An Experimental Cold Gas Cannon for the Study of Porcine Lung Contusion and Behind Armor Blunt Trauma

Behind armor blunt trauma (BABT) is a non-penetrating injury caused by the rapid deformation of body armor, by a projectile, which may in extreme circumstances cause death. The understanding of the mechanisms is still low, in relation to what is needed for safety threshold levels. Few models of graded kinetic energy transfer to the body exist. We established an experimental model for graded BABT. The cold gas cannon was air-driven, consisted of a pressure vessel, a barrel, and a pressure actuator. It required short training to operate and was constructed by standard components. It produced standardized expulsion of plastic projectiles with 65 mm and weight 58 g. Velocity correlated linearly to pressure (R 0.9602, p < 0.0001), equation Y = 6.558*X + 46.50. Maximum tested pressure was 10 bar, velocity 110 m/s and kinetic energy (Ek) 351 J. Crossbred male swine (n = 10) mean weight (SD) 56 ± 3 kg, were subjected to BABT, mean Ek (SD) 318 (61) J, to a fix point on the right lateral thorax. Pulmonary contusion was confirmed by physiological parameters pO2 (p < 0.05), SaO2 (p < 0.01), pCO2 (p < 0.01), etCO2 (p < 0.01), MPAP (p < 0.01), Cstat (p < 0.01), intrapulmonary shunt (Q's/Q't) (p < 0.05), and qualified trans-thoracic ultrasound (p < 0.0001). The consistent injury profile enabled for the addition of future experimental interventions.

[Bilateral thoracic trauma-"double the trouble"?]

BACKGROUND

Thoracic trauma is associated with a high morbidity and mortality. Assessing the risk for complications is essential for planning the further treatment strategies and managing resources in thoracic trauma.

OBJECTIVE

The aim of the study was to analyze concomitant injuries in unilateral and bilateral rib fractures and pulmonary contusions and evaluate differences in complication rates between the two.

MATERIAL AND METHODS

In a retrospective study, data from all patients diagnosed with thoracic trauma at a level I trauma center were analyzed. Bivariate and multivariate analysis were used to examine an association of unilateral or bilateral rib fractures, serial rib fractures, and pulmonary contusions with multiple injuries and outcomes. In addition, multivariate regression analysis was utilized to determine the impact of age, gender and additional injuries on outcome.

RESULTS

A total of 714 patients were included in the analysis. The mean Injury Severity Score (ISS) was 19. Patients with an additional thoracic spine injury had a significantly higher incidence of bilateral rib fractures. Pulmonary contusions were associated with younger age. Abdominal injuries were predictors for bilateral pulmonary contusions. Complications occurred in 36% of the patients. Bilateral injuries increased the complication rate up to 70%. Pelvic and abdominal injuries as well as the need for a chest drain were significant risk factors for complications. The mortality rate was 10%, with higher age, head and pelvic injuries as predictors.

CONCLUSION

Patients with bilateral chest trauma had an increased incidence of complications and a higher mortality rate. Bilateral injuries and significant risk factors must therefore be considered. Injury of the thoracic spine should be excluded in those patients.

Pulmonary contusion: automated deep learning-based quantitative visualization

PURPOSE

Rapid automated CT volumetry of pulmonary contusion may predict progression to Acute Respiratory Distress Syndrome (ARDS) and help guide early clinical management in at-risk trauma patients. This study aims to train and validate state-of-the-art deep learning models to quantify pulmonary contusion as a percentage of total lung volume (Lung Contusion Index, or auto-LCI) and assess the relationship between auto-LCI and relevant clinical outcomes.

METHODS

302 adult patients (age ≥ 18) with pulmonary contusion were retrospectively identified from reports between 2016 and 2021. nnU-Net was trained on manual contusion and whole-lung segmentations. Point-of-care candidate variables for multivariate regression included oxygen saturation, heart rate, and systolic blood pressure on admission. Logistic regression was used to assess ARDS risk, and Cox proportional hazards models were used to determine differences in ICU length of stay and mechanical ventilation time.

RESULTS

Mean Volume Similarity Index and mean Dice scores were 0.82 and 0.67. Interclass correlation coefficient and Pearson r between ground-truth and predicted volumes were 0.90 and 0.91. 38 (14%) patients developed ARDS. In bivariate analysis, auto-LCI was associated with ARDS (p < 0.001), ICU admission (p < 0.001), and need for mechanical ventilation (p < 0.001). In multivariate analyses, auto-LCI was associated with ARDS (p = 0.04), longer length of stay in the ICU (p = 0.02) and longer time on mechanical ventilation (p = 0.04). AUC of multivariate regression to predict ARDS using auto-LCI and clinical variables was 0.70 while AUC using auto-LCI alone was 0.68.

CONCLUSION

Increasing auto-LCI values corresponded with increased risk of ARDS, longer ICU admissions, and longer periods of mechanical ventilation.

Development and validation of a pulmonary complications prediction model based on the Yang's index

Background

Blunt chest trauma patients with pulmonary contusion are susceptible to pulmonary complications, and severe cases may develop respiratory failure. Some studies have suggested the extent of pulmonary contusion to be the main predictor of pulmonary complications. However, no simple and effective method to assess the severity of pulmonary contusion has been available yet. A reliable prognostic prediction model would facilitate the identification of high-risk patients, so that early intervention can be given to reduce pulmonary complications; however, no suitable model based on such an assumption has been available yet.

