Early CT scanning in the emergency department in patients with penetrating injuries: does it affect outcome?

Trauma systems were introduced almost 40 years ago. Proof of their effectiveness is an ongoing issue [1] with many studies on the outcomes written in the past decades [2‐5]. During the 1990s the Dutch trauma society, collaborating with all other trauma care partners, initiated several projects on improving quality of care for polytrauma patients [6], ranging from the introduction of modern programmes (such as Advanced Trauma Life Support) for teaching and training, to regionalization of specialized trauma care. As a result, trauma centers with three levels of care, with different criteria were designated in the Netherlands. The first Dutch level I trauma center was initiated in 1999 and since then eleven trauma centers were designated as a level I. To be categorized as a level I, immediate availability of ultrasonography (FAST), computed tomography (CT) scanner, angiography, intensive care beds, a stand-by operating room, and surgical team in the ED are obligatory [7].

In the Netherlands, several studies have been published evaluating the effect of the implementation of designated centers; these data show a reduction in overall mortality [8‐10]. So far, none of these studies have specifically assessed the impact of the direct availability of a CT scanner. Medical Center Haaglanden (MCH) part of the trauma center West Netherlands (TCWN), with 50,000 patients per year presenting at the ED (including 0.2% patients with penetrating injuries) implemented a CT scanner [General Electric (GE) bright speed 16 slides] in the ED in 2007. Early CT scanning can detect (potentially life threatening) injuries in an early stage, since it is easily accessible, reduces time to diagnosis and there are less patient transfers to a location elsewhere in the hospital [11, 12]. Furthermore, several other studies analysed whether performing a CT scan results in accurate decision making in patients with penetrating injury [13‐19].

The aim of this study was to analyse the effects of implementing a CT scanner in the ED in a level I trauma center in the Western part of the Netherlands, for patients with penetrating injuries. We hypothesized that a CT scanner in the ED would result in an increased usage and as a consequence improved outcomes in patients with penetrating injuries.

A total of 899 patients with penetrating injuries presented at the ED between 2000 and 2014. A total of 575 patients were excluded (Fig. 1), resulting in 424 eligible patients: 217 in the before (2000–2006) and 188 in the after group (2008–2014).

During the 1990’s many studies were published on the effect of implementing a level I trauma center [2‐5]. To be a level 1 trauma center a CT scanner in the ED is considered desirable [7]. Other studies analysed other aspects of having the CT scanner in the ED: time till diagnosis, time from first arrival in the ED to first CT imaging, and overall time spent in the ED [23‐25]. However, of those studies only Saltzherr et al. and Lee et al. focussed on clinical outcomes, both showing no significant differences in 30-day and 1-year mortality, H-LOS, and ICU-LOS. They concluded that implementing a CT scanner in the ED showed a faster availability of first CT [11, 26]. However, the power of the study of Saltzherr et al., using prespecified groups (multiple trauma patients and severe trauma brain injury patients), was low [11].

Analysing the impact on outcomes after implementing a CT scanner in the ED, we specifically studied patients with shot or stab wounds. We found a significant increase in the use of the CT scanner, which could be explained through logistics (the scanner being so close by). The current literature confirms the trend of the use of more defensive medical care, which may explain the increase in the use of CT scan in our study [27]. This increase in use often results in higher costs [27, 28]. Additionally, a CT scan has become the ‘gold standard’ as definitive diagnostic imaging of most injuries in severely and potentially severely injured patients. However, too severely injured patients will receive emergency surgery without diagnostic procedures, because of time pressure. Having the CT scanner in the ED improves workflow, since it reduces time from arrival to first CT, because it reduces the time of patient transfer to a CT scanner elsewhere in the hospital resulting in early diagnosis and goal-directed therapy [11, 12].

Minor downside of performing more CT scans is the increased radiation exposure per patient [29]. Mean effective dose of a CT scan abdomen compared to an X-ray (exclusive chest X-ray) for each intervention was 10.28 millisievert (mSv) against 0.13 mSv (measured in the Netherlands in 2013), although there is a wide range of dose exposure per intervention per body area. Abdominal CT scanning contributes most to radiation exposure of all CT scans [30, 31]. However, developments in technology as well as modified protocols will result in a decreased radiation exposure [32].

