Why are children and obstetric patients not included in the programme?
The scope of the programme is limited to adult inpatients. The strongest current evidence for predicting deterioration is based on studies of the adult (non-pregnant) population. Because physiology changes with age and pregnancy, vital signs that are abnormal in non-pregnant adults may be normal for children or pregnant women.
A maternity early warning system is being developed through the maternal morbidity working group.
How does the programme address sepsis?
Evidence shows up to 30 percent of patients who have a rapid response call while in hospital have sepsis (Cross et al 2015). The recently updated consensus definitions for sepsis use the quick Sepsis-related Organ Failure Assessment (qSOFA) tool to identify patients with suspected infection who are at a greater risk for a poor outcome (Singer et al 2016).
The qSOFA tool uses fast respiratory rate, low blood pressure and altered level of consciousness – three parameters that are already scored in the proposed New Zealand Early Warning Score (NZEWS). A recent study of 30,000 patients has shown the British national EWS (on which the proposed NZEWS score is based) is more accurate than qSOFA for predicting death and transfer to an intensive care unit (ICU) in non-ICU patients. The authors conclude that qSOFA scores should not replace early warning scores when identifying the level of risk for patients with suspected infection (Churpek et al 2016).
We’ve developed a factsheet on how sepsis relates to the patient deterioration.
- Cross G, Bligrami I, Eastwood G, et al. 2015. The epidemiology of sepsis during rapid response team reviews in a teaching hospital. Anaesthesia in Intensive Care 43: 193–8.
- Singer M, Deutschman CS, Seymour C, et al. 2016. The third international consensus definitions for sepsis and septic shock (sepsis-3). Journal of the American Medical Association 315: 801–10.
- Churpek M, Snyder A, Han X, et al. 2016. qSOFA, SIRS and early warning scores for detecting clinical deterioration in infected patients outside the ICU. American Journal of Respiratory and Critical Care Medicine.
How does the latest version of the UK’s national early warning score impact on the New Zealand early warning score?
The New Zealand early warning score (NZEWS) continues to track with the latest version of the UK national early warning score released (NEWS) by the UK Royal College of Physicians (RCP) in December 2017 (‘NEWS2’).
The national vital signs chart includes:
- the ability to modify scored parameters to account for individual patient variation (such as chronic hypoxaemia)
- oxygen supplementation charted in litres/minute
- capacity to indicate when patients require room air only
- parameters ordered by an ‘ABCDE’ approach
- clear instruction to escalate care for any clinical concern regardless of vital signs (this would include concern for new confusion).
The key changes to the UK vital signs chart, based on feedback from clinicians, are:
- introduction of separate pulse oximetry saturation scores for patients with known chronic obstructive pulmonary disease. This was implemented to ameliorate the risk of over-oxygenating chronically hypoxaemic patients.
- addition of oxygen administration device and litres/min (rather than ‘inspired O2 %’)
- reordering of charted parameters to reflect an ‘ABCDE’ approach to assessment
- inclusion of new confusion as a marker of deterioration.
Other recommendations included in the UK update relate to escalation of care based on clinical risk associated with increasing scores. The NZ national vital signs chart has four bands of escalation for which individual district health boards have been asked to map the clinical risk to patients within each band to an appropriate local response.
There are other minor updates to the NEWS2 chart (such as colour choices affected by red-green colour blindness) that relate to human factors that impact upon usability. Human factors were considered during design of the NZEWS vital signs chart and its usability has been thoroughly tested in clinical practice.
The RCP recommendations for NEWS2 can be found here: www.rcplondon.ac.uk/projects/outputs/national-early-warning-score-news-2.
Why does the New Zealand early warning score use ‘AVPU’ to assess levels of consciousness?
Changes in level of consciousness may be overt (unconscious) or subtle (personality change) and may reflect a variety of causes. AVPU (alert / responds to voice only / responds to pain only / unresponsive) is simple to use. Evidence also shows it is better at identifying early deterioration in consciousness level in critically ill ward patients (McNarry and Goldhill 2004).
Some systems have used other ways to assess and document changes in level of consciousness linked with specific conditions or interventions. For example, research shows sedation scores are an effective way of detecting the impact of sedative medicines like opioids but not for detecting changes in level of consciousness from other causes (such as infection, hypotension or hypercapnia) (Nisbet and Mooney-Cotter 2009).
Similarly, the Glasgow Coma Scale (GCS) was developed as a tool for assessing patients with neurological injury. As a relatively complex scoring system, it has significant interrater variability (Gill et al 2007). For patients with specific neurological injury, clinicians must use the individual components of the GCS. Tertiary hospitals usually manage such patients in specific neurosurgical or neurology wards where clinicians are more familiar with the complexity of the GCS.
- McNarry AF, Goldhill DR. 2004. Simple bedside assessment of level of consciousness: comparison of two simple assessment scales with the Glasgow Coma Scale. Anaesthesia 59: 34–7.
- Nisbet A, Mooney-Cotter F. 2009. Comparison of selected sedation scales for reporting opiod-induced sedation assessment. Pain Management Nursing 10: 154–64.