Methods

In this study, a new method for assessing lung contusion by the product of the three dimensions of the lung window on the computed tomography (CT) image was proposed. We conducted a retrospective study on patients with both thoracic trauma and pulmonary contusion admitted to 8 trauma centers in China from January 2014 to June 2020. Using patients from 2 centers with a large number of patients as the training set and patients from the other 6 centers as the validation set, a prediction model for pulmonary complications was established with Yang's index and rib fractures, etc., being the predictors. The pulmonary complications included pulmonary infection and respiratory failure.

Results

This study included 515 patients, among whom 188 developed pulmonary complications, including 92 with respiratory failure. Risk factors contributing to pulmonary complications were identified, and a scoring system and prediction model were constructed. Using the training set, models for adverse outcomes and severe adverse outcomes were developed, and area under the curve (AUC) of 0.852 and 0.788 were achieved in the validation set. In the model performance for predicting pulmonary complications, the positive predictive value of the model is 0.938, the sensitivity of the model is 0.563 and the specificity of the model is 0.958.

Conclusions

The generated indicator, called Yang's index, was proven to be an easy-to-use method for the evaluation of pulmonary contusion severity. The prediction model based on Yang's index could facilitate early identification of patients at risk of pulmonary complications, yet the effectiveness of the model remains to be validated and its performance remains to be improved in further studies with larger sample sizes.

The incidence, clinical characteristics, and outcome of polytrauma patients with the combination of pulmonary contusion, flail chest and upper thoracic spinal injury

BACKGROUND

Chest trauma was the third most common cause of death in polytrauma patients, accounting for 25% of all deaths from traumatic injury. Chest trauma involves in injury to the bony thorax, intrathoracic organs and thoracic medulla. This study aimed to investigate the incidence, clinical characteristics, and outcome of polytrauma patients with pulmonary contusion, flail chest and upper thoracic spinal injury.

METHODS

Patients who met inclusion criteria were divided into groups: Pulmonary contusion group (PC); Pulmonary contusion and flail chest group (PC + FC); Pulmonary contusion and upper thoracic spinal cord injury group (PC + UTSCI); Thoracic trauma triad group (TTT): included patients with flail chest, pulmonary contusion and the upper thoracic spinal cord injury coexisted. Outcomes were determined, including 30-day mortality and 6-month mortality.

RESULTS

A total 84 patients (2.0%) with TTT out of 4176 polytrauma patients presented to Tongji trauma center. There was no difference in mean ISS among PC + FC group, PC + UTSCI group and TTT group. Patients with TTT had a longer ICU stay (21.4 days vs. 7.5 and 6.2; p<0.01), relatively higher 30-day mortality (40.5% vs. 6.0% and 4.3%; p<0.01), and especially higher 6-month mortality (71.4% vs. 6.5%, 13.0%; p<0.01), compared to patients with PC + FC or with PC + UTSCI. The leading causes of death for patients with TTT were ARDS (44.1%) and pulmonary infection (26.5%) during first 30 days after admission. For those patients who died later than 30 days during the 6 months, the predominant underlying cause of death was MOF (53.8%).

CONCLUSIONS

Lethal triad of thoracic trauma (LTTT) were described in this study, which consisting of pulmonary contusion,flail chest and the upper thoracic spine cord injury. Like the classic "lethal triad", there was a synergy between the factors when they coexist, resulting in especially high mortality rates. Polytrauma patients with LTTT were presented relatively high 30-day mortality and 6 months mortality. We should pay much more attention to the patients with LTTT for further minimizing complications and mortality.

Traumatic brain injury in children with thoracic injury: clinical significance and impact on ventilatory management

PURPOSE

This study aims to describe the epidemiology and management of chest trauma in our center, and to compare patterns of mechanical ventilation in patients with or without associated moderate-to-severe traumatic brain injury (TBI).

METHODS

All children admitted to our level-1 trauma center from February 2012 to December 2018 following chest trauma were included in this retrospective study.

RESULTS

A total of 75 patients with a median age of 11 [6-13] years, with thoracic injuries were included. Most patients also had extra-thoracic injuries (n = 71, 95%) and 59 (79%) had TBI. A total of 52 patients (69%) were admitted to intensive care and 31 (41%) were mechanically ventilated. In patients requiring mechanical ventilation, there was no difference in tidal volume or positive end-expiratory pressure in patients with moderate-to-severe TBI when compared with those with no-or-mild TBI. Only one patient developed Acute Respiratory Distress Syndrome. A total of 6 patients (8%) died and all had moderate-to-severe TBI.

CONCLUSION

In this small retrospective series, most patients requiring mechanical ventilation following chest trauma had associated moderate-to-severe TBI. Mechanical ventilation to manage TBI does not seem to be associated with more acute respiratory distress syndrome occurrence.

Contribution of Bone Marrow-Derived Mesenchymal Stem Cells to Healing of Pulmonary Contusion-Created Rats

BACKGROUND

The most common thoracic injury in children, resulting in trauma, is pulmonary contusion (PC). Bone marrow-derived mesenchymal stem cells (BM-MSCs) are used in wound healing and many other diseases. This study aims to examine the effects of BM-MSCs on PC healing in rats.

