Pulmonary contusions after blunt chest trauma: clinical significance and evaluation of patient management

Classification methods of pulmonary contusion based on chest CT and the association with in-hospital outcomes: a systematic review of literature

INTRODUCTION

Patients sustaining pulmonary contusion (PC) have a higher risk of complications and long-term respiratory difficulty. Computed tomography (CT) scans have a high sensitivity for PC. However, since PC develops over time, CT scans made directly post-trauma may underestimate the full extent of PC. This creates a need to better define in which PC-patients complications are more likely. The aim of this systematic review was to identify different classification systems of PC, and investigate the association between amount of PC and in-hospital outcomes.

METHODS

A systematic review was conducted in accordance with PRISMA guidelines. Studies reporting a classification system for PC after blunt thoracic trauma based on a CT scan were included. Outcomes were classification method of PC and the relation between classification and pulmonary complications and in-hospital outcomes.

RESULTS

Twenty studies were included. Total number of patients ranged from 49 to 148,140 patients. The most common classification system used was calculating the percentage of contused lung volume. Other classification methods were based on Blunt Pulmonary Contusion score-6 and -18, Abbreviated Injury Score and Thoracic Trauma Severity scores. Worse outcomes were generally associated with between > 18 to > 24% contusion volume.

DISCUSSION

The heterogeneity of currently available literature makes comparing classification methods challenging. The most common classification of PC was based on volumetric analysis. Calculating a percentage of PC as part of the total volume allows for the highest level of segmentation of lung parenchyma as compared to using BPC-6, BPC-18, or AIS. Contusion volume exceeding 18-24% was generally associated with worse outcomes.

Ultrasonography in thoracic and abdominal stab wound injury: results from the FETTHA study

BACKGROUND

While the role of Extended Focused Assessment with Sonography in Trauma (eFAST) is well defined in the management of severe blunt trauma, its performance in injuries caused by stab wounds has been poorly assessed.

METHODS

Prospective single centre study which included all patients with stab wounds to the thorax or abdomen between December 2016 and December 2018. All patients underwent initial investigation with both eFAST and CT scan, except in cases of haemodynamic or respiratory instability, and in cases with a positive diagnosis by eFAST in which case surgery without CT scan was performed.

RESULTS

Of the 200 consecutive patients included, 14 unstable patients underwent surgery immediately after eFAST. In these 14 patients, 9 had cardiac tamponade identified by eFAST and all were confirmed by surgery. In the remaining 186 patients, the median time between eFAST and CT scan was 30 min (IQR 20-49 min). Test characteristics (including 95% CI) for eFAST compared with reference standard of CT scan for detecting pneumothorax were as follows: sensitivity 77% (54%-92%), specificity 93% (90%-97%), positive predictive value (PPV) 60% (49%-83%), negative predictive value (NPV) 97% (93%-99%). Test characteristics (including 95% CI) for eFAST compared with CT scan for detecting haemothorax were as follows: sensitivity 97% (74%-99%), specificity 96% (92%-98%), PPV 83% (63%-93%) and NPV 99% (96%-100%). Finally, test characteristics (including 95% CI) for eFAST compared with CT scan for detecting haemoperitoneum were as follows: sensitivity 75% (35%-97%), specificity 97% (93%-99%), PPV 55% (23%-83%) and NPV 99% (96%-99%).

CONCLUSIONS

In patients admitted with stab wounds to the torso, eFAST was not sensitive enough to diagnose pneumothorax and haemoperitoneum, but performed better in the detection of cardiac tamponade and haemothorax than the other injuries. More robust multicentre studies are needed to better define the role of eFAST in this specific population.

