Download Addendum 1: The Manchester Triage System

A triage system for dogs and cats:
Is it significantly better than common sense?
Author:
M.E.Gunning
Studentnr. 0245976
June 2008 – October 2009
Supervisors:
J.H. Robben, PhD, Diplomate European College of Veterinary Internal Medicine –
Companion Animals
Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine,
Utrecht University, The Netherlands.
L.J. Ruys, Resident Emergency and Critical Care
Spoedkliniek voor Dieren Amsterdam, The Netherlands.
Small Animal Clinics, Faculty of Veterinary Medicine, University of Bern, Switzerland.
-A triage system for dogs and cats: Is it significantly better than common sense?-
Contents
Contents __________________________________________________________________ 2
Abstract ___________________________________________________________________ 3
Introduction _______________________________________________________________ 5
Materials and Methods _______________________________________________________ 7
Results ___________________________________________________________________ 11
Discussion ________________________________________________________________ 20
Acknowledgements _________________________________________________________ 24
References ________________________________________________________________ 25
Addendum 1: The Manchester Triage System (MTS) _____________________________ 26
Addendum 2: Flow charts of the VTS __________________________________________ 28
Addendum 3: Assignment of patients __________________________________________ 40
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-A triage system for dogs and cats: Is it significantly better than common sense?-
Abstract
Introduction - Triage refers to the process of prioritizing patients based on the urgency of their
medical condition so as to treat patients in an appropriate order when resources are
insufficient for all to be treated simultaneously. With an increase in both patient numbers and
waiting time periods in veterinary emergency clinics, it becomes more and more important to
sort all patients appropriately in order to be able to give all of them the medical treatment they
need in a timely manner. There is still no such thing as a widely accepted and standardized
veterinary triage system. Most veterinary nurses tend to sort patients intuitively or based on
prior experience, or apply a self-construed, non-validated triage system. The veterinary
emergency clinic “Spoedkliniek voor Dieren in Amsterdam” currently uses a highly
subjective triage based on intuition, experience and common sense of the veterinary nurses.
The aim of the present study was to determine whether this subjective triage is adequate in
comparison to a newly designed Veterinary Triage System (VTS) based on the human
Manchester Triage System (MTS). Additional aims were to determine if nurses, when triaging
their patients, link higher urgency to priority over less urgent patients and if decisions differ
for trauma and non-trauma patients.
Materials & Methods - This study recorded the actual waiting time period (i.e. the
time period the patient had to wait before it was seen by a veterinarian), history and data from
a physical examination for 500 patients (193 dogs and 307 cats) visiting a companion animal
emergency clinic, the “Spoedkliniek voor Dieren Amsterdam” (SDA). In addition, at arrival
of the patient, the veterinary nurse was asked to state the desired waiting time period for each
patient, i.e. the time period in minutes the nurse considered acceptable for each patient to wait
before being seen by a veterinarian. In retrospect all 500 history and physical examination
data were evaluated and subsequently the patients were labelled with an urgency category
based on the VTS. Furthermore, 109 patients presented with a history of trauma were
considered separately.
Results - This study demonstrates that significant correlation exists between actual and
desired waiting time periods and urgency categories determined in retrospect, declining with
lower urgency. Despite this correlation, over 50% of cases is over- or underestimated by
nurses, compared to the VTS. Nurses tend to overtriage more than undertriage patients.
Overtriage is also reflected by the 0.52 predictive value of the estimation of high urgency by
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-A triage system for dogs and cats: Is it significantly better than common sense?-
nurses. Trends are similar for trauma patients, with the exception of a much higher percentage
of prioritisation of urgent patients.
Discussion - Although it is difficult to tell how much overtriage is still acceptable,
Long et al. described the “next-to-ideal” criteria as having 15-20% overtriage and no
undertriage3. Both overtriage (37.8%) and undertriage (21.2%) in this study fail to meet these
criteria, which could be caused by the lack of objective measures to determine the need for
immediate veterinary care. Recognition of urgency did not lead to the prioritisation of urgent
patients per se. Improving communication between nurses and veterinarians will probably
lead to more efficiency on this level. Possibly, nurses prioritize trauma patients more because
of their presentation or worried owners.
Conclusions - This study demonstrates that nurses’ triage decisions of both trauma and
non-trauma patients based on experience, intuition and common sense differ significantly
from urgency classifications stated retrospectively using the VTS. However, further studies on
the reliability and validity of the VTS are needed. The underestimation of immediate and very
urgent patients and the overestimation of less urgent patients makes triage without guidelines
inefficient. The development of a veterinary triage system, increasing reliability of urgency
estimations and thereby safety of patient care in small animal emergency departments, should
be considered.
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-A triage system for dogs and cats: Is it significantly better than common sense?-
Introduction
The concept of triage was first developed on the battlefields to sort the treatment of injured
soldiers in order to make sure that those who were able to fight again after treatment were
taken care of first. However, the concept has become more widely known because of its use in
waiting rooms of emergency services with a somewhat different goal. Triage in this situation
refers to the process of prioritizing patients based on the urgency of their medical condition so
as to treat patients in an appropriate order when resources are insufficient for all to be treated
simultaneously. The word “triage” is derived from the French word “trier” which means “to
sort”. In human hospitals triage has become a vital part of the emergency service and is
gaining more and more significance caused by the growing workload at these departments.
The growing number of self-referring patients has made it necessary to distinguish the urgent
patients from people suffering from only minor injury or illness. A well known and widely
used triage system in human medicine is the Manchester Triage System (MTS). This system
is not based on diagnoses, but on the patients’ presenting complaints, the main signs and
symptoms that bring the patient to the treatment centre. The MTS works with colour codes
that are linked to the degree of emergency for the potential condition(s) underlying the
complaints (see Addendum 1 for more information). The MTS has shown to be a sensitive
tool for detecting those who need emergency care1. However, it did fail to detect some
patients who deteriorated after arrival. This emphasizes the fact that triage systems have to be
used as dynamic systems.
