucial, especially with the focus on reducing preload and afterload to improve myocardial oxygen demand and cardiac output.
Assess fluid status and administer a bolus of 100-200 mL of crystalloid for patients with ischemia and diastolic dysfunction. Consider starting with nitrates, particularly nitroglycerin (0.1–100 mcg/kg/min or 5–200 mcg/min).
- At lower doses, nitroglycerin works by reducing preload through venous vasodilation.
- At higher doses, it causes arterial dilation, which helps reduce afterload.
In cases where hypertension persists despite increased doses of nitroglycerin, sodium nitroprusside (titrate to desired effects - initiate slowly, 0.1–8 mcg/kg/min) may be considered. Next, be prepared to use diuretics for patients with significant fluid overload. Loop diuretics, like furosemide, help reduce preload by causing venous vasodilation. Always monitor for electrolyte imbalances and hypotension, especially when initiating diuretic therapy.
Inotropic and vasopressor agents such as dobutamine, milrinone, epinephrine, and norepinephrine are key in improving myocardial contractility, heart rate, and peripheral vascular tone.
- Norepinephrine (0.05-0.4 mcg/kg/minute) is often the first-line vasopressor, as it effectively increases contractility and heart rate while improving arterial pressure.
- Dobutamine (2.5-20 mcg/kg/minute) improves contractility and heart rate but has less effect on peripheral vasodilation.
- Milrinone (0.125-0.75 mcg/kg/minute), though not without controversy, is often preferred by cardiologists because it tends to have less impact on myocardial oxygen demand compared to dobutamine.
Remember that inotropic agents should generally be initiated only after optimizing nitrates and diuretics. Use these medications judiciously and adjust based on the patient’s hemodynamic response to ensure adequate cardiac output and tissue perfusion. At discharge, ensure patients are informed about the importance of continuous monitoring and follow-up for adjustments to therapy.
References
- Scott MC, and Winters ME: Congestive heart failure. Emerg Med Clin N Am 2015; 33: pp. 553-562.
- Koster G, Bekema HJ, Wetterslev J, et al: Milrinone for cardiac dysfunction in critically ill adult patients: a systematic review of randomised clinical trials with meta-analysis and trial sequential analysis. Intensive Care Med 2016; 42: pp. 1322-1335.
- Yancy CW, Jessup M, Bozkurt B, et al: 2013 ACCF/AHA guideline for the management of heart failure: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Amn Coll Cardiol 2013; 62: pp. e147-239.
