26
Triage
Adriaan Hopperus Buma and Walter Henny
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Introduction
Traditionally, triage refers to a situation in which a medical system receives large numbers of casualties over a short period of time and is in danger of getting overwhelmed. This context originates from military and disaster medicine: the “most experienced surgeon” was supposed to sort the casu- alties into priority groups, deciding at what stage they should receive operative care.
Over the years, the term triage gradually developed to setting priorities repetitively from the point of wounding until the final treatment.
Nowadays, triage is performed whenever there is a discrepancy between the number of casualties and the available medical assets. Triaging is the sorting of patients into priority groups with the aim to do the best for most.
It should be understood that the principles of triage apply to both military and civilian circumstances.
Given its repetitive character,any medical worker (medics,ambulance per- sonnel, nurses, and doctors) can be called upon to perform triage. Triaging requires training; it is not something that can be done spontaneously.
Although the technical aspect is not too difficult to master, it should be real- ized that triage has a considerable emotional impact. The process seems to go against the grain because the most serious casualty is not always cared for first. Recently, the word triage has been used increasingly to describe a method for managing every-day flow of patients in emergency departments.
The latter is not the subject for this chapter.It starts with a historical overview, which is followed by an explanation about the different triage techniques.
Historical Overview
Situations in which medical personnel have been confronted with over- whelming numbers of casualties are from all ages. An important example is the horrible experience for Henri Dunant after the battle of Solferino in
1859, where he saw thousands of casualties on the battlefield with minimal resources available. This event led to the start of the International Red Cross Organization.
The French military surgeon Larrey, who served under Napoleon in the early nineteenth century, is attributed with the introduction of triage as a technique to do the best for most. Based on his vast surgical experience, he sorted the casualties into priority groups for treatment. Interestingly, he treated the lightly wounded first because they were the most likely to survive. Triage relates to the French word trier, meaning to sort or to sift.
Initially, the process was predominantly based on the expected outcome of surgical treatment. Later, due to a better understanding of pathophysi- ology, triage shifted towards a method aiming at improved survival, taking into account physiological parameters such as heart rate, perfusion, and mental status. Furthermore, it became obvious that triage should be an ongoing process from the point of wounding until the final treatment. Addi- tional factors, such as survivability, type of injury, and distance (time) of evacuation, are also considered. Although triage has been adapted over the years, the aim has remained the same: to do the most for the most. Triage has become a well-known technique for all medical personnel involved in disaster and military medicine.
The Techniques of Triage
Triage Systems
Many systems for triage have been developed over the years, with the obvious disadvantage that different people working in the same medical chain may use different systems; this will lead to confusion. The differences may consist of different definitions of triage categories and/or different cri- teria attached to each category. It is impossible to describe “everything that’s on the market,” but a strong plea should be made for national and international standardization. An effective triage system should enable the person performing triage to expeditiously define the casualties’ condition.
At present, systems using physiological parameters seem to be better suited than systems using anatomical descriptions.
Two triage systems have received much attention. The P (priority) system is to be used in situations in which each casualty is expected to receive all necessary treatment. It defines 3 categories: P1(immediate), P2 (urgent), and P3 (delayed).
P1 casualties need instant treatment because of “ABC” instabilities.
P2 casualties are ABC stable, but they need surgical treatment as expe- ditiously as possible.
Treatment of P3 casualties, who are always ABC stable, can be deferred for a longer time if necessary.
The T (triage) system is to be used in mass casualty situations. It defines 4 categories: the first three categories are basically identical to the P groups, but a fourth group (“expectant”) encompasses casualties “who are not expected to survive.” The latter is politically very sensitive.
Within the P system, a further subgroup (“P1 Hold”) has come into use (which is basically the same as T4).
The text below has been written “from a military perspective”; on closer inspection, it will become obvious that, as far as triage is concerned, there are many similarities between the military and civilian arenas.
Considerations
Triage is usually thought to be a consequence of situations in which there are multiple casualties. It becomes operational as soon as there is a mis- match between demand for and availability of care. Furthermore, it is a dynamic process that is to be repeated at all instances when choices have to be made; for example, who will be transported first, who can withstand postponement of surgical treatment etc., depending on the casualties’ con- dition amongst others.
