Conservative Management in Traumatic Pneumothoraces: An Observational Study

Using chest X-ray to predict tube thoracostomy in traumatic pneumothorax: A single-institution retrospective review

BACKGROUND

Traumatic pneumothorax (PTX) is a common occurrence in thoracic trauma patients, with a majority requiring tube thoracostomy (TT) for management. Recently, the "35-mm" rule has advocated for observation of patients with PTX less than 35 mm on chest computed tomography (CT) scan. This rule has not been examined in chest x-ray (CXR). We hypothesize that a similar size cutoff can be determined in CXR predictive of need for tube thoracostomy.

METHODS

We performed a single-institution retrospective review of patients with traumatic PTX from 2018 to 2022, excluding those who underwent TT prior to CXR. Primary outcomes were size of pneumothorax on CXR and need for TT; secondary outcome was failed observation, defined as TT more than 4 hours after presentation. To determine the size cutoff on CXR to predict TT need, area under the receiver operating curve (AUROC) analyses were performed and Youden's index calculated (significance at p < 0.05). Predictors of failure were calculated using logistic regression.

RESULTS

There were 341 pneumothoraces in 304 patients (94.4% blunt trauma, median injury severity score 14). Of these, 82 (24.0%) had a TT placed within the first 4 hours. Fifty-five of observed patients (21.2%) failed, and these patients had a larger PTX on CXR (8.6 mm [5.0-18.0 mm] vs. 0.0 mm [0.0-2.3 mm] ( p < 0.001)). Chest x-ray PTX size correlated moderately with CT size (r = 0.31, p < 0.001) and was highly predictive of need for TT insertion (AUC 0.75, p < 0.0001), with an optimal size cutoff predicting TT need of 38 mm.

CONCLUSION

Chest x-ray imaging size was predictive of need for TT, with an optimal size cutoff on CXR of 38 mm, approaching the "35-mm rule." In addition to size, failed observation was predicted by presenting lactic acidosis and need for supplemental oxygen. This demonstrates this cutoff should be considered for prospective study in CXR.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level IV.

Conservative management versus invasive management of significant traumatic pneumothoraces in the emergency department (the CoMiTED trial): a study protocol for a randomised non-inferiority trial

INTRODUCTION

Traumatic pneumothoraces are present in one of five victims of severe trauma. Current guidelines advise chest drain insertion for most traumatic pneumothoraces, although very small pneumothoraces can be managed with observation at the treating clinician's discretion. There remains a large proportion of patients in whom there is clinical uncertainty as to whether an immediate chest drain is required, with no robust evidence to inform practice. Chest drains carry a high risk of complications such as bleeding and infection. The default to invasive treatment may be causing potentially avoidable pain, distress and complications. We are evaluating the clinical and cost-effectiveness of an initial conservative approach to the management of patients with traumatic pneumothoraces.

METHODS AND ANALYSIS

The CoMiTED (Conservative Management in Traumatic Pneumothoraces in the Emergency Department) trial is a multicentre, pragmatic parallel group, individually randomised controlled non-inferiority trial to establish whether initial conservative management of significant traumatic pneumothoraces is non-inferior to invasive management in terms of subsequent emergency pleural interventions, complications, pain, breathlessness and quality of life. We aim to recruit 750 patients from at least 40 UK National Health Service hospitals. Patients allocated to the control (invasive management) group will have a chest drain inserted in the emergency department. For those in the intervention (initial conservative management) group, the treating clinician will be advised to manage the participant without chest drain insertion and undertake observation. The primary outcome is a binary measure of the need for one or more subsequent emergency pleural interventions within 30 days of randomisation. Secondary outcomes include complications, cost-effectiveness, patient-reported quality of life and patient and clinician views of the two treatment options; participants are followed up for 6 months.

ETHICS AND DISSEMINATION

This trial received approval from the Wales Research Ethics Committee 4 (reference: 22/WA/0118) and the Health Research Authority. Results will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ISRCTN35574247.

