What actions should be taken in response to a Modified Early Warning Score (MEWS) trigger?

Responding to a Modified Early Warning Score (MEWS) Trigger

When a Modified Early Warning Score (MEWS) trigger occurs, healthcare providers should immediately activate the Rapid Response Team (RRT) or Medical Emergency Team (MET) to assess the patient and intervene to prevent further clinical deterioration, cardiac arrest, and death. 1

Understanding MEWS and Its Significance

MEWS is a validated composite scoring system that evaluates:

• Vital signs (temperature, blood pressure, pulse, respiratory rate)
• Level of consciousness
• Other physiological parameters

The significance of MEWS lies in its ability to:

• Detect early physiological deterioration before overt clinical decline
• Predict complications up to 3 days before their diagnosis 1
• Reduce in-hospital cardiac arrests and mortality 2, 3

Immediate Actions Following a MEWS Trigger

1. Alert the appropriate response team:

   • For MEWS ≥4: Activate RRT/MET 4
   • For systolic BP >180 mmHg: Immediate assessment and treatment 1

2. Perform rapid bedside assessment:

   • Assess airway, breathing, circulation
   • Evaluate adequacy of ventilation and analgesia 1
   • Check for signs of organ dysfunction

3. Increase monitoring frequency:

   • Implement more frequent vital sign measurements 1
   • Consider continuous monitoring for high-risk patients

4. Initiate appropriate interventions:

   • Address underlying causes (pain, hypoxemia, hypovolemia)
   • Administer oxygen if needed
   • Establish IV access if not present
   • Begin fluid resuscitation if indicated

Escalation Protocol Based on MEWS Value

MEWS 3-4:

• Increase vital sign frequency to every 1-2 hours
• Notify primary team
• Consider RRT consultation

MEWS 5-6:

• Increase vital sign frequency to every 30-60 minutes
• Mandatory RRT activation
• Consider transfer to higher level of care
• Implement continuous monitoring

MEWS ≥7 (Warning Zone):

• Immediate RRT/MET activation
• Consider ICU transfer 1, 3
• Implement continuous monitoring
• Prepare for possible interventions including intubation or vasopressors

Special Considerations

• Postoperative patients: Higher vigilance needed as complications peak on day 3 after surgery 1
• Elderly patients: More vulnerable to failure to rescue, particularly after pulmonary or infectious complications 1
• Patients with cardiovascular or renal complications: These complications are highly predictive of mortality 1

Pitfalls to Avoid

1. Relying solely on MEWS: While valuable, MEWS alone is not sensitive enough and should be combined with clinical judgment and other criteria such as "worried" about patient condition 1

2. Delayed response: Failure to rescue is a significant contributor to mortality; prompt response to MEWS triggers is essential 1

3. Inadequate documentation: Ensure proper documentation of MEWS, interventions, and response

4. Insufficient follow-up: Patients require continuous assessment until stabilized 1

5. Missing subtle signs: Pay attention to trends in MEWS rather than single values

Evidence of Effectiveness

Implementation of MEWS systems has demonstrated:

• Increase in RRT activations (0.24 to 0.48 per 100 patient-days) 2
• Decrease in code blue events (0.05 to 0.02 per 100 patient-days) 2
• Reduction in overall inpatient mortality (2.3% to 1.2%) 2
• Decrease in in-hospital cardiac arrest rates from 5.21 to 2.05 per 1000 admissions 3

The MEWS system with a threshold of 4 or more has shown 75% sensitivity and 83% specificity for identifying patients requiring transfer to ICU or HDU 4, making it an effective risk-management tool for early intervention.