The value of the Modified Early Warning Score for unplanned Intensive Care Unit admissions of patients treated in hospital general wards

Abstract

Aim: To determine the value of the Modified Early Warning Score (MEWS) for general ward patients and its potential use as an alarm tool for ward nurses.

Methods: A combined prospective-retrospective observational study was conducted with 153 patients in a university hospital (2013-2014). All patients were admitted to the intensive care unit (ICU) from general wards. Parameters retrospectively studied were 5 MEWS values at 4 hourly intervals, up to 20 hours before ICU admission. Parameters prospectively studied were ICU length of stay, ICU mortality, and mortality after ICU discharge.

Results: Most frequent severe adverse events were acute respiratory failure (39.9%) and septic shock (20.3%). Modified Early Warning Score increased gradually during the last 20 hours, and most patients remained in the wards, above a cut-off point ≥7 recorded at 4 hours before admission. Significant associations between latest MEWS score and ICU mortality and ICU length of stay were found. MEWS score≥ 7 hours before admission was highly associated with increased ICU and hospital mortality.

Conclusion: Patient deterioration in general wards can result in severe adverse events. Modified Early Warning Score is a strong predictor of outcome and may be used as a monitoring tool for potentially avoidable deaths and unplanned admissions to ICU.

Keywords: Modified Early Warning Score; critically ill; intensive care unit; mortality; nursing observation.