Chapter 6. The Role of Vital Signs in ESI Triage
In this chapter, we focus on decision point D—the
patient's vital signs. To reach this point in the ESI
algorithm, the triage nurse has already determined
that the patient does not meet ESI level-1 or 2
criteria, and that he or she will require two or more
resources. Since the patient requires two or more
resources, he or she meets the criteria for at least an
ESI level 3. It is at this point in the algorithm that
vital signs data are considered, so the triage nurse's
next step is to assess the patient's heart rate,
respiratory rate, and oxygen saturation, and, when
appropriate (for children under age 3), temperature.
If the danger zone vital sign limits are exceeded (as
illustrated in decision point D, Figure 6-1), the triage
nurse must strongly consider up-triaging the patient
from a level 3 to a level 2.
Figure 6-1. Danger Zone Vital Signs
During the ESI triage educational program, a
considerable amount of time should be devoted to
exploring the importance of vital signs in the
decision to move a patient from ESI level 3 to an ESI
level 2. It should be stressed that it is always the
decision of the experienced triage nurse to determine
whether the patient meets criteria for ESI level 2,
based upon their past medical history, current
medications, and subjective and objective assessment
that includes general appearance. This decision is
based on the triage nurse's clinical judgment and
knowledge of normal vital sign parameters for all
ages and the influence of factors such as medications,
past medical history, and pain level.
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What Are Vital Signs?
Vital signs traditionally include simple measurements
of physiological parameters including temperature,
blood pressure, pulse, and respiratory rate as well as
pulse oximetry (Table 6-1). They frequently prompt a health care worker to follow a particular
path of action. Recently, the nursing literature has
placed increased emphasis on pain. The American
Pain Society adopted the phrase "Pain: the fifth vital
sign" to increase healthcare workers' awareness of
the importance of assessment and management of
pain. Pain assessment is an important component of
ESI and is actually assessed earlier in the algorithm.
So, for the purpose of ESI, heart rate, respiratory rate,
oxygen saturation and temperature in children
under age 3 are the vital sign parameters considered
in decision point D.
Vital signs represent a set of
objective data for use in determining general
parameters of patients' health and viability. The
values we obtain influence our interpretation of a
patient's overall condition and, therefore, the path
we take in establishing a diagnosis and treatment for
the patient. However, vital signs alone do not paint
a complete picture of the patient's condition. Vital
signs may be affected by a variety of factors
including prescription medications, herbals, and
recreational drugs. For example, beta-blockers cause
bradycardia and blunt the tachycardic response to
shock. Hypothyroidism, common in the elderly,
may lead to the finding of low temperature, even in
the face of sepsis. A young adult may have an
elevated body temperature due to recreational drug
Vital signs are variable, dynamic indicators that are
an adjunct to a patient's evaluation. Vital sign
measurements may also be operator dependent, and
the definition of normal vital signs varies according
to the reference consulted. Even under the best
conditions, vital signs are not always reliable or
accurate (Edmonds, Mower, Lovato & Lomeli, 2002).
The patient's general appearance and clinical picture
frequently prove to be of the most value. However,
if in a triage nurse's judgment, knowing a patient's
vital signs would help with risk analysis, then vital
signs should be measured. For example, if the
patient is using immunosuppressive medications or
chemotherapy or is immunosuppressed by an illness
such as AIDS, then the body temperature should be
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Are Vital Signs Necessary at Triage?