Watch Out for the Early Killers: Imaging Diagnosis of Thoracic Trauma

Radiologists and trauma surgeons should monitor for early killers among patients with thoracic trauma, such as tension pneumothorax, tracheobronchial injuries, flail chest, aortic injury, mediastinal hematomas, and severe pulmonary parenchymal injury. With the advent of cutting-edge technology, rapid volumetric computed tomography of the chest has become the most definitive diagnostic tool for establishing or excluding thoracic trauma. With the notion of "time is life" at emergency settings, radiologists must find ways to shorten the turnaround time of reports. One way to interpret chest findings is to use a systemic approach, as advocated in this study. Our interpretation of chest findings for thoracic trauma follows the acronym "ABC-Please" in which "A" stands for abnormal air, "B" stands for abnormal bones, "C" stands for abnormal cardiovascular system, and "P" in "Please" stands for abnormal pulmonary parenchyma and vessels. In the future, utilizing an artificial intelligence software can be an alternative, which can highlight significant findings as "warm zones" on the heatmap and can re-prioritize important examinations at the top of the reading list for radiologists to expedite the final reports.

Severe non-cardiovascular thoracic trauma: diagnostic clues on computed tomography

OBJECTIVE

About 60% of multiple trauma patients have thoracic trauma, and thoracic trauma results in the death of 10% of these patients. Computed tomography (CT) is the most sensitive and specific imaging modality for the diagnosis of acute disease, and it helps in the management and prognostic evaluation of patients with high-impact trauma. This paper aims to show the practical points that are key for diagnosing severe non-cardiovascular thoracic trauma by CT.

CONCLUSION

Knowing the key features of severe acute thoracic trauma on CT is crucial to avoid diagnostic errors. Radiologists play a fundamental role in the accurate early diagnosis of severe non-cardiovascular thoracic trauma, because the patient's management and outcome will depend largely on the imaging findings.

Imaging findings of pulmonary contusions on multidetector CT: A retrospective study comparing adults and children

To describe imaging findings of pulmonary contusions (PC) in adults and children using multidetector computed tomography (CT) scanners. We conducted a retrospective single center study. All chest multidetector computed tomography (MDCT) scans of victims of blunt trauma admitted to the emergency unit of a reference trauma center of Brazil between January 2015 and December 2016 were reviewed in search of opacities compatible with PC. The CT images were analyzed in conjunction with medical records, that provided demographic and clinical data. The obtained data were analyzed in the overall population and comparing children and adults. Significant P value was defined as <.05. 52.7% of patients presented bilateral opacities. Middle third, posterior and peripheral portions of the lungs were more frequently affected, in the craniocaudal, anteroposterior and axial axes, respectively. A vast majority of patients (80.6%) presented multiple opacities, whereas a minority showed subpleural sparing (26.9%) and fissure crossing (22.6%), with similar frequencies in children and adults. Children, although, more frequently presented consolidation and more diffuse lesions in the anteroposterior axis compared to adults, with statistically significant differences. PC usually are multiple and predominate in middle, posterior and peripheral portions of the lungs. Subpleural sparing and fissure crossing seems to be infrequent and have similar frequencies between children and adults. Although, there are differences between these age groups, as younger people tend to have more consolidation and diffuse opacities in the anteroposterior axis than older ones.

Blunt thoracic trauma: role of chest radiography and comparison with CT - findings and literature review

In the setting of acute trauma where identification of critical injuries is time-sensitive, a portable chest radiograph is broadly accepted as an initial diagnostic test for identifying benign and life-threatening pathologies and guiding further imaging and interventions. This article describes chest radiographic findings associated with various injuries resulting from blunt chest trauma and compares the efficacy of the chest radiograph in these settings with computed tomography (CT). Common chest radiographic findings in blunt thoracic injuries will be reviewed to improve radiologic identification, expedite management, and improve trauma morbidity and mortality. This article discusses demographic information, mechanism of specific injuries, common imaging findings, imaging pearls, and pitfalls and exhibits several classic imaging findings in blunt chest trauma. Thoracic structures commonly injured in blunt trauma that will be discussed in this article include vasculature structures (aortic trauma), the heart (cardiac contusion, pericardial effusion), the esophagus (esophageal perforation), pleural space and airways (pneumothorax, hemothorax, bronchial injury), lungs (pulmonary contusion), the diaphragm (diaphragmatic rupture), and the chest wall (flail chest). Chest radiography plays an important role in the initial evaluation of blunt chest trauma. While CT imaging has a higher sensitivity than chest radiography, it remains a valuable tool due to its ability to provide rapid diagnostic information in time-sensitive trauma situations and is ubiquitously available in the trauma bay. Familiarity with the gamut of injuries that may occur as well as identification of the associated chest radiograph findings can aid in timely diagnoses and prompt management in the setting of acute blunt chest trauma.

