High positive end-expiratory pressure ventilation mitigates the progression from unilateral pulmonary contusion to ARDS: An animal study.

BACKGROUND: Pulmonary contusion (PC) is common in severely traumatized patients and can lead to respiratory failure requiring mechanical ventilation (MV). Ventilator-induced lung injury (VILI) might aggravate lung damage. Despite underrepresentation of trauma patients in trials on lung-protective MV, results are extrapolated to these patients, potentially disregarding important pathophysiological differences. METHODS: Three MV protocols with different positive end-expiratory pressure (PEEP) levels: ARDSnetwork lower PEEP (ARDSnet-low), ARDSnetwork higher PEEP (ARDSnet-high), and open lung concept (OLC) were applied in swine for 24 hours following PC. Gas exchange, lung mechanics, quantitative computed tomography, and diffuse alveolar damage (DAD) score were analyzed. Results are given as median (interquartile range) at 24 hours. Statistical testing was performed using general linear models (group effect) over all measurement points and pairwise Mann-Whitney U tests for DAD. RESULTS: There were significant differences between groups: PEEP ( p < 0.0001) ARDSnet-low (8 [8-10] cmH 2 O), ARDSnet-high (12 [12-12] cmH 2 O), OLC (21 [20-22] cmH 2 O). The fraction of arterial partial pressure of oxygen and inspired oxygen fraction ( p = 0.0016) was lowest in ARDSnet-low (78 (73-111) mm Hg) compared with ARDSnet-high (375 (365-423) mm Hg) and OLC (499 (430-523) mm Hg). The end-expiratory lung volume (EELV) differed significantly ( p < 0.0001), with highest values in OLC (64% [60-70%]) and lowest in ARDSnet-low (34% [24-37%]). Costa's surrogate for mechanical power differed significantly ( p < 0.0001), with lowest values for ARDSnet-high (73 [58-76]) compared with OLC (105 [108-116]). Diffuse alveolar damage was lower in ARDSnet-high compared with ARDSnet-low (0.0007). CONCLUSION: Progression to ARDS, 24 hours after PC, was mitigated by OLC and ARDSnet-high. Both concepts restored EELV. ARDSnet-high had the lowest mechanical power surrogate and DAD. Our data suggest, that ARDSnet-high restored oxygenation and functional lung volume and reduced physiological and histological surrogates for VILI. ARDSnet-low generated unfavorable outcomes, such as loss of EELV, increased mechanical power and DAD after PC in swine. The high respiratory rate in the OLC may blunt favorable effects of lung recruitment.

Mortality With and Without Whole-Body CT in Severely Injured Children.

BACKGROUND: The choice of imaging modality-the use of whole-body computed tomography (WB-CT) versus a step-wise diagnostic procedure-in injured children is controversial. In this study we availed ourselves of data from the TR-DGU, the trauma registry of the German Society for Trauma Surgery (Deutsche Gesellschaft für Unfallchirurgie), to investigate whether the use of WB-CT improves the outcome. METHODS: The TR-DGU data from the period 2012-2021 were evaluated. A three-stage analysis began with comparison of children with adults aged ≤ 50 years. As a second step, the observed and expected mortality in children with WB-CT was compared with the mortality in children without WB-CT. Finally, predictors of the use of WB-CT were identified so that a propensity score analysis of matched pairs could be performed. RESULTS: A total of 65 092 patients were included, 4573 children (7%) and 60 519 adults (93%), with differences in accident type and injury pattern. Comparison of the ratio of observed to expected mortality revealed no difference between the two groups of children (standardized mortality ratio 0.97 with WB-CT, 0.95 without WB-CT). In adults, however, there was an advantage for the WB-CT group. The propensity score analysis of 1101 matched pairs showed identical mortality in the two groups (3.9% with WB-CT, 4.0% without WB-CT). CONCLUSION: The TR-DGU data show no benefit of WB-CT compared with step-wise diagnosis in the care of severely injured children. In view of the radiation exposure involved, with the danger of inducing malignancy, the benefits and risks of the use of WB-CT in children should be weighed up carefully in team discussions.

