6.14 Scoring Systems, NEWS + ICNARC Flashcards
Scoring systems are routinely used in intensive care units for critically ill patients.
a) What is a scoring system?
● Scoring systems integrate easily measured data
from patients into a statistical algorithm
to provide a single score.
● This helps to predict the progress
of a patient’s illness and
how they will respond to a clinical intervention.
b) What types of scoring systems are you aware of in critical care patients?
● Illness severity scores —
Sequential Organ Failure Assessment (SOFA).
● Outcome prediction models —
Acute Physiology and Chronic Health Evaluation (APACHE) series — (APACHE IV validated in 2006.)
c) Describe the commonly used score in your intensive care unit
and explain how you would use it.
APACHE II is commonly used in the UK still;
it has only 17 variables.
● Provides a score of 0 to 71.
● Worst values over 24 hours are included.
● A score of 25 indicates a predicted mortality of 50%.
● A score of 35 or more indicates a predicted mortality of 80%.
● It is only an admission score and does not take into account any resuscitative or therapeutic efforts done before intensive care admission.
d) Why are early warning scores useful in acute illness and sepsis?
● Timely recognition.
● Intervention and escalation of care.
● Improves patient outcomes and safety.
e) Give some examples of early intervention that could be offered if the early warning scores indicate the need.
● Early antibiotics and infection source control in sepsis.
● Escalate care to the high dependency unit or intensive care unit
f) List the advantages and limits of early warning scores.
Advantages:
● A single physiologic parameter or
several variables are combined to
give an aggregate weighted score.
● Reflect acute illness severity.
● Common mode of communication among
a range of health care professionals.
● Aim to escalate care in those at high risk
______________________________________
Limits:
● User error.
● Inaccurate recording.
● Patients with chronic illness might
already have abnormal results.
● Do not replace clinical judgement.
g) List the features used in the National Early Warning Score
(NEWS).
● A national standardised approach from the
Royal College of
Physicians (2012).
● Six physiological variables —
respiratory rate,
SpO2,
temperature,
systolic BP,
heart rate,
level of consciousness
along with supplemental oxygen use.
● Urine output is excluded as this is not measured at the first
assessment and not routinely measured.
● Superior to early warning scores.
● Refined in 2017 (NEWS2).
h) What are the ICNARC reports?
● Intensive Care National Audit and Research Centre (ICNARC) — hospitals in England, Wales and Northern Ireland participate in the Case Mix Programme (CMP) and submit scoring system data over a time period; this helps to measure performance and compare with other intensive care units.
● Assist in decision-making,
resource allocation and
quality improvement.
● The ICNARC score incorporates physiological,
haematological, biochemical variables
with age, severe chronic disease and
circumstances related to intensive care admission.
i) What are the limitations of the ICNARC reports?
● Limits related to scores to derive SMR
(Standardised Mortality Ratio).
● Limits of unit comparison beyond scoring systems.
● Calibration of illness severity score weakens over time.
● APACHE II is not validated for children,
or less than an 8-hour stay in the intensive care unit
or readmissions.
● Excludes certain populations,
e.g. burns, CABG, liver transplants.
● Do not correlate well with circumstances of admission.
● Overestimates the mortality risk for patients with DKA or major
surgery with postoperative pain,
or those under the effects of GA.
● Regional variations exist in the HDU and ICU.
● Not for highly specialised services,
e.g. cardiac, ECMO, transplants.
● There is a selection bias as they
do not include patients who are
refused admission to the ICU.