As in human medicine, the workload at veterinary emergency clinics is gradually
increasing2. With an increase in both patient numbers and waiting time periods in veterinary
emergency clinics, it becomes more and more important to sort all patients appropriately in
order to be able to give all of them the medical treatment they need in a timely manner. Many
veterinary clinics have some sort of triage system instated based on intuition, experience,
common sense. At present there is not a widely accepted and validated triage system for use
in companion animals.
The veterinary emergency clinic “Spoedkliniek voor Dieren in Amsterdam” (SDA)
currently uses highly subjective triage based on intuition, experience and common sense of
the veterinary nurses. The aim of the present study was to determine whether this subjective
and experience based triage is adequate in comparison to a newly designed Veterinary Triage
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-A triage system for dogs and cats: Is it significantly better than common sense?-
System (VTS) based on the MTS. Additional aims were to determine if nurses, when triaging
their patients, link higher urgency to priority over less urgent patients and if decisions differ
for trauma and non-trauma patients.
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-A triage system for dogs and cats: Is it significantly better than common sense?-
Materials and Methods
Patients
During a two-month period, all dogs and cats that were presented to the Spoedkliniek voor
Dieren Amsterdam (SDA) were enrolled in the study with the prerequisite that at least one of
two researchers (LR, MG) was present in the clinic.
All patients were subdivided into “presentation groups” (PGs) based on their major reason
for presentation. These PGs were selected by the researchers prior to the start of the study
based on the 12 most common clinical presentations of cats and dogs visiting the SDA in the
past. Twelve PGs were distinguished:
1. Trauma
7. Abscesses & local inflammations
2. Gastrointestinal problems
8. Urinary problems
3. Abnormal behaviour & seizures
9. Abnormal posture & gait
4. Respiratory problems
10. Collapse & anorexia
5. Suspicion intake poison/foreign body
11. Pregnancy & genital problems
6. Progression of known problem
12. Haemorrhage.
Data collection
Instruction of personnel
Prior to the start of the study, the personnel of the SDA were informed about their tasks in the
study through a short presentation and a written correspondence. This was done for several
reasons. Since this study was carried out in a busy clinic with many nurses and veterinarians
in the two busiest months of the year, preparing all personnel for their tasks could increase
adherence to study methods and data collection. Also, patient emergency care was not to
suffer under the study, so preparing personnel for their tasks could reduce the time needed to
fulfil them. Nurses and veterinarians were only told about their tasks, not about hypotheses or
goals of the study. Although this could have caused a bias effect, the researchers thought these
measures were necessary in the interest of the patients.
Waiting time periods
On presentation of the patient, the receiving nurse stated a “desired waiting time period”
(DWTP) (i.e. the time period in minutes the nurse considered acceptable for the patient to
wait prior to be seen by a veterinarian) based on their impression of the emergency of the
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-A triage system for dogs and cats: Is it significantly better than common sense?-
case. To estimate the DWTP the nurse was free to examine the patient and ask the owner
questions but no procedure guidelines were provided. The options for the DWTP to choose
from were: 0, 15, 30, 60 and 120 minutes. Subsequently, the patient was sent to the waiting
room and clients were asked to wait for the veterinarian to call them in. The DWTP was not
entered in the digitalized patient record and was not presented to the veterinarian on call.
Therefore, no consequences were coupled to the statement of the DWTP by the nurse. If the
nurse thought a patient needed priority the veterinarian was warned following normal routine
in the clinic.
Retrospectively an “actual waiting time period” (AWTP) was calculated based on the
difference between the time of arrival in the waiting room of the clinic and the time the
patient was seen by the veterinarian.
Physical examination
The following physical parameters were recorded by the receiving veterinarian: mental status,
type and frequency of breathing, presence of dyspnoea, heart rate, presence and intensity of a
heart murmur, intensity of the pulse, colour and moistness of mucous membranes, capillary
refill time, peripheral and rectal temperature, lung auscultation and abdominal palpation.
Additionally to these data the history and additional findings from the physical examination
were recorded in the digitalized patient data system.
The Veterinary Triage System
The Veterinary Triage System was formed by extrapolating the discriminators of the flowcharts of the MTS to the veterinary situation. Additional discriminators have been added,
based on the opinion of several veterinary specialists. After careful selection of the final
discriminators 12 veterinary triage flow charts were constructed based on the PGs mentioned
earlier, finally forming the Veterinary Triage System (VTS) (see Addendum 2).
Retrospective use of the Veterinary Triage System
Based on the patient’s presenting symptoms/signs a specific flow chart of the VTS was
chosen. Within this flow chart, we used specific data from history and physical examination
as discriminators to determine what urgency category had to be chosen by the nurse. We
assigned patients to either urgency category 1 (acute, patient should be seen by a veterinarian
immediately), 2 (very urgent, patient should be seen by a veterinarian within 30 minutes), 3
(urgent, patient should be seen by a veterinarian within 60 minutes), 4 (standard, patient
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-A triage system for dogs and cats: Is it significantly better than common sense?-
should be seen by a veterinarian within 120 minutes) or 5 (not an emergency patient,
treatment of medical condition can wait until tomorrow without deterioration). Determination
of the category took place in a stepwise manner starting with category 1. In case none of the
discriminators was present, the patient ended up by default in category 5. In this way a UC of
the VTS was selected for each patient based on the data collected at their presentation in the
clinic.
Priority
To determine if nurses linked higher urgency to priority, the researchers retrospectively
classified each patient as “priority given”, “no priority given” and “no priority needed”. A
patient was classified as “priority given” if the patient was prioritized by the nurse over
another patient with a longer DWTP. If a patient arrived at the clinic with no other patients
waiting, there was no priority to be given and the patient was classified as “no priority
needed”.