Prior to the advent of five-level triage in the United
States, tradition dictated that every patient
presenting to an emergency department should have
a set of vital signs taken before triage level
assignment. Vital signs were considered an integral
component of the initial nursing assessment and
were often used as a decisionmaking tool. In a
traditional three-level triage system, vital signs
helped determine how long a patient could wait for
treatment (i.e., if no abnormal vital signs were
present, in many cases, the patient could wait a
longer period of time). Vital signs, therefore, in the
past weighted heavily in the patient triage
assessment, with variable emphasis placed on the
More recently, newer triage models advocate
selective use of vital signs at triage (Gilboy, Travers &
Wuerz, 2000). Initial vital signs are not a mandatory
component of other five-level triage systems and in
general are not reported during the triage phase of a
level-1 or 2 patient (i.e., those patients with the
highest acuity). For example, the Guidelines for
Implementation of the Australasian Triage Scale in
Emergency Departments states that "vital signs should
only be measured at triage if required to estimate
urgency, or if time permits" (Australasian College for
Emergency Medicine, 2000). Similarly, the Canadian
Triage and Acuity Scale (CTAS) upholds the need for
vital signs if, and only if, they are necessary to
determine a triage level (in the cases of levels 3, 4,
and 5) as time permits (Beveridge, et al., 2002). The
Manchester Triage Group uses specific vital sign
parameters as discriminators within a presentational
flow chart. The vital sign parameter is one of the
factors that help the triage nurse assign an acuity
Vital signs may not always be the most appropriate
tool to determine triage acuity. At least one study
has suggested that vital signs are not always
necessary in the initial assessment of the patient at
triage. In 2002, Cooper, Flaherty, Lin, and Hubbell
examined the use of vital signs to determine a
patient's triage status. They considered age and
communication ability as factors. Twenty-four
different U.S. emergency departments and more
than 14,000 patients participated in that study. Final
results demonstrated that vital signs changed the
level of triage acuity status in only eight percent of
the cases. When further examining individual age
groups, pediatric patients age 2 or younger showed
the largest variation in triage decision with an 11.4-percent change once vital signs were collected.
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Vital Signs and ESI Triage
Using ESI triage, the only absolute requirement for
vital signs assessment is for patients who don't
initially meet ESI level-1 or 2 criteria, but who are of vital signs at triage is optional and at the
discretion of the triage nurse for patients triaged as
ESI level 1, 2, 4, or 5. While the ESI system does not
require vital signs assessment on all patients who
present to triage, local policies may dictate a
different procedure. Factors such as staffing levels,
casemix, and local resources influence individual
hospital policies regarding vital signs at triage and
are beyond the scope of this handbook. In general
when triaging a stable patient, it is never wrong to
obtain a set of vital signs. ESI requires vital signs for
only level-3 patients (Table 6-2).
The developers of the ESI and the current ESI
research team believe that experienced ED nurses
can use vital sign data as an adjunct to sound
clinical judgment when rating patients with the ESI.
There is limited evidence on vital sign abnormalities
as they relate to ED acuity and that are proven to
truly represent serious illness. The ESI has been
revised over time to reflect changes in the available
evidence and recommendations from the literature.
The ESI working group initially used the systemic
inflammatory response syndrome (SIRS) literature
(Rangel-Frausto, et al., 1995) in developing the
danger zone vital sign box and accompanying
The first version of the ESI used the SIRS
criteria to include a heart rate of greater than 90 (for
adults) as an absolute indicator to up-triage from ESI
level 3 to level 2 (Wuerz, Milne, Eitel, Traers &
Gilboy, 2000). The SIRS research was based on
predictors of mortality in an intensive care unit
population. Based on an excess of false positives
using these criteria for ED patients at the initial ESI
hospitals, the heart rate cutoff was changed to 100
in ESI version 2, and nurses were instructed to
consider up-triage to ESI 2 for adult patients with
heart rates greater than 100 (Wuerz, et al., 2001; Gilboy, Tanabe, Travers, Eitel & amp; Wuerz, 2003).
Additionally, pediatric vital signs were added to the
danger zone vital signs box.
When using ESI as a triage system, vital signs
assessment is not necessary in the triage area for
patients who are immediately categorized as level 1
or 2. If the patient appears unstable or presents with
a chief complaint that necessitates immediate
treatment, then transport of the patient directly to
the treatment area should be expedited. For these
patients, the resuscitation team is responsible for
obtaining and monitoring vital signs at the bedside.
This would include patients that have clinical
appearances that indicate high risk or need for
immediate cardiovascular or respiratory
intervention. These patients may appear pale,
diaphoretic, or cyanotic. However, the triage nurse
has the option to perform vitals in the triage area, if
an open bed is not immediately available or if he or
she feels that the vital signs may assist in confirming
the triage acuity level.