Structural and Process Data on Radiological Imaging in the Treatment of Severely Injured Patients - Results of a Survey of Level I and II Trauma Centers in Germany. / Struktur- und Prozessdaten zur radiologischen Bildgebung bei Behandlung schwerstverletzter Patienten ­ Ergebnisse einer Befragung überregionaler und regionaler TraumaZentren in Deutschland.

PURPOSE: Systematic data collection regarding the integration of radiology as well as structural and process characteristics of radiological diagnostics of severely injured patients in Germany using a structured questionnaire. MATERIALS AND METHODS: Personal contact with all certified Level I and Level II Trauma Centers in Germany. Data on infrastructure, composition of the trauma room team, equipment, and data on the organization/performance of primary major trauma diagnostics were collected. RESULTS: With a participation rate of 46.9 % (n = 151) of all German trauma centers (N = 322), a solid database is available. There were highly significant differences in the structural characteristics incl. CT equipment between the level I and II centers: In 63.8 % of the level II centers, the CT unit was located more than 50 m away from the trauma room (34.2 % in the level I centers). A radiologist was part of the trauma room team in 59.5 % of level II centers (level I 88.1 %). Additionally, highly significant differences were found comparing 24-h provision of other radiologic examinations and interventions, such as MRI (level II 44.9 %, level I 92.8 %) and angiography (level II 69.2 %, level I 97.1 %). CONCLUSION: Heterogeneous structural and process characteristics of the diagnosis of severely injured patients in Germany were revealed, with highly significant differences between level I and level II centers. KEY POINTS: · This is the first study on the diagnostic reality of radiology in severely injured patients in Germany. Despite a high level of standardization, significant differences were observed.. CITATION FORMAT: · Ernstberger A, Reske SU, Brandl A et al. Structural and Process Data on Radiological Imaging in the Treatment of Severely Injured Patients - Results of a Survey of Level I and II Trauma Centers in Germany. Fortschr Röntgenstr 2022; 194: 505 - 514.

Detection of posttraumatic pneumothorax using electrical impedance tomography-An observer-blinded study in pigs with blunt chest trauma.

INTRODUCTION: Posttraumatic pneumothorax (PTX) is often overseen in anteroposterior chest X-ray. Chest sonography and Electrical Impedance Tomography (EIT) can both be used at the bedside and may provide complementary information. We evaluated the performance of EIT for diagnosing posttraumatic PTX in a pig model. METHODS: This study used images from an existing database of images acquired from 17 mechanically ventilated pigs, which had sustained standardized blunt chest trauma and had undergone repeated thoracic CT and EIT. 100 corresponding EIT/CT datasets were randomly chosen from the database and anonymized. Two independent and blinded observers analyzed the EIT data for presence and location of PTX. Analysis of the corresponding CTs by a radiologist served as reference. RESULTS: 87/100 cases had at least one PTX detected by CT. Fourty-two cases showed a PTX > 20% of the sternovertebral diameter (PTXtrans20), whereas 52/100 PTX showed a PTX>3 cm in the craniocaudal diameter (PTXcc3), with 20 cases showing both a PTXtranscc and a PTXcc3. We found a very low agreement between both EIT observers considering the classification overall PTX/noPTX (κ = 0.09, p = 0.183). For PTXtrans20, sensitivity was 59% for observer 1 and 17% for observer 2, with a specificity of 48% and 50%, respectively. For PTXcc3, observer 1 showed a sensitivity of 60% with a specificity of 51% while the sensitivity of observer 2 was 17%, with a specificity of 89%. By programming a semi-automatized detection algorithm, we significantly improved the detection rate of PTXcc3, with a sensitivity of 73% and a specificity of 70%. However, detection of PTXtranscc was not improved. CONCLUSION: In our analysis, visual interpretation of EIT without specific image processing or comparison with baseline data did not allow clinically useful diagnosis of posttraumatic PTX. Multimodal imaging approaches, technical improvements and image postprocessing algorithms might improve the performance of EIT for diagnosing PTX in the future.

Structural effects of variation in the human clavicle.

