Mortality of trauma patients treated at trauma centers compared to non-trauma centers in Sweden: a retrospective study

Objective: The main objective was to compare the 30-day mortality rate of trauma patients treated at trauma centers as compared to non-trauma centers in Sweden. The secondary objective was to evaluate how injury severity influences the potential survival benefit of specialized care. Methods: This retrospective study included 29,864 patients from the national Swedish Trauma Registry (SweTrau) during the period 2013–2017. Three sampling exclusion criteria were applied: (1) Injury Severity Score (ISS) of zero; (2) missing data in any variable of interest; (3) data falling outside realistic values and duplicate registrations. University hospitals were classified as trauma centers; other hospitals as non-trauma centers. Logistic regression was used to analyze the effect of trauma center care on mortality rate, while adjusting for other factors potentially affecting the risk of death. Results: Treatment at a trauma center in Sweden was associated with a 41% lower adjusted 30-day mortality (odds ratio 0.59 [0.50–0.70], p < 0.0001) compared to non-trauma center care, considering all injured patients (ISS ≥ 1). The potential survival benefit increased substantially with higher injury severity, with up to > 70% mortality decrease for the most critically injured group (ISS ≥ 50). Conclusions: There exists a potentially substantial survival benefit for trauma patients treated at trauma centers in Sweden, especially for the most severely injured. This study motivates a critical review and possible reorganization of the national trauma system, and further research to identify the characteristics of patients in most need of specialized care

On Scene Injury Severity Prediction (OSISP) model for trauma developed using the Swedish Trauma Registry

Background: Providing optimal care for trauma, the leading cause of death for young adults, remains a challenge e.g., due to field triage limitations in assessing a patient’s condition and deciding on transport destination. Data-driven On Scene Injury Severity Prediction (OSISP) models for motor vehicle crashes have shown potential for providing real-time decision support. The objective of this study is therefore to evaluate if an Artificial Intelligence (AI) based clinical decision support system can identify severely injured trauma patients in the prehospital setting. Methods: The Swedish Trauma Registry was used to train and validate five models – Logistic Regression, Random Forest, XGBoost, Support Vector Machine and Artificial Neural Network – in a stratified 10-fold cross validation setting and hold-out analysis. The models performed binary classification of the New Injury Severity Score and were evaluated using accuracy metrics, area under the receiver operating characteristic curve (AUC) and Precision-Recall curve (AUCPR), and under- and overtriage rates. Results: There were 75,602 registrations between 2013–2020 and 47,357 (62.6%) remained after eligibility criteria were applied. Models were based on 21 predictors, including injury location. From the clinical outcome, about 40% of patients\ua0were undertriaged and 46% were overtriaged. Models demonstrated potential for improved triaging and yielded AUC between 0.80–0.89 and AUCPR between 0.43–0.62. Conclusions: AI based OSISP models have potential to provide support during assessment of injury severity. The findings may be used for developing tools to complement field triage protocols, with potential to improve prehospital trauma care and thereby reduce morbidity and mortality for a large patient population

Surgical stabilization versus nonoperative treatment for flail and non-flail rib fracture patterns in patients with traumatic brain injury

Purpose Literature on outcomes after SSRF, stratified for rib fracture pattern is scarce in patients with moderate to severe traumatic brain injury (TBI; Glasgow Coma Scale ≤ 12). We hypothesized that SSRF is associated with improved outcomes as compared to nonoperative management without hampering neurological recovery in these patients. Methods A post hoc subgroup analysis of the multicenter, retrospective CWIS-TBI study was performed in patients with TBI and stratified by having sustained a non-flail fracture pattern or flail chest between January 1, 2012 and July 31, 2019. The primary outcome was mechanical ventilation-free days and secondary outcomes were in-hospital outcomes. In multivariable analysis, outcomes were assessed, stratified for rib fracture pattern. Results In total, 449 patients were analyzed. In patients with a non-flail fracture pattern, 25 of 228 (11.0%) underwent SSRF and in patients with a flail chest, 86 of 221 (38.9%). In multivariable analysis, ventilator-free days were similar in both treatment groups. For patients with a non-flail fracture pattern, the odds of pneumonia were significantly lower after SSRF (odds ratio 0.29; 95% CI 0.11–0.77; p = 0.013). In patients with a flail chest, the ICU LOS was significantly shorter in the SSRF group (beta, − 2.96 days; 95% CI − 5.70 to − 0.23; p = 0.034). Conclusion In patients with TBI and a non-flail fracture pattern, SSRF was associated with a reduced pneumonia risk. In patients with TBI and a flail chest, a shorter ICU LOS was observed in the SSRF group. In both groups, SSRF was safe and did not hamper neurological recovery