Our study shows a decreasing trend in overall mortality from 6.9 to 3.7%. Performing a CT scan more often and earlier reduces time till diagnosis and facilitates faster decision making for therapeutic interventions [24, 25], which could result in a decreasing overall mortality. Additionally, the significant decrease in shot wounds and shot wounds to the head after 2007 could also contribute to a decreasing overall mortality, considering that the outcomes after shot wounds, especially to the head is worse than for stab wounds in general.

Other studies have found that performing CT scan in patients with penetrating injuries in general decreases mortality [33, 34], which is in line with our study. However, our results are not statistically significant, which can be explained by the fact that our sample size is too small. The trend towards a decreasing overall mortality rate after implementation of a level I trauma center was confirmed by other Dutch studies [8‐10].

Another focus point was the effect of CT scanning on performing interventions; our study shows a decrease in patients undergoing exploratory laparotomy and other interventions. It also showed a decrease in H-LOS and number of ICU-admissions, which is in line with current literature. Grossman et al. concluded that performing a CT scan in patients with penetrating injuries results in more accurate decision making in performing other imaging diagnostics [14]. Performing a CT scan can also safely limit the use of surgical interventions (reducing negative exploratory laparotomies) or predict the need for it [13, 16, 18, 19], resulting in earlier discharge of patients after a shorter period of observation [35, 36]. The CT scan is a diagnostic tool with a high sensitivity, specificity and accuracy, to detect peritoneal violation and predict the need for a laparotomy in patients with penetrating injuries [13, 37, 38]. In the review of Goodman et al., pooled weighted estimates of sensitivity specificity and accuracy of the CT scan to predict the need for laparotomy were 94.9, 95.38 and 94.7%, respectively [39]. However, bowel injuries are challenging to diagnose on CT, using a variety of CT criteria can achieve accurate results [40].

Another variable is the costs of these additional CT scans, especially when plotted against the clinical relevance they have.

Based on the costs calculated in the REACT-trial [41] (a hospital general ward day costing 504 euros and an ICU day 1782 euros), performing a CT scan seems to be a non-expensive intervention, less than 100 euro per CT scan. So while the number of CT scans performed increases, resulting in higher overall costs for diagnostic imaging, it results in a decrease in H-LOS, number of ICU-admissions, and number of laparotomies, making it a cost-effective tool. The REACT-trial also confirmed a decrease in costs of surgical interventions in hospitals with early CT in the ED compared to a hospital without direct availability of a CT scanner in the ED.

Our study has several limitations, primarily since it is retrospective in nature. The data used from the trauma registry were only available from 2003 onwards. Data were sometimes incomplete.

It was not possible to adjust for all possible confounders such as improvements in medical care, medical knowledge, technical skills, imaging techniques, and hospital care, which all could have contributed to better care and subsequently influence our outcomes. Furthermore, selective non-operative management can be safely applied in patients with penetrating injuries [42‐44]. During the 14-year period, patients were possibly treated more often by principles of selective non-operative management, which could subsequently influence our outcomes as well.

Our study does not include the logistic part behind implementation of a CT scanner in the ED (variables such as time till diagnosis, mean time duration from arrival to first CT, and time in the ED). In the REACT-trial mean time from arrival till first CT after implementation of a CT scanner in the ED is reduced by 13 min (median time 49 min vs. median time of 36). The hospital in the REACT-trail and our hospital are both level I trauma centers with a CT scanner in the ED in the Netherlands. Therefore, the mean time reduction from arrival till first CT will also be around 13 min in our hospital after implementation of the CT scanner in the ED [11].

We recommend a larger prospective study in the future to look at the effect of the CT scanner in the ED in patients with penetrating injuries, focusing on clinical outcomes, time-aspects and provide a detailed cost-effective analysis.

In conclusion, the availability of a CT scanner in the ED especially in patients with penetrating injuries, results in more goal-directed treatment, and improvement of outcomes; it significantly reduces ICU-admissions and decreases H-LOS. Therefore, we can and should use it as a relatively cheap and non-invasive diagnostic tool due to its significant clinical impact.