Some patients may not
initially be identified as ESI level 1 until vital signs
are taken. For example, an awake, alert elderly
patient who complains of dizziness might be found
to have a life-threatening condition when a heart
rate of 32 or 180 is discovered during vital sign
As shown in the ESI algorithm in Chapter 3, if
patients do not meet ESI level-1 or 2 criteria, the
triage nurse comes to decision point C. The nurse
then determines how many resources the patient is
expected to need in the ED. If the patient is
expected to need one or no resources, he or she can
be assigned an ESI level of 4 or 5 and no vital sign
assessment is necessary. But if the patient is expected
to need two or more resources, then the nurse
comes to decision point D and vital signs should be
Vital signs can play a more important role
in the evaluation of some patients at triage,
especially those triaged as ESI level 3. The range of
vital signs may provide supporting data for potential
indicators of serious illness. If any of the danger
zone vital signs are exceeded, it is recommended
that the triage nurse consider up-triaging the patient
from level 3 to level 2.
Vital signs that are explicitly included in ESI triage
are heart rate, respiratory rate, and oxygen
saturation (for patients with potential respiratory
compromise). Temperature is specifically used in ESI
triage for children under age 3. It is
important to note that when considering abnormal
vital signs, blood pressure is not included in the ESI
algorithm. This does not mean that the triage nurse
should not take a blood pressure or a temperature
on older children or adults but that these vital signs
are not necessarily used to assist in selecting the
appropriate triage acuity level.
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Vital Signs and Pediatric Fever
In this version of the ESI Handbook, version 4 (v.4)
of the ESI algorithm has been updated to include
more current pediatric fever criteria. As shown in
Figure 6-2, note D of the ESI algorithm addresses
pediatric fever considerations for ESI triage. This
section incorporates recommendations from the
American College of Emergency Physicians' Clinical
Policy for Children Younger Than Three Years
Presenting to the Emergency Department With Fever
Figure 6-2. Danger Zone Vital Signs
D. Danger Zone Vital Signs. Consider uptriage to ESI 2 if any vital sign criterion is exceeded.
Pediatric Fever Considerations:
- 1 to 28 days of age: assign at least ESI 2 if temp >38.0 C (100.4F)
- 1-3 months of age: consider assigning ESI 2 if temp >38.0 C (100.4F)
- 3 months to 3 yrs of age: consider assigning ESI 3 if: temp >39.0 C (102.2 F), or incomplete immunizations, or no obvious source of fever.
The ESI Triage Research Team recommends that vital
signs in patients under age 3 be assessed at triage. In
particular, temperature measurement is important
during triage of all children from newborn through
36 months of age, and vital sign evaluation is
essential to the overall assessment of a known febrile
infant under age 36 months (Baraff, 2000). This
helps to differentiate ESI level-2 and 3 patients and
minimize the risk that potentially bacteremic
children will be sent to an express care area or
otherwise experience an inappropriate wait.
Remember, if a patient is in immediate danger or high risk, he or she will be assigned to either ESI
level 1 or 2.
Table 6-3 provides direction for the triage nurse in
using the ESI to assess the febrile child and
determine the most appropriate triage level. The
generally accepted definition of fever is a rectal
temperature greater than 38.0° C (100.4° F) (Baraff, et
al., 1993; ACEP, 2003). The infant less than 28 days
old with a fever should be considered high risk and
assigned to at least ESI level 2. There are no clear
guidelines for the infant between 28 days and 3
months of age. The ESI research team recommends
triage nurses rely on local hospital guidelines. We
suggest that the nurse consider assigning at least an
ESI level 2 for such patients.
In v. 4 of the ESI, we have incorporated a different
set of pediatric fever guidelines for children ages 3 to
36 months. These pediatric fever considerations
pertain to highly febrile children, defined as those
with a fever of greater than 39.0° C (102.2° F) (ACEP, 2003). When triaging a child between 3 and 36
months of age who is highly febrile, it is important
for the triage nurse to assess the child's
immunization status and whether there is an
identifiable source for the fever.