Comparison of Observation Alone Versus Interventional Procedures in Hemodynamically Stable Patients With Pneumothorax: A Systematic Review and Meta-Analysis

Several studies indicate that observation alone is sufficient for the management of stable pneumothorax. To compare clinical efficacy, tolerability, and safety outcomes for treating hemodynamically stable adult patients with pneumothorax, the present review compared observation alone versus interventional procedures. We searched PubMed and Google Scholar from inception until June 24, 2020, for randomized controlled trials (RCTs) comparing observational therapy with conventional therapy for the treatment of adult pneumothorax. The pediatric age group and patients with tension pneumothorax were not included. Four hundred and forty-six patients were enrolled in three RCTs. The failure rate (relative risk (RR) 4.30; 95% CI = 0.23-81.82, p = 0.33) and mortality (RR 1.01; 95% CI = 0.31-3.33, p = 0.98) of observation were comparable to those of the chest tube. Chest tube and observation both carried comparable risks of complications, including tension pneumothorax and empyema (RR 3.15; 95% CI = 0.67-1) and (RR 1.55; 95% CI = 0.21-11.56, p = 0.67), respectively. Between chest tubes and observation, there was no statistically significant difference in the duration of hospital stay. We conclude that observation is as safe and effective at treating adult patients with stable pneumothorax as a chest tube.

Management of Blunt Chest Trauma

Common mechanisms of blunt thoracic injury include motor vehicle collisions and falls. Chest wall injuries include rib fractures and sternal fractures; treatment involves supportive care, multimodal analgesia, and pulmonary toilet. Pneumothorax, hemothorax, and pulmonary contusions are also common and may be managed expectantly or with tube thoracostomy as indicated. Surgical treatment may be considered in select cases. Less common injury patterns include blunt trauma to the tracheobronchial tree, esophagus, diaphragm, heart, or aorta. Operative intervention is more often required to address these injuries.

Successful Needle Aspiration of a Traumatic Pneumothorax: A Case Report and Literature Review

Traumatic pneumothorax (PTX) occurs in up to 50% of patients with severe polytrauma and chest injuries. Patients with a traumatic PTX with clinical signs of tension physiology and hemodynamic instability are typically treated with an urgent decompressive thoracostomy, tube thoracostomy, or needle decompression. There is recent evidence that non-breathless patients with a hemodynamically stable traumatic PTX can be managed conservatively through observation or a percutaneous pigtail catheter. We present here a 52-year-old woman who presented to the emergency department with a 55 mm traumatic PTX. Following aspiration of 1500 mL of air, a clinical improvement was immediately observed, allowing the patient to be discharged shortly thereafter. In hemodynamically stable patients with a post-traumatic PTX, without specific risk factors or oxygen desaturation, observation or simple needle aspiration can be a reasonable approach. Although the recent medical literature supports conservative management of small traumatic PTXs, guidelines are lacking for hemodynamically stable patients with a significantly large PTX. This case report documents our successful experience with needle aspiration in such a setting of large traumatic PTX. We aimed in this article to review the available literature on needle aspiration and conservative treatment of traumatic pneumothorax. A total of 12 studies were selected out of 190 articles on traumatic PTX where conservative treatment and chest tube decompression were compared. Our case report offers a novel contribution by illustrating the successful resolution of a sizable pneumothorax through needle aspiration, suggesting that even a large PTX in a hemodynamically stable patient, without other risk conditions, can be successfully treated conservatively with simple needle aspiration in order to avoid tube thoracostomy complications.

Clinical outcomes of traumatic pneumothoraces undergoing conservative management following detection by prehospital physicians

OBJECTIVE

To describe the clinical and transport characteristics of patients diagnosed with a suspected traumatic pneumothorax and managed conservatively by prehospital medical teams including secondary deterioration during transfer and the subsequent rate of in-hospital tube thoracostomy.

METHODS

Retrospective observational study of all adult trauma patients diagnosed with a suspected pneumothorax on ultrasound and managed conservatively by their treating prehospital medical team between 2018 and 2020. Descriptive analysis was performed comparing patients who did and did not receive in-hospital tube thoracostomy.

