Triage. From Wikipedia, the free encyclopedia
Triage station at the Pentagon after the impact of American Airlines Flight 77 during the September 11, 2001 attacks. In medicine, triage (/ˈtriːɑːʒ, triˈɑːʒ/) is a practice invoked when acute care cannot be provided for lack of resources. The process rations care towards those who are most in need of immediate care, and who benefit most from it. More generally it refers to prioritisation of medical care as a whole. In its acute form it is most often required on the battlefield, during a pandemic, or at peacetime when an accident results in a mass casualty which swamps nearby healthcare facilities' capacity.
Triage always follows the modern interpretation of the Hippocratic oath, but otherwise there is plenty of leeway in interpretation, leading to more than one simultaneous idea of its nature. The best settled theories and practical scoring systems used in here come from the area of acute physical trauma in an emergency room setting; a broken bone obviously counts for less than uncontrolled arterial bleeding, apt to lead to death. But no current principle carries too well over to mental health, reproductive health (such as abortion), chronic medical conditions, geriatrics, or palliative care (including euthanasia). This is because triage needs to balance multiple and sometimes contradictory objectives simultaneously, most of them being fundamental to personhood: likelihood of death, efficacy of treatment, patients' remaining lifespan, ethics and religion of them all.
History. The term comes from the French verb trier, meaning to separate, sort, shift, or select.[1] "Structured triage" was introduced by Holy Roman Emperor Maximilian I. It was in his armies that the wounded were first categorized and treated according to an order of priority – in times of war, higher priority was given to military personnel over civilians, and the higher-ranked over the lower-ranked. The practice spread to other armies in the following centuries and was coined "triage" by the French.[2][3]
Modern medical triage was invented by Dominique Jean Larrey, a surgeon during the Napoleonic Wars, who "treated the wounded according to the observed gravity of their injuries and the urgency for medical care, regardless of their rank or nationality",[4] though the general concept of prioritizing by prognosis is foreshadowed in a 17th-century BCE Egyptian document.[5] Triage was used further during World War I by French doctors treating the battlefield wounded at the aid stations behind the front. Those responsible for the removal of the wounded from a battlefield or their care afterwards would divide the victims into three categories:[6][7]
For many emergency medical services (EMS) systems, a similar model may sometimes still be applied. In the earliest stages of an incident, such as when one or two paramedics exist to 20 or more patients, practicality demands that the above, more "primitive" model will be used. However, once a full response has occurred and many hands are available, paramedics will usually use the model included in their service policy and standing orders. As medical technology has advanced, so have modern approaches to triage, which are increasingly based on scientific models. The categorizations of the victims are frequently the result of triage scores based on specific physiological assessment findings. Some models, such as the START model may be algorithm-based. As triage concepts become more sophisticated, and to improve patient safety and quality of care, several human-in-the-loop decision-support tools have been designed on top of triage systems to standardize and automate the triage process (e.g., eCTAS, NHS 111) in both hospitals and the field.[8] Moreover, the recent development of new machine learning methods offers the possibility to learn optimal triage policies from data and in time could replace or improve upon expert-crafted models.[9]
Concepts in triage. Vital signs defining the color-coded triage. RR: respiratory rate; SpO2: saturation of peripheral oxygen (pulse oximetry); HR: heart rate; GCS: Glasgow Coma Score; Tp: temperature. Abnormal vital signs are strong predictors for intensive care unit admission and in-hospital mortality in adults triaged in the emergency department.