The patient with
incomplete immunizations or with no identifiable
source for the fever should be assigned to at least ESI
level 3. If the patient has an identifiable source for
the fever and his or her immunizations are up to
date, then a rating of 4 or 5 is appropriate. For
example, a 7-month-old who is followed by a
pediatrician, has had the Haemophilus influenza
type b (HIB) vaccine and presents with a fever and
pulling on his ear could be assigned to an ESI
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The following case studies are examples of how vital
signs data are used in ESI triage:
- "My doctor told me I am about 6 weeks pregnant
and now I think I am having a miscarriage,"
reports a healthy looking 28-year-old female. "I
started spotting this morning and now I am
cramping." No allergies, no PMH, medications:
prenatal vitamins. Vital signs: T 98° F, HR 112, RR
22, BP 90/60.
This patient meets the criteria for being up-triaged
from a level 3 to a level 2 based on her vital signs.
Her increased heart rate, respiratory rate, and
decreased blood pressure are a concern. These factors
could indicate internal bleeding from a ruptured
- "The baby has had diarrhea since yesterday. The
whole family has had that GI bug that is going
around," reports the mother of a 15-month-old.
She tells you the baby has had a decreased
appetite, a low-grade temperature, and numerous
liquid stools. The baby is sitting quietly on the
mother's lap. The triage nurse notes signs of
dehydration. No PMH, NKDA, no medications.
Vital signs: T 100.4° F, HR 142, RR 48, BP 76/50.
This patient meets the criteria for at least ESI level 3.
For resources he would require labs and IV fluid.
Based on his vital signs the triage nurse can uptriage
him to an ESI level 2. For a baby this age, both
heart rate and respiratory rate criteria are violated.
- "I need to see a doctor for my cough. I just can't
seem to shake it. Last night I didn't get much
sleep because I was coughing so much, I am just
so tired," reports a 57-year-old female. She tells
you that she had a temperature of 101° last night
and that she is coughing up this yellow stuff. Her
history includes a hysterectomy 3 years ago; she
takes no medications but is allergic to Penicillin.
Vital signs: T 101.4°, RR 28, HR 100, SpO2 90
At the beginning of her triage assessment, this
patient sounds as though she could have pneumonia. She will need two or more resources but
her low oxygen saturation and increased respiratory
rate are a concern. After looking at her vital signs
the triage nurse should up-triage the patient to an
ESI level 2.
- A 34-year-old obese female presents to triage
complaining of generalized abdominal pain (pain
scale rating: 6/10) for 2 days. She has vomited
several times and states her last bowel movement
was 3 days ago. She has a history of back surgery,
takes no medications, and is allergic to peanuts.
Vital signs: T 97.8° F, HR 104, RR 16, BP 132/80,
SpO2 99 percent.
This patient will need a minimum of two or more
resources: lab, IV fluids, perhaps IV medication for
nausea, and a CT scan. The triage nurse would
review the patient's vital signs and consider the
heart rate. The heart rate falls just outside the
accepted parameter for the age of the patient but
could be due to pain or exertion. In this case, the
decision should be to assign the patient to ESI
- A tearful 9-year-old presents to triage with her
mother. She slipped on an icy sidewalk and
injured her right forearm. The forearm is
obviously deformed but has good color,
sensation, and movement. The mother reports
she has no allergies, takes no medications, and is
healthy. Vital signs: BP 100/68, HR 124, RR 32,
and SpO2 99 percent.
This child is experiencing pain from her fall and is
obviously upset. She will require at least two
resources: x-ray and orthopedic consult, and perhaps
conscious sedation. Her heart rate and respiratory
rate are elevated, but the triage nurse should feel
comfortable assigning this patient to ESI level 3. Her
vital sign changes are likely due to pain and distress.