Scalable Deep Learning Algorithm to Compute Percent Pulmonary Contusion among Patients with Rib Fractures

BACKGROUND

Pulmonary contusion exists along a spectrum of severity, yet is commonly binarily classified as present or absent. We aimed to develop a deep learning algorithm to automate percent pulmonary contusion computation and exemplify how transfer learning could facilitate large-scale validation. We hypothesized our deep learning algorithm could automate percent pulmonary contusion computation and that greater percent contusion would be associated with higher odds of adverse inpatient outcomes among patients with rib fractures.

METHODS

We evaluated admission-day chest computed tomography (CT) scans of adults aged ≥18 years admitted to our institution with multiple rib fractures and pulmonary contusions (2010-2020). We adapted a pre-trained convolutional neural network that segments 3-dimensional lung volumes and segmented contused lung parenchyma, pulmonary blood vessels, and computed percent pulmonary contusion. Exploratory analysis evaluated associations between percent pulmonary contusion (quartiles) and odds of mechanical ventilation, mortality, and prolonged hospital length-of-stay using multivariable logistic regression. Sensitivity analysis included pulmonary blood vessel volumes during percent contusion computation.

RESULTS

A total of 332 patients met inclusion criteria (median 5 rib fractures), among whom 28% underwent mechanical ventilation and 6% died. The study population's median (IQR) percent pulmonary contusion was 4(2-8)%. Compared to the lowest quartile of percent pulmonary contusion, each increasing quartile was associated with higher adjusted odds of undergoing mechanical ventilation (OR[95%CI]: 1.5[1.1-2.1]) and prolonged hospitalization (OR[95%CI]: 1.6[1.1-2.2]), but not with mortality (OR[95%CI]: 1.1 [0.6-2.0]. Findings were similar on sensitivity analysis.

CONCLUSION

We developed a scalable deep learning algorithm to automate percent pulmonary contusion calculating using chest CTs of adults admitted with rib fractures. Open code sharing and collaborative research is needed to validate our algorithm and exploratory analysis at large scale. Transfer learning can help harness the full potential of big data and high-performing algorithms to bring precision medicine to the bedside.

LEVEL OF EVIDENCE

IV.

Imaging Manifestations of Chest Trauma

Trauma is the leading cause of death among individuals under 40 years of age, and pulmonary trauma is common in high-impact injuries. Unlike most other organs, the lung is elastic and distensible, with a physiologic capacity to withstand significant changes in contour and volume. The most common types of lung parenchymal injury are contusions, lacerations, and hematomas, each having characteristic imaging appearances. A less common type of lung injury is herniation. Chest radiography is often the first-line imaging modality performed in the assessment of the acutely injured patient, although there are inherent limitations in the use of this modality in trauma. CT images are more accurate for the assessment of the nature and extent of pulmonary injury than the single-view anteroposterior chest radiograph that is typically obtained in the trauma bay. However, the primary limitations of CT concern the need to transport the patient to the CT scanner and a longer processing time. The American Association for the Surgery of Trauma has established the most widely used grading scale to describe lung injury, which serves to communicate severity, guide management, and provide useful prognostic factors in a systematic fashion. The authors provide an in-depth exploration of the most common types of pulmonary parenchymal, pleural, and airway injuries. Injury grading, patient management, and potential complications of pulmonary injury are also discussed. ^©RSNA, 2021.

Evaluation of Lung Contusion, Associated Injuries, and Outcome in a Major Trauma Center in Shiraz, Southern Iran

Objective

Blunt chest trauma as one of the most common injuries in trauma cases can cause significant morbidity and mortality. The purpose of this study was to determine the clinical course of traumatic injuries with an initial diagnosis of a pulmonary contusion in patients.

Method

In this retrospective study, we evaluated the demographic and clinical features of patients who were referred to a major trauma center in southern Iran. In our study, patients were enrolled with the diagnosis of pulmonary contusion. All included patients were above 16 years of age, with an initial CT scan in favor of pulmonary contusion, while patients not being hospitalized for more than 48 hours were excluded from the study.