Outcome After Surgical Stabilization of Rib Fractures Versus Nonoperative Treatment in Patients With Multiple Rib Fractures and Moderate to Severe Traumatic Brain Injury (CWIS-TBI)

BACKGROUND Outcomes after surgical stabilization of rib fractures (SSRF) have not been studied in patients with multiple rib fractures and traumatic brain injury (TBI). We hypothesized that SSRF, as compared with nonoperative management, is associated with favorable outcomes in patients with TBI. METHODS A multicenter, retrospective cohort study was performed in patients with rib fractures and TBI between January 2012 and July 2019. Patients who underwent SSRF were compared to those managed nonoperatively. The primary outcome was mechanical ventilation-free days. Secondary outcomes were intensive care unit length of stay and hospital length of stay, tracheostomy, occurrence of complications, neurologic outcome, and mortality. Patients were further stratified into moderate (GCS score, 9–12) and severe (GCS score, ≤8) TBI. RESULTS The study cohort consisted of 456 patients of which 111 (24.3%) underwent SSRF. The SSRF was performed at a median of 3 days, and SSRF-related complication rate was 3.6%. In multivariable analyses, there was no difference in mechanical ventilation-free days between the SSRF and nonoperative groups. The odds of developing pneumonia (odds ratio [OR], 0.59; 95% confidence interval [95% CI], 0.38–0.98; p = 0.043) and 30-day mortality (OR, 0.32; 95% CI, 0.11–0.91; p = 0.032) were significantly lower in the SSRF group. Patients with moderate TBI had similar outcome in both groups. In patients with severe TBI, the odds of 30-day mortality was significantly lower after SSRF (OR, 0.19; 95% CI, 0.04–0.88; p = 0.034). CONCLUSION In patients with multiple rib fractures and TBI, the mechanical ventilation-free days did not differ between the two treatment groups. In addition, SSRF was associated with a significantly lower risk of pneumonia and 30-day mortality. In patients with moderate TBI, outcome was similar. In patients with severe TBI a lower 30-day mortality was observed. There was a low SSRF-related complication risk. These data suggest a potential role for SSRF in select patients with TBI. LEVEL OF EVIDENCE Therapeutic, level IV

Surgical Management of Rib Fractures Following Trauma

Background: Surgical management of chest wall injuries has received increasing attention in recent years. The aim of this thesis was to study the mechanism of injury (MOI) in relation to chest wall injury patterns and short- and long-term outcome of surgery in patients with multiple rib fractures and unstable thoracic cage injuries. Methods: Paper I is a retrospective study (n=211) of the association of MOI and injury patterns in patients operated for acute chest wall injuries. Paper II is a prospective longitudinal study (n=54) of the long-term outcome of surgery in patients with multiple rib fractures and flail chest. Paper III is a cross-sectional study (n=37) of the use of CT-lung volume estimation as a marker for lung function in patients operated for flail chest. Paper IV is a prospective controlled study (n=139) of the short- and long-term outcome of surgery in patients with unstable thoracic cage injuries. Results: The MOI differs according to age and is associated with different chest wall injury patterns. Lateral and posterior flail segments are the most commonly seen. Symptoms of pain, lung function and Quality of Life (QoL), improve during the first post-operative year. CT-lung volume estimates increase significantly from preoperative values to post-operative values and there is a high correlation between post-operative CT-lung volume and lung function. Surgery for unstable thoracic cage injuries does not decrease the need for mechanical ventilation. However, surgically managed patients have a decreased incidence of pneumonia (17% vs. 36%, p=0.013) and less pain (29% vs. 57%, p<0.05) the first months’ post trauma. Patients operated without thoracotomy have a better residual lung function and lung volume. A gradual improvement in patient symptoms was seen and after one year there was no difference in symptoms, function or QoL between surgically and conservatively managed patients. Conclusions: The MOI influences rib fracture pattern and associated injuries. Lung volume estimated by CT can be used as a marker for lung function. Surgery for unstable thoracic cage injuries decreases the incidence of pneumonia and reduces pain. Patients continue to improve gradually and no difference can be seen between the surgically and conservatively managed patients one year post trauma

