Modified early warning score (MEWS) is a simple guide used by emergency medical services

Emergency medical services

Emergency medical services are a type of emergency service dedicated to providing out-of-hospital acute medical care and/or transport to definitive care, to patients with illnesses and injuries which the patient, or the medical practitioner, believes constitutes a medical emergency...

 to quickly determine the risk of death of a subject. It is based on data derived from four physiological readings (systolic blood pressure

Blood pressure

Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...

, heart rate

Heart rate

Heart rate is the number of heartbeats per unit of time, typically expressed as beats per minute . Heart rate can vary as the body's need to absorb oxygen and excrete carbon dioxide changes, such as during exercise or sleep....

, respiratory rate

Respiratory rate

Respiratory rate is also known by respiration rate, pulmonary ventilation rate, ventilation rate, or breathing frequency is the number of breaths taken within a set amount of time, typically 60 seconds....

, body temperature) and one observation (level of consciousness, AVPU

AVPU

The AVPU scale is a system by which a first aider, ambulance crew or health care professional can measure and record a patient's responsiveness, indicating their level of consciousness....

). The resulting observations are compared to a normal range to generate a single score as follows:

Score	3	2	1	0	1	2	3
Systolic BP	<45%	30%	15% down	Normal for patient	15% up	30%	>45%
Heart rate (BPM)	—	<40	41-50	51-100	101-110	111-129	>130
Respiratory rate (RPM)	—	<9	—	9-14	15-20	21-29	>30
Temperature (°C)	—	<35	—	35.0-38.4	—	>38.5	—
AVPU AVPU The AVPU scale is a system by which a first aider, ambulance crew or health care professional can measure and record a patient's responsiveness, indicating their level of consciousness....	—	—	—	A	V	P	U

A score of five or more is clearly linked to increased likelihood of death and admission to a intensive care unit

Intensive Care Unit

thumb|220px|ICU roomAn intensive-care unit , critical-care unit , intensive-therapy unit/intensive-treatment unit is a specialized department in a hospital that provides intensive-care medicine...

.

Leeds Teaching Hospitals Trust (LTHT) Guidelines 2011

The MEWS may differ according to various Trusts. The Leeds Teaching Hospitals use a scoring system as shown below (accurate as of February 2011)

Score	3	2	1	0	1	2	3
Systolic BP	<45%	<30%	15% down	Normal for patient	15% up	30% up	>45%
Heart rate (BPM)	<40	—	40-50	51-100	101-110	111-130	>130
Respiratory rate (RPM)	<8	—	8-11	12-20	21-25	26-30	>30
Oxygen Saturations (%)	<85	>85	>90	>94	—	—	—
Respiratory Support	CPAP BiPAP	>60%	O2	Nil	—	—	—
AVPU AVPU The AVPU scale is a system by which a first aider, ambulance crew or health care professional can measure and record a patient's responsiveness, indicating their level of consciousness....	—	—	—	Alert	Voice	Pain	Unconscious
Urine Output (mls)	<80	80-119	120-200	>200	>800	—	—
Pain Score	Severe	Moderate	Mild	None	—	—	—