RESULTS

In total, 181 patients were diagnosed with suspected traumatic pneumothoraces on prehospital ultrasound of which 75 (41.4%) were managed conservatively by their treating medical team whilst 106 (58.6%) underwent pleural decompression. There were no recorded cases of emergent pleural decompression required in transit. Of the 75 conservatively managed patients, 42 (56%) had an intercostal catheter (ICC) placed within four hours of hospital arrival and another nine (17.6%) had an ICC placed between four- and 24-hours post-hospital arrival. There was no significant difference in prehospital clinical characteristics between patients who did and did not receive an in-hospital ICC. The detection of a pneumothorax on the initial chest x-ray and larger pneumothorax volume visualised on computed tomography imaging were significantly more common in patients receiving in-hospital ICCs. Aviation factors including flight altitude and duration of flight were not associated with subsequent in-hospital tube thoracostomy.

CONCLUSION

Prehospital medical teams can safely identify patients who have a traumatic pneumothorax and can be transported to hospital without pleural decompression. Patient characteristics at the time of hospital arrival combined with the size of pneumothorax identified on imaging appear most likely to influence subsequent urgent in-hospital tube thoracostomy placement.

Comparison of outcomes between observation and tube thoracostomy for small traumatic pneumothoraces

BACKGROUND

Traumatic pneumothorax management has evolved to include the use of smaller caliber tube thoracostomy and even observation alone. Data is limited comparing tube thoracostomy to observation for small traumatic pneumothoraces. We aimed to investigate whether observing patients with a small traumatic pneumothorax on initial chest radiograph (CXR) is associated with improved outcomes compared to tube thoracostomy.

METHODS

We retrospectively reviewed trauma patients at our level 1 trauma center from January 1, 2016 through December 31, 2020. We included those with a pneumothorax size <30 mm as measured from apex to cupola on initial CXR. We excluded patients with injury severity score ≥ 25, operative requirements, hemothorax, bilateral pneumothoraces, and intensive care unit admission. Patients were grouped by management strategy (observation vs tube thoracostomy). Our primary outcome was length of stay with secondary outcomes of pulmonary infection, failed trial of observation, readmission, and mortality. Results are listed as mean ± standard error of the mean.

RESULTS

Of patients who met criteria, 39 were in the observation group, and 34 were in the tube thoracostomy group. Baseline characteristics were similar between the groups. Average pneumothorax size on CXR was 18 ± 1.0 mm in the observation group and 18 ± 0.84 mm in the tube thoracostomy group (p > 0.99). Average pneumothorax sizes on computed tomography were 25 ± 2.1 and 37 ± 3.9 mm in the observation and tube thoracostomy groups, respectively (p = 0.01). Length of stay in the observation group was significantly shorter than the tube thoracostomy group (3.6 ± 0.33 vs 5.8 ± 0.81 days, p < 0.01). While pneumothorax size on computed tomography was associated with tube thoracostomy, only tube thoracostomy correlated with length of stay on multivariable analysis; pneumothorax size on CXR and computed tomography did not. There were no deaths or readmissions in either cohort. One patient in the observation group required tube thoracostomy after 18 h for worsening subcutaneous emphysema, and one patient in the tube thoracostomy group developed an empyema.

CONCLUSIONS

Select patients with small traumatic pneumothoraces on initial chest radiograph who were treated with observation experienced an average length of stay over two days shorter than those treated with tube thoracostomy. Outcomes were otherwise similar between the two groups suggesting that an observation-first strategy may be a superior treatment approach for these patients.

Thoracic point-of-care ultrasound is an accurate diagnostic modality for clinically significant traumatic pneumothorax

OBJECTIVE

There are conflicting data regarding the accuracy of thoracic point-of-care ultrasound (POCUS) in detecting traumatic pneumothorax (PTX). The purpose of our study was to determine the accuracy of thoracic POCUS performed by emergency physicians for the detection of clinically significant PTX in blunt and penetrating trauma patients.