It is also possible that triage should not be performed, that is, when the environment is too dangerous: being under fire, obvious threat of explo- sions, etc. The best approach then is to get out or to get the upper hand.
There is a strong relationship between triage and treatment (or lack thereof); the assigned triage category directs the desired treatment (which may or may not be then performed, depending on extraneous factors) and the treatment given also influences subsequent triage decisions.
The more experienced the triaging person is, the more they may use intangible factors to decide on the casualty’s triage category. The level of an individual’s formal education does not necessarily equate with compe- tence to perform triage; it is an art that can and should be learned by all medical personnel.
Effective triaging is much more than assigning casualties into categories based on physiological parameters. The person responsible for triage should also take into account issues such as:
Extraneous Factors
– location [in the field, on entering a medical treatment facility (MTF), in a preoperative holding area, after receiving medical care, etc.]
– number of casualties
– number and competencies of available medical personnel – availability of equipment
– tactical situation (insecure; secure; MTF expected to move on short notice, etc.)
– type and availability of transportation – transportation times
– capabilities and assets of MTFs
– required time for (operative) treatment – salvageability of casualties
Casualty-Related Factors – type of injury
– location of injury
Sometimes all relevant factors are known; under austere conditions, they usually are not. Sometimes decisions need to be made in seconds. Conse- quently, all these factors need to have been considered before triage starts.
An explanation of the different triage techniques follows next.
A Tiered Approach
Considering the fact that there is a variety of circumstances in which triage may be performed, we present a tiered approach. These tiers are just an indication; the person performing triage should be able and willing to adapt triage to the actual circumstances. Generally speaking, the more austere the environment is, the quicker and simpler triage should be.
Unsafe Environment “Under Fire”
By far the best approach is “to get the upper hand or to get out.”
No triage is to be performed. Treatment should be kept to the barest minimum (stanching external hemorrhage, if possible).
No Direct Threat, But Away from Medical Facility:
Small Number of Casualties Closely Together
Attention should be directed first to those casualties who are “silent.” They are either dead, “unhurt,” or have a real problem. The remaining casualties can then be triaged.
During triage, intervention should be restricted to opening the airway and, if applicable, having external bleeding stanched by a “third party”
(somebody who is not injured or possibly some other casualty who is still
“vocal” and able to walk).
After triage, further first aid measures should be instituted as circum- stances and available assets allow.
No Direct Threat, But Away from Medical Facility:
Larger Number of Casualties Dispersed
It is extremely important to obtain an overview first. Those people who are able to walk are asked to gather at an easily recognizable location. They are by definition categorized as P3. The remaining casualties are then addressed. Those who do not respond are turned into the recovery position.
External bleeding is stanched, if possible, but by someone other than the
person doing the triage. Those who do respond are assessed for external bleeding, which should be stanched, preferably by the casualty himself.
Only if time and circumstances allow, a second round is made in which all non-walking casualties are further triaged and treatment instituted.
Outside MTF, Aid Becoming Organized, Environment Secure
When casualties have been removed from the site of wounding or from the site of the accident and when aid is becoming organized, one person should assess all casualties (for condition). An effective method is to use the sieve algorithm, as depicted below. This algorithm uses simple physiological para- meters and defines three categories: P1, P2, and P3. The criteria are indi- cated in the Figure 26-1.
Depending on the circumstances (darkness, low ambient temperature), the refill criterion for circulation may be replaced by pulse rate. A pulse rate of less than 120 per minute leads to a classification of P2; a rate of 120 per minute or higher is classified as P1. Treatment (i.e., first aid measures) is instituted as circumstances and available assets allow.
Algorithm Triage Sieve
Breathing no
yes Wounded P 3
Walking
yes
Respiratory rate
no Airway Manoeuvre Not wounded
Breathing
Pulse rate
No Dead
Yes
<11/min P 1
>29/min 11-29/min
P 2
< 120/min
≥ 120/min Capillary refill
≥ 2 sec
< 2 sec or
Figure 26-1. The algorithm triage sieve chart. BATLS manual (2nd Edn) D/AMD/113/23 Army Code No 63726 (2000). Advanced Life Support Group Major Incident Medical Management and Support (2nd Edn), London: BMJ Books; 2002 with permission.