Epidemiology of firearm injuries in Sweden

Background: Gun violence is a global health problem. Population-based research on firearm-related injuries has been relatively limited considering the burden of disease. The aim of this study was to analyze nationwide epidemiological trends of firearm injuries. Methods: This is a retrospective nationwide epidemiological study including all patients with firearm injuries from the Swedish Trauma Registry (SweTrau) during the period 2011 and 2019. Registry data were merged with data from the Swedish National Council for Crime Prevention and the Swedish Police Authority. Results: There were 1010 patients admitted with firearm injuries, 96.6% men and 3.4% women, median age 26.0 years [IQR 22.0–36.3]. The overall number of firearm injuries increased on a yearly basis (P < 0.001). The most common anatomical injury location was lower extremity (29.7%) followed by upper extremity (13.8%), abdomen (13.8%), and chest (12.5%). The head was the most severely injured body region with a median abbreviated injury scale (AIS) of 5 [IQR 3.2–5]. Vascular injuries were mainly located to the lower extremity (42%; 74/175). Majority of patients (51.3%) had more than one anatomic injury location. The median hospital length of stay was 3 days [IQR 2–8]. 154 patients (15.2%) died within 24 h of admission. The 30-day and 90-day mortality was 16.7% (169/1010) and 17.5% (177/1010), respectively. There was an association between 24-h mortality and emergency department systolic blood pressure < 90 mmHg [OR 30.3, 95% CI 16.1–56.9] as well as the following injuries with AIS ≥ 3; head [OR 11.8, 95% CI 7.5–18.5], chest [OR 2.3, 95% CI 1.3–4.1], and upper extremity [OR 3.6, CI 1.3–10.1]. Conclusions: This nationwide study shows an annual increase of firearm-related injuries and fatalities. Firearm injuries affect people of all ages but more frequently young males in major cities. One in six patients succumbed from their injuries within 30 days with most deaths occurring within 24 h of hospital admission. Given the impact of firearm-related injuries on society additional research on a national level is critical

Management and outcomes of firearm-related vascular injuries

Background: Violence due to firearms is a major global public health issue and vascular injuries from firearms are particularly lethal. The aim of this study was to analyse population-based epidemiology of firearm-related vascular injuries. Methods: This was a retrospective nationwide epidemiological study including all patients with firearm injuries from the national Swedish Trauma Registry (SweTrau) from January 1, 2011 to December 31, 2019. There were 71,879 trauma patients registered during the study period, of which 1010 patients were identified with firearm injuries (1.4%), and 162 (16.0%) patients with at least one firearm-related vascular injury. Results: There were 162 patients admitted with 238 firearm-related vascular injuries, 96.9% men (n = 157), median age 26.0 years [IQR 22–33]. There was an increase in vascular firearm injuries over time (P < 0.005). The most common anatomical vascular injury location was lower extremity (41.7%) followed by abdomen (18.9%) and chest (18.9%). The dominating vascular injuries were common femoral artery (17.6%, 42/238), superficial femoral artery (7.1%, 17/238), and iliac artery (7.1%, 17/238). Systolic blood pressure (SBP) < 90 mmHg or no palpable radial pulse in the emergency department was seen in 37.7% (58/154) of patients. The most common vascular injuries in this cohort with hemodynamic instability were thoracic aorta 16.5% (16/97), femoral artery 10.3% (10/97), inferior vena cava 7.2% (7/97), lung vessels 6.2% (6/97) and iliac vessels 5.2% (5/97). There were 156 registered vascular surgery procedures including vascular suturing (22%, 34/156) and bypass/interposition graft (21%, 32/156). Endovascular stent was placed in five patients (3.2%). The 30-day and 90-day mortality was 29.9% (50/162) and 33.3% (54/162), respectively. Most deaths (79.6%; 43/54) were within 24-h of injury. In the multivariate regression analysis, vascular injury to chest (P < 0.001) or abdomen (P = 0.002) and injury specifically to thoracic aorta (P < 0.001) or femoral artery (P = 0.022) were associated with 24-h mortality. Conclusions: Firearm-related vascular injuries caused significant morbidity and mortality. The lower extremity was the most common injury location but vascular injuries to chest and abdomen were most lethal. Improved early hemorrhage control strategies seem critical for better outcome

Bioimpedance technology for detection of thoracic injury

Objective: Thoracic trauma is one of the most common and lethal types of injury, causing over a quarter of traumatic deaths. Severe thoracic injuries are often occult and difficult to diagnose in the field. There is a need for a point-of-care diagnostic device for severe thoracic injuries in the prehospital setting. Electrical bioimpedance (EBI) is non-invasive, portable, rapid and easy to use technology that can provide objective and quantitative diagnostic information for the prehospital environment. Here, we evaluated the performance of EBI to detect thoracic injuries. Approach: In this open study, EBI resistance (R), reactance (X) and phase angle (PA) of both sides of the thorax were measured at 50 kHz on patients suffering from thoracic injuries (n = 20). In parallel, a control group consisting of healthy subjects (n = 20) was recruited. A diagnostic mathematical algorithm, fed with input parameters derived from EBI data, was designed to differentiate patients from healthy controls. Main results: Ratios between the X and PA measurements of both sides of the thorax were significantly different (