Statistical analysis
All data were collected in a spread sheet program (MS Excel®: Microsoft, Seattle, USA) in
preparation of statistical analysis. Separate statistical analysis was done for the total patient
group and for patients of the PG “trauma”. AWTPs and DWTPs were compared to the UCs
assigned based on the VTS using the Kruskal-Wallis and Chi square test. Using the KruskallWallis test patients were assigned to a certain rank, depending on their AWTP and DWTP.
This rank denotes a score through which independent groups can be compared using a nonparametric test. Regression was investigated through analysis of variance (ANOVA). To see
which of the UCs were different from each other, a Mann Whitney U test for individual
groups comparison was performed on AWTPs, DWTPs and UCs with an adjusted level of
significance because of multiple testing (P<0.01). The Mann Whitney U test for comparison
between AWTPs and UCs was two-tailed. Statistical analysis was performed with SPSS15.0
(SPSS Inc., USA).
DWTPs were compared with target waiting times of the retrospectively assigned UCs
of the VTS in order to see how many patients were given a higher or lower urgency by the
nurses. If a patient is given a shorter DWTP and thus a higher urgency, this patient is
“overtriaged”. If a patient is given a longer DWTP and thus a lower urgency, this patient is
“undertriaged”.
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Sensitivity, specificity and predictive values of the estimated urgency were calculated.
For this purpose, a dichotomy was created between the life-threatening or potentially lifethreatening categories of urgency (UC 1/2 and DWTP 0/15/30) and the remaining categories
(UC 3/4/5 and DWTP 60/120).
Data are presented as mean ± standard deviation (sd) if not stated otherwise. Results
were considered as statistically significant for P values <0.05 if not stated otherwise.
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Results
All patients
A total of 500 patients were enrolled in the study: 307 were dogs, 193 were cats. In the end, 5
patients were taken out of the study. Excluded were patients of which no UC could be
determined during the review of their file and physical examination form due to lack of data.
A high workload and ethical considerations (one patient of which the owner requested
immediate euthanasia) were the reason that not all data could be collected in these cases. See
addendum 3 for more information about the assignment of enrolled patients to the 12 PGs.
Urgency categories
Urgency categories are summarized in Table 1. For more detailed information on the
distribution of urgency categories over the 12 PGs, see addendum 3.
Table 1: Distribution of patients over urgency categories.
Urgency category
Total number (%)
Number of trauma patients (%)
1
64 (12.8%)
4 (3.7%)
2
88 (17.6%)
22 (20.2%)
3
177 (35.4%)
42 (38.5%)
4
164 (32.8%)
40 (36.7%)
5
7 (1.4%)
1 (0.9%)
Total
500 (100%)
109 (100%)
Comparison of waiting time periods with urgency categories in the total patient group
The average AWTP and DWTP for all 500 patients and UCs was 31.0 ± 27.9 minutes and
55.1 ± 41.1 minutes, respectively.
Using the Kruskall-Wallis test, the mean ranks of all 5 UCs were compared (Table 2).
There was a significant difference between AWTPs of patients in all UCs except between
categories 3 and 4 and between category 5 and all other four categories. Figure 1 displays the
means of AWTPs for the 5 UCs.
There was a significant difference between DWTPs of patients in all UCs except
between 3 and 5 and between 4 and 5. Figure 2 shows the means of DWTPs for the 5 UCs.
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Table 2: Mean ranks of actual waiting time periods (AWTP) and desired waiting time periods (DWTP)
in the 5 urgency categories in the total patient group.
Urgency category
1
N
64
Mean rank AWTP
156.45
Mean rank DWTP
96.57
2
88
215.01
186.65
3
177
276.05
264.20
4
164
279.56
324.41
5
7
229.71
382.57
Total
500
N = number of patients in each category.
Brackets denote significant differences between urgency categories.
Figure 1. Actual waiting time periods (AWTP) (mean ± standard deviation (whiskers)) in the 5
urgency categories for all patients.
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Figure 2: Desired waiting time periods (DWTP) (mean ± standard deviation (whiskers)) in the 5
urgency categories for all patients.
An analysis of variance demonstrated that AWTP and DWTP were significantly
correlated (P<0.001).
Over- and undertriage in the total patient group
For 205 (41.0%) of triage contacts in the total patient group, the urgency estimation by DWTP
was in concordance with the retrospectively assigned UC (Table 3). For the 295 nonconcordance contacts, the urgency estimate of 231 (46.2%) triage contacts differed not more
than 1 category, and for 64 (12.8%) of the contacts, the urgency estimates differed more than
2 categories. For 189 (37.8%) contacts the nurses scored higher urgency and for 106 (21.2%)
contacts the nurses scored lower urgency than the urgency category assigned afterwards.
In UC 1, 34 of the 64 patients were undertriaged. This means that for these 34 patients
the nurses chose a desired waiting time of 15 minutes or more. Overtriage in this category was
not possible. Within UC 2 12.5% of patients was overtriaged; 35.2% was undertriaged. In UC
3 40.6% was overtriaged and 23.2% was undertriaged. In the UC 4 60.4% was overtriaged;
undertriage was not possible as a waiting time of 120 minutes was the highest possible choice
for the nurses.
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Table 3: Urgency as set by nurses through the desired waiting time period (DWTP) relative to urgency
category in all patients.
DWTP
0
15
30
60
120
Total
Urgency category
1
2
30
11
18
26
11
20
3
25
2
6
64
88
3
9
24
39
64
41
177
4
2
7
28
62
65
164
5
0
0
0
3
4
7
Underlined number denote correct estimation, compared to the retrospectively assigned urgency
categories using the VTS.
Sensitivity, specificity and predictive values of DWTPs
The capacity of the nurses to discriminate (potentially) life-threatening cases from less urgent
cases was examined through comparison of estimations of life-threatening and non-lifethreatening urgency with life-threatening and non-life-threatening UCs. The sensitivity was
0.76 (116/152) and the specificity was 0.69 (239/348). The positive predictive value of the
estimates of the nurses was 0.52 (116/225). This is higher than the 0.30 ((64+88)/500) a priori
probability of a life-threatening problem. The negative predictive value of the estimates of the
nurses was 0.87 (239/275), while the a priori probability of a non-life-threatening problem
was 0.69 ((177+164+7)/500).
