suPARcharging triage – Empowering clinical decisions
Triage in the Emergency Department
Initial triaging in the Emergency Department is one of the most critical steps to securing good patient outcomes. All around the world, clinicians have different methods to assess the risk stratification of patients in hospitals to categorise the urgency and need of care.
Triage involves a complex decision-making process carried out by specially trained nurses, technicians, and doctors based on vital signs, complaints, respiratory rate, oxygen saturation in blood, pulse, level of consciousness, blood pressure, age, and body temperature15.
Internationally there is, however, no consensus on the protocol used for the decision-making process. Therefore several triage scales have been adopted by specific regions that guide healthcare professionals in their clinical decision-making.
Risk Scoring Systems for Triage
The qSOFA score is a bedside assessment that can identify patients with suspected infection who are at greater risk of having a poor outcome outside of the intensive care unit (ICU). qSOFA uses three criteria, assigning one point for low blood pressure (SBP≤100 mmHg), high respiratory rate (≥22 breaths per min), or altered mentation (Glasgow coma scale<15)48.
This triage scoring system was developed in Sweden and is currently used in hospitals across Sweden and some in Denmark. The scoring system is based on a patient’s vital signs (ABCD-system) and a short questionnaire for each complaint. The patients are divided into: a) red (life-threatening), b) orange (seriously ill), c) yellow (ill), d) green (need of assessment), or e) blue (fast track)49.
This risk scoring system is based on the following parameters50:
- Respiratory rate (A)
- Oxygen saturation (B)
- Blood pressure (C)
- Level of consciousness (D)
- Temperature (E)
The scoring system is based on 12 physiologic variables, age, type of admission, and existing medical conditions in the patient51.
The scoring system is based on 12 physiologic criteria, age of the patient, and pre-existing condition of the patient51.
SIRS is defined by the following four criteria (Note: SIRS replaced by the qSOFA in most hospitals, but still used in some countries)52:
- Increased heart rate (>90 beats /min)
- Increased respiratory rate (> 20 breaths/min)
- Fever or hypothermia (> 38 degrees or <36 degrees)
- Increased White blood cell count > 1,200/ mm3
Limitations of conventional triage
Conventional triage processes carried out by visual and physical examinations have the following limitations:
- A study found clinical triage efficiency was significantly influenced by the experience and training of individual nurses18. This results in high variability. Since conventional triages are not based on objective measurements, it can be influenced by personal bias and cultural differences.
- Triage stratifications based on visible vital signs may ineffectively diagnose penetrating injuries and blunt trauma. More mistakes are likely to be made if the patient is unconscious and unable to communicate their symptoms.
Even widely used triage protocols like the Manchester Triage system were found to lead to several cases of sub and super-triage (under and over-classification of severity)19. Errors in categorisation were most commonly seen in patients presenting with chest pain, resulting in long waiting times and ineffective treatment20. A meta-analysis study in Great Britain found triage decisions made in most hospitals across the country were based on insufficient evidence, resulting in repeat re-admissions and increased mortality15.
The prognostic biomarker suPAR is a data-based scientific tool that empowers healthcare professionals to make quick triage decisions across diseases. Implementing suPAR in triage, improves patient outcomes and reduce healthcare costs44,54.
suPARnostic products are approved for all the major chemical analysers, fits existing hospital laboratory workflows and delivers results in less than 20 mins.
How to interpret suPAR results
suPAR level < 4 ng/mL
Supports patient discharge
suPAR level > 6 ng/mL
Supports patient hospitalisation
Soluble urokinase plasminogen activator (suPAR) may be of particularly high value in triage in the Emergency Department due to the high degree of unspecificity. A randomised controlled study showed that patients with measured suPAR levels, were more often discharged early, and on average, stayed 6,5 hours shorter in hospital compared to the control group without suPAR measurement44.
