4.2 Recognising & Escalating Clinical Deterioration (Early Warning Scores)
Key Takeaways
- The New Zealand Early Warning Score (NZEWS) is a nationally standardized tool developed by the Health Quality & Safety Commission (HQSC) to detect acute adult physiological deterioration.
- NZEWS tracks seven key physiological parameters: Respiratory Rate, SpO2, Oxygen Requirement, Systolic BP, Pulse Rate, AVPU score, and Temperature.
- Single-parameter extreme scores (Score 3 in any single physiological parameter) indicate significant deterioration and require immediate clinical escalation regardless of total score.
- Mandatory Medical Emergency Team (MET) / Rapid Response Call criteria must be triggered immediately for critical red-flag values such as airway threat, RR ≤8 or ≥30, SBP <90, or GCS drop >2 points.
- The SBAR (Situation, Background, Assessment, Recommendation) structured communication tool ensures clear, concise, and unambiguous escalation during clinical deterioration.
4.2 Recognising & Escalating Clinical Deterioration (Early Warning Scores)
Early recognition of physiological deterioration is a critical competency for registered nurses in New Zealand. Unrecognised acute deterioration leads to preventable adverse events, unplanned intensive care admissions, cardiac arrests, and patient mortality. Te Whatu Ora hospitals utilize the New Zealand Early Warning Score (NZEWS) system, developed by the Health Quality & Safety Commission (HQSC), as part of the mandatory Adult Deterioration System.
The New Zealand Early Warning Score (NZEWS) Framework
NZEWS provides a standardized framework across acute adult healthcare settings in New Zealand. It converts baseline physiological vital signs into numerical values (0 to 3) based on their variance from normal physiological parameters.
Core Physiological Parameters Scored in NZEWS
- Respiratory Rate (RR)
- Oxygen Saturation (SpO2) (Scale 1 for general patients; Scale 2 for target SpO2 88–92% in chronic hypercapnia)
- Air or Oxygen Requirement (Air vs. Supplemental Oxygen)
- Systolic Blood Pressure (SBP)
- Pulse Rate (Heart Rate)
- Level of Consciousness (AVPU)
- Temperature
NZEWS Scoring Matrix & Parameter Values
The table below demonstrates how physiological deviations map to NZEWS points (0, 1, 2, 3).
| Physiological Parameter | Score 3 | Score 2 | Score 1 | Score 0 | Score 1 | Score 2 | Score 3 |
|---|---|---|---|---|---|---|---|
| Respiratory Rate (bpm) | ≤ 8 | 9 – 11 | 12 – 20 | 21 – 24 | ≥ 25 | ||
| SpO2 Scale 1 (%) | ≤ 91 | 92 – 93 | 94 – 95 | ≥ 96 | |||
| Supplemental O2 | Air | Oxygen | |||||
| Systolic BP (mmHg) | ≤ 90 | 91 – 100 | 101 – 110 | 111 – 219 | ≥ 220 | ||
| Pulse Rate (bpm) | ≤ 40 | 41 – 50 | 51 – 90 | 91 – 110 | 111 – 130 | ≥ 131 | |
| Consciousness (AVPU) | Alert (A) | Voice/Pain/Unresponsive (V, P, U) | |||||
| Temperature (°C) | ≤ 35.0 | 35.1 – 36.0 | 36.1 – 38.0 | 38.1 – 39.0 | ≥ 39.1 |
CRITICAL RULE: Any single parameter scoring 3 points represents a significant single-parameter trigger that mandates immediate escalation, even if the total aggregate NZEWS is low.
NZEWS Escalation Response Protocols
Te Whatu Ora hospitals operate structured response protocols mapped directly to the aggregate NZEWS score and single-parameter triggers.
+-----------------------------------------------------------------------------+
| NZEWS ESCALATION PROTOCOL |
+-----------------------------------------------------------------------------+
| TOTAL SCORE 1 - 5 --> LOW RISK: Increase vital sign frequency (4-hourly). |
| Inform primary nurse. |
| |
| TOTAL SCORE 6 - 7 --> MEDIUM RISK: Mandatory urgent ward-based doctor |
| or SINGLE SCORE 3 review within 30 minutes. Increase monitoring. |
| |
| TOTAL SCORE 8+ --> HIGH RISK / CRITICAL: Immediate Emergency Call / |
| or RED FLAG CALL Medical Emergency Team (MET) / RRT response |
| (Immediate within 5-10 mins). |
+-----------------------------------------------------------------------------+
1. Low Risk (NZEWS Total 1 – 5)
- Action: Repeat vital signs in 4 hours (or sooner as clinically indicated).