METHODS

We conducted a retrospective institutional review board-approved study of trauma patients 15 years or older presenting to our urban Level I academic trauma center from December 2021 to June 2022. All study patients were imaged with single-view chest radiography (CXR) and thoracic POCUS. The presence or absence of PTX was determined by multidetector computed tomography (CT) or CXR and ultrasound (US) with tube thoracostomy placement.

RESULTS

A total of 846 patients were included, with 803 (95%) sustaining blunt trauma. POCUS identified 13/15 clinically significant PTXs (defined as ≥35 mm of pleural separation on a blinded overread or placement of a tube thoracostomy prior to CT) with a sensitivity of 87% (95% confidence interval [CI] 58-97), specificity of 100% (95% CI 99-100), positive predictive value of 81% (95% CI 54%-95%), and negative predictive value of 100% (95% CI 99%-100%). The positive likelihood ratio was 484 and the negative likelihood ratio was 0.1. CXR identified eight (53%) clinically significant PTXs, with a sensitivity of 53% (95% CI 27%-78%) and a specificity of 100%, when correlated with the CT. The most common reason for a missed PTX identified on expert-blinded overread was failure to recognize a lung point sign that was present on US.

CONCLUSIONS

Thoracic POCUS accurately identifies the majority of clinically significant PTXs in both blunt and penetrating trauma patients. Common themes for false-negative thoracic US in the expert-blinded overread process identified key gaps in training to inspire US education and medical education research.

Case series: acupuncture-related pneumothorax

Background

Acupuncture has become a more popular complementary and alternative medicine worldwide. As pneumothorax is a rare acupuncture-related adverse event (AE), it is thought to be under-recognized by acupuncturists and emergency physicians, and the public is often not aware of this potential AE resulting in delayed hospital presentation.

Methods

This is a case series of acupuncture-related pneumothoraces diagnosed in an emergency department (ED) in Singapore. Data was collected retrospectively from patients’ notes and prospectively from the patients over the phone.

Case presentations

Between 2017 and 2021, 4 out of 474 (0.84%) pneumothoraces were acupuncture related. Three of these patients consented to participate in this study. One patient developed bilateral pneumothoraces. All 3 patients claimed that they were not informed by the acupuncturists of potential serious AEs prior to acupuncture treatments and that they were not aware that such AE could occur. All 3 patients had reported their symptoms of chest pain and/or breathlessness to their acupuncturists post-treatment, but they were not advised to seek urgent medical attention. When the 3 patients had informed their acupuncturists about their diagnosis of pneumothorax, 2 of the acupuncturists did not seem to be aware of this acupuncture-related AE.

Discussion

When pneumothorax manifests, there is a potential need for an invasive procedure and continuous monitoring as it may devolve into a life-threatening condition with cardiovascular compromise. Early medical recognition and attention are needed to ensure optimal patient outcomes. In the appropriate population cohort, a history of prior acupuncture treatments should be included as part of history-taking assessment in patients presenting with chest pain and/or breathlessness.

Conclusion

Emergency physicians should be vigilant of this potentially serious and life-threatening complication for anyone presenting with chest discomfort and/or breathlessness after recently undergoing acupuncture to ensure earlier diagnosis, management, and better patient outcome.

Cardiac-Device Implantation and Pneumothorax—A Symptom-Based Approach: Experience from a District General Hospital

In patients undergoing cardiac-device implantation, pneumothorax incidence occurs in 1–6%, and is more common in women over 80 years of age with chronic obstructive pulmonary disease (COPD). The aim of this study was to do a service review to identify ways to improve care delivery. Caldicott approval was gained. Those complicated by a pneumothorax were further analysed regarding basic demographics and pleural interventions and outcomes. Continuous variables are presented as mean (range) or median (with interquartile ranges) and categorical variables are presented as percentages where appropriate. A total of 2056 implantation episodes from January 2010 to December 2020 occurred with 70 pneumothoraxes (3.4%), which were all related to pacemaker insertion. The mean age was 68.1 years (17–97), 39 were female, and 31 were male. A total of 36 pneumothoraxes were small and were 34 large according to British Thoracic Society (BTS) criteria. We initially observed 56 patients with minimal or no symptoms (30 were large pneumothoraxes), with five requiring intercostal drainage (ICD). A total of 14 pneumothoraxes were treated with ICD as a first-line treatment: the mean age was 78 years (69–89) and eight patients had COPD. Five pneumothoraxes were large. All had significant symptoms. All pneumothoraxes resolved within six weeks with no associated mortality.

