Documenting Rapid Response System afferent limb failure and associated patient outcomes

Area of Science:

• Critical Care Medicine
• Patient Safety
• Health Systems Science

Background:

• The Rapid Response System (RRS) aims to prevent adverse events in hospitalized patients.
• Afferent limb failure (ALF) represents a critical gap in RRS activation, where criteria are met but no RRS is called.
• Understanding ALF is crucial for improving patient outcomes and system performance.

Purpose of the Study:

• To define and quantify afferent limb failure (ALF) within a hospital setting.
• To investigate the association between ALF and patient outcomes, including unplanned Intensive Care Unit (ICU) admissions and mortality.
• To evaluate ALF as a performance metric for mature RRS.

Main Methods:

• Retrospective review of adult inpatient medical records and databases.
• Inclusion criteria: hospital length of stay >24 hours.
• Events analyzed: cardiac arrest, Medical Emergency Team (MET) call, or unanticipated ICU admission.

Main Results:

• Over six months, 35 (6.1%) cardiac arrests, 395 (68.7%) MET calls, and 145 (25.2%) ICU admissions occurred.
• Documented ALF was present in 131 (22.8%) of events, with 35.9% having criteria across multiple time periods.
• Patients with ALF were more likely to have unanticipated ICU admissions (34.4% vs 22.5%, p=0.01).
• Hospital mortality was higher for ALF patients with criteria across multiple time periods (52.5%) compared to single periods (31.9%, p=0.03).

Conclusions:

• Afferent limb failure (ALF) is a valuable performance indicator for established RRS.
• ALF is significantly associated with an increased likelihood of unanticipated ICU admissions.
• The duration of ALF, rather than the specific timing of criterion occurrence, may influence hospital mortality.