- Gill M, Martens K, Lynch EL, et al. 2007. Interrater reliability of three simplified neurologic scales applied to adults presenting to the emergency department with altered levels of consciousness. Annals of Emergency Medicine 49: 403–7.e1.
How is level of consciousness scored if the patient is asleep?
You need to wake patients to do a full set of vital signs. If the patient does not wake normally from sleep, then score that. If you think a patient has low clinical risk and does not need to be woken to record a full set of vital signs at night, then document it in their monitoring plan.
Why aren’t pain scores part of the NZEWS?
Some, particularly specialist pain teams, have proposed pain as a vital sign for a number of years (Lynch 2001; Purser et al 2014). To date, no research has validated pain scores as a component of early warning scores. However, it is important to record pain on the vital signs chart to help interpret abnormal vital signs and effectively manage patients’ pain.
- Lynch M. 2001. Pain: the fifth vital sign. Comprehensive assessment leads to proper treatment. Advanced Nursing Practice 9: 28–36.
- Purser L, Warfield K, Richardson C. 2014. Making pain visible: an audit and review of documentation to improve the use of pain assessment by implementing pain as the fifth vital sign. Pain Management Nursing 15: 137–42.
What about deterioration from opioids?
The New Zealand early warning score (NZEWS) will detect both early and late signs of opioid toxicity by scoring abnormal respiratory rate, heart rate, systolic blood pressure and, subsequently, altered conscious state or hypoxaemia. Such abnormalities will prompt escalation to those with the skills needed to assess and manage opioid toxicity.
We have received a few queries about using the national adult vital signs chart to capture some of the opioid monitoring parameters. Using the adult vital signs chart is not ‘a requirement’. The Commission’s preference is for hospitals to use a separate opioid observation chart to capture the parameters necessary for monitoring opioid therapy.
Using a separate opioid observation chart is preferred because the opioid programme is focused specifically on surgical in-patients receiving opioids and the national adult vital signs chart is designed for a wider patient group - all non-pregnant adult in-patients. The opioid observation chart complements the national adult vital signs chart (for example ‘respiratory rate’ is included in the adult vital signs chart but is not repeated in the suggested opioid observation chart).
There is space on the national adult vital signs chart for up to two additional parameters to be monitored using the chart. These additional parameters can be selected by each organisation to reflect local practice needs. However, selecting these additional parameters should be based on the need for monitoring at a frequency similar to that for the core vital signs so that trends over time can easily be identified.
Why isn’t urine output part of the New Zealand early warning score?
Although it can be useful to identify end-organ perfusion, urine output is difficult to measure in certain circumstances and can be affected by a variety of factors. Ambulant patients without a urinary catheter who are able to walk to the toilet will be difficult to assess, as will patients with chronic renal failure who may normally produce little or no urine.
Some medicines may either increase or decrease the volume of urine output. Another influence can be normal post-operative states where there is an appropriate release of antidiuretic hormone to conserve volume in the face of (elective surgical) trauma. For these reasons, urine output is not part of the proposed New Zealand early warning score.
Why do we not record fluid balance on the vital signs chart?
Fluid balance is measured over a 24-hour period. Vital signs charts may cover much longer periods depending on how frequently the patient develops vital signs, which varies with the degree of illness. For this reason, the vital signs chart does not include fluid balance.
Where should we record bowel function and weight?
Bowel function and weight are not vital signs and therefore you should not document them on a vital signs chart. Weight is mainly used to calculate medication and you have space on the national medication chart to record that.
If you need to weigh a patient daily, record the measurement on a daily weight chart so you can see the trend over time. Record bowel function on a bowel chart if there are particular concerns, or in the clinical record.
Why do we score oxygen?
Oxygen is a medicine and should be prescribed and titrated to a target oxygen saturation (usually measured with a pulse oximeter) (Beasley et al 2015). Any patient who develops a new need for supplemental oxygen to maintain normoxia is at higher risk of deterioration. This is recognised in both the score weighting. Patients who receive oxygen at home or require it for other reasons (eg, carbon monoxide poisoning, decompression sickness) should have their New Zealand early warning score modified if it is clinically appropriate.
Patients who are hypoxaemic despite receiving additional oxygen will score twice (once for their hypoxaemia and once for the supplemental oxygen). Such patients are at greater risk of adverse outcomes so require more senior review. Other methods of oxygen delivery, such as high-flow devices or non-invasive ventilation, may be required.
In situations where oxygen is routinely administered regardless of oxygen saturation (such as in a post-anaesthetic care unit), a time-limited modification for supplemental oxygen may be required.
In some hospitals, patients leaving a post-anaesthetic care unit with oxygen have their supplemental oxygen score modified to 0, which expires 4 hours after returning to the ward. Patients who still require supplemental oxygen after this time should be medically reviewed for atelectasis or aspiration events.
We’ve developed a factsheet that provides guidance to clinicians on modifying the NZEWS trigger for patients receiving supplemental oxygen.
- Beasley R, Chien J, Douglas J, et al. 2015. Thoracic Society of Australia and New Zealand oxygen guidelines for acute oxygen use in adults: 'Swimming between the flags'. Respirology 20: 1182–91.