MATERIALS AND METHODS

A total of 45 male Wistar albino rats were used. Four groups were formed. BM-MSCs were labeled with the green fluorescent protein. PC was observed in the control group. In group II, PC occured and left to spontaneous healing. In group III, PC formed and BM-MSCs were given. In group IV, BM-MSCs were given without PC formation. Subjects were sacrificed 1 week later. Whether there was any difference in terms of BM-MSC involvement and lung injury score was investigated. Statistical analysis was performed using the Statistical Package for Social Sciences (SPSS), version 17.0, software (SPSS Inc., Chicago, IL), and p value of <0.05 was considered statistically significant.

RESULTS

BM-MSCs were collected much more in the lungs in group III than in group IV. Group III had a lower lung injury score value than group II.

CONCLUSION

The greater involvement of the BM-MSCs in the injury site, and further reductions in lung injury score suggest that BM-MSCs are contributing to the healing of the injury. The use of BM-MSCs in risky patients with diffuse PC may be an alternative treatment to conventional methods.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) in a swine model of hemorrhagic shock and blunt thoracic injury

PURPOSE

While resuscitative endovascular balloon occlusion of the aorta (REBOA) is contraindicated in patients with aortic injuries, this technique may benefit poly-trauma patients with less extreme thoracic injuries. The purpose of this study was to characterize the effects of thoracic injury on hemodynamics during REBOA and the changes in pulmonary contusion over time in a swine model.

METHODS

Twelve swine were anesthetized, instrumented, and randomized to receive either a thoracic injury with 5 impacts to the chest or no injury. All animals underwent controlled hemorrhage of 25% blood volume followed by 45 min of Zone 1 REBOA. Animals were then resuscitated with shed blood, observed during a critical care period, and euthanized after 6 h of total experimental time.

RESULTS

There were no differences between the groups at baseline. The only difference after 6 h was a lower hemoglobin in the thoracic trauma group (8.4 ± 0.8 versus 9.4 ± 0.6 g/dL, P = 0.04). The average proximal mean arterial pressures were significantly lower in the thoracic trauma group during aortic occlusion [103 (98-108) versus 117 (115-124) mmHg, P = 0.04]. There were no differences between the pulmonary contusion before REBOA and at the end of the experiment in size (402 ± 263 versus 356 ± 291 mL, P = 0.782) or density (- 406 ± 127 versus - 299 ± 175 HFU, P = 0.256).

CONCLUSIONS

Thoracic trauma blunted the proximal arterial pressure augmentation during REBOA but had minimal impacts on resuscitative outcomes. This initial study indicates that REBOA does not seem to exacerbate pulmonary contusion in swine, but blunt thoracic injuries may attenuate the expected rises in proximal blood pressure during REBOA.

Massive pulmonary haemorrhage due to severe trauma treated with repeated alveolar lavage combined with extracorporeal membrane oxygenation: A case report

BACKGROUND

Massive pulmonary haemorrhage can spoil the entire lung and block the airway in a short period of time due to severe bleeding, which quickly leads to death. Alveolar lavage is an effective method for haemostasis and airway maintenance. However, patients often cannot tolerate alveolar lavage due to severe hypoxia. We used extracorporeal membrane oxygenation (ECMO) to overcome this limitation in a patient with massive pulmonary haemorrhage due to severe trauma and succeeded in saving the life by repeated alveolar lavage.

CASE SUMMARY

A 22-year-old man sustained multiple injuries in a motor vehicle accident and was transferred to our emergency department. On admission, he had a slight cough and a small amount of bloody sputum; computed tomography revealed multiple fractures and mild pulmonary contusion. At 37 h after admission, he developed severe chest tightness, chest pain, dizziness and haemoptysis. His oxygen saturation was 68%. Emergency endotracheal intubation was performed, and a large amount of bloody sputum was suctioned. After transfer to the intensive care unit, he developed refractory hypoxemia and heparin-free venovenous ECMO was initiated. Fibreoptic bronchoscopy revealed diffuse and profuse blood in all bronchopulmonary segment. Bleeding was observed in the trachea and right bronchus, and repeated alveolar lavage was performed. On day 3, the patient’s haemoptysis ceased, and ECMO support was terminated 10 d later. Tracheostomy was performed on day 15, and the patient was weaned from the ventilator on day 21.

CONCLUSION

Alveolar lavage combined with ECMO can control bleeding in trauma-induced massive pulmonary haemorrhage, is safe and can be performed bedside.

[Risk factors for mechanical ventilation in patients with severe multiple trauma]

OBJECTIVE

To eludicate the risk factors of mechanical ventilation and prolonged mechanical ventilation in patients with severe multiple injuries.

METHODS

Consecutive patients with severe multiple injures who were treated in Peking University People's Hospital Trauma Medical Center between December 2016 and December 2019 were enrolled in this restropective chart-review study. According to mechanical ventilation and ventilatory time, the patients were divided into mechanical ventilation (MV) group and non-mechanical ventilation (NMV) groups, prolonged mechanical ventilation (PMV) group and shortened mechanical ventilation (SMV) groups. Clinical data such as gender, age, base excess, mechanism of injury, Glasgow Coma Scale (GCS), abbreviated injury scale (AIS) and injury severity score (ISS) were collected. To indentify the risk factors of mechanical ventilation and prolonged mecha-nical ventilation, univariate and multivariate Logistic analyses were carried out.