Priority
In the total patient group (Table 4), 5 immediate and 53 very urgent patients (13 with a
DWTP of 15 minutes, 40 with a DWTP of 30 minutes) were not prioritized over patients with
a longer DWTP (and thus lower estimated urgency). This is respectively 9.4% and 30.8% of
the immediate and very urgent patients according to the nurses based on DWTP.
Table 4: Priority given by nurses over 5 categories of desired waiting time periods in all patients
Desired waiting time
No priority given
Priority given
No priority needed
0
5
21
27
15
13
14
47
30
40
4
54
60
92
0
65
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120
59
0
59
In situations where patients with an DWTP of 0, 15 or 30 minutes did not receive priority
over patients with a longer DWTP, this was not because another urgent patient got priority
over them.
Trauma patient group
The trauma patient group included 72 dogs and 37 cats. Most common causes for presentation
of patients in the trauma group were bite wounds, falls from heights and car accidents.
Comparison of waiting time periods with urgency categories
In the trauma group the average AWTP and DWTP was 28.3 ± 27.3 minutes and 54.0 ± 42.0
minutes, respectively. DWTPs and AWTPs of the trauma patients were compared to the UCs
retrospectively assigned based on the VTS.
Using the Kruskall-Wallis test, the mean ranks of all 5 UCs were compared (see Table
5). There was a significant difference between AWTPs of patients in all UCs except between
all UCs and UC 5, between 2 and 4 and between 3 and 4. Figure 3 shows the means of
AWTPs in the 5 UCs. There was a significant difference between DWTPs of patients in all
UCs except between 3 and 4 and between 5 and all other UCs. Figure 4 shows the means of
the DWTPs in the 5 UCs.
An analysis of variance demonstrated that AWTP and DWTP were not significantly
correlated in the trauma patients group (P=0.230).
Table 5: Mean ranks of actual waiting time periods (AWTP) and desired waiting time periods (DWTP)
with urgency categories in the trauma patient group .
Urgency category
1
N
4
Mean rank AWTP
7.38
Mean rank DWTP
7.00
2
22
38.61
29.23
3
42
66.32
57.63
4
40
57.70
70.89
5
1
22.50
68.00
109
Total
N = number of patients in each category.
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Brackets denote significant differences between urgency categories
Figure 3: Actual waiting time periods (AWTP) (mean ± standard deviation (whiskers)) in the 5
urgency categories in the trauma patient group
Figure 4: Mean of desired waiting times (DWTP) (mean ± standard deviation (whiskers)) in the 5
urgency categories in the trauma patient group
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Over- and undertriage
For 39.4% of all trauma patient triage contacts, the urgency estimation by DWTP was in
concordance with the UC assigned afterwards (see Table 6). For the 66 non-concordance
contacts, the DWTP of 49.5% triage contacts differed not more than 1 UC, 11.0% differed
more than 2 UCs from the UC assigned afterwards. For 48.6% of contacts the nurses scored
higher urgency and for 11.9% lower urgency than the UC assigned afterwards.
Table 6: Urgency as set by nurses through the desired waiting time period (DWTP) relative to urgency
category in the trauma patient group.
Desired Waiting Time
0
15
30
60
120
Total
Urgency category
1
2
4
7
0
7
0
5
0
2
0
1
4
22
3
1
8
11
12
10
42
4
1
2
6
16
15
40
5
0
0
0
1
0
1
Underlined number denote correct estimation, compared to the retrospectively assigned urgency
categories using the VTS.
Sensitivity, specificity and predictive values of DWTPs
The capacity of the nurses to discriminate (potentially) life-threatening cases from less urgent
cases in the trauma patient group was examined. The sensitivity was 0.88 (23/26) and the
specificity was 0.65 (54/83). The positive predictive value of the estimates of the nurses was
0.44 (23/52). This is higher than the 0.24 ((4+22)/109) a priori probability of a lifethreatening problem. The negative predictive value of the estimates of the nurses was 0.95
(54/57), while the a priori probability of a non-life-threatening problem was 0.76
((42+40+1)/109).
Priority
In the trauma patient group (see Table 7), all immediate patients were prioritized in case other
patients were ahead of them in the waiting room. Of the patients with an DWTP of 15 and 30
minutes, 20.5% of the very urgent patients were not prioritized over less urgent patients by the
nurses based on DWTP.
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Table 7: Priority given by nurses over 5 categories of desired waiting times in trauma patients
Desired waiting time
No priority given
Priority given
No priority needed
0
0
5
8
15
2
3
12
30
6
1
15
60
21
0
8
120
14
0
14
In situations where patients with an DWTP of 0, 15 or 30 minutes did not receive priority
over patients with a longer DWTP, this was not because another urgent patient got priority
over them.
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Discussion
This study demonstrates that significant correlation exists between AWTPs, DWTPs and UCs,
declining in the lower UCs. Despite this correlation, over 50% of cases is over- or undetriaged
by nurses, in comparison to a triage based on the VTS. Nurses tend to overtriage more than
undertriage patients, but still the degree of undertriage of urgent patients is unsatisfactory.
Overtriage is also reflected by the extremely low predictive value of the estimation of high
urgency by nurses. Although it is difficult to tell how much overtriage is still acceptable, Long
et al. described the “next-to-ideal” criteria as having 15-20% overtriage and no undertriage3.
The triage by the nurses fails to meet these criteria, which could be caused by the lack of
objective measures to determine the need for immediate veterinary care. Recognition of
urgency did not lead to the prioritisation of urgent patients per se. Improving communication
between nurses and veterinarians will probably lead to more efficiency on this level. Trends
are similar for trauma patients, with the exception of a much higher percentage of
prioritisation of urgent patients. Possibly, nurses prioritize these patients more because of
their presentation and/or worried owners.