Results

Among the 434 patients included in our study, 366 (84%) were male and the mean age was 41.17 (SD = 17.89). Among them, the majority (80.4%) had right side lung contusion and 47 patients (10.8%) had right rib fracture. The most common injuries were head and neck injury (56.9%) and limbs (30%). In 25% of cases, pulmonary contusion was associated with pneumothorax and 15.8% with hemothorax. Also, 49.6% of patients were transferred to the ICU. The mortality rate in our study was 15.2% (n = 66).

Conclusion

Although recent advances in pulmonary care and ventilator management have been achieved, there is still considerable morbidity and mortality associated with this condition. Therefore, there is a need to provide a national guideline based on native patient information for better management.

Noninvasive ventilation with a helmet in patients with acute respiratory failure caused by chest trauma: a randomized controlled trial

Noninvasive ventilation (NIV) is beneficial in acute respiratory failure (ARF) caused by chest trauma; however, NIV-related complications affect the efficacy. We evaluated whether NIV with helmet decreases the incidence of complications and improves its effects in a single center. Patients with ARF after chest trauma were randomized to receive NIV with helmet or face mask. The primary outcome was the rate of NIV-related complications. Secondary outcomes were PaO₂/FiO₂, patient’s tolerance, intubation rate, length of intensive care unit (ICU) stay, and ICU mortality. The trial was terminated early after an interim analysis with 59 patients. The incidence of complications was lower in the helmet group [10% (3/29) vs 43% (13/30), P = 0.004], and PaO₂/FiO₂s were higher at 1 h and at the end of NIV (253.14 ± 64.74 mmHg vs 216.06 ± 43.86 mmHg, 277.07 ± 84.89 mmHg vs 225.81 ± 63.64 mmHg, P = 0.013 and 0.012) compared with them in face mask group. More patients reported excellent tolerance of the helmet vs face mask after 4 h of NIV [83% (24/29) vs 47% (14/30), P = 0.004] and at the end of NIV [69% (20/29) vs 30% (9/30), P = 0.03]. Differences in intubation rate, ICU stay, and mortality were non-significant (P = 0.612, 0.100, 1.000, respectively). NIV with helmet decreased NIV-related complications, increased PaO₂/FiO₂, and improved tolerance compared with NIV with face mask in patients with chest trauma.

Trial registration: Registered in the Chinese Clinical Trial Registry (ChiCTR1900025915), a WHO International Clinical Trials Registry Platform (http://www.chictr.org.cn/searchprojen.aspx).

IL-17 is a potential biomarker for predicting the severity and outcomes of pulmonary contusion in trauma patients

Pulmonary contusion (PC) is very common in blunt chest trauma, and always results in negative pulmonary outcomes, such as pneumonia, acute respiratory distress syndrome (ARDS), respiratory failure or even death. However, there are no effective biomarkers which can be used to predict the outcomes in these patients. The present study aimed to determine the value of interleukin (IL)-17 and IL-22 in predicting the severity and outcomes of PC in trauma patients. All trauma patients admitted to The First Affiliated Hospital of Guangxi Medical University between January 2015 and December 2017, were studied. Patients aged >14 years old with a diagnosis of PC upon their admission to the emergency department were included. Patients with PC were enrolled as the PC group, patients without PC were enrolled as the non-PC group, and healthy individuals were selected as the control group. Clinical information, including sociodemographic parameters, clinical data, biological findings and therapeutic interventions were recorded for all patients who were enrolled. Blood samples were collected and stored according to the established protocols. PC volume was measured by computed tomography and plasma cytokine levels were assayed by ELISA. A total of 151 patients with PC (PC group) and 159 patients without PC (non-PC group) were included in the present study. In addition, 50 healthy individuals were used as the control group. The primary cause of PC was motor vehicle crashes. PC patients had more rib fractures, but similar injury severity scores compared with other patients. More patients received Pleurocan drainage treatment and had pneumonia complications in the PC group compared with the other two groups. PC patients had a high incidence of ARDS and admission to the intensive care unit (ICU). PC patients also experienced longer periods on mechanical ventilation and had longer stays in the ICU and hospital. PC volume was effective in predicting the outcomes of PC patients. IL-22 levels were similar in the PC group and non-PC group. However, IL-17 could be used as a biomarker to predict the severity of PC, and was strongly associated with PC volume. IL-17 was significantly associated with pro-inflammatory complications in PC patients and could be used as a biomarker for predicting in-patient outcomes of patients with PC. In conclusion, IL-17 is a potential biomarker for predicting the severity and outcomes of PC in trauma patients.

