Written by Bengt Widgren, Senior Consultant, Medical Doctor.

Updated 2019-03-08

Most triage or decision support contains some form of primary sorting of patients with different needs for emergency care where the division is based on different scales that indicate the calculated/assessed current medical risk of waiting for medical assessment of the doctor or medical measure.

In the decision supporting instrument RETTS, there is a triage module as well as a module that aims to give a recommendation on how care processes should be controlled from a medical safety perspective. The medical responsibility for diagnosis and treatment lies with the individual and medical officer in any given situation.

Vital Parameter Algorithm

The triage module in RETTS consists of several steps where the first step is to obtain an objective picture of the patient’s condition in the form of a direct medical physical examination according to an algorithm which intends to capture signs of failure in one or more organ systems. This is called in the RETTS vital parameter algorithm (VP) and intends to provide an image of A + B respiratory and C, circulatory organs function, D, degree of alertness (CNS) and also E, body temperature. Measurement, assessment and control of VP should be performed simultaneously with capturing a structured history based on the current primary and main search cause. At the same time as a brief history of current search cause, the history is supplemented by a number of yes/no issues concerning conditions with known increased co-morbidity (at the same time sickness), such as known cardiovascular disease, diabetes, kidney failure, liver failure etc. These conditions were included for in something called Charlsons co-morbidity index and means that if the patient brings these diagnoses/conditions into emergency care, the patient has a higher risk of both morbidity and mortality than those who lack these diagnoses/conditions. The idea is that this process forms the basis for a structured documentation.


In RETTS VP, from 2019 there is also a scoring system (RETTS Score) inserted which, together with the priority color, also gives a score that separates the patients within each color from each other in a clearer way. RETTS Score can also be used inside the hospital’s departments. Other systems do not differ significantly from RETTS VP. It is especially important in the priority groups where the most difficult sickness ports. The RETTS Score indicates the medical complexity while the medical priority color or level indicates the individual medical risk involved. One can imagine that in the emergency room there are 12 patients with medical priority Orange. There is often a problem with how the capacity is to be distributed within the prio group. Then you take help of the score and secondary-prioritize based on the highest score in a systematic way. Everyone with priority Orange has the same priority and resembled medical risk, but sometimes differs slightly from each other regarding the medical complexity.

ESS (Emergency Symptoms and Signs)

In step two of the decision support RETTS, there are search causes based on symptoms and clinical signs. All search causes are also classified as ICD-10 codes (International Statistical Classification of Diseases and Related Health Problems). The search causes are collected in algorithms or ESS (emergency symptoms and signs) that contain one or more search causes according to ICD-10 and should provide support in the collection of the history and in the observation of clinical signs such as ECG, chills, skin rashes, injuries or vegetative signs (cold sweats , nausea etc). In each ESS algorithm there are various symptoms and clinical signs graded or other important information that provides guidance on what RETTS recommends and which should be the correct priority level, expressed in RETTS as a color. The recommended priority in the ESS should be weighed together and combined with the priority given by VP and the sum of objective and more subjective observations gives the final priority together with the assessor’s own experience and competence which is the third step which is a review step. The highest priority algorithm VP or ESS becomes the ultimate priority.


The priority of RETTS is only based on the patient’s medical risk and needs and has nothing to do with order or time to doctors, x-rays or other measures. The priority level should be seen as a recommendation to the user to deliver emergency care directly or if the patient can wait without medical risk until the capacity exists. In RETTS, therefore, there are no time indications on how long a patient with a certain priority can wait for a doctor or measure. Basically, all patients should be taken care of directly, but in practice this is of course impossible because the variation in inflow is often not in balance with the existing capacity. In practice, this means that if you utilize the existing capacity to 100% at any given time, there is always a sense of a capacity shortage or a queue that must be managed by the organization that decides on the capacity.


In RETTS, two medical accessibility levels are specified, “emergency care directly” or “can wait”, but without RETTS indicating a recommended waiting time in minutes. The reason for the RETTS recommendation is that it is based on the validations in the form of observation studies made by the METTS/RETTS system, but also the fact that if you specify a waiting time/lead time in minutes, it always tends to be achieved or exceeded. RETTS also states what is recommended for direct actions and what type of logistics should be used. In the validations that have been made there is a connection between priority according to RETTS and the need for inpatient care. It should be emphasized, however, that this relationship should not be used as a basis for decision that everyone with a red/orange priority should be cared for in hospital and that all patients with yellow or green priority do not have an absolute medical need for inpatient care or the resources and competence of the emergency department and ambulance care.

