Abstract
Purpose: Effective resource allocation in prehospital care for severely injured patients hinges on accurate injury severity assessment, known as triage. Current triage algorithms often lack specificity, leading to unnecessary trauma team activations (over-triage) and inefficient resource utilization. A robust prehospital triage system must reliably identify patients with critical bleeding or significant brain injuries. Integrating established in-hospital point-of-care (POC) tools into prehospital settings holds the potential as a point of care diagnostic tool to enhance triage sensitivity. Promising POC tools include lactate measurement, thorax, abdomen, and vena cava sonography, sonographic intracranial pressure (ICP) measurement, and capnometry in spontaneously breathing patients. This review aims to evaluate the potential of point of care diagnostic tool and establish diagnostic cut-off values for selected instrument-based POC tools, ultimately proposing their integration into a refined ABCDE-based triage algorithm.
Methods: A comprehensive systematic search across MEDLINE via PubMed, LIVIVO, and Embase was conducted, focusing on preclinical applications of selected POC tools in acute care settings. The search targeted studies identifying critical cranial and peripheral bleeding and detecting cerebral trauma sequelae. The Newcastle-Ottawa scale assessed the risk of bias in selected papers, and quality criteria were applied to categorize studies as suitable or unsuitable for cut-off value determination. PROSPERO Registration: CRD 42022339193.
Results: Out of 267 potentially relevant papers reviewed in full text, 61 were selected for final evaluation, with 13 proving crucial for defining cut-off values. The findings underscore the feasibility of preclinical point-of-care diagnostics, demonstrating their potential as a point of care diagnostic tool to offer valuable insights into patients’ clinical trajectories. Clinical outcomes such as mortality, emergency surgery requirements, and intensive care unit (ICU) stay were considered, allowing for the determination of hypothetical trauma team activation cut-off values for each adjunct. These cut-off values are: end-expiratory CO2: ≤ 2 mmHg; lactate: > 2 mmol/L; optic nerve sheath diameter (ONSD) in sonography: > 4.7 mm. Sonography for thorax and abdomen indicated anomalies (free fluid, free air, lung sliding, etc.) as a trigger.
Discussion: This review proposes a preliminary modified triage algorithm incorporating hypothetical cut-off values for trauma team activation based on POC diagnostics. However, further research is essential to refine these cut-off values and evaluate the practical implementation of this enhanced algorithm. Feasibility (application time, technical aspects) and the algorithm’s impact on over-triage rates require thorough investigation. Limitations include search restrictions and heterogeneity across studies (variations in measurement devices and techniques).
Supplementary Information: The online version contains supplementary material available at 10.1007/s00068-023-02226-8.
Keywords: Triage, Emergency Medical Service, Advanced Trauma Life Support, Point-of-Care Testing, Focused Assessment with Sonography for Trauma, Prehospital Care, Diagnostic Tool.
Introduction
In emergency medical services worldwide, the accurate prehospital triage of patients experiencing significant trauma mechanisms, even without overt injury signs, remains a daily challenge. Trauma ranks as the sixth leading cause of death globally (2012) and is the primary cause of mortality and disability in individuals under 35 [1]. In Germany alone, in 2022, 36,222 trauma patients required resuscitation room admission, subsequently needing intensive care or succumbing to their injuries in the resuscitation setting [2].
International emergency departments have established various triage systems for general patient populations [3] and specifically for trauma patients, defining criteria for trauma team activation [4, 5]. However, the cornerstone of effective trauma care is the most precise triage possible in the prehospital environment.
Optimal triage necessitates aligning medical resource allocation with injury severity, maximizing both sensitivity and specificity to prevent both over-triage and under-triage. Over-triage, the false elevation of treatment urgency, leads to the wasteful deployment of human and economic resources [6, 7]. Conversely, under-triage, an underestimation of urgency, can result in inadequate care and increased mortality for injured patients [8].
Recent years have witnessed the development of various strategies to enhance triage accuracy [9]. Algorithm-based systems like “Advanced Trauma Life Support (ATLS)” utilize the ABCDE mnemonic, providing a rapid, comprehensive examination framework based on a prioritized approach [10]. This structured approach aims to deliver a quick but thorough assessment of potentially life-threatening conditions. Despite these systems, triage often results in under-triage rates ranging from 1 to 71.9% and over-triage rates from 19 to 79% [11]. The American College of Surgeons Committee on Trauma (ACS-COT) recommends an under-triage rate of no more than 5% and an over-triage rate not exceeding 35% for contemporary triage systems [7].
In Germany, prehospital trauma triage is guided by the “Criteria for admission to the shock room of a trauma center by the German Society for Traumatology (DGU)” [12]. Trauma team activation is based on patient categorization into Grade A (vital parameter disturbance or significant injuries) or Grade B (specific accident mechanism or constellation, such as falls from > 3 m or high-impact traffic accidents, even without obvious injuries) [12, 13]. Retrospective analysis at a German level-1 trauma center revealed that increased trauma team utilization in recent years is partly attributed to Grade B classifications. Notably, a substantial portion of patients classified under Grade B and requiring a trauma team showed no traumatic pathologies after complete diagnosis [14], indicating increased over-triage in this patient group [15]. Furthermore, with 29% of patients in the TraumaRegister DGU® in 2020 being 70 years or older, additional triage tools are needed, as non-age-adapted criteria can lead to under-triage in elderly patients [16]. Age-related physiological compensation changes and atypical symptom presentations contribute to this challenge [17, 18].
With the aim of achieving the recommended over-triage rate of under 35%, and based on the hypothesis that in-hospital point-of-care (POC) tools could effectively identify critically injured patients prehospitally, this study investigates the potential of point of care diagnostic tool. The focus is on early detection of injuries necessitating resuscitation room resources, specifically critical cranial and/or peripheral hemorrhages and the identification of brain trauma sequelae.
The in-hospital ATLS protocol includes POC tools as “adjuncts” in the primary survey to aid in identifying critically injured patients. These adjuncts include capnography (for intubated patients), sonography (E-FAST), chest and pelvis X-rays, and laboratory testing including blood gas analysis (BGA) [19]. Each tool was assessed for prehospital applicability, considering feasibility and existing prehospital implementation.
This systematic review aims to assess the diagnostic capabilities of selected POC tools – lactate measurement, abdominal, vena cava, and thorax sonography, sonographic ICP measurement, and capnometry in spontaneously breathing patients – in the prehospital setting. The objective is to determine potential cut-off values for identifying critical injuries based on defined quality criteria, exploring their potential as a point of care diagnostic tool to enhance trauma triage.
Methods
This systematic review adheres to PRISMA reporting guidelines [20] and uses SWIM guidelines (Synthesis without Meta-Analysis) for synthesis and result reporting, as no meta-analysis was planned [21]. The retrospectively registered study protocol is available on PROSPERO (CRD 42022339193). Following protocol registration, study designs were refined, and the inclusion criterion of “patient age” was broadened to encompass all ages, primarily focusing on adult patient cohorts (excluding pediatric cohorts).
Eligibility criteria
This review investigates the diagnostic potential as a point of care diagnostic tool of selected tools: lactate measurement, abdominal, vena cava, and thorax sonography, sonographic intracranial pressure measurement, and capnometry in spontaneously breathing patients. A PICOS framework (Table 1) guided the inclusion criteria.
Table 1. PICOS Criteria
| PICO |