RESULTS

In the present study, 112 patients (82 male, 30 female) with severe multiple injuries having a median age of 52 (range: 16-89 years) and a median ISS of 34 (range: 16-66) were enrolled. The primary mechanism of injury was traffic accident injury and falling injury. In the study, 62 and 50 patients were assigned to MV and NMV groups, respectively. Logistic analysis showed that GCS (OR=0.72, 95%CI: 0.53-0.92, P=0.03), base excess (OR=0.56, 95%CI: 0.37-0.88, P=0.002) and multiple rib fracture (OR=1.72, 95%CI: 1.60-2.80, P=0.012) were independent significant risk factors for mechanical ventilation after severe multiple injuries. Within the mechanical ventilation group, 38 and 24 patients were assigned to PMV and SMVgroups, respectively. Compared with the SMV group, the PMV group had a higher ISS and higher rate of severe head trauma. The length of hospital stay of PMV group was longer than that of SMV groups. Meanwhile, the incidence of tracheotomy in PMV group was high.

CONCLUSIONS

GCS, base excess and rib fracture might be independent risk factors for mechanical ventilation. Higher ISS and lower GCS might prolong the ventilatory time and the length of hospital stay. Meanwhile, the incidence of tracheotomy was high in PMV group because of the longer ventilatory time and poor consciousness.

Pulmonary contusion during the COVID-19 pandemic: challenges in diagnosis and treatment

Managing patients with pulmonary contusion safely and effectively during the coronavirus disease 2019 (COVID-19) pandemic is challenging. This retrospective study analyzes the clinical data of 29 consecutive patients with pulmonary contusion, including two with COVID-19, at Tongji Hospital, Wuhan, China, in January and February, 2020. We analyzed the clinical manifestations, laboratory test results, computed tomography (CT) images, treatment, and clinical outcomes. The two patients with pulmonary contusion and COVID-19 had increased leukocyte and neutrophil counts, similar to the patients with pulmonary contusion alone. Interestingly, both these patients had subpleural ground glass opacity on CT images as a typical manifestation of COVID-19. All 29 patients were treated conservatively, including with closed thoracic drainage, instead of with thoracotomy. Six patients died of ARDS or craniocerebral injury, but the others stabilized. During the COVID-19 pandemic, patients with pulmonary contusion should be tested for SARS-CoV-2 and unless critical, thoracotomy should be avoided.

Blunt trauma related chest wall and pulmonary injuries: An overview

Physical traumas are tragic and multifaceted injuries that suddenly threaten life. Although it is the third most common cause of death in all age groups, one out of four trauma patients die due to thoracic injury or its complications. Blunt injuries constitute the majority of chest trauma. This indicates the importance of chest trauma among all traumas. Blunt chest trauma is usually caused by motor vehicle accident, falling from height, blunt instrument injury and physical assault. As a result of chest trauma, many injuries may occur, such as pulmonary injuries, and these require urgent intervention. Chest wall and pulmonary injuries range from rib fractures to flail chest, pneumothorax to hemothorax and pulmonary contusion to tracheobronchial injuries. Following these injuries, patients may present with a simple dyspnea or even respiratory arrest. For such patient, it is important to understand the treatment logic and to take a multidisciplinary approach to treat the pulmonary and chest wall injuries. This is because only 10% of thoracic trauma patients require surgical operation and the remaining 90% can be treated with simple methods such as appropriate airway, oxygen support, maneuvers, volume support and tube thoracostomy. Adequate pain control in chest trauma is sometimes the most basic and best treatment. With definite diagnosis, the morbidity and mortality can be significantly reduced by simple treatment methods.

Pulmonary contusion mimicking COVID-19: A case report

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a major public health emergency with obvious characteristics of human-to-human transmission, and there are infective asymptomatic carriers. Early identification and proper management of patients with COVID-19 are important. Features in chest computed tomography (CT) can facilitate identifying newly infected individuals. However, CT findings of some lung contusions are similar to those of COVID-19, as shown in the present case.

CASE SUMMARY

A 46-year-old woman was admitted to hospital for backache and foot pain caused by a fall injury 1 d before hospitalization. She was suspected of having COVID-19, since there was a confirmed COVID-19 case near her residence. But she had no fever, cough, chest tightness, difficult breathing, nausea, vomiting, or diarrhea, etc. On physical examination, the lower posterior chest of both sides showed dullness on percussion and moist rales at the end of inspiration on auscultation. The white blood cell count and lymphocyte count were 10.88 × 10⁹/L and 1.04 × 10⁹/L, respectively. CT performed on February 7, 2020 revealed that both lungs were scattered with patchy ground-glass opacity. The patient was diagnosed with pulmonary contusion with thoracic spinal fracture (T12), calcaneal fracture, and pelvic fracture. On day 9 after conservative treatment, her condition was alleviated. On review of the chest CT, the previous shadows were significantly reduced.

CONCLUSION

Differential diagnosis of lung contusion and COVID-19 must be emphasized. Both conditions require effective prompt actions, especially COVID-19.

Chest Trauma Scoring Systems for Predicting Respiratory Complications in Isolated Rib Fracture

BACKGROUND

We retrospectively compared chest trauma scoring systems in patients with rib fractures without major extrathoracic injury for predicting respiratory complications. We also evaluated the predictive power according to the presence or absence of pulmonary contusion.

