Discussion

Almost 25% of the world population is less than 15 years of age and unfortunately, by 2016, shootings were the leading cause of death in the pediatric population in the United States surpassing motor vehicle collisions. ^{31–Reference Goldstick, Cunningham and Carter33} More often, this means that 25% of patients in MCIs may be pediatric patients. Multiple systems are used around the world to help prioritize care and efficiently allocate resources in such a way as to improve population outcomes overall. Although some systems are used more commonly than others, all MCI triage tools have the following principle in common: assignment of resources based on the initial patient assessment and consideration of available resources. ³⁴

‘Children are not little adults.’ This well-known and used expression timelessly encapsulates the significant differences in anatomy, physiology, and clinical characteristics between children and adults. There exist numerous important variances in head and neck, thoracoabdominal and musculoskeletal injury patterns, as well as a child’s physiologic response to injury. ^{Reference Figaji35} There is also a wide spectrum for categorizing pediatric trauma, based upon upper age limits (e.g., 12-21yr/ preadolescent), weight (e.g., ≥ 50kg) and/ or presence of secondary sex characteristics. ^{Reference Hardin, Hackell, Committee On and Ambulatory36} Thus, while current algorithms are structured similarly regardless of age, these variances should be taken into consideration.

Another important and controversial point is the definition of accuracy and finding the ‘best’ triage system. Some authors like Shaban et al. and Wallis et al. compared different algorithms to a predefined score like Criteria Outcomes Tool (COT) for the former, and the ISS, NISS, and Garner criteria for the latter, with the triage algorithm that is most comparable to the predefined score being the most accurate. ^{Reference Shaban, Donofrio, Kaji and Cicero22,Reference Wallis and Carley23} Other studies looked at the providers’ perspective and ease of use either in a tabletop or using a Delphi method during a simulation. ^{Reference Cheng, Staats and D’Arcy20,Reference Cicero, Overly and Brown37} Also, Cross et al. retrospectively looked at trauma patients that were hospitalized and compared the outcome (mortality) while applying different triage algorithms upon first presentation to identify the best algorithm with the lowest mortality. ^{Reference Cross and Cicero26}

JS is the most commonly used system in the USA, ^{Reference Nadeau and Cicero24} and this can be partially due to its derivation from an adult system, START, that is the most widely used system in the USA. ^{Reference Bazyar, Farrokhi and Khankeh38} JS was designed for use in children 8 years of age and younger, but more recently, generally applied in all pre-adolescent patients. It was found to have the best outcomes in terms of mortality in this age group compared to other algorithms. However, JS can have low sensitivity when compared to the New Injury Severity Score (NISS) and the Injury Severity Score (ISS). These are 2 scores used to classify the severity of injury in individualized patients, which can lead to unacceptable rates of under-triage as missing patients with high NISS or ISS, means missing patients with higher risk of morbidity, and/or mortality. ^{Reference Price, Brace-McDonnell, Stallard, Bleetman, Maconochie and Perkins21,Reference Wallis and Carley23} While over-triage means that resources will be overutilized, under-triage is by definition more serious and can lead to increased mortality or other adverse outcomes. ^{Reference Peng and Xiang39} The American College of Surgeons Committee on Trauma (ACS-COT) has defined an under-triage rate of < 5% and over-triage rate of < 35% as acceptable. ^{Reference Escobar and Morris40}

SALT, a more detailed algorithm used in the USA, was developed in 2008 by the Centers for Disease Control and prevention (CDC) as a newer and more advanced triage system. ^{Reference Lerner, Schwartz and Coule41} This review shows a higher over-triage rate in the pediatric population, which in fact, was an important limitation of the older START protocol. ^{Reference Lee42} Another, more serious problem, arose when evaluating IRR with high numbers of casualties, where SALT had an unacceptable rate of under-triage, specifically in the pediatric population. ^{Reference McGlynn, Claudius and Kaji15}

In this review, CF, developed in Australia but currently replaced by Sieve and the PTT in the UK, was 1 of the best algorithms for the pediatric population. It is simple and was found to be accurate in multiple studies. However, as with most triage tools, CF was not adapted specifically to the pediatric population. Driven by the positive results in this review, CF could be used as the basis for development of a pediatric algorithm.

In the UK, the most frequently used algorithm is Sieve and its pediatric adaptation: the PTT. The PTT is a visual tape that is placed next to the patient, like the Broselow® tape. A Sieve algorithm is then applied according to the height of the patient. Although this method is the most adapted to the pediatric population, this review shows that it can also have a high rate of under-triage. ^{Reference Wallis and Carley16} The combination of PTT and other methods (like T-RTS) has been explored but is yet to be validated. ^{Reference Chayen, O’Leary, Major, Dawson and Gosby17}

Worthy of note is the fact that most systems share a common weakness, and this is the first step of the algorithm. The assessment of a patient’s state based on their ability to walk has clear limitations when assessing infants and toddlers who are developmentally unable to ambulate independently. This also presents limitations for those who have baseline disabilities affecting their mobility. The assessment of developmentally appropriate mobility requires a certain degree of pediatric expertise. STM is the only system in the identified list which did not rely on the patient’s ability to walk as a method for initial sorting. Unfortunately, the data gathered on STM is conflicting. Furthermore, this algorithm is anchored on specific vital sign values that are adapted to the adult population. ^{Reference Jenkins, McCarthy and Sauer43} Another consideration is that these algorithms are mainly trauma oriented. Pediatric patients may present in different ways in an MCI, being severely compromised but still able to walk. For example, an asthmatic pediatric patient could present walking in an MCI with severe shortness of breath and could be dangerously under-triaged.

On the other hand, the evaluation of secondary triage methods in this review found all 3 studies that determined that PPATS to be better than the more traditional algorithms like T-RTS in predicting mortality and patients needing ICU. This algorithm needs to be prospectively validated in a real-life MCI to further strengthen its external validation as an in-hospital triage system.