High plasma suPAR levels have been associated with increased severity and mortality in COVID-1956, 57, HIV35, sepsis28, tuberculosis36 , malaria37, auto-immune diseases, Streptococcus pneumonia bacteremia, cancer38, Alzheimer’s39, cardiovascular diseases40, organ failure, neoplastic and pregnancy relation conditions, and type 2 diabetes mellitus41. High plasma concentrations of suPAR have also been associated with a high risk of mortality and longer hospital stay45, 46.
The most commonly used inflammatory biomarker is C-reactive protein measured using high-sensitivity (hsCRP) assays. Elevated CRP levels have also been linked with cancer, CVD, and all-cause mortality4.
Interestingly, suPAR outperforms CRP in prognosing a range of diseases. Additionally, suPAR is linked to a biochemical pathway more closely associated with organ damage than CRP and is therefore poised to be more sensitive40. Similarly, although troponins are the preferred biomarker in CVD prognosis, troponin levels rise only 2-6 after a myocardial infarction (MI) event, and measurements at 1 and 3 hours are needed to determine MI. In contrast, one measurement of suPAR is sufficient to rule out severe disease44.
The Charlson Comorbidity score predicts the annual mortality of a patient with a range of co-morbid diseases such as heart disease, diabetes, HIV, cancer, etc. The inclusion of suPAR in the Charlson algorithm was able to predict disease severity better42.
Fever is a fairly common presenting symptom in hospitals. But, it can be easily misdiagnosed due to its highly variable etiology. In such cases, there is a need for an objective biomarker that would accurately reflect the severity and magnitude of the infection43. suPAR is an ideal candidate due to its highly nonspecific nature. Low plasma levels can be used to identify patients with a good prognosis and enable early discharge. In Denmark, suPAR based stratification helped reduce ED overcrowding without any adverse on mortality or morbidity44.
The use of suPAR for triage in hospitals has been researched. Some of the essential findings from clinical studies are listed below:
- A study published in 2019 in the Scandinavian Journal of Trauma, Resuscitation, and Emergency Medicine studied the effectiveness of suPAR in grouping patients into high and low-risk after they arrive in the Emergency Department (ED). The study’s findings revealed that measurement of suPAR in relation to the triage process can allow more accurate identification of ED patients at risk54.
- Another study from 2019 published in the Journal of Family Medicine and Primary Care found that suPAR can be reliably used in the emergency department for triage and prognostic assessment of patients55.
Triage is a process by which injured or sick individuals are grouped into various categories. The basis of the grouping relies on the patients’ need for immediate medical treatment or the degree of benefit a patient may derive from emergency medical attention47.
Patients visit the hospital for a variety of reasons ranging from minor injuries to life-threatening conditions. The American college of emergency physicians (ACEP) reports a rising trend in patients visiting the Emergency Department (ED). In 2007, the number even surpassed the size of the population of the U.S two-fold. However, hospital resources are limited. Therefore not all patients can be treated simultaneously. Consequentially, the average waiting time before a patient receives medical care has increased by 25% 1.
Under these circumstances, it is imperative to accurately distinguish patients who need immediate attention from those who can wait. Using triage, patients are sorted based on vital signs, level of consciousness, pain, etc. The resulting scale can then be used to predict disease severity and risk of death2.
There is a plethora of evidence from around the world establishing the beneficial effect of triage categorisation on clinical outcomes, safety, and waiting time3,4,5,6,7,8,9,10,11. A shorter hospital stay consecutively lowers the risk of hospital-acquired infections, shortens immobilisation, and reduces cost. Triage has also helped reduce the proportion of patients leaving EDs without seeing a doctor12.
Triage can be carried out in pre-hospital settings, the accident site, during transport, or at the emergency department. Most hospitals have a dedicated triage area where specially trained nurses, emergency responders, or doctors will follow specific protocols to categorise patients.
In most western countries, triage is carried out at two levels; Primary triage is performed based on visual symptoms at the first point of contact. While secondary triage is made by conducting a thorough examination. In some cases, a tertiary triage may also be carried out in the ICU 13.