MATERIALS AND METHODS

Data from 177 patients with isolated rib fractures were included (December 2013 to April 2018). The primary outcome was respiratory complications (pneumonia, respiratory failure, or empyema). The Abbreviated Injury Scale (AIS), Thoracic Trauma Severity Score (TTSS), Chest Trauma Score (CTS), Rib Fracture Score (RFS), and RibScore were evaluated using univariate and receiver operating characteristic (ROC) analyses to determine their predictive value for pulmonary complications. We divided patients into two groups according to the presence or absence of pulmonary contusion, and constructed ROC curves for both groups.

RESULTS

Twenty-eight patients (15.8%) had ≥1 respiratory complication, with significantly higher numbers of standard, segmental, and displaced rib fractures as well as significantly higher TTSS, CTS, RFS, and AIS scores. In all patients, the TTSS (0.723, 95% confidence interval [CI] 0.651-0.788) showed the highest area under the ROC curve (AUROC), followed by the CTS, RFS, AIS, and RibScore. In patients with pulmonary contusion, TTSS also showed the highest AUROC (0.704, 95% CI 0.613-0.784). In patients without pulmonary contusion, RFS showed the highest AUROC (0.759, 95% CI 0.630-0.861).

CONCLUSIONS

TTSS was the most useful system for predicting respiratory complications in isolated rib fracture patients with pulmonary contusion. By contrast, RFS was the most useful in patients without pulmonary contusion.

Impact of blunt pulmonary contusion in polytrauma patients with rib fractures

BACKGROUND

We investigated the impact of blunt pulmonary contusion (BPC) in patients with rib fractures.

METHODS

Adult patients with rib fractures caused by blunt mechanisms were enrolled over 3 years at a Level 1 trauma center. BPC was defined according to percentage of lung affected as: moderate (1-19% contusion) or severe (≥20% contusion).

RESULTS

In total, 1448 of the 7238 admitted patients had rib fractures. Of these, 321 (22.2%) had BPC: 236 moderate and 85 severe. Patients with BPC were more likely to be admitted to the ICU (moderate: OR 1.55, 95% CI 1.10-2.19; severe: OR 2.74, 95% CI 1.41-5.32). Significantly increased rates of pneumonia (OR 2.52, 95% CI 1.43-4.90) and empyema (OR 4.80, 95% CI 1.07-21.54) were found for moderate and severe BPC, respectively.

CONCLUSIONS

ICU admission and infectious pulmonary complications were more likely with BPC. The presence of BPC on admission CT is also prognostic of increased resource utilization.

Pulmonary contusions in the elderly after blunt trauma: incidence and outcomes

BACKGROUND

In the general population with blunt chest trauma, pulmonary contusions (PCs) are commonly identified. However, there is limited research in the elderly. We sought to evaluate the incidence and outcomes of PCs in elderly blunt trauma admissions.

METHODS

We retrospectively reviewed the trauma registry at a level I trauma center for all blunt thoracic trauma patients aged ≥65 y, who were admitted between 2007 and 2015. The medical records of PC patients were reviewed.

RESULTS

There were 956 admissions with blunt thoracic trauma; of which 778 had no pulmonary contusion (NO) and 178 had PC. The major mechanisms of injury were falls (58.7% NO, 39.3% PC, P <0.001) and motor vehicle crash/motor cycle crash (35.6% NO, 51.7% PC, P <0.001). Rib fractures were present in 79.8% of PC and 73.8% of NO patients, P = 0.1. PC patients more often had serious (AIS ≥3) head/neck (30.3% versus 20.6%, P <0.001), abdomen (12.4% versus 6.6%, P <0.001), and extremity injuries (20.8% versus 11.4%, P <0.001). Complication (46.1% PC versus 26.6% NO, P <0.001) and mortality (14.0% PC versus 6.2% NO, P = 0.0003) rates were higher in PC patients. On multivariate logistic regression analyses, PC presence was significantly associated with mechanical ventilation (odds ratio 2.5), intensive care unit admission (odds ratio 2.3), and mortality (odds ratio 1.9).

CONCLUSIONS

Over 18.6% of elderly blunt thoracic trauma patients sustained PC, despite an often low energy mechanism of injury. The presence of a PC should prompt investigation for other serious intrathoracic and extrathoracic injuries. PC presence is associated with substantial morbidity and mortality.

Patterns of invasive mechanical ventilation in patients with severe blunt chest trauma and lung contusion: A French multicentric evaluation of practices

Introduction

This study investigated invasive mechanical ventilation modalities used in severe blunt chest trauma patients with pulmonary contusion. Occurrence, risk factors, and outcomes of early onset acute respiratory distress syndrome were also evaluated.

Methods

We performed a retrospective multicenter observational study including 115 adult patients hospitalized in six level 1 trauma intensive care units between April and September of 2014. Independent predictors of early onset acute respiratory distress syndrome were determined by multiple logistic regression analysis based on clinical characteristics and initial management.

Results

Protective ventilation principles were highly implemented, even prophylactically before acute respiratory distress syndrome occurrence. Early onset acute respiratory distress syndrome appeared to be associated with lung contusion of >20% of total lung volume and early onset pneumonia.

Conclusions

Predictors of early onset acute respiratory distress syndrome could help with identifying high-risk populations, potentially improving case management through specific protocol development for these patients.

Thoracic Trauma

Management of chest trauma is integral to patient outcomes owing to the vital structures held within the thoracic cavity. Understanding traumatic chest injuries and appropriate management plays a pivotal role in the overall well-being of both blunt and penetrating trauma patients. Whether the injury includes rib fractures, associated pulmonary injuries, or tracheobronchial tree injuries, every facet of management may impact the short- and long-term outcomes, including mortality. This article elucidates the workup and management of the thoracic cage, pulmonary and tracheobronchial injuries.