Simulated Mass Casualty Incident Triage Exercise for Training Medical Personnel

Audience

The target audience is any medical professional who requires training in mass casualty incident (MCI) triage. This could apply to pre-hospital specialists, nurses, medical students, residents, and physicians.

Introduction

Emergency medicine specialists must be able to triage patients quickly, especially in an MCI scenario. The simple triage and rapid treatment (START) system allows providers to categorize patients according to the urgency with which patients must access limited resources. Providers should be comfortable utilizing the START triage system before an MCI or disaster so that they can be prepared to implement it if necessary. This exercise uses simulation and gamification as instructional strategies to encourage knowledge of and comfort with the START triage system for emergency providers.

Educational Objectives

By the end of this exercise, learners should be able to (1) recite the basic START patient categories (2) discuss the physical exam signs associated with each START category, (3) assign roles to medical providers in a mass casualty scenario, (4) accurately categorize patients into triage categories: green, yellow, red, and black, and (5) manage limited resources when demand exceeds availability.

Educational Methods

Gamification is the use of elements of game design in non-game contexts.1 Gamification was implemented in this scenario by assigning participants to roles and teams, while creating an engaging, fun, and competitive environment. The exercise also uses low fidelity simulation (without simulation equipment) to encourage learners to practice using the START triage system in a low stakes environment.2 It is possible for the learners to be divided into two groups that each have the same patients, resources, and objectives. The team that finishes triaging all patients first would be declared the winner. However, in our implementation, we completed the exercise as a single group of learners and patients.

Research Methods

Learners were given a survey at the end of implementation and also given the opportunity to discuss feedback with the instructors in a group discussion after completing the exercise. There was no formal assessment completed after the exercise.

Results

Informal feedback was collected at the end of the exercise. Residents and medical students all enjoyed the experience. The feedback was overwhelmingly positive. All participants providing feedback stated they would enjoy participating in the exercise again and suggested that it is implemented annually for review of triage topics. We also received informal feedback for suggested changes which we will discuss in this article. An optional, anonymous survey was given to participants at the end of the exercise. There were six responses. Of those surveyed, 100% of participants stated the effectiveness and value of the exercise was outstanding (a rating of five on a scale of one to five). Regarding the quality of the exercise, and whether the participants felt engaged, 100% of responses gave a rating of five. When asked to consider the relevance of the session, 100% of participants selected a score of five ("I loved this session"). Regarding whether the content was applicable to practice of emergency medicine, 80% of respondents stated the session was highly relevant and 20% of responses selected a score of mostly relevant. One question asked for points of improvement for the session to which there were no responses.

Discussion

Learners were assigned roles in the exercise by the incident commander, fulfilling objective three. The START categories were discussed at the beginning of the exercise by the lead proctor (using PowerPoint) and then utilized throughout the exercise, thus accomplishing objectives one and two. The residents/students filling the triage roles were primarily responsible for fulfilling objective four; however, all participants assisted in categorization of patients throughout the exercise. Finally, objective five was addressed through the various social situations and complications that can be implemented during the exercise. We chose not to implement the additional "radiation contamination" scenario (details available in the article text) due to time constraints; however, this is an additional option to address objective five. The implementation was effective based on informal feedback from participants and proctors as well as evidenced by the responses to the anonymous survey. Learners found the aspects of resource management, review of START triage, repetition of the START triage system, and medical management of various types of trauma informative and meaningful. We received valuable feedback from both learners and proctors, which we will discuss in this article.

Topics

Mass casualty incident, disaster, START, gamification, simulation, emergency medicine, triage, triage category, contamination, teamwork, trauma, projectile trauma, penetrating injury, blunt trauma, intracranial hemorrhage, fracture, trauma in pregnancy, active shooter, radiation, radio communication.

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.