Management of the circulation on the intensive care unit

Abstract

Mean arterial pressure (MAP) is a product of cardiac output (CO) and systemic vascular resistance. CO is calculated by multiplying stroke volume (SV) by heart rate. SV is determined by preload, cardiac contractility and afterload. These physiological parameters are targeted to manage blood pressure to maintain organ perfusion. In the hypotensive patient, assess fluid status and give intravenous (IV) crystalloid fluid resuscitation if appropriate. This optimizes the cardiac output, through an increase in end diastolic volume, based on the Frank–Starling law. If the patient's blood pressure is not fluid responsive, pharmacological intervention through inotropes, chronotropes and vasopressors may be required. A target MAP may be personalized based upon history and clinical examination. When the vasoactive intervention is escalating, cardiac monitoring may help guide further management. Mechanical circulatory support may be used in specialist centres. The hypertensive patient will be admitted to the intensive care unit (ICU) for invasive blood pressure monitoring and screening for end organ damage. Start by treating pain and anxiety. Regular oral antihypertensives may be continued if not contraindicated. IV antihypertensives in the form of beta blockers, calcium channel blockers and vasodilators may be started. Blood pressure is reduced in a controlled and rapid manner.