The general principle is to have P1 casualties transported first, P2 casu- alties next, and finally P3 casualties. Decisions of whether or not to insti- tute “treatment” on the spot and when to transport the casualties to which destination are also influenced by the extraneous factors, as far as they are applicable in the actual situation. For instance, if transport distance and time are short, it may be better to “scoop and run.”
On Arrival at the MTF
Re-triage is performed by using the sieve algorithm. If the person per- forming triage is experienced, casualties will occasionally be assigned to a higher category than the actual physiological parameters warrant because of expected developments based on his/her experience and clinical judgement.
In case of multiple casualties arriving over a short period of time, a “P1 Hold” group may be instituted. P1 casualties are then resuscitated follow- ing the Advance Trauma Life Support (ATLS) protocol. “P1 Hold” casual- ties should be reviewed and resuscitated, if appropriate, as soon as all
“original” P1 casualties have been treated.
Within the MTF
Further care can be either within the MTF (including operative treatment) or at some other facility. Within the facility it may be appropriate to use the methodology of the triage sort, as shown in Figure 26-2. This system is based on the Revised Trauma Score. It defines four categories: T1–T4. The crite- ria are indicated in the figure.
Those in T4 should be re-triaged as T1 as soon as all “original” T1 casu- alties have been treated.
The decision when to operate upon the casualty also may be influenced by the type and location of the injury. Again, only experienced personnel will be able to include these considerations in their decision-making process.The decision when and where to send the casualty (inside or outside the MTF) is also influenced by extraneous factors, as far as they are applic- able in the actual situation.
Conclusions
In conclusion, triage means sorting casualties into priority groups with the aim to do the most for most. It should be performed whenever there is a discrepancy between the number of casualties and the medical assets. The technique itself is straightforward. However, it should be adapted continu- ously to the actual circumstances; they are often complex and therefore dictate the final outcome.
Further Reading
Ryan J, Mahoney PF, Greaves I, Bowyer G. Conflict and Catastrophe Medicine.
London: Springer-Verlag; 2002.
Driscoll P, Skinner D, Earlam R. ABC of Major Trauma, 3rd ed. London: BMJ Books; 2000.
Student Manual, Battlefield Advanced Trauma Life Support, 2nd ed. Ash Vale: Direc- tor General Army Medical Services; 2000.
Subcommittee on Trauma. Manual Advanced Trauma Life Support, 6th ed. Chicago:
American College of Surgeons; 1997.
Advance Life Support Group. Major Incident Medical Management and Support, 2nd ed. London: BMJ Books; 2002.
Caroline NL. Emergency Care In The Streets, 5th ed. Boston: Little, Brown and Company; 1995.
Methodology for Triage Sort based on Revised Trauma Score
Respiratory rate (breaths/min) score
10 - 29 4
> 29 3
2 1 0 6 - 9
1- 5 0
Systolic blood pressure (mmHg) score
> 90 4
75 - 90 3
50 - 74 2
1 - 49 1
0 0
Glasgow coma scale (EMV) score
13 - 15 4
9 - 12 3
2 1 0 6 - 8
4 - 5 3
Scores converted to Triage Groups
Total score Triage Group
4 - 10 T 1
11 T 2
12 T 3
1 - 3
0 Dead
T 4
Figure 26-2. The methodology for triage sort chart. BATLS manual (2nd Edn) D/AMD/113/23 Army Code No 63726 (2000). Advanced Life Support Group Major Incident Medical Management and Support (2nd Edn), London: BMJ Books; 2002 with permission.
Bellamy RF, Zajtchuk R. Conventional Warfare: Ballistic, blast and burn injuries.
Textbook of Military medicine Part 1, vol. 5. Washington DC: WRAMC/WRAIR;
1991.
Butler FK, Hagmann J, Butler E. Tactical combat casualty care in special operations.
Milit Med. 1996;161(Suppl. 3):3–16.
Burkle FM, Orebaugh S, Barendse BR. Emergency medicine in the Persian Gulf—
Part 1: Preparations for triage and combat casualty care. Ann Emerg Med.
1994;23:742–747.
Burkle FM, Newland C, Orebaugh S, Blood CG. Emergency medicine in the Persian Gulf—Part 2: Triage methodology and lessons learned. Ann Emerg Med.
1994;23:748–754.