Chest Tube Placement in Mechanically Ventilated Trauma Patients: Differences between Computed Tomography-Based Indication and Clinical Decision

The rate of occult pneumothorax in intubated and mechanically ventilated trauma patients until initial computed tomography (CT) remains undetermined. The primary aims of this study were to analyze initial chest CTs with respect to the thoracic pathology of trauma, the clinical injury severity, and chest tube placement (CTP) before and after CT. In a single-center retrospective analysis of 616 intubated and mechanically ventilated adult patients admitted directly from the scene to the emergency department (ED), 224 underwent CTP (36%). Of these, 142 patients (62%) underwent CTP before CT, of which, 125 (88%) had significant chest injury on CT. Seventeen patients had minor or absent chest injuries, most of which were associated with transient or unrecognized tracheal tube malposition. After CT, CTP was performed in another 82 patients, of which, 56 (68.3%) had relevant pneumothorax and 26 had minor findings on CT. Sixty patients who had already undergone CTP before CT received another CTP after CT, of which, 15 (25%) had relevant pneumothorax and 45 (75%) had functionality issues or malposition requiring replacement. Nine patients showed small pneumothorax on CT, and did not undergo CTP (including four patients with CTP before CT). The physiological variables were unspecific, and the trauma scores were dependent on the CT findings for identifying patients at risk for CTP. In conclusion, the clinical decisions for CTP before CT are associated with relevant false-negative and false-positive cases. Clinical assessment and CT imaging, together, are important indicators for CTP decisions that cannot be achieved by using clinical assessment or CT alone.

Physician-Led Thoracic Trauma Management in a Specialist Emergency Care Centre

INTRODUCTION

Falls cause 75% of trauma in patients above 65 years of age, and thoracic trauma is the second commonest injury; rib fractures are the most common thoracic injury. These patients have up to 12% mortality, with 31% developing pneumonias. There is wide variation in care. Northumbria Healthcare has a team of respiratory consultants, physiotherapists, specialist nurses and anesthetists for thoracic-trauma management on a respiratory support unit.

METHODS

With Caldicott approval, basic demographics and clinical outcomes of patients admitted with thoracic trauma between 20 August-21 April were analyzed. A descriptive statistical methodology was applied.

RESULTS

A total of 119 patients were identified with a mean age of 71.1 years (range 23-97). Of the 119 patients, 53 were male, 66 females. The main mechanism of injury was falls from standing (65) and falls down stairs/bed or in the bath (18). Length of stay was 7.3 days (range 1-54). In total, 85 patients had more than one co-morbidity, 26 had a full trauma assessment and 75 had pan CTs. The mean number of rib fractures was 3.6 and 31 (26%) patients had a pneumothorax and/or haemothorax. A total of 18 chest drains were inserted (all small bore) and one needle aspiration was performed. No cardiothoracic input was required. Isolated chest trauma was present only in 45 patients. All patients had a pain team review, 22 erector spinae catheters were inserted with 2 paravertebral blocks. Overall, 82 patients did not require oxygen, 1 required CPAP and 1 HFNC. 7 needed intensive care transfer. Furthermore, 20 (17%) developed pneumonias and 16 (14%) deaths occurred within 30 days-all were in those with falls from standing. There was no correlation between number of fractured ribs, length of stay and mortality.

CONCLUSIONS

High level care for thoracic trauma can be performed by a physician led team. Overall, 42% pneumothoraces/haemothoraces were observed. Further large scale randomised trials are warranted for definitive outcomes.

Conservative management of occult pneumothorax in mechanically ventilated patients: A systematic review and meta-analysis

BACKGROUND

The aim of this systematic review was to investigate the safety and effectiveness of conservative management versus prophylactic intercostal catheter (ICC) insertion for the management of occult pneumothoraces in mechanically ventilated patients.