Fluid Therapy in Lung Disease

Fluid therapy is the cornerstone of supportive care in veterinary medicine. In dogs and cats with preexisting confirmed or suspected pulmonary disease, concerns may exist that the fluid therapy may impair gas exchange, either through increases in hydrostatic pressures or extravasation. Colloidal therapy is more likely to magnify lung injury compared with isotonic crystalloids. Radiographic evidence of fluid overload is a late-stage finding, whereas point-of-care ultrasound may provide earlier information that can also be assessed periodically at the patient side. Cases should be evaluated individually, but generally a conservative fluid therapy plan is preferred with close monitoring of its tolerance.

The diagnostic value of serum pentraxin 3 levels in pulmonary contusion

PURPOSE

To investigate the difference in pentraxin 3 (PTX 3) levels between patients with pulmonary contusion and healthy volunteers.

MATERIALS AND METHODS

This study was conducted with a group of 20 trauma patients diagnosed with pulmonary contusion and 30 healthy individuals enrolled as a control group in a tertiary university hospital.

RESULTS

Median PTX 3 levels were 7.05 (3.29-13.1), ng/ml in the contusion group and 1.03 (0.7-1.58) ng/ml in the control group. PTX 3 titers were significantly higher in patients with pulmonary contusion compared to those of the control group (p<0.001). An area under the curve (AUC) value of 0.968 investigated using ROC analysis to determine the diagnostic value of the PTX-3 in pulmonary contusion patients was measured. A PTX-3 cut-off value of 2.06 produced 95.5% sensitivity and 86.7% specificity.

CONCLUSION

PTX 3 levels in pulmonary contusion increased significantly compared to the healthy control group. If supported by wider series, PTX 3 may be expected to be capable of use as a marker in pulmonary contusion.

Effects of trauma, hemorrhagic shock, and chronic stress on lung vascular endothelial growth factor

BACKGROUND

Vascular endothelial growth factor (VEGF) and its receptors (VEGFR-1 and VEGFR-2) regulate vascular permeability and endothelial cell survival. We hypothesized that hemorrhagic shock (HS) and chronic stress (CS) would increase expression of lung VEGF and its receptors, potentiating pulmonary edema in lung tissue.

MATERIALS AND METHODS

Male Sprague-Dawley rats aged 8-9 wk were randomized: naïve control, lung contusion (LC), LC followed by HS (LCHS), and LCHS with CS in a restraint cylinder for 2 h/d (LCHS/CS). Animals were sacrificed on days 1 and 7. Expressions of lung VEGF, VEGFR-1, and VEGFR-2 were determined by polymerase chain reaction. Lung Injury Score (LIS) was graded on light microscopy by inflammatory cell counts, interstitial edema, pulmonary edema, and alveolar integrity (range: 0 = normal; 8 = severe injury).

RESULTS

Seven days after LC, lung VEGF and VEGFR-1 were increased, and lung tissue healed (LIS: 0.8 ± 0.8). However, 7 d after LCHS and LCHS/CS, lung VEGF and VEGFR-1 expressions were decreased. VEGFR-2 was also decreased after LCHS/CS. LIS was elevated 7 d after LCHS and LCHS/CS (6.5 ± 1.0 and 8.2 ± 0.8). Increased LIS after LCHS and LCHS/CS was because of higher inflammatory cell counts, increased interstitial edema, and loss of alveolar integrity, whereas pulmonary edema was unchanged.

CONCLUSIONS

Elevation of lung VEGF and VEGFR-1 expressions after LC alone was associated with healing of injured lung tissue. Expressions of VEGF, VEGFR-1, and VEGFR-2 were reduced after LCHS and LCHS/CS, and injured lung tissue did not heal. Persistent lung injury after severe trauma was because of inflammation rather than pulmonary edema.

Pulmonary contusion in the pan-scan era

BACKGROUND

Although pulmonary contusion (PC) is traditionally considered a major injury requiring intensive monitoring, more frequent detection by chest CT in blunt trauma evaluation may diagnose clinically irrelevant PC.

OBJECTIVES

We sought to determine (1) the frequency of PC diagnosis by chest CT versus chest X-ray (CXR), (2) the frequency of PC-associated thoracic injuries, and (3) PC patient clinical outcomes (mortality, length of stay [LOS], and need for mechanical ventilation), considering patients with PC seen on chest CT only (SOCTO) and isolated PC (PC without other thoracic injury).

METHODS

Focusing primarily on patients who had both CXR and chest CT, we conducted a pre-planned analysis of two prospectively enrolled cohorts with the following inclusion criteria: age >14 years, blunt trauma within 24h of emergency department presentation, and receiving CXR or chest CT during trauma evaluation. We defined PC and other thoracic injuries according to CT reports and followed patients through their hospital course to determine clinical outcomes.

RESULTS

Of 21,382 enrolled subjects, 8661 (40.5%) had both CXR and chest CT and 1012 (11.7%) of these had PC, making it the second most common injury after rib fracture. PC was SOCTO in 739 (73.0%). Most (73.5%) PC patients had other thoracic injury. PC patients had higher admission rates (91.9% versus 61.7%; mean difference 30.2%; 95% confidence interval [CI] 28.1-32.1%) and mortality (4.7% versus 2.0%: mean difference 2.8%; 95% CI 1.6-4.3%) than non-PC patients, but mortality was restricted to patients with other injuries (injury severity scores>10). Patients with PC SOCTO had low rates of associated mechanical ventilation (4.6%) and patients with isolated PC SOCTO had low mortality (2.6%), comparable to that of patients without PC.

