A Medical Emergency Team (MET) is a rapid-response unit within a hospital dedicated to the care of non-Intensive Care Unit (ICU) patients showing signs of clinical decline. The team is composed of critical care experts, such as ICU nurses, respiratory therapists, and physicians. The primary purpose of the MET is to provide proactive and immediate intervention, stabilizing the patient’s condition before it progresses to a severe, life-threatening event like a cardiac or respiratory arrest.
The Core Mission: Early Recognition and Intervention
The central objective of the Medical Emergency Team is to identify and treat physiological deterioration early, thereby addressing a phenomenon often termed “failure to rescue.” This phrase describes the inability of the medical system to prevent death or severe disability after a patient develops a complication on a general hospital ward. A significant majority of in-hospital cardiac arrests are preceded by noticeable changes in the patient’s condition that may occur hours before the actual event.
The team’s intervention is triggered by measurable signs of instability, which indicate the body is struggling to maintain normal function. These signs include changes in heart rate or blood pressure, or respiratory distress signaled by a rapid breathing rate or a drop in oxygen saturation levels.
By arriving quickly, the MET transports the capabilities of the Intensive Care Unit to the patient, avoiding delays caused by transfer. This immediate assessment allows for rapid diagnosis and the implementation of advanced life support measures, such as securing an airway or administering specialized medications. The goal is to stabilize the patient’s condition, reverse the deterioration, and prevent the cascade of events that leads to organ failure or cardiopulmonary arrest. This proactive approach reduces both the overall hospital mortality rate and the incidence of cardiac arrests outside of the ICU setting.
How a Medical Emergency Team Differs from a Code Blue Response
The distinction between a Medical Emergency Team activation and a Code Blue is based on the patient’s physiological state. A Code Blue is a reactive measure called when a patient has already experienced cardiopulmonary arrest, meaning the heart has stopped or breathing has ceased. The goal of a Code Blue team is resuscitation, which involves immediate chest compressions and advanced life support procedures.
In contrast, a MET is activated when a patient shows signs that an arrest is likely to occur, but has not happened yet. The team responds to a crisis in progress, aiming to prevent the patient from needing resuscitation. The MET acts as a safety net, intercepting the decline to avoid the more severe Code Blue event.
The MET focuses on early stabilization and treatment of the underlying cause of deterioration, such as severe infection or fluid imbalance. A Code Blue focuses on restoring circulation and breathing after they have ceased. Therefore, the MET is a preventative system, while the Code Blue is a salvaging one.
When and How the Team is Activated
Activation of the Medical Emergency Team is governed by specific, objective physiological parameters known as “trigger criteria.” These criteria are standardized across the hospital and include absolute limits for vital signs that prompt a call. Common triggers include a respiratory rate falling below or exceeding set limits, a systolic blood pressure dropping below a predetermined threshold, or a sudden, acute change in mental status.
The system empowers any staff member who recognizes a patient meeting these criteria to activate the team without delay. This includes bedside nurses, doctors, and respiratory therapists. Nurses are often the first to notice subtle changes in a patient’s condition. In many modern hospitals, the activation process has been expanded to include family members who have serious concerns about a patient’s well-being, though they typically notify a nurse first.
Activation is typically achieved by calling a specific internal number, which initiates a rapid, coordinated response from the MET. The team is expected to arrive at the patient’s location quickly, often within a few minutes, to begin immediate assessment and intervention. This fast response time is a necessary component of the MET model, ensuring the window for preventing a full-blown arrest is not missed.