Pathophysiology
Clinical meaning
Early warning score (EWS) systems are standardized tools that aggregate multiple vital sign parameters into a composite score to identify patients at risk for clinical deterioration. The National Early Warning Score 2 (NEWS2) assigns points based on respiratory rate, oxygen saturation, supplemental oxygen use, temperature, systolic blood pressure, heart rate, and level of consciousness. A total score of 0-4 indicates low risk, 5-6 indicates medium risk requiring increased monitoring, and ≥7 indicates high risk requiring urgent clinical review. The Modified Early Warning Score (MEWS) is a simpler version using five parameters. Pediatric Early Warning Score (PEWS) adapts criteria for children. Single-parameter triggers (any one vital sign severely abnormal) also warrant escalation regardless of total score. EWS systems standardize the recognition and communication of patient deterioration, reducing subjectivity and empowering all staff to escalate concerns objectively.