CONCLUSIONS

PC is commonly diagnosed under current blunt trauma imaging protocols and most PC are SOCTO with other thoracic injury. Given that they are associated with low mortality and uncommon need for mechanical ventilation, isolated PC and PC SOCTO may be of limited clinical significance.

Thoracic Trauma Severity score on admission allows to determine the risk of delayed ARDS in trauma patients with pulmonary contusion

BACKGROUND

Pulmonary contusion is a major risk factor of acute respiratory distress syndrome (ARDS) in trauma patients. As this complication may appear after a free interval of 24-48 h, detection of patients at risk is essential. The main objective of this study was to assess the performance of the Thoracic Trauma Severity (TTS) score upon admission in predicting delayed ARDS in blunt trauma patients with pulmonary contusion.

METHODS

All blunt thoracic trauma patients admitted consecutively to our trauma centre between January 2005 and December 2009 were retrospectively included if they presented a pulmonary contusion on the admission chest computed tomography scan. Main outcome measure was the presence of moderate or severe ARDS (PaO2/FiO2 ratio≤200) for 48 h or more. The global ability of the TTS score to predict ARDS was studied by ROC curves with a threshold analysis using a grey zone approach.

RESULTS

Of 329 patients studied (75% men, mean age 36.9 years [SD 17.8 years], mean Injury Severity Score 21.7 [SD 16.0]), 82 (25%) presented with ARDS (mean lowest PaO2/FiO2 ratio of 131 [SD 34]). The area under the ROC curves for the TTS score in predicting ARDS was 0.82 (95% CI 0.78-0.86) in the overall population. TTS scores between 8 and 12 belonged to the inconclusive grey zone. A TTS score of 13-25 was found to be independent risk factors of ARDS (OR 25.8 [95% CI 6.7-99.6] P<0.001).

CONCLUSIONS

An extreme TTS score on admission accurately predicts the occurrence of delayed ARDS in blunt thoracic trauma patients affected by pulmonary contusion. This simple score could guide early decision making and management for a non-negligible proportion of this specific population.

Trauma-associated pneumonia: time to redefine ventilator-associated pneumonia in trauma patients

BACKGROUND

The high prevalence of ventilator-associated pneumonia (VAP) in trauma patients has been reported in the literature, but the reasons for this observation remain unclear. We hypothesize that trauma factors play critical roles in VAP etiology.

METHODS

In this retrospective study, 1,044 ventilated trauma patients were identified from December 2010 to December 2013. Patient-level trauma factors were used to predict pneumonia as study endpoint.

RESULTS

Ninety-five of the 1,044 ventilated trauma patients developed pneumonia. Rib fractures, pulmonary contusion, and failed prehospital intubation were significant predictors of pneumonia in a multivariate model.

CONCLUSIONS

It is time to redefine VAP in trauma patients based on the effect of rib fractures, pulmonary contusions, and failed prehospital intubations. The Centers for Disease Control and Prevention definition of VAP needs to be modified to reflect the effect of trauma factors in the etiology of trauma-associated pneumonia.

Effects of sphingosylphosphorylcholine against oxidative stress and acute lung ınjury ınduced by pulmonary contusion in rats

BACKGROUND/PURPOSE

The goal of this study was to evaluate effects of exogenous sphingosylphosphorylcholine (SPC) administration on acute lung injury induced by pulmonary contusion in rats.

METHODS

Eight animals were included in each of the following five groups: control, contusion, contusion phosphate-buffered solution (PBS), contusion SPC 2, contusion SPC 10. SPC was administered 3 days at a daily two different doses of 2 μm/ml and 10 μm/ml intraperitoneally. The severity of lung injury was determined by the neutrophil activation and histological and immunohistochemical changes in the lung. Malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione (GSH) were determined to evaluate the oxidative status in the lung tissue.

RESULTS

Treatment with 2 μM SPC inhibited the increase in lung MDA and NO levels significantly and also attenuated the depletion of SOD, GPx, and GSH in the lung injury induced by pulmonary contusion. These data were supported by histopathological findings. The inducible nitric oxide synthase (iNOS) positive cells and apoptotic cells in the lung tissue were observed to be reduced with the 2 μM SPC treatment. But, the 10 μM SPC treatment did not provide similar effects.

CONCLUSIONS

In conclusion, these findings suggested that 2 μM SPC can attenuate lung damage in pulmonary contusion by prevention of oxidative stress, inflammatory process and apoptosis. All these findings suggest that low dose SPC may be a promising new therapeutic agent for acute lung injury.