In this study, urgency estimations of nurses were compared to UCs assigned to
patients in retrospect, based on the VTS. The VTS is based on an accepted human system; the
MTS. The MTS is a triage system that in human hospitals has demonstrated to be a sensitive
tool for detecting those who need emergency care1. We carefully reconstructed the MTS for
companion animals based on the experience of veterinary emergency clinicians, resulting in
the VTS. Although the resulting VTS has not yet been validated, the authors have chosen to
use it because there is no other alternative described. However, future studies must validate
the usefulness of this system.
Clearly, a decision that underestimates a patient’s level of clinical urgency may
impede time-critical intervention4 and thus lead to possibly dangerous delays in patient care.
Causes for undertriage by nurses could be inadequate knowledge and skills in emergency
patient triage assessment and the lack of guidelines for decision-making. Overtriage, affecting
patient care more indirectly, leads to inefficiency in the triage process. If non-urgent patients
are wrongly assessed by nurses as urgent, the emergency care for truly urgent patients may be
delayed5. In the human paediatric population, overtriage also seems to be a problem using the
MTS. Triage of paediatric patients is difficult as triage nurses are more dependent on nonverbal communication. This is also the case in veterinary patients and thus further evaluation
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on using the (adjusted) MTS in cats and dogs is needed to prevent this kind of timeconsuming overtriage. However, in the author’s opinion, a large contribution to both overand undertriage is made by the lack of objective measures to determine the need for
immediate veterinary care. Also, the presence of owners or staff of animal ambulance may
influence the decisions of nurses about the urgency of a patient. Education on the recognition
of urgency in companion animals could improve the quality of triage decisions by veterinary
nurses.
For a triage process to function well, it is not only important that nurses are able to
make a good assessment of the urgency of a patient, but also that a patient that is classified as
acute or very urgent will indeed get priority over a patient with less need for urgent veterinary
care. Or in other words: do nurses link higher urgency to priority? This acting as a
consequence of a detection made is one of the fundamental criteria that determines if a triage
system will succeed or fail6. In most immediate cases, nurses do link higher urgency to
priority. If a patient’s urgency allows a small waiting period like in UC 2, however,
prioritisation by nurses over less urgent patients declines. Possibly, nurses tend to “forget”
urgency of patients if there is no need to act on it right away. Also, it may be more difficult to
justify the urgency of these patients to owners of non-prioritized patients in the waiting room
and thereby pose a higher risk of discontent among them. For a triage system to work properly
and safely, this prioritisation must be further improved, since the classification of a patient as
urgent only makes sense if consequences are carried out to act on this urgency. Enhancing
objectiveness of nurses and transparency to owners in the waiting room could ameliorate this
process.
Prioritisation of urgent trauma patients turned out to be much better than of other
urgent emergency patients. Nurses also generally overestimated the urgency of trauma
patients even more than the urgency of other patients. This difference may be due to patient
presentation and high appreciation of the trauma history by nurses. These patients’ urgency is
more overt to owners of less urgent patients as well, making prioritisation easier for nurses.
Studies in human trauma patient triage have demonstrated that improved efficiency was
reached by using physiological and anatomical criteria instead of criteria based on the
mechanism of injury7. Similar effects might be seen in companion animal triage.
The UCs retrospectively assigned to the emergency patients are based on the VTS, a
triage system that hasn’t been tested or validated yet. Although deduced from the reliable and
validated human MTS, the VTS is not a gold standard and there are no guarantees to the
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-A triage system for dogs and cats: Is it significantly better than common sense?-
correctness of urgency classifications. Also, urgency classification in retrospect has its
limitations compared to triage at arrival of the patient.
The 5 possible DWTPs that nurses were asked to choose from, were different from the
target waiting times used in the MTS. The nurses were given one extra option, namely 30
minutes and were not given the option of “no urgency”. This was done because the evaluation
of the MTS in The Netherlands revealed that the target waiting time for category 2 (orange,
10 minutes) was possibly not realistic6. Also, the real waiting time of human category 2
patients was 30.82 minutes. The target waiting time of the VTS category 2 was thus stated 30
minutes in stead of the 10 minutes originally used in the MTS. Both 15 and 30 minutes were
interpreted as category 2. Category 2, as stated in the VTS, thus undoubtedly differs from
category orange in the MTS. Additional studies are indicated to determine the ideal target
waiting time of veterinary category 2. Not providing the nurses with the option “no urgency”
creates some overestimation of urgency by the nurses. Since only 7 patients were classified as
category 5 (non-urgent), the effect of this overestimation was minimal.
Since the nurses in this study were asked to write down a desired waiting time they
were forced to think over every patient’s urgency. It is not inconceivable that actual waiting
times would have differed from the actual waiting times recorded in this study when no
desired waiting times were asked. This forced point of urgency estimation could both shorten
and prolong total waiting times. Shorten, because focussing the nurses on urgency estimation
could improve recognition of very urgent patients, thus prioritizing them over less urgent
patients. Prolong, because a little bit of extra time of the nurses is asked to estimate the
urgency, time that cannot be used to continue their regular tasks.
The strength of this study lies in the fact that it was performed in a real-world setting
that is comparable with the structure of many companion animal emergency clinics. Complete
data were available from 500 consecutive patients reflecting a broad spectrum of emergencies
from trifles to life-threatening conditions.
This study demonstrates that nurses’ triage decisions of both trauma and non-trauma
patients based on experience, intuition and common sense differ significantly from urgency
classifications stated retrospectively using the VTS. However, further studies on the reliability
and validity of the VTS are needed. The underestimation of immediate and very urgent
patients and the overestimation of less urgent patients makes triage without guidelines
inefficient. The development of a veterinary triage system, increasing reliability of urgency
estimations and thereby safety of patient care in small animal emergency departments, should
be considered.
