Advanced Trauma Life Support ATLS Student Course Manual 2018

TRAUMA SCORES
Correct triage is essential to the effective functioning
of regional trauma systems. Over-triage can
inundate trauma centers with minimally injured
patients and delay care for severely injured patients, and
under-triage can produce inadequate initial care and
cause preventable morbidity and mortality. In fact the
National Study on the Costs and Outcomes of Trauma
(NSCOT) found a relative risk reduction of 25% when
severely injured adult patients received their care at a
Level I trauma center rather than a nontrauma center.
Unfortunately, the perfect triage tool does not exist.
For this reason, most experts now advocate using
the “Guidelines for Field Triage of Injured Patients:
Recommendations of the National Expert Panel on
Field Triage, 2011” in lieu of trauma scores per se. A
recent review of the sensitivity and specificity of these
guidelines found the sensitivity to be 66.2% and the
specificity to be 87.3% for an injury severity score of
greater than 16; sensitivity was 80.1% and specificity
was 87.3% for early critical resource use. The sensitivity
decreased as a function of age.
However, because many emergency medical services
(EMS) systems still rely on trauma scores and scales
as tools for field triage, some of the most commonly
used are described here. None of these are universally
accepted as completely effective triage tools. The
Glasgow Coma Score (GCS) is used worldwide to rapidly
assess the level of consciousness of the trauma patient
(see Table 6-2 in Student Manual Chapter 6). Many
studies have demonstrated a good correlation between
GCS and neurological outcome. The motor response
contributes the greatest to the discriminatory power
of the score.
The Trauma Score (TS) calculation is based on five
variables: GCS, respiratory rate (RR), respiratory effort,
systolic blood pressure (SBP), and capillary refill. Values
range from 16 to 1 and are derived by adding the scores
assigned to each value. This system was revised in
1989 based on the analysis of 2000 cases. The Revised
Trauma Score (RTS) is calculated based on values (0–4)
assigned to three variables: GCS, SBP, and RR. These
values are assigned a weight and then the score is
calculated; it varies between 0 and 7.8408. Higher
scores are associated with higher probability of survival.
The Pediatric Trauma Score (PTS) was developed to
address concerns that RTS may not apply directly to the
pediatric population. This score is based on the sum of
six measures including the child’s weight, SBP, level of
consciousness, presence of fracture, presence of open
wound, and state of the airway. The score correlates
with injury severity, mortality, resource utilization,
and need for transport to a pediatric trauma center.
The PTS serves as a simple checklist, ensuring that all
components critical to initial assessment of the injured
child have been considered. It is useful for paramedics
in the field as well as doctors in facilities other than
pediatric trauma units. All injured children with a PTS of
less than 8 should be triaged to an appropriate pediatric
trauma center because they have the highest potential
for preventable mortality, morbidity, and disability.
According to National Pediatric Trauma Registry
statistics, this group represents approximately 25%
of all pediatric trauma victims and clearly requires the
most aggressive monitoring and observation. Studies
comparing the PTS with the RTS have identified similar
performances of both scores in predicting potential
for mortality. Unfortunately, the RTS produces what
most experts believe to be unacceptable levels of
under-triage, which is an inadequate trade-off for its
greater simplicity.
Traumatic injuries can be classified using an
Abbreviated Injury Severity (AIS) score. The scale was
first published in 1971 and graded the severity of tissue
injury associated with automotive trauma. It is now
widely used to grade injuries related to all types of
blunt and penetrating trauma. The scale ranges from
1 (minor) to 6 (unsurvivable). It is the basis of Injury
Severity Score (ISS). This score was first proposed in
1974 and is derived from the sum of the squares of
highest three scores in six body regions (head and
neck, face, chest, abdomen, limbs, and external). Scores
range from a minimum of 1 to a maximum of 75 (when
a score of 6 is given in any area, a score of 75 is assigned
regardless of other injuries). Mortality increases
with injury severity. A score of less than 15 generally
indicates mild injury. ISS tends to underestimate injury
in penetrating trauma because injuries in the same body
region are not accounted for. The New Injury Severity
Score (NISS) was developed to address this issue.
The sum of the squares of the most severely injured
areas, disregarding body region, is used to improve
score sensitivity.
Similarly to pediatrics, previously described tools
may not accurately predict the impact of injury in the
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