METHODS

PubMed, Embase, CINAHL, Web of Science, Cochrane Central, and other trial registries were searched. Eligible studies were critically appraised using standardized instruments. Meta-analysis was performed with mixed-methods logistic regression where appropriate and sensitivity analyses were performed with alternative statistical methods (Stata™ 15 or RevMan 5.3) or summarized in narrative. Randomized controlled trials (RCTs) and cohort studies were analyzed separately.

RESULTS

Twelve studies with a total of 354 participants were included; three RCTs (178 participants) and nine cohort studies (176 participants). The majority of the included studies, particularly the cohort studies, were well conducted. Two of the RCTs were rated as low quality. Statistically significant differences were observed in the RCT analysis: ICC insertion (any reason) (odds ratio, 2.86; 95% confidence interval, 1.26-6.43, 2 RCTs) in favor of prophylactic ICC; ICC complications (odds ratio, 0.12; 95% confidence interval, 0.02-0.62, 2 RCTs) in favor of conservative management. Nonstatistically significant differences were observed for progression of pneumothorax, ICC insertion (progression to simple pneumothorax), and ICC insertion (nonpneumothorax reasons). Results of analyses showed high imprecision (wide confidence limits). Conservative management showed a low rate of tension pneumothorax (2.8%). Complications were higher in the ICC group (19.5% vs. 5.8%).

CONCLUSION

Available evidence suggests that conservative management is safe for the management of occult pneumothoraces in mechanically ventilated patients, especially when undergoing short-term (<4 days) ventilation. We recommend that patients undergoing mechanical ventilation for a procedure alone and patients suspected to be ventilated less than 4 days can be conservatively managed.

LEVEL OF EVIDENCE

Systematic review and meta-analysis, level III.

Management of Pneumothorax

Pneumothorax is a common medical condition encountered in a wide variety of clinical presentations, ranging from asymptomatic to life threatening. When symptomatic, it is important to remove air from the pleural space and provide re-expansion of the lung. Additionally, patients who experience a spontaneous pneumothorax are at high risk for recurrence, so treatment goals also include recurrence prevention. Several recent studies have evaluated less invasive management strategies for pneumothorax, including conservative or outpatient management. Future studies may help to identify who is greatest at risk for recurrence and direct earlier definitive management strategies, including thoracoscopic surgery, to those patients.

Conservative management of traumatic pneumothoraces: A retrospective cohort study

OBJECTIVE

Traumatic pneumothoraces (T-PTXs) are traditionally managed with an intercostal catheter (ICC), despite little evidence for this. Success with conservative management of primary spontaneous PTX has been demonstrated, and our ED has adopted a conservative approach where safe for all PTX.

METHODS

We reviewed all T-PTXs at our institution over a 7-year period to assess outcomes of those conservatively managed and compare with those who received an ICC. A total of 144 cases were identified, 65 managed conservatively and 79 invasively. Each was individually reviewed and variables including demographics, aetiology, smoking/lung disease history, T-PTX size (apical interpleural distance and hemithorax percentage), length of stay, Revised Trauma Score, Injury Severity Score and delayed intervention/complications were recorded. Chi-squared, Z-score, Mann-Whitney U and t-tests were used for analysis.

RESULTS

The mean apical interpleural distance was 26.8 mm (95% confidence interval [CI] 22.1-29.7 mm) in the conservative group and 49.1 mm (95% CI 41.2-57.0 mm) in the ICC group (P < 0.05 for difference between groups). Mean T-PTX percentage 25.9% (95% CI 22.1-29.7%) in the conservative group versus 45.9% (95% CI 39.7-50.5%) in the ICC group (P < 0.05 for difference between two groups) and mean Revised Trauma Score 7.4 (conservative) versus 6.8 (invasive) (P < 0.05). No conservatively managed patient required a delayed intervention for their T-PTX, and 2 of 79 (3%) patients in the ICC group had a complication (one infection, one haemothorax).

