perfusiepressures

Perfusion pressures, or perfusiepressures in Dutch, refer to the pressure gradients that drive blood flow through tissues. They are typically described as the difference between a driving arterial pressure and a downstream venous or outflow pressure. In clinical practice, different contexts use related but specific measures of perfusion pressure to assess tissue blood flow and oxygen delivery.

A well-known example is cerebral perfusion pressure (CPP), defined as mean arterial pressure (MAP) minus intracranial pressure (ICP). This metric helps guide management in patients with brain injury or conditions affecting intracranial dynamics. In other organs, perfusion pressure can be expressed as arterial pressure minus central venous pressure or other downstream pressures, and it is often used in discussions of renal, hepatic, or myocardial perfusion. In organ perfusion and during machine perfusion, perfusion pressure describes the pressure within the perfusion circuit that drives flow into the organ, typically measured as inlet pressure minus outlet or venous pressure.

Measurement and calculation involve direct pressure readings from arterial lines and venous or reservoir pressures, or from perfusion circuit gauges during surgery and organ preservation. Perfusion pressure is influenced by systemic hemodynamics (such as MAP and venous pressures), vascular resistance, body position, intra-abdominal pressure, and autoregulatory mechanisms that vary by tissue.

Clinical relevance lies in maintaining adequate perfusion pressures to prevent tissue ischemia, while avoiding excessive pressures that can cause edema or vascular injury. Understanding perfusion pressures is important in critical care, neurology, nephrology, and transplant medicine, where targeted pressures support organ function and recovery. See also cerebral perfusion pressure and general concepts of tissue perfusion.