22
-A triage system for dogs and cats: Is it significantly better than common sense?-
23
-A triage system for dogs and cats: Is it significantly better than common sense?-
Acknowledgements
This study couldn’t have taken place without the cooperation of all nurses, veterinarians and
staff of the SDA. Also, both the statistical analyses and the reviewing of E. Teske were of
crucial importance.
24
-A triage system for dogs and cats: Is it significantly better than common sense?-
References
1. Cooke MW, Jinks S. Does the manchester triage system detect the critically ill? J of Acc
and Emer Med. 1999;16:179-181.
2. Drobatz KJ, Syring R, Reineke E, Meadows C. Association of holidays, fullmoon, friday
the 13th,day of week, time of day, day of week, and time of year on case distribution in an
urban referral small animal emergency clinic. J Vet Em Crit Care. 2009;19:Published
Online: Sep 11 2009.
3. Long WB, Bachulis BL, Hynes GD. Accuracy and relationship of mechanisms of injury,
trauma scores, and injury severity scores in identifying major trauma. Am J Surg.
986;151:581-584.
4. Gerdtz MF, Bucknall TK. Triage nurses' clinical decision making. an observational study
of urgency assessment. J Adv Nur. 2001;35:350-361.
5. Roukema J, Steyerberg EW, Meurs Av, Ruige M, Lei Jvd, Moll HA. Validity of the
manchester triage system in paediatric emergency care. Emer Med J. 2006;23:906-910.
6. Coenen IGA, Hagemeijer A, Caluwé Rd, Voeght FJd, Jochems PJJ. Richtlijn Triage Op
De Spoedeisende Hulp. ; 2005.
7. Uleberg O, Vinjevoll OP, Eriksson U, Aadahl P, Skogvoll E. Overtriage in trauma - what
are the causes? Acta Anaest Scan. 2007;51:1178-1183.
8. Manchester Triage Group. Emergency Triage. second ed. Blackwell Publishing Ltd; 2006.
9. Windle J. The extent to which the environment, triage event, documentation, components
of the assessment and training & development affect departmental accuracy when using
the manchester triage system. Sheffield: University of Sheffield. 2001.
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-A triage system for dogs and cats: Is it significantly better than common sense?-
Addendum 1: The Manchester Triage System (MTS)
The Manchester Triage System (MTS) originated in 1997 from a collaboration of experienced
nurses and doctors of several emergency departments from the area in and around Manchester
with the aim to obtain consensus on triage standards. They wanted a simple and unambiguous
system to quickly recognise and canalize severe pathology8. The MTS is an algorithmic aid to
the process of triage. It utilises a series of flow charts that lead the triage nurse to a logical
choice of triage category using a five-point scale. The MTS is considered to fit the European
health care system better than other 5 point systems6.
The basic principles that drive the MTS are recognition of the presentation of an
emergency patient and consequently choosing a logical discriminator that will lead through a
flow chart. Note that the system is not about diagnoses but about clinical priority; two patients
with the same diagnosis may present with different complaints and thus enter the system
through a different flow chart or in a different urgency category. The MTS has shown to be a
sensitive tool for detecting those who need emergency care1. Research of the MTS for human
emergency departments indicates that the MTS had a high interrater reliability9.
Urgency categories are linked to colour codes and target waiting times, which provides
the patients with both transparency and predictability. The system works with 5 different
urgency categories: red (immediate), orange (very urgent), yellow (urgent), green (standard)
and blue (non-urgent). Patients that enter the emergency department are seen by a triage
nurse, who chooses a suitable flow chart based on the main problem of the patient. Within this
flow chart the urgency category is selected based on the most urgent clinical sign (the
discriminator) present in the patient. Say a patient arrives at the emergency department with
abdominal pain. The patient is briefly examined and questioned by a triage nurse. The nurse
chooses the flow chart that matches the main problem of the patient (e.g. abdominal pain, see
figure 5). The flow chart, consisting of a list of key symptoms (so called discriminators) is
checked. A symptom is either present or not. These discriminators were carefully selected to
detect possible urgent causes of a general problem (e.g. gastric bleeding in abdominal pain).
Every discriminator is linked to one of the urgency categories. The first discriminator present
in the patient, determines his or her urgency category. If a patient with abdominal pain
presents with vomiting blood and category red discriminators ‘threatened airway’,
‘insufficient breathing’ and ‘shock’ are excluded, urgency category orange is selected.
