Early warning system (medical)

A system to identify patients at risk of deterioration

An early warning system (EWS) in the medical context is a tool used by healthcare professionals to identify patients at risk of clinical deterioration. These systems are designed to provide an early alert to healthcare staff, allowing for timely intervention and potentially preventing adverse outcomes such as cardiac arrest or unplanned admission to intensive care units.

Overview

Early warning systems are typically based on the regular monitoring of physiological parameters. These parameters are often combined into a single score that reflects the patient's overall condition. The score is calculated using a predefined algorithm, and thresholds are set to trigger alerts when the score indicates a high risk of deterioration.

Components of an Early Warning System

Physiological Parameters

The core of an early warning system is the set of physiological parameters that are monitored. Common parameters include:

• Heart rate
• Respiratory rate
• Blood pressure
• Body temperature
• Oxygen saturation
• Level of consciousness, often assessed using the Glasgow Coma Scale

Scoring Systems

The parameters are used to calculate a score that reflects the patient's condition. Different systems use different scoring methods, but they generally follow a similar principle: the more abnormal the parameter, the higher the score.

Sample Adult Deterioration Detection System chart

Thresholds and Alerts

Thresholds are set to determine when an alert should be triggered. These thresholds are based on the score and are designed to prompt a response from healthcare staff. The response may vary depending on the severity of the score, ranging from increased monitoring to immediate medical intervention.

Types of Early Warning Systems

National Early Warning Score (NEWS)

The National Early Warning Score (NEWS) is a widely used system in the United Kingdom. It was developed by the Royal College of Physicians and is used to standardize the assessment of acute-illness severity in the NHS.

National Early Warning Score chart, Royal College of Physicians, version 2

Modified Early Warning Score (MEWS)

The Modified Early Warning Score (MEWS) is another commonly used system. It is similar to NEWS but may include different parameters or scoring methods tailored to specific patient populations or healthcare settings.

Implementation and Challenges

Implementing an early warning system requires training healthcare staff to use the system effectively. Challenges include ensuring accurate data entry, maintaining staff compliance, and integrating the system into existing workflows. Additionally, there is a need to balance sensitivity and specificity to minimize false alarms while ensuring that true cases of deterioration are not missed.

Benefits of Early Warning Systems

Early warning systems have been shown to improve patient outcomes by enabling earlier detection of deterioration. This can lead to more timely interventions, reduced length of hospital stays, and decreased mortality rates. They also help in resource allocation by identifying patients who need more intensive monitoring or care.

Related pages

• Patient safety
• Intensive care unit
• Clinical deterioration
• Vital signs