5.2 NEWS2 Escalation & Clinical Risk Assessment Tools (Waterlow, MUST)

NEWS2 Escalation & Clinical Risk Assessment Tools (Waterlow, MUST)

Standardized risk assessment tools are mandated across the NHS and UK independent health sectors to eliminate variation in practice, support clinical decision-making, and enable timely escalation of care. Registered nurses must demonstrate high competency in calculating and interpreting scores for physiological deterioration (NEWS2), tissue viability (Waterlow), and nutritional risk (MUST).

The National Early Warning Score 2 (NEWS2)

The National Early Warning Score 2 (NEWS2), developed by the Royal College of Physicians (RCP) and endorsed by NHS England and the NMC, standardizes the detection and response to acute illness, sepsis, and clinical deterioration.

The 7 Physiological Parameters of NEWS2

NEWS2 evaluates seven parameters, scoring each from 0 to 3 based on physiological disturbance:

1. Respiratory Rate: Normal 12–20 breaths/min (score 0). $\le 8$ or $\ge 25$ scores 3 points.
2. Oxygen Saturations ($SpO_2$):
   • Scale 1 (Standard target 94–98%): $\ge 96%$ scores 0; 94–95% scores 1; 92–93% scores 2; $\le 91%$ scores 3.
   • Scale 2 (Hypercapnic respiratory drive, e.g., COPD target 88–92%): Used ONLY when prescribed by a doctor for confirmed hypercapnic risk. 88–92% on air scores 0.
3. Air or Oxygen: Room air scores 0; supplemental oxygen scores 2.
4. Systolic Blood Pressure (SBP): Normal 111–219 mmHg (score 0). $\le 90$ mmHg or $\ge 220$ mmHg scores 3 points. (Diastolic BP is recorded but not scored).
5. Pulse / Heart Rate: Normal 51–90 beats/min (score 0). $\le 40$ or $\ge 131$ bpm scores 3 points.
6. Consciousness (ACVPU): Alert (A) scores 0. New Confusion (C), Voice (V), Pain (P), or Unresponsive (U) scores 3 points.
7. Temperature: Normal 36.1–38.0°C (score 0). $\le 35.0^\circ\text{C}$ scores 3 points; $\ge 39.1^\circ\text{C}$ scores 2 points.

NEWS2 Scoring Thresholds & Clinical Escalation Protocol

The total aggregate score (0–20) determines clinical urgency, monitoring frequency, and required level of clinician response:

• Aggregate Score 0–4 (Low Risk): Ward-based registered nurse assessment; baseline observation frequency minimum 4–12 hourly.
• Red Score = 3 in a Single Parameter (Low-Medium Risk): An individual parameter scoring 3 (e.g., new confusion or $SBP \le 90$) triggers an urgent registered nurse review within 30 minutes to decide if medical escalation is needed. Monitoring frequency increases to minimum 1 hour.
• Aggregate Score 5–6 (Medium Risk): Urgent clinical review by a doctor or advanced nurse practitioner (ANP) trained in managing acute illness; transfer to a higher care environment considered. Minimum hourly monitoring.
• Aggregate Score 7 or higher (High Risk): Emergency response! Immediate escalation to medical team with critical care skills (e.g., Medical Emergency Team / Cardiac Arrest / Critical Care Outreach). Continuous monitoring of vital signs and transfer to high dependency unit (HDU) or intensive care unit (ICU).

Waterlow Pressure Ulcer Risk Assessment Scale

Pressure ulcer prevention is a major clinical governance mandate under NMC Platform 3. The Waterlow scale evaluates tissue viability risk across multiple categories:

• Build / Weight for Height (BMI): Average, above average, obese, below average.
• Visual Skin Type & Risk Areas: Healthy, tissue thin, dry, edematous, clammy/feverish, discolored, broken.
• Sex and Age: Male/Female points added for age brackets (e.g., 65-74, 75-80, 81+).
• Continence: Complete/catheterized, urinary incontinence, fecal incontinence, double incontinence.
• Mobility: Fully mobile, restless/fidgety, apathetic, restricted, bedbound, chairbound.
• Special Risk Factors: Malnutrition, neurological deficit (stroke, paraplegia), major surgery/trauma, and high-risk medications (steroids, cytotoxics, anti-inflammatories).

Waterlow Risk Tiers & Nursing Interventions

• Score 10–14 (At Risk): Standard prevention: high-spec foam mattress, 2–4 hourly turning clock, barrier cream application for moisture, skin checks twice daily.
• Score 15–19 (High Risk): High-risk interventions: dynamic overlay or alternating pressure air mattress, strict repositioning schedule, tissue viability referral, nutritional support.
• Score $\ge 20$ (Very High Risk): Advanced interventions: specialized dynamic continuous low-pressure bed system, urgent tissue viability specialist referral, continuous pressure offloading, multi-disciplinary ulcer management.

Malnutrition Universal Screening Tool (MUST)

The MUST tool, developed by the British Association for Parenteral and Enteral Nutrition (BAPEN), is a 5-step screening framework used to identify adults at risk of malnutrition:

1. Step 1 – BMI Score: Calculate $\text{BMI} = \text{weight (kg)} / [\text{height (m)}]^2$.
   • $\text{BMI} > 20.0 = 0$
   • $\text{BMI } 18.5 - 20.0 = 1$
   • $\text{BMI} < 18.5 = 2$
2. Step 2 – Weight Loss Score: Unplanned weight loss over past 3–6 months.
   • $<5% = 0$
   • $5% - 10% = 1$
   • $>10% = 2$
3. Step 3 – Acute Disease Effect Score: Patient is acutely ill AND there has been or is likely to be no nutritional intake for $>5$ days $= 2$ points.
4. Step 4 – Overall Risk Score: Add Step 1 + Step 2 + Step 3.
   • Score 0 = Low Risk
   • Score 1 = Medium Risk
   • Score $\ge 2$ = High Risk
5. Step 5 – Management Actions:
   • Low Risk (0): Routine clinical care; re-screen weekly in hospital, monthly in care homes.
   • Medium Risk (1): Document 3-day food and fluid intake; encourage intake and fortify meals; re-screen weekly.
   • High Risk ($\ge 2$): Refer immediately to a registered dietitian and SALT (if swallowing difficulties present); prescribe high-calorie/high-protein oral nutritional supplements (ONS); monitor daily food intake and fluid balance.