Simple triage. Simple triage is usually used in a scene of an accident or "mass-casualty incident" (MCI), in order to sort patients into those who need critical attention and immediate transport to the hospital and those with less serious injuries. This step can be started before transportation becomes available. Upon completion of the initial assessment by physicians, nurses or paramedical personnel, each patient may be labelled which may identify the patient, display assessment findings, and identify the priority of the patient's need for medical treatment and transport from the emergency scene. At its most primitive, patients may be simply marked with coloured flagging tape or with marker pens. Pre-printed cards for this purpose are known as a triage tags.[10]
Tags. Many triage systems use triage tags with specific formats. Emergency Triage (E/T) Lights – particularly useful at night or under adverse conditions. A triage tag is a prefabricated label placed on each patient that serves to accomplish several objectives:
Triage tags may take a variety of forms. Some countries use a nationally standardized triage tag,[11] while in other countries commercially available triage tags are used, and these will vary by jurisdictional choice.[12] The most commonly used commercial systems include the METTAG,[13] the SMARTTAG,[14] E/T LIGHT tm[15] and the CRUCIFORM systems.[16] More advanced tagging systems incorporate special markers to indicate whether or not patients have been contaminated by hazardous materials, and also tear off strips for tracking the movement of patients through the process. Some of these tracking systems are beginning to incorporate the use of handheld computers, and in some cases, bar code scanners.
Advanced triage. In advanced triage, specially trained doctors, nurses and paramedics may decide that some seriously injured people should not receive advanced care because they are unlikely to survive. It is used to divert scarce resources away from patients with little chance of survival in order to increase the chances for others with higher likelihoods. The use of advanced triage may become necessary when medical professionals decide that the medical resources available are not sufficient to treat all the people who need help. The treatment being prioritized can include the time spent on medical care, or drugs or other limited resources. This has happened in disasters such as terrorist attacks, mass shootings, volcanic eruptions, earthquakes, tornadoes, thunderstorms, and rail accidents. In these cases some percentage of patients will die regardless of medical care because of the severity of their injuries. Others would live if given immediate medical care, but would die without it.
In these extreme situations, any medical care given to people who will die anyway can be considered to be care withdrawn from others who might have survived (or perhaps had less severe disability from their injuries) had they been treated instead. It becomes the task of the disaster medical authorities to set aside some victims as hopeless, to avoid trying to save one life at the expense of several others.
If immediate treatment is successful, the patient may improve (although this may be temporary) and this improvement may allow the patient to be categorized to a lower priority in the short term. Triage should be a continuous process and categories should be checked regularly to ensure that the priority remains correct given the patient's condition. A trauma score is invariably taken when the victim first comes into hospital and subsequent trauma scores are taken to account for any changes in the victim's physiological parameters. If a record is maintained, the receiving hospital doctor can see a trauma score time series from the start of the incident, which may allow definitive treatment earlier.
Reverse triage. There are a number of concepts referred to as Reverse Triage, the first is concerned with the discharge of patients from hospital. This makes resources available within a healthcare or hospital for incoming patients. The second concept of Reverse Triage is utilised for certain conditions such as lightning injuries, where those appearing to be dead may be treated ahead of other patients.[17] The third is the concept of treating the least injured, often to return them to functional capability. This approach originated in the military, where returning combatants to the theatre of war may lead to overall victory (and survivability).[18]
Reverse Triage - Early Discharge. Usually, triage refers to prioritizing admission. A similar process can be applied to discharging patients early when the medical system is stressed. This process has been called "reverse triage".[19] When a major wave of patients arrive to a hospital, such as immediately after a natural disaster, many hospital beds will be already occupied by regular non-critical patients. To accommodate a greater number of the new critical patients, the existing patients may be triaged, and those who will not need immediate care can be discharged until the surge has dissipated, for example through the establishment of temporary medical facilities in the region.
Undertriage is underestimating the severity of an illness or injury. An example of this would be categorizing a Priority 1 (Immediate) patient as a Priority 2 (Delayed) or Priority 3 (Minimal). Historically, acceptable undertriage rates have been deemed 5% or less.
Overtriage is the overestimating of the severity of an illness or injury. An example of this would be categorizing a Priority 3 (Minimal) patient as a Priority 2 (Delayed) or Priority 1 (Immediate). Acceptable overtriage rates have been typically up to 50% in an effort to avoid undertriage. Some studies suggest that overtriage is less likely to occur when triaging is performed by hospital medical teams, rather than paramedics or EMTs.[20]