It is important that the entire care chain works with the same standard and that the system is followed, which creates a chain of trust and confidence in RETTS in the organization. We have therefore postulated that the person who carries out the assessment process and assesses the patient always does the right based on the conditions and data that existed during the assessment. The following level of care or officer can always make a new assessment if one considers that the current state deviates from the primary assessment which may also have changed over time. It is important to remind that healthcare professionals and doctors at the emergency department always have a personal medical responsibility to assess the reasonableness of the RETTS recommendation.

Importance of physiological parameters in RETTS

The algorithm for VP is based on previously known concepts such as ABCDE and is used in different waysin health care for a long time. VP are all dynamic parameters which means that it is notonly the individual measurement value that gives direct information about the state, without the change ofmeasured values ​​over time are at least as important.

A = Airways In this part, it is judged whether the patient has any form of respiratory disorder that can express himself asstridor or other symptoms and signs of respiratory impairment. Fighters are an unusual condition withinadult emergency care but much more common in the emergency care of children where respiratory infectionscan often give a stridorous breathing. If you find signs of respiratory impairment then the patient is,regardless of age, in RETTS ‘priority RED until the patient is examined by a doctor who canchoose to prioritize the patient if the examination shows that there is no risk of breathingexists.

B = Breathing (respiration) In this one of the VP algorithm, both respiratory rate, as breath/minute andoxygen saturation measured by pulse oximetry.

C = Circulation VP circulation consists of several different parameters where heart rate and blood pressure are the objective VP measured in RETTS. Peripheral circulation is a more subjective parameter that should, howeveris assessed but not stated as an objective parameter in the algorithm for VP. 

D = Disability The alertness is a clear VP that is relatively easy to determine and also monitor in both adults and children. Here are two scales used in Sweden, RLS (reaction level scale) and GCS (glascow coma scale). Both are capable of using in RETTS and with respect to D, tradition is different in Sweden both between emergency departments and between prehospital and hospital care. In this VP, there is a very clear boundary between the unconscious and the unconscious patient regarding the risk of complication and death. In RETTS are always unconscious RED, ie > 3 in RLS or <8 in GCS.

E = Environment or exposure This variable is, in certain conditions, important for finding patients with both high and lowbody temperature. In adult patients, body temperature is very rare

RETTS process levels

In RETTS there are five process levels, blue, green, yellow, orange and red, in increasing priority and severity expressed as risk of death and/or need for emergency care directly or within reasonable time. The RETTS system also specifies the way in which the patient is to be treated in the emergency process regarding monitoring, and what degree of closeness and supervision that healthcare personnel should provide.

  • RED is classified as a direct life threat and means “emergency care directly”.
  • ORANGE is classified as a potential life threat and means “emergency care directly”
  • YELLOW is classified if not life threatening but needs emergency care within a reasonable time but “can wait” which is based solely on the patient being able to wait without obvious medical risk.
  • GREEN is classified as non-life threat but needs care within a reasonable time but “can wait” which is based solely on the patient being able to wait without obvious medical risk.
  • BLUE is classified patients with a very limited acute need for emergency care at the time of the search, and who is looking for more trivial medical problems that can sometimes be solved as a healthcare treatment or referred directly to other care level.


The NEWS Scoring System

Physiological parameter
Respiration rate (per minute)≤89–11 12–20 21–24 ≥25
SpO2 Scale 1 (%) ≤9192–9394–95≥96
SpO2 Scale 2 (%) ≤8384–8586–8788–92
≥93 on air
93–94 on oxygen95–96 on oxygen≥97 on oxygen
Air or oxygen?Oxygen Air
Systolic blood pressure (mmHg)≤9091–100101–110111–219≥220
Pulse (per minute)≤4041–50 51–90 91–110 111–130 ≥131
Temperature (°C)≤35.035.1–36.0 36.1–38.0 38.1–39.0 ≥39.1