Predictive powers of the Modified Early Warning Score and the National Early Warning Score in general ward patients who activated the medical emergency team

Abstract

Background The current early warning scores may be insufficient for medical emergency teams (METs) to use in assessing the severity and the prognosis of activated patients. We evaluated the predictive powers of the Modified Early Warning Score (MEWS) and the National Early Warning Score (NEWS) for 28-day mortality and to analyze predictors of 28-day mortality in general ward patients who activate the MET. Methods Adult general ward inpatients who activated the MET in a tertiary referral teaching hospital between March 2009 and December 2016 were included. The demographic and clinical characteristics and physiologic parameters at the time of MET activation were collected, and MEWS and NEWS were calculated. Results A total of 6,729 MET activation events were analyzed. Patients who died within 28 days were younger (mean age 60 vs 62 years), were more likely to have malignancy (72% vs 53%), were more likely to be admitted to the medical department rather than the surgical department (93% vs 80%), had longer intervals from admission to MET activation (median, 7 vs 5 days), and were less likely to activate the MET during nighttime hours (5 PM to 8 AM) (61% vs 66%) compared with those who did not die within 28 days (P < 0.001 for all comparisons). The areas under the receiver operating characteristic curves of MEWS and NEWS for 28-day mortality were 0.58 (95% CI, 0.56-0.59) and 0.60 (95% CI, 0.59-0.62), which were inferior to that of the logistics regression model (0.73; 95% CI, 0.72-0.74; P < 0.001 for both comparisons).

Impact of hospitalization duration before medical emergency team activation: A retrospective cohort study

“…It consists of three members of the ICU staff (intensivist), four ICU fellows, two internal medicine residents, and nine dedicated nurses with experience in critical care. At least one intensivist or fellow, one resident, and two dedicated nurses work on every duty [ 7 ]. The three types of MET triggers are as follows: 1) doctors, nurses, and other health care workers call the MET for help, or 2) the measurement of a patient`s vital signs and laboratory tests exceeded the pre-defined criteria in the electronic medical record-based automatic screening system, or 3) code blue was announced for cardiopulmonary arrest, as published previously [ 7 , 8 ].…”

“…A MET is called by a general ward nurse or resident using dedicated MET numbers. The calling criteria for MET activation include crisis components based on the following physiological parameters: threatened airway, respiratory rate >30 breaths/min or <6 breaths/min, oxygen saturation <90% on the venturi mask 40% or O 2 at a flow rate of 12 L/min, pulse rate <40 beats/min or >140 beats/min, systolic blood pressure <90 mm/Hg, sudden mental change [ 7 ]. The MET is a team that responds quickly and accurately to deteriorating adult hospitalized patients and its main activities are as follows: 1) interventions for vital signs stabilization in situations such as sepsis, shock, respiratory failure, and cardiac arrest, 2) advanced airway management (intubation for difficult airway, cricothyroidotomy), 3) device insertion for hemodynamic monitoring and checking point-of-care-testing (POCT) that includes arterial blood gas monitoring, chemistry, lactic acid and 4) determination of a treatment plan.…”

“…The causes of activation were categorized as follows: respiratory distress, sepsis, hypovolemic shock, anaphylactic shock, altered mental status, metabolic acidosis, or others (including hypotension, education for nurse, simple procedures). In addition, data on hospital mortality in the patients with MET activation were collected daily and inspected monthly [ 7 ]. The MET nursing staff reviewed electrical medical records (EMRs) for the patient characteristics, which were recorded during patient assessment and treatment using formal data extraction forms.…”

A physician-led medical emergency team increases the rate of medical interventions: A multicenter study in Korea

“…The RRS aims to prevent unexpected patient death and cardiac arrest resulting from unpredictable deterioration of the patient’s condition in the general ward and emergency room. The RRS is composed of two limbs—an afferent limb that can quickly recognize a patient’s sudden deterioration and risk situation and an efferent limb that triages patients, performs resuscitation, and stabilizes the patients at the bedside [ 5 ]. Mainly, the efferent limb of the RRS includes the following interventions for resuscitation: therapy prescription, advanced airway management, central vascular line establishment, and intensive care unit (ICU)-level care initiation at the bedside [ 6 ].…”

“…According to team composition, responding teams were named as the rapid response team (RRT), medical emergency team (MET), and critical care outreach (CCO) [ 3 ]. RRTs and CCO are often nurse-led, whereas the MET is a physician-led team that mainly plays the role of an efferent limb of the RRS [ 3 , 5 ]. According to the MERIT study published in 2005, the introduction of the MET did not reduce the incidence of cardiac arrests, unplanned ICU admissions, or unexpected deaths [ 7 ].…”