Immediate total-body CT scanning versus conventional imaging and selective CT scanning in patients with severe trauma (REACT-2): a randomised controlled trial

Summary

Background

Published work suggests a survival benefit for patients with trauma who undergo total-body CT scanning during the initial trauma assessment; however, level 1 evidence is absent. We aimed to assess the effect of total-body CT scanning compared with the standard work-up on in-hospital mortality in patients with trauma.

Methods

We undertook an international, multicentre, randomised controlled trial at four hospitals in the Netherlands and one in Switzerland. Patients aged 18 years or older with trauma with compromised vital parameters, clinical suspicion of life-threatening injuries, or severe injury were randomly assigned (1:1) by ALEA randomisation to immediate total-body CT scanning or to a standard work-up with conventional imaging supplemented with selective CT scanning. Neither doctors nor patients were masked to treatment allocation. The primary endpoint was in-hospital mortality, analysed in the intention-to-treat population and in subgroups of patients with polytrauma and those with traumatic brain injury. The χ² test was used to assess differences in mortality. This trial is registered with ClinicalTrials.gov, number NCT01523626.

Findings

Between April 22, 2011, and Jan 1, 2014, 5475 patients were assessed for eligibility, 1403 of whom were randomly assigned: 702 to immediate total-body CT scanning and 701 to the standard work-up. 541 patients in the immediate total-body CT scanning group and 542 in the standard work-up group were included in the primary analysis. In-hospital mortality did not differ between groups (total-body CT 86 [16%] of 541 vs standard work-up 85 [16%] of 542; p=0·92). In-hospital mortality also did not differ between groups in subgroup analyses in patients with polytrauma (total-body CT 81 [22%] of 362 vs standard work-up 82 [25%] of 331; p=0·46) and traumatic brain injury (68 [38%] of 178 vs 66 [44%] of 151; p=0·31). Three serious adverse events were reported in patients in the total-body CT group (1%), one in the standard work-up group (<1%), and one in a patient who was excluded after random allocation. All five patients died.

Interpretation

Diagnosing patients with an immediate total-body CT scan does not reduce in-hospital mortality compared with the standard radiological work-up. Because of the increased radiation dose, future research should focus on the selection of patients who will benefit from immediate total-body CT.

Funding

ZonMw, the Netherlands Organisation for Health Research and Development.

Introduction

Total-body CT scanning is increasingly used in the primary assessment of patients with trauma, and is done according to Advanced Trauma Life Support (ATLS) guidelines.¹ CT scanning is accurate and safe for the detection of traumatic injuries.² A substantial advantage of total-body imaging compared with the standard work-up with radiographs, ultrasound, and selective CT scanning is the rapid and complete overview of life-threatening traumatic injuries. Time benefits in favour of total-body CT scanning compared with the standard work-up,3, 4, 5, 6 changes in treatment associated with total-body CT scanning,⁷ and potential survival benefits of total-body CT scanning3, 8, 9, 10, 11, 12, 13 have been described previously.

A potential disadvantage of total-body CT scanning of patients with trauma is the increased exposure to radiation.14, 15 As a side-effect, incidental (ie, unrelated to the trauma) findings are more frequently found with total-body CT scanning16, 17, 18 than standard work-up. Despite the absence of level 1 scientific evidence for the use of total-body CT scanning in the assessment of patients with trauma,2, 19, 20 an increasing number of trauma centres have incorporated this imaging strategy into their daily practice.6, 7, 13, 21 The total-body CT scan could be used as a supplemental instrument to standard radiological imaging or even as a replacement, without the need for previous conventional imaging (ie, radiographs and ultrasound).