- Response: Primary nurse evaluates clinical context, pain, fluid status, or analgesia effects.
2. Medium Risk (NZEWS Total 6 – 7 OR Any Single Score 3)
- Action: Inform the charge nurse / associate charge nurse manager (ACNM).
- Mandatory Medical Response: Urgent review by house officer / registrar within 30 minutes.
- Monitoring: Increase vital sign frequency to at least 30–60 minutes until stabilized.
3. High Risk / Critical Deterioration (NZEWS Total 8+ OR MET Criteria)
- Action: Immediately initiate an Emergency Call / MET Call (Medical Emergency Team) or Rapid Response Call via hospital emergency speed-dial (e.g., 777 in NZ public hospitals).
- Mandatory Medical Response: Senior registrar / ICU Registrar / MET arrive at bedside within 5 to 10 minutes.
- Monitoring: Continuous physiological monitoring (ECG, continuous SpO2, automated 5-minute BP).
Mandatory Rapid Response / MET Call Red-Flag Criteria
Nurses must call an immediate MET / 777 Emergency Call if any of the following critical red-flag indicators are met, regardless of the calculated NZEWS total:
- Airway: Threatened or obstructed airway; stridor; acute upper airway swelling.
- Breathing: Respiratory arrest; RR ≤ 8 or ≥ 30 breaths/min; severe respiratory distress.
- Circulation: Cardiac arrest; HR ≤ 40 or ≥ 140 bpm; Systolic BP < 80 mmHg despite initial fluid bolus.
- Disability: Sudden collapse; prolonged seizure activity; acute drop in GCS of > 2 points; sudden unresponsiveness.
- Clinical Concern: Nurse or family member is seriously concerned about the patient's acute decline ("Worry / Gut Feeling" trigger).
Escalation Communication: The SBAR Framework
When escalating clinical deterioration to medical staff or calling a MET response, nurses must use the SBAR (Situation, Background, Assessment, Recommendation) structured communication tool to ensure succinct, structured information transfer.
| SBAR Component | Description | Clinical Example Script |
|---|---|---|
| S — Situation | Identify self, unit, patient name, and immediate reason for call. | "This is Nurse Sarah on Ward 5. I am calling about Mr. John Smith in Bed 12. I am calling because his NZEWS has spiked to 9 and he is hypotensive and tachypnoeic." |
| B — Background | Relevant clinical history, admission diagnosis, and current interventions. | "Mr. Smith is a 72-year-old post-op bowel resection patient from yesterday. He has a history of heart failure and has had IV fluids running at 80 mL/hr." |
| A — Assessment | Current vital signs, NZEWS breakdown, physical findings, and trends. | "His vital signs are: BP 82/50 mmHg (Score 3), HR 125 bpm (Score 2), RR 26 (Score 3), SpO2 92% on air (Score 2), Temp 38.6°C. Total NZEWS is 10. His surgical dressing is dry, but skin is cool and mottled." |
| R — Recommendation | Explicit request or recommended action plan. | "I recommend an immediate bedside review by the Registrar. I request a medical fluid bolus order, urgent blood gas, and sepsis screen." |
A patient on a surgical ward has a total NZEWS score of 4, but their respiratory rate is measured at 7 breaths/min (scoring 3 points for that single parameter). What is the mandatory clinical escalation requirement under NZEWS guidelines?
Which set of vital signs represents a mandatory Medical Emergency Team (MET) / Emergency Red Flag call in a New Zealand acute hospital?
When delivering an SBAR handover call for a deteriorating patient, which statement represents the 'Assessment' (A) phase?
According to HQSC Adult Deterioration System guidelines, what is the target timeframe for a senior medical officer or Medical Emergency Team (MET) to arrive at the bedside following a High Risk (NZEWS 8+) emergency call?