26
-A triage system for dogs and cats: Is it significantly better than common sense?-
Abdominal pain
Threatened airway
Insufficient breathing
Shock
+
Red
+
Orange
+
Yellow
+
Green
Severe pain
Pain radiating to the back
Vomiting blood
Rectal blood loss (fresh/old)
Vaginal blood loss
> 20 weeks pregnant
Very high fever
Possibly pregnant
Pain shoulder
Black or dark red stools
Vomiting blood in history
Persistent vomiting
Fever
Moderate pain
Recent mild pain
Vomiting
Recent problem
-
Blue
Figure 5: Triage flow chart “Abdominal pain adult” as used in the human Manchester Triage System
27
-A triage system for dogs and cats: Is it significantly better than common sense?-
Addendum 2: Flow charts of the VTS
Flowchart 1:Trauma
E.g. falls, hit by car, bites, stings, burns, eye trauma, being jammed, shot wounds
UC 1
Airway compromise/ inadequate breathing
Exsanguinating hemorrhage
Acutely distended abdomen
Shock
Unresponsive
Eyeball luxation
Acute chemical eye injury
UC 2
Increased work of breathing
Uncontrollable hemorrhage
Severe pain
Vascular compromise
Continuous abnormal vocalizations
High lethality envenomation
Subcutaneous gas
Very high fever
Fever puppy/ kitten
Altered conscious level
Under anesthesia
Abnormal pulse (arrhythmia)
Externalization of organs
Penetrating eye injury
Cold
UC 3
Mild dyspnea
Open fracture/ gross deformity
Acute neurologic deficit/ deterioration
Uncontrollable minor hemorrhage
History of unconsciousness or head trauma
Moderate lethality envenomation
Moderate pain
Severe itch
Fever
Widespread rashes or blistering
Anorexia puppy/ kitten
UC 4
Local inflammation
Recent mild pain
Recent problem
Swelling
Warmth
28
-A triage system for dogs and cats: Is it significantly better than common sense?-
Flowchart 2: Gastro-intestinal
Vomiting, diarrhea, constipation, drooling, anorexia, swallowing or retching
UC 1
Airway compromise/ inadequate breathing
Exsanguinating hemorrhage
Acutely distended abdomen
Unproductive retching
Shock
Unresponsive
UC 2
History of poisoning
History of ingestion of foreign body
Floppy
Continuous abnormal vocalizations
Petechiae/ purpura/ ecchymosis
Severe dehydration (> 8%)
Severe pain
Very high fever
Fever puppy/ kitten
Altered conscious level
Abnormal pulse (arrhythmia)
Cold
UC 3
Vomiting blood
Persistent vomiting
Persistent straining
Melena or hematochezia
Ingestion of toxin with moderate lethality
Dehydration (5 – 8%)
Moderate pain
Fever
Anorexia puppy/ kitten
UC 4
Vomiting
Recent mild pain
Recent problem
Warmth
29
-A triage system for dogs and cats: Is it significantly better than common sense?-
Flowchart 3: Abnormal behaviour, neurologic deficits and seizures
UC 1
Airway compromise/ inadequate breathing
Hypoglycemia
Currently fitting
Acutely distended abdomen
Unproductive retching
Shock
Unresponsive
UC 2
Increased work of breathing
History of poisoning
Signs of meningism
Continuous abnormal vocalizations
Floppy
Altered conscious level
Severe dehydration (> 8%)
Risk of self harm or harm to others
Abnormal pulse (arrhythmia)
Petechiae/ purpura/ ecchymosis
Severe pain
Very high fever
Fever puppy/ kitten
Cold
UC 3
Mild dyspnea
Acute neurologic deficit/ deterioration
History of unconsciousness or head trauma
Ventroflexion of the head
Dehydration (5 – 8%)
Moderate pain
Severe itch
Fever
Anorexia puppy/ kitten
UC 4
Itch
Recent mild pain
Recent problem
Warmth
30
-A triage system for dogs and cats: Is it significantly better than common sense?-
Flowchart 4: Respiration
Dyspnea, coughing, sneezing
UC 1
Airway compromise/ inadequate breathing
Acutely distended abdomen
Unproductive retching
Shock
Unresponsive
UC 2
Increased work of breathing
Acute onset after injury
Exhaustion
History of poisoning
Continuous abnormal vocalizations
Floppy
Altered conscious level
Severe dehydration (> 8%)
Abnormal pulse (arrhythmia)
Petechiae/ purpura/ ecchymosis
Severe pain
Very high fever
Fever puppy/ kitten
UC 3
Mild dyspnea
No improvement with own medications
Dehydration (5 – 8%)
Moderate pain
Fever adult
Anorexia puppy/ kitten
UC 4
Chest injury
Recent mild pain
Recent problem
Warmth adult
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-A triage system for dogs and cats: Is it significantly better than common sense?-
Flowchart 5: Intoxication and foreign body
UC 1
Airway compromise/ inadequate breathing
Currently fitting
Exsanguinating hemorrhage
Acutely distended abdomen
Unproductive retching
Shock
Unresponsive
UC 2
Increased work of breathing
Uncontrollable hemorrhage
History of poisoning
History of intake foreign body
Continuous abnormal vocalizations
Floppy
Altered conscious level
Severe dehydration (> 8%)
Abnormal pulse (arrhythmia)
Petechiae/ purpura/ ecchymosis
Severe pain
Very high fever
Fever puppy/ kitten
UC 3
Mild dyspnea
Acute neurologic deficit/ deterioration
Dehydration (5 – 8%)
Restlessness
Persistent straining
Black or redcurrant stool
Moderate pain
Fever adult
Anorexia puppy/ kitten
UC 4
Vomiting
Recent mild pain
Recent problem
Warmth
32
-A triage system for dogs and cats: Is it significantly better than common sense?-
Flowchart 6: Progression of known problem
UC 1
Airway compromise/ inadequate breathing
Currently fitting
Hypoglycemia
Exsanguinating hemorrhage
Acutely distended abdomen
Shock
Unresponsive
UC 2
Increased work of breathing
Uncontrollable hemorrhage
Continuous abnormal vocalizations
Ketoacidosis
Floppy
Altered conscious level
Severe dehydration (> 8%)
Abnormal pulse (arrhythmia)
Petechiae/ purpura/ ecchymosis
Severe pain
Very high fever
Fever puppy/ kitten
Cold
UC 3
Vomiting blood
Persistent vomiting
Persistant straining
Melena or hematochezia
Mild dyspnea
Acute neurologic deficit/ deterioration
Ventroflexion of the head
Dehydration (5 – 8%)
Hyperglycemia
Moderate pain
Fever
Anorexia puppy/ kitten
UC 4
Vomiting
Recent mild pain
