Frequency and nature of medical emergency team afferent limb failure in patients with documented vital sign abnormalities: A retrospective point prevalence study.

Background: Medical emergency team (MET) afferent limb failure is the presence of MET triggers and the absence of a documented MET call.

Objectives: The aim of this study was to measure and understand the frequency and nature of MET afferent limb failure in patients with documented vital sign abnormalities in an Australian major teaching hospital.

Methods: A retrospective point prevalence study was conducted at a 600-bed teaching hospital in Melbourne, Australia. Data were collected for all adult inpatients (aged ≥18 years) on 13 wards (three general medicine, three surgical, and seven specialist wards) during a randomly selected 24-h period. Data were extracted from the electronic medical record.

Results: There were 357 patients included in the study, with a median age of 72 y. Of the 9716 vital sign measures extracted, 0.9% fulfilled patient-specific MET activation criteria. There were 93 MET triggers documented in 36 patients: 25 patients experienced MET afferent limb failure. The major issues related to MET afferent limb failure were MET trigger modification processes, resolution of vital sign abnormalities, alternative escalation of care, and limitations of medical treatment orders without specific modifications to MET triggers.

Conclusions: Mandating MET activation for one aberrant vital sign at a single point in time warrants further assessment: lack of timely vital sign resolution may be a more appropriate trigger for MET calls and should be formally tested in future research. The frequency and effectiveness of alternative escalation pathways and local management of patients with MET triggers also warrant further investigation.