Outcome variation among Canadian trauma centres: toward a clinical prediction rule for standardizing approaches to clinical assessment of hemorrhage

Dufresne and colleagues¹ recently reported on the impact of trauma centre designation on patient-centred outcomes following hemorrhagic shock. The authors showed that patients treated at level I trauma centres had significantly lower odds of dying than those treated at lower-level centres — findings consistent with previous work. The authors hypothesized that differences in outcomes were associated with the initial assessment and management, where higher surgical volumes, greater clinical expertise and availability of resources, such as computed tomography (CT), could play an important role.

We agree that early recognition of hemorrhage is essential to allow aggressive, effective therapeutic interventions that can improve outcomes and reduce mortality. Although adoption of the Advanced Trauma Life Support (ATLS) guidelines could, in theory, contribute to the standardization of the initial evaluation for traumatic hemorrhage, the ATLS classification of hemorrhage has recently been shown to have poor overall accuracy,² leading to overestimation of the presence of hypotension and tachycardia in bleeding patients.³ An international survey of ATLS course instructors found that only 1 in 10 respondents believed the ATLS classification to be a “good guide for fluid resuscitation and blood product transfusion.”⁴

We recently conducted a national survey of Canadian traumatologists as part of a larger project that aims to describe, understand and offer evidence-based refinement to this critical process through the development of a high-quality clinical prediction rule. The survey was electronically distributed to all 153 Trauma Association of Canada staff physician members in April 2017. Respondents were asked to rank the top 5 variables predicting the need for major intervention (surgery, embolization, massive transfusion) in bleeding patients among clinical, laboratory or imaging available within the first hour of assessment.

We received responses from 52 of 153 clinicians (34.0%). Most respondents were Canadian (86.5%) and practised at level I (71.2%), level II (17.3%) or level III (11.5%) equivalent trauma centres. The most common residency training programs completed were surgery (67.3%) and emergency medicine (19.2%). Hemodynamics was ranked within the top 5 predictors for all 52 respondents. Clinical examination, focused assessment with sonography for trauma (FAST), mechanism, blood gases and CT findings received top 5 ranks among more than half of respondents. In contrast, complete blood count, demographics and Glasgow Coma Scale score placed within the top 5 predictors for fewer than 10% of respondents.

The results from our survey show that the most highly ranked components of the hemorrhage assessment remain the classical “circulation” aspect of the primary survey in terms of patient hemodynamics and obvious sources of bleeding. Current practice preferences appear to align well with recently validated massive transfusion prediction scores. All 4 predictors (penetrating mechanism, systolic blood pressure [BP], heart rate and FAST) making up the Assessment of Blood Consumption (ABC) score were ranked within the top 5 in our survey. Similarly, 5 of the 8 predictors (unstable pelvis, FAST, heart rate, systolic BP, base excess) making up the Trauma-Associated Severe Hemorrhage (TASH) score are also ranked quite highly. Interestingly, this observation is coupled with what appears to be the modernization of the trauma assessment —– an evolving appreciation for CT imaging, which ranked just outside the top 5.

Whereas some patients arrive in hospital in obvious extremis with a clear indication for urgent intervention, there remains a subset of the trauma population for whom the classical clinical and biochemical signs of hemorrhage may not be as readily apparent. As Dufresne and colleagues have alluded to, outcome differences among centres identified in their cohort are likely influenced by nonuniform approaches to traumatic hemorrhage assessment, whether related to limitations in resources or variable clinical expertise. This highlights the importance of establishing a practical, evidence-based and universally applicable tool for triage, assessment and determination of appropriateness for intervention in bleeding patients. The results from our survey will be used, together with a systematic review,⁵ to inform the specification and derivation of such a tool.