Recent problem
Warmth
33
-A triage system for dogs and cats: Is it significantly better than common sense?-
Flowchart 7: Abscesses, local inflammations and rashes
Including eyes, ears, gingiva
UC 1
Airway compromise/ inadequate breathing
Stridor
Shock
Unresponsive
UC 2
Continuous abnormal vocalizations
Uncontrollable hemorrhage
Altered conscious level
Increased work of breathing
Subcutaneous gas
Oedema of the tongue
Significant history of allergy
Petechiae/ purpura/ ecchymosis
Vascular compromise
Severe pain
Very high fever
Fever puppy/ kitten
Abnormal pulse (arrhythmia)
UC 3
Uncontrollable minor hemorrhage
Mild dyspnea
Facial edema
Widespread rashes or blistering
Moderate pain
Severe itch
Fever
Anorexia puppy/ kitten
UC 4
Local inflammation
Othematoma
Head tilt
Recent mild pain or itch
Recent problem
Swelling
Warmth
34
-A triage system for dogs and cats: Is it significantly better than common sense?-
Flowchart 8: Urinary problems
UC 1
Airway compromise/ inadequate breathing
Acutely distended abdomen
Shock
Unresponsive
UC 2
Unable to urinate (large, tense bladder)
Continuous abnormal vocalizations
Severe dehydration (> 8%)
Altered conscious level
Severe pain
Very high fever
Fever puppy/ kitten
Abnormal pulse (arrhythmia)
Cold
UC 3
Persistent straining (small bladder)
Hematuria without straining
Persistent vomiting
Dehydration (5 – 8%)
Moderate pain
Fever
UC 4
Vomiting
Recent mild pain
Recent problem
Warmth
35
-A triage system for dogs and cats: Is it significantly better than common sense?-
Flowchart 9: Abnormal posture and gait
UC 1
Airway compromise/ inadequate breathing
Exsanguinating hemorrhage
Acutely distended abdomen
Shock
UC 2
Continuous abnormal vocalizations
Increased work of breathing
Vascular compromise
Signs of meningism
Unable to urinate (large, tense bladder)
Petechiae/ purpura/ ecchymosis
Uncontrollable hemorrhage
Altered conscious level
Severe pain
Very high fever
Fever puppy/ kitten
UC 3
Open fracture/ gross deformity
Mild dyspnea
Acute neurologic deficit/ deterioration
Uncontrollable minor hemorrhage
History of unconsciousness or head trauma
Persistent straining (small bladder)
Ventroflexion of the head
Moderate pain
Fever
Anorexia puppy/ kitten
UC 4
Local inflammation
Deformity
Recent mild pain
Recent problem
Swelling
Warmth
36
-A triage system for dogs and cats: Is it significantly better than common sense?-
Flowchart 10: Collapse
UC 1
Airway compromise/ inadequate breathing
Unresponsive
Exsanguinating hemorrhage
Acutely distended abdomen
Unproductive retching
Hypoglycemia
Currently fitting
Shock
UC 2
History of poisoning
History of ingestion of foreign body
Unable to urinate (large, tense bladder)
Hyperglycemia with ketosis
Increased work of breathing
Uncontrollable hemorrhage
Significant history of allergy
Abnormal pulse (arrhythmia)
Floppy
Severe dehydration (> 8%)
Altered conscious level
Continuous abnormal vocalizations
Petechiae/ purpura/ ecchymosis
Severe pain
Very high fever
Fever puppy/ kitten
Cold
UC 3
Persistent straining (small bladder)
Hyperglycemia
Vomiting blood
Persistent vomiting
Melena or hematochezia
Increased work of breathing
Ventroflexion of the head
Acute neurologic deficit/ deterioration
History of unconsciousness or head trauma
Dehydration (5 – 8%)
Moderate pain
Fever
Anorexia puppy/ kitten
UC 4
Vomiting
Recent mild pain
Recent problem
Warmth
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-A triage system for dogs and cats: Is it significantly better than common sense?-
Flowchart 11: Pregnancy, parturition and sexual organs
UC 1
Airway compromise/ inadequate breathing
Unresponsive
Exsanguinating hemorrhage
Currently fitting
Acutely distended abdomen
Shock
Presenting fetal parts
UC 2
Continuous abnormal vocalizations
In active labour
History of fitting
Heavy blood loss per vaginam
Scrotal gangrene
Phimosis
Petechiae/ purpura/ ecchymosis
Altered conscious level
Severe pain
Very high fever
Cold
UC 3
History of trauma (pregnancy)
Abnormal blood loss per vaginam
Persistent vomiting
Moderate pain
Fever
UC 4
Local inflammation
Recent mild pain
Recent problem
Warmth
38
-A triage system for dogs and cats: Is it significantly better than common sense?-
Flowchart 12: Hemorrhage
UC 1
Airway compromise/ inadequate breathing
Exsanguinating hemorrhage
Acutely distended abdomen
Shock
Unresponsive
UC 2
Uncontrollable hemorrhage
Heavy blood loss per vaginam
Continuous abnormal vocalizations
Heavy blood loss per vaginam
Petechiae/ purpura/ ecchymosis
Vascular compromise
High lethality envenomation
Increased work of breathing
Severe pain
Abnormal pulse (arrhythmia)
Altered conscious level
Very high fever
Fever puppy/ kitten
Cold
UC 3
Vomiting blood
Melena or hematochezia
Hematuria without straining
History of or suspected of bleeding disorder
Uncontrollable minor hemorrhage
Moderate lethality envenomation
Mild dyspnea
Moderate pain
Fever
UC 4
Recent mild pain
Recent problem
Warmth
39
-A triage system for dogs and cats: Is it significantly better than common sense?-
Addendum 3: Assignment of patients
Table 1: Assignment of patients to the 12 different presentation groups and distribution over urgency
categories.
Patient groups
1. Trauma patients
2. Gastrointestinal problems
3. Abnormal behaviour & Seizures
4. Respiratory problems
5. Suspicion poison/foreign body
6. Progression of known problem
7. Abscesses & local inflammations
8. Urinary problems
9. Abnormal posture & Gait
10. Collapse & Anorexia
11. Pregnancy & Genital problems
12. Haemmorhage
Total
Percentage
21.8%
18.6%
5.2%
5.6%
2.8%
3.6%
9.2%
9.6%
6.6%
15%
1.4%
0.6%
100%
40
Total
109
93
26
28
14
18
46
48
33
75
7
3
500
UC1
4
8
3
10
0
4
1
2
0
31
1
0
64
UC2
22
8
0
8
3
5
1
8
4
25
3
1
88
UC3
42
42
14
4
9
5
15
15
16
13
1
1
177
UC4
40
35
9
6
1
2
28
23
13
5
1
1
164
UC5
1
0
0
0
1
2
1
0
0
1
1
0
7