MEWS – Modified Early Warning Score
Updated: Jun 16, 2021
Towards the end of the 20th century, accumulating evidence suggested that people in hospital wards were dying and suffering harm unnecessarily. Multiple studies have demonstrated that cardiac arrest or death is commonly preceded by several hours of deranged physiology. Recommendations were made to put systems in place to use this information to identify and respond to previously unrecognized deterioration in patients. In response, the first early warning score (EWS) was published in 1997 – Morgan’s Early Warning Score.
In 1999, the Audit Commission of the UK reported that the effectiveness of critical care services varied between hospitals and recommended the development of early warning systems (EWSs) to help ward staff identify when to call for specialist advice. In 1999, a team of researchers led by Stenhouse C. proposed a modification of one of the first existing early warning scores – Morgan’s Early Warning Score. This Modified Early Warning Score (MEWS) was evaluated in 206 surgical patients over 9 months. Fifty-seven (17%) ward patients triggered the call-out algorithm by scoring four or more on MEWS. Emergency patients were more likely to trigger the system than elective patients. Sixteen (5% of the total) patients were admitted to the ITU or HDU. MEWS with a threshold of four or more was 75% sensitive and 83% specific for patients who required transfer to ITU or HDU.
The purpose of the MEWS is to facilitate prompt communication between nursing and medical staff when deterioration in a ward patient’s condition first becomes apparent in the observations chart. The authors intended this system to result in earlier intervention on the ward so that transfer to a critical care facility is either prevented or occurs without unnecessary delay.
There are now many EWSs available. They are routinely used in several countries, including the Netherlands, USA, and Australia, and their use in UK hospitals is mandated as a standard of care by the National Institute For Health and Clinical Excellence (NICE).
MEWS – How is it calculated
It is a comprehensive measure of clinical deterioration of a person’s health which accounts for the breathing rate, heart rate, level of alertness (alert or unresponsive), body temperature, and blood pressure (BP). A numerical score is given for all these factors, a higher score signifying higher risk. The scores in all these 5 factors are added up to get the MEWS.
What are these scores and how are they given?
The score for all these 5 factors are given as per the table shown in the image below. A higher score indicates a higher risk.
A higher score indicates higher risk.
What is the safe and risky range of MEWS?
A score >= 4 (sum of all the above 5 physiological parameters) for MEWS is statistically linked to an increased likelihood of death or admission to an intensive care unit.
For any single physiological parameter with a score of +3, shows that the patient needs a higher level of care.
A score >= 9 for MEWS is highly risky and could be a sign of imminent death
MEWS on Dozee
Dozee can detect your heart rate, respiration rate, and level of responsiveness. BP and body temperature is a limitation for us, YET. R&D projects in the underway to find these too.
Dozee can calculate MEWS for any given time frame – 10 minutes, 30 minutes, an hour, a day, anything. Based on these MEWS values calculated by Dozee, an alert can be generated if and when a patient gets critical. This will reduce a tremendous amount of pressure on the Junior Doctors’ daily workload in the wards, nurses, and a lot of other healthcare personnel.
On the Sens dashboard, the graph you see for MEWS (screenshot attached above) is for every hour.