The CentriMag system is an external device designed to provide temporary mechanical support for a patient’s circulatory system in critical care settings. It functions as a powerful blood pump, stepping in when the heart or lungs are too compromised to maintain adequate blood flow and oxygenation. This technology is used for short periods, typically days to weeks, to stabilize a patient. Stabilization allows time for the underlying medical issue to resolve or for a plan for longer-term therapy. The system includes a disposable blood pump head, a motor, and a console that controls and monitors the support.
The Engineering Behind Centrifugal Flow
The unique function of the CentriMag pump head is rooted in its use of centrifugal force to propel blood through the circuit. Inside the pump’s housing, a rotating component called an impeller spins rapidly, imparting energy to the blood and pushing it outward. This design moves blood with a continuous, non-pulsatile flow, which is fundamentally different from the heart’s natural pumping action.
A defining feature of the CentriMag is its use of Full MagLev, or magnetic levitation, technology to suspend the impeller inside the pump chamber. This magnetic suspension eliminates the need for mechanical bearings, seals, or other physical components that would normally contact the blood. By creating a contact-free environment, the system drastically reduces friction and shear stress on blood components. This minimizes damage to red blood cells, a phenomenon known as hemolysis, which is a common concern with older mechanical circulatory devices.
When Temporary Circulatory Support is Needed
The CentriMag system addresses a wide range of acute heart and lung failures, primarily serving as a bridge to a different outcome. Its primary role is as a Ventricular Assist Device (VAD), taking over the work of the failing left, right, or both ventricles of the heart. This is often seen in patients with severe cardiogenic shock. It is indicated for temporary circulatory support for up to 30 days for patients who cannot be weaned from cardiopulmonary bypass after heart surgery.
The system is also frequently integrated into an Extracorporeal Membrane Oxygenation (ECMO) circuit, where it acts as the blood propulsion mechanism. In this setup, the pump drives blood through an external oxygenator, providing both circulatory and respiratory support. This is used for patients experiencing acute respiratory distress or cardiopulmonary failure. By stabilizing the patient, the device provides a “Bridge to Decision,” allowing the medical team time to determine if the patient requires a “Bridge to Transplant” or if recovery is possible.
Clinical Management While on the System
Patients receiving support from the CentriMag system require continuous, intensive monitoring in a critical care unit. The clinical team constantly adjusts the pump’s rotational speed (RPM) to achieve the desired blood flow rate, typically measured in liters per minute. Adjustments must be made gradually to balance the mechanical support with the heart’s native function and maintain stable blood pressure.
A major component of managing patients on external circulatory support is the use of anticoagulation to prevent the formation of blood clots in the tubing or the pump head. Heparin is commonly administered as a continuous infusion to keep the blood thin enough to flow smoothly through the circuit. The level of anticoagulation must be carefully balanced to minimize the risk of major bleeding complications.
The console and motor are portable, allowing patients to be transported within the hospital for necessary procedures or diagnostic tests while remaining on support. The duration of support varies, with median use often around two weeks, though the device is cleared for up to 30 days of continuous assistance. Weaning from the system is a carefully managed process where the pump speed is slowly reduced, allowing the native heart to gradually resume its full workload until the device can be safely removed.
Understanding Adverse Events
Despite the life-saving capabilities of the CentriMag, its use carries several recognized risks common to mechanical circulatory support. The most frequent complication is major bleeding, which is directly related to the high level of anticoagulation required to keep the circuit free of clots. This bleeding can occur at the cannulation sites or internally, necessitating frequent blood transfusions and surgical intervention.
Thromboembolism, or the formation of blood clots, remains a concern even with aggressive anticoagulation, potentially leading to a stroke or blockage in other organs. The risk of these adverse events is often related to the duration of support. The insertion sites and the presence of the external circuitry create a pathway for bacteria, making infection, such as pneumonia or a bloodstream infection, a significant risk for patients supported by the device.