- A 72-year-old patient presents to the ED with her
oxygen via nasal cannula for her advanced
COPD. She informs the triage nurse that she has
an infected cat bite on her left hand. The hand is
red, tender, and swollen. The patient has no
other medical problems, uses albuterol prn, and
takes an aspirin daily, NKDA. Vital signs: T 99.6°
F, HR 88, RR 22, BP 138/80, SpO2 91 percent. She
denies respiratory distress.
This patient will require two or more resources: labs
and IV antibiotics. She meets the criteria for ESI level
3. The triage nurse notices that her oxygen
saturation and respiratory rate are outside the
accepted parameters for the adult but this patient
has advanced COPD. These vital signs are not a
concern so the patient will not be up-triaged but
will stay an ESI level 3.
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The information in this chapter provides a
foundation for understanding the role of vital signs
in the Emergency Severity Index triage system. We
addressed the special case of patients under 36
months of age. Further research is necessary to
clarify the best vital sign thresholds used in
emergency department triage. Further study will also
examine pediatric populations presenting to the
emergency department. It is our hope that future
versions of the ESI will be based on additional
evidence regarding the predictive value of triage
vital signs for pediatric and adult patients.
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American College of Emergency Physicians (2003). Clinical policy for children younger than 3 years
presenting to the emergency department with fever.
Annals of Emergency Medicine 43(4):530-45.
Australasian College for Emergency Medicine (2000).
Policy document—the Australasian triage scale. Retrieved
March 27, 2002, from http://www.acem.org.au/open/documents/triage.htm
Australasian College for Emergency Medicine (2000). Guidelines for the implementation of the Australasian
triage scale in emergency departments. Retrieved March
27, 2002, from http://www.acem.org.au/open/documents/triageguide.htm
Baraff LJ (2000). Management of fever without source in
infants and children. Annals of Emergency Medicine 36:602-14.
Baraff LJ, Bass JW, Fleisher GR, Klein JO,
McCracken GH, Powell KR, et al. (1993). Practice
guideline for the management of infants and children
0 to 36 months of age with fever without source.
Agency for Health Care Policy and Research. Annals of
Emergency Medicine 22:1198-210.
Beveridge R, Clarke B, Janes L, Savage N, Thompson J, Dodd G, et al. Implementation guidelines for the
Canadian emergency department triage and acuity
scale (CTAS). Retrieved March 27, 2001, from
Cooper R, Flaherty H, Lin E, Hubbell K (2002).
Effect of vital signs on triage decisions. Annals of
Emergency Medicine 39:223-32.
Edmonds Z, Mower W, Lovato L, Lomeli R (2002).
The reliability of vital sign measurements. Annals of
Emergency Medicine 39:233-7.
Gilboy N, Travers DA, Wuerz RC (2000). Reevaluating
triage in the new millennium: A
comprehensive look at the need for standardization
and quality. Journal of Emergency Nursing 25(6):468-73.
Gilboy N, Tanabe P, Travers DA, Eitel DR, Wuerz RC (2003). The Emergency Severity Index Implementation
Handbook: A five-level triage system. Des Plaines, IL:
Emergency Nurses Association.
Paris P (1989). No pain, no pain. American Journal of
Emergency Medicine 7:660.
Rangel-Frausto M, Pittet D, Costigan M, Hwang T,
Davis C, Wenzel R (1995). The natural history of
the systemic inflammatory response syndrome (SIRS): A
prospective study. Journal of the American Medical
Stedman's Medical Dictionary (26th ed.) (1995). Baltimore:
Williams & Wilkins.
Tintinalli J, Kelen G, Stapczynski J (2000). Emergency
medicine: A comprehensive study guide (5th ed.). New
Wuerz R, Milne LW, Eitel DR, Travers D, Gilboy N (2000). Reliability and validity of a new five-level
triage instrument. Academic Emergency Medicine 7(3):236-42.
Wuerz R, Travers D, Gilboy N, Eitel DR, Rosenau A,
Yazhari R (2001). Implementation and refinement
of the emergency severity index. Academic Emergency Medicine 8(2):170-6.
Note: Appendix A of this handbook includes frequently
asked questions and post-test assessment questions for
Chapters 3 through 8. These sections can be incorporated
into the ESI training course.
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