Most previous studies retrospectively included a specific cohort of patients (eg, patients with polytrauma, defined as patients with an Injury Severity Score [ISS] of ≥16).3, 13 Because the ISS is calculated retrospectively at discharge, this parameter is not available in daily clinical practice and cannot be used as a triage method for the selection of severely injured patients. Therefore, intrinsic methodological limitations and the risk of selection bias are confounders in these studies. The need for a randomised clinical trial has been highlighted³ and was the primary conclusion of all systematic reviews.2, 19, 20, 22, 23, 24

Research in context

Evidence before this study

Before the start of REACT-2, we undertook a systematic review to assess the value of immediate total-body CT during the primary survey of injured patients compared with conventional radiographic imaging supplemented with selective CT. We did a systematic search of MEDLINE, Embase, Web of Science, and Cochrane Library databases. The search consisted of all articles published between 1947 and Nov 1, 2010, and terms searched for were (“fbct” or “tbct” or “ whole body ct” or “ total body ct” or “full body ct”) OR ([“whole body” or “total body” or “full body”] AND [“scan*” or “tomograph*” or “ct scan”]). These terms were combined with the following terms: “trauma” or “injur*” or “shock*” or “emerg*”. All articles in English or Dutch were included. Reports were eligible if they contained original data that compared immediate total-body CT with conventional imaging supplemented with selective CT in injured patients. The main outcomes of interest were overall mortality and time in the emergency room. Four studies were included that described a total of 5470 patients; one study included 4621 patients (84%). All four studies were non-randomised cohort studies with retrospective data collection and were of proper methodological quality. Mortality was reported in three studies. Absolute mortality differed substantially between studies, but within studies mortality rates were comparable between immediate total-body CT and conventional imaging strategies (pooled odds ratio 0·91, 95% CI 0·79–1·05). After adjustment for confounders, one of the studies showed an increase in probability of survival in favour of patients with total-body CT. Time in the emergency room was described in three studies; in two emergency rooms, time was significantly shorter in patients who underwent immediate total-body CT (70 min vs 104 min; p=0·025; and 47 min vs 82 min; p<0·001). In conclusion, the substantial reduction in time in the emergency room is a promising feature of immediate total-body CT scanning, but well designed and larger randomised studies are needed to see how this will translate into clinical outcomes.

Added value of this study

Total-body imaging is theoretically so promising that several trauma centres around the world incorporated the total-body CT scan into their daily practice, without level 1 evidence. However, total-body CT scanning is associated with higher radiation exposure and health-care costs. REACT-2 showed that immediate total-body CT scanning is safe, shortens the time to end of imaging, and does not increase direct medical costs; however, it does not improve survival. REACT-2 is, to our knowledge, the first randomised trial on this topic and a substantial number of patients were included. Our study was well designed and patient characteristics were comparable between the randomly assigned cohorts. REACT-2 provided Oxford level 1a evidence to the question of whether use of the immediate total-body CT scan during assessment of trauma is justified.

Implications of all the available evidence

Findings from REACT-2 show that the immediate total-body CT scan should be used cautiously in clinical practice. Although we noted no survival benefit, there was no increase in medical costs and there was a time benefit in favour of total-body CT scanning. In severely injured patients in whom CT examinations of several body regions were expected, total-body CT scanning was beneficial since such patients received a similar or higher radiation dose with the standard work-up. Future studies should aim to optimise the selection criteria for total-body CT in severely injured patients. REACT-2 showed the difficulty of trying to establish beforehand which patients are severely injured, as opposed to selecting patients with polytrauma retrospectively, when results of radiography are known and an Injury Severity Score is already attributed to the patient. The injury mechanism, vital parameters, and clinical suspicion of potential injuries as used in REACT-2 are a good, but certainly not the ideal, starting point for future studies. Another point of interest is whether the total-body CT scan should be used as a supplement to or as a replacement for conventional imaging. Even in haemodynamically compromised patients, the total-body CT scan could be a safe or even preferred imaging method. If conventional imaging can be omitted, radiation exposure in total-body CT will further decline and more time will be saved. However, large prospective series of haemodynamically unstable patient cohorts should be done to provide information on the transition point between those who are unstable but stable enough for a total-body CT scan and those who are too unstable to undertake a total-body CT scan. Another important group are patients with severe traumatic brain injury, especially if combined with injuries in other body regions. The rapid and detailed information on the absence or presence, and severity, of injuries provided by the total-body CT scan might direct important therapeutic decisions.

We undertook a randomised clinical trial (REACT-2) to examine the effect of immediate total-body CT scanning as part of the primary assessment of patients with severe trauma on in-hospital mortality, and compared it with that of the standard work-up of conventional imaging supplemented with selective CT scanning.