OBJECTIVES: Purported evolutionary shifts in shoulder structure have been linked to changes in hominin behavior and adaptation. Researchers use clavicle morphology to infer these shifts. However, there is a lack of empirical data underlying such predictive relationships. This study investigates how clavicle morphology affects articulated shoulder girdle and upper thorax configuration in humans. MATERIALS AND METHODS: Landmarks and scalar measurements on the clavicle, scapula, and ribs 1-3 were collected from three-dimensional computed tomographic scans of living humans. Covariation between disarticulated and articulated morphology was assessed using partial least squares and regression analyses. RESULTS: We found support for hypotheses linking combined dimensions of the clavicle, ribs, and scapula to resting protraction. Individuals with relatively short clavicles tend to exhibit protracted and elevated resting positions of the scapula. It is more difficult to predict superoinferior configuration, which is only minimally affected by clavicle curvature. Instead, the superoinferior position of the scapula on the thorax is governed equally by clavicle orientation and rib declination. Shoulder breadth is determined primarily by clavicle length, but orientation has a comparable effect. Therefore, reliable reconstructions of shoulder breadth can be established using clavicle length, together with consideration of orientation. Relationships between clavicle and thorax morphology are weaker. DISCUSSION: Understanding the determinants of variation in human shoulder structure informs interpretation of skeletal remains. Our investigations describe how important aspects of shoulder structure can be inferred from disarticulated clavicles and we provide the attendant predictive equations. Future work on interspecific variation will improve skeletal reconstruction for more ancient hominins.

Whole-Body CT in Multiple Trauma Patients: Clinically Adapted Usage of Differently Weighted CT Protocols. / Polytrauma-Ganzkörper-CT: Klinisch adaptierter Einsatz unterschiedlich gewichteter CT-Untersuchungsprotokolle.

PURPOSE: Whole-body CT (wbCT) has been established as an internationally accepted diagnostic modality in multiple trauma. Until 2011, a uniform CT scanning protocol was used for all multiple trauma patients (pat.) at our hospital (OLD protocol = OP). In 2011, 2 new differently weighted protocols were introduced: TIME protocol (TP) for hemodynamically unstable pat. and DOSE protocol (DP) for pat. with stable vital parameters. The aim of this study was to compare the original "One-fits-all-concept" with the new, clinically oriented approach to wbCT. MATERIALS AND METHODS: This study retrospectively evaluated 3 distinct wbCT protocols, looking at automatic exposure control variation (AEC; OP/TP) and arm positioning close to the body/overhead (TP/DP). The analysis included waist circumference (WC, cm), injury severity score (ISS), examination time (ET, min), image noise (IN), and effective dose (E, mSv). Normality of distribution was assessed with the Kolmogorov-Smirnov test. Data are given as median and range. Test of significance with Kruskal-Wallis test or Mann-Whitney-U-test. Level of significance: 0.05. RESULTS: 308 pat. were included in the study (77 % m; age: 46 a, 18 - 90 a; WC: 93 cm, 66 - 145 cm). ISS was 14 (OP; n = 104; 0 - 75), 18 (TP; n = 102; 0 - 75) and 9 (DP; n = 102; 0 - 50). ET was 3.9 min (OP; 3.3 - 5.6 min), 4.1 min (TP; 2.8 - 7.2 min) and 7.7 min (DP; 6 - 10 min). IN showed no significant differences when comparing OP/TP but was significantly reduced in DP. For a wbCT (vertex to ischium), E could be reduced from 49.7 mSv to 35.4 mSv by optimizing AEC (OP/TP). Through the overhead repositioning of the arms in DP, a further reduction to 28.2 mSv was achieved. CONCLUSION: AEC and arm repositioning have a crucial influence on image quality and dose. The presented clinical approach is superior to the original concept. KEY POINTS: · The use of 2 differently weighted wbCT protocols allows a more flexible approach to the patient's clinical presentation.. · The clinically adapted concept presented in this study allows trauma care centers to reduce the collective dose.. · Whole-body CT is leading to exposure to relevant radiation doses - further multicenter research is required.. CITATION FORMAT: · Reske SU, Braunschweig R, Reske AW et al. Whole-Body CT in Multiple Trauma Patients: Clinically Adapted Usage of Differently Weighted CT Protocols. Fortschr Röntgenstr 2018; 190: 1141 - 1151.