Triage is a complex decision-making process carried out by nurses, technicians, or doctors who have been specially trained for the purpose. In the UK and Scandinavia, nurse-led units (NLUs) are predominantly used to assess patients14. The decision can be made based on vital signs, chief complaint, respiratory rate, oxygen saturation in blood, pulse, level of consciousness, blood pressure, age, and body temperature15. However, internationally there is no consensus on the protocol used for the decision-making process. However, several triage scales have been adopted by specific regions that guide the health care technician in their decision-making.
Every triage system is unique. Some are used to decide waiting time, while others can determine the length of hospital stay, treatment strategy, or choice of investigative protocol. The most commonly used risk stratification system in EDs around the world has five levels or categories.
|2||Very Urgent||2 -10 Minutes|
|5||Not Urgent||Two hours|
Category 1: These patients are critically impaired but likely survive if given immediate, life-saving treatment. Therefore, they are given first priority towards resources.
Category 2: This category includes patients with severe life-threatening illnesses who require intervention as soon as possible. They are generally attended to within 10 minutes.
Category 3: These patients have severe illnesses and need to be treated within 30 minutes.
Category 4: This category includes patients with a potentially severe condition that must be treated within an hour.
Category 5: These patients have less urgent conditions and can wait up to 2 hours.
- The patient’s ability to walk
- Respiratory rate
- Capillary filling
- Radial pulse
- Obeying the commands of the healthcare professional
After examining each of the above criteria, the patient is marked by one of the red, yellow, green, and black tags. The four-color tags mean the following47:
- Red: Patients who need immediate medical care are put in this category. These patients cannot follow commands, do not have a radial pulse, and their respiratory rate is > 30 breaths/min.
- Yellow: Urgent non-ambulatory patients who can follow commands.
- Green: Non-urgent patients who can walk.
- Black: Deceased patients
Many biomarkers have been identified for their prognostic ability and included in Emergency departments across the world. These include lactate21, copeptin22, pro-adrenomedullin (proADM)23,26,27,28, albumin24, procalcitonin (PCT)23, C-reactive protein (CRP)25 and soluble urokinase plasminogen activator receptor (suPAR).
Chest pain is the most common cause of ED visits worldwide. However, traditional evaluation methods such as physical examinations, X-rays, and EKG are less sensitive and time-consuming. The detection of improved cardiac biomarkers, including Ck-MB, troponin, myoglobin29 , etc., has enabled enhance risk stratifications that do not require admission to the hospital, thus vastly reducing healthcare costs30.
Even in resource-poor settings in Tanzania, a combination of 11 host-response biomarkers, including STREM 1, C-reactive protein (CRP), and procalcitonin (PCT), outperformed conventional triages in accurately stratifying patients31.
In some diseases such as septicaemia, pneumonia, stroke, and myocardial infarction, early risk categorisation using biomarkers has helped save lives23. Similarly, in patients with prostate cancer, triaging using Prostate Cancer Antigen (PCA3), TMPRSS2-ERG, SelectMDx, and S3M resulted in early diagnosis and reduced mortality32.
Biomarkers have proved particularly useful in etiologically variant conditions that are hard to diagnose visually. Respiratory infections are the most common cause of ED visits in low-income countries. In these patients, proADM assays have helped accurately detect the severity of infection, thus reducing the length of stay and rate of readmissions33.
Biomarkers assays are also significant in conditions that appear curable but may rarely lead to sepsis and mortality. For example, febrile urinary tract infections are usually treatable with oral anti-microbial, but in rare cases lead to septic shock. The biomarker MR-proADM was able to accurately detect people who required subsequent hospitalisation34.
CRP is a protein produced by liver cells. The concentration of CRP in the bloodstream increases in the presence of infection and inflammation. Thus, the level of CRP in blood samples is a sensitive indicator of inflammatory conditions, infections, etc. CRP has been found to be an effective biomarker for triage53. A high CRP is indicative of bacterial infection and is often used to prescribe antibiotics.
suPAR is a non-specific marker for inflammation and overall patient health status. Compared to CRP, suPAR is a stronger indicator of patient prognosis and disease severity. As suPAR has a high negative predictive value, a low suPAR level is often used for the decision of discharge in combination with clinical signs 54.
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