Noninvasive ventilation in trauma

Trauma patients are a diverse population with heterogeneous needs for ventilatory support. This requirement depends mainly on the severity of their ventilatory dysfunction, degree of deterioration in gaseous exchange, any associated injuries, and the individual feasibility of potentially using a noninvasive ventilation approach. Noninvasive ventilation may reduce the need to intubate patients with trauma-related hypoxemia. It is well-known that these patients are at increased risk to develop hypoxemic respiratory failure which may or may not be associated with hypercapnia. Hypoxemia in these patients is due to ventilation perfusion mismatching and right to left shunt because of lung contusion, atelectasis, an inability to clear secretions as well as pneumothorax and/or hemothorax, all of which are common in trauma patients. Noninvasive ventilation has been tried in these patients in order to avoid the complications related to endotracheal intubation, mainly ventilator-associated pneumonia. The potential usefulness of noninvasive ventilation in the ventilatory management of trauma patients, though reported in various studies, has not been sufficiently investigated on a large scale. According to the British Thoracic Society guidelines, the indications and efficacy of noninvasive ventilation treatment in respiratory distress induced by trauma have thus far been inconsistent and merely received a low grade recommendation. In this review paper, we analyse and compare the results of various studies in which noninvasive ventilation was applied and discuss the role and efficacy of this ventilator modality in trauma.

Lung Contusion: A Clinico-Pathological Entity with Unpredictable Clinical Course

Lung contusion is an entity involving injury to the alveolar capillaries, without any tear or cut in the lung tissue. This results in accumulation of blood and other fluids within the lung tissue. The excess fluid interferes with gas exchange leading to hypoxia. The pathophysiology of lung contusion includes ventilation/perfusion mismatching, increased intrapulmonary shunting, increased lung water, segmental lung damage, and a loss of compliance. Clinically, patient's presents with hypoxiemia, hypercarbia and increase in laboured breathing. Patients are treated with supplemental oxygen and mechanical ventilation whenever indicated. Treatment is primarily supportive. Computed tomography (CT) is very sensitive for diagnosing pulmonary contusion. Pulmonary contusion occurs in 25-35% of all blunt chest traumas.

Initial assessment of chest X-ray in thoracic trauma patients: Awareness of specific injuries

AIM: To compare the reported injuries on initial assessment of the chest X-ray (CXR) in thoracic trauma patients to a second read performed by a dedicated trauma radiologist.

METHODS: By retrospective analysis of a prospective database, 712 patients with an injury to the chest admitted to the University Medical Center Utrecht were studied. All patients with a CXR were included in the study. Every CXR was re-evaluated by a trauma radiologist, who was blinded for the initial results. The findings of the trauma radiologist regarding rib fractures, pneumothoraces, hemothoraces and lung contusions were compared with the initial reports from the trauma team, derived from the original patient files.

RESULTS: A total of 516 patients with both thorax trauma and an initial CXR were included in the study. After re-evaluation of the initial CXR significantly more lung contusions (53.3% vs 34.1%, P < 0.001), hemothoraces (17.8% vs 11.0%, P < 0.001) and pneumothoraces (34.4% vs 26.4%, P < 0.001) were detected. During initial assessment significantly more rib fractures were reported (69.8% vs 62.3%, P < 0.001).

CONCLUSION: During the initial assessment of a CXR from trauma patients in the emergency department, a significant number of treatment-dictating injuries are missed. More awareness for these specific injuries is needed.

Expression patterns of plasma von Willebrand factor and serum interleukin-8 in patients with early-stage severe pulmonary contusion

BACKGROUND

von Willebrand factor (vWF) is only released from endothelial cells and platelets and is an in vivo and in vitro marker of endothelial injury in septic patients with acute lung injury (ALI). Interleukin-8 (IL-8), as a proinflammatory mediator causing recruitment of inflammatory cells, induces an increase in oxidant stress mediators and makes it as a key parameter for localized inflammation. However, it has not been well established whether the level of serum IL-8 is associated with the severity of lung injury and whether it is a prognosis marker for severe lung contusion. This study was to investigate the expression of plasma vWF and IL-8 and their association with the severity and outcomes of severe pulmonary contusion.

METHODS

A total of 63 patients were divided into a severe pulmonary contusion with acute respiratory distress syndrome (ARDS) group and a non-ARDS group, or a survivor group and a non-survivor group, or an injury severity score (ISS) <20 group and an ISS ≥20 group. Another 20 healthy volunteers served as controls. The levels of plasma vWF and serum IL-8 were measured by enzyme-linked immunosorbent assay (ELISA) at 1, 3, 5 and 7 days after injury. The expression patterns of the plasma vWF and serum IL-8 were compared between different groups.

RESULTS

The concentrations of plasma vWF and serum IL-8 were significantly increased in all severe pulmonary contusion patients at all time points in comparison with the control group. The concentrations of plasma vWF in patients with ARDS increased during the whole study period, but vWF in patients with non-ARDS increased gradually until day 5 and then decreased at day 7. The concentration of serum IL-8 showed a similar expression pattern in both groups, but the expression increased more significantly in the ARDS group than in the non-ARDS group. Interestingly, both plasma vWF and serum IL-8 levels steadily increased in the non-survivor group. Furthermore, the level of plasma vWF was higher in the ISS≥20 group than in the ISS<20 group. The level of serum IL-8 in the ISS≥20 group was consistently high, while that in the ISS<20 group peaked at day 3 and decreased at day 5. In addition, the level of plasma vWF was positively correlated with platelet count, but negatively correlated with oxygen index. The level of serum IL-8 was positively correlated with white blood cell count and ISS score, and inversely correlated with oxygen index.

CONCLUSION

The elevated levels of plasma vWF and serum IL-8 in severe pulmonary contusion patients reflect the severity of pulmonary injury and patients outcomes, suggesting that the plasma vWF and serum IL-8 are sensitive markers for clinical evaluation of the severity of pulmonary injury and predication of patient prognosis.