CONCLUSION

Our data support conservative management of selected T-PTXs and shows a need for a prospective randomised trial to further examine this intervention.

Current management of moderate to severe traumatic pneumothoraces: a survey of emergency clinicians

BACKGROUND

Traumatic pneumothoraces are present in one-fifth of multiple trauma victims. Traditional teaching mandates the insertion of a chest drain in the majority of cases. However, recent observational evidence suggests a trend towards conservative management. The aim of this survey was to understand current emergency medicine (EM) practice in placing chest drains for the management of moderate to severe traumatic pneumothoraces.

METHODOLOGY

The survey was developed through expert consensus and sent electronically to senior EM doctors in 21 sites internationally. It described six clinical/imaging vignettes asking 'how likely are you to insert an intercostal chest drain to manage the pneumothorax in ED?'. A five-point response was available from very unlikely to very likely. All pneumothoraces were >1 cm on imaging, but mechanism, physiology and need for ventilation varied.

RESULTS

Of a potential 606 respondents, 222 responses were received (37% response rate). Respondents were from five different countries, with the majority qualified for more than 10 years (median; 18 years). Within each scenario, there was a large variation in responses with the exception of tension pneumothorax. For vignettes without tension pneumothorax, there was a range from 52% (non-compromised 1 cm pneumothorax in a ventilated patient) to 89% (open pneumothorax with minimal clinical compromise) in respondents reporting that they would be likely or very likely to insert a chest drain.

CONCLUSION

There is considerable variation in clinical practice involving both conservative and invasive strategies in the treatment of moderate to severe traumatic pneumothoraces. This suggests clinical equipoise for interventional trials to determine the optimal management strategy for this patient group.

Deep learning detection and quantification of pneumothorax in heterogeneous routine chest computed tomography

BACKGROUND

Automatically detecting and quantifying pneumothorax on chest computed tomography (CT) may impact clinical decision-making. Machine learning methods published so far struggle with the heterogeneity of technical parameters and the presence of additional pathologies, highlighting the importance of stable algorithms.

METHODS

A deep residual UNet was developed and evaluated for automated, volume-level pneumothorax grading (i.e., labelling a volume whether a pneumothorax was present or not), and pixel-level classification (i.e., segmentation and quantification of pneumothorax), on a retrospective series of routine chest CT data. Ground truth annotations were provided by radiologists. The fully automated pixel-level pneumothorax segmentation method was trained using 43 chest CT scans and evaluated on 9 chest CT scans with pixel-level annotation basis and 567 chest CT scans on a volume-level basis.

RESULTS

This method achieved a receiver operating characteristic area under the curve (AUC) of 0.98, an average precision of 0.97, and a Dice similarity coefficient (DSC) of 0.94. This segmentation performance resulted to be similar to the inter-rater segmentation accuracy of two radiologists, who achieved a DSC of 0.92. The comparison of manual and automated pneumothorax quantification yielded a Pearson correlation coefficient of 0.996. The volume-level pneumothorax grading accuracy was evaluated on 567 chest CT scans and yielded an AUC of 0.98 and an average precision of 0.95.

CONCLUSIONS

We proposed a deep learning method for the detection and quantification of pneumothorax in heterogeneous routine clinical data that may facilitate the automated triage of urgent examinations and enable treatment decision support.

Are expiratory radiographs more sensitive than inspiratory radiographs for the diagnosis of pneumothorax in the emergency department? A retrospective observational study

OBJECTIVES

Expiratory radiographs are sometimes performed in addition to inspiratory radiographs when a diagnosis of pneumothorax is suspected. There is little published evidence to support this practice and most studies suggest the additional radiograph does not confer any benefit in terms of increased sensitivity. The present study is the first to assess if specialist emergency physicians are more likely to detect a pneumothorax on an inspiratory radiograph compared to an expiratory radiograph.

METHODS

Across two urban district EDs 103 paired radiographs positive for pneumothorax and 112 negative controls were identified for inclusion in the study. These were reviewed by three specialist emergency physicians who rated them as either positive or negative for pneumothorax.

RESULTS

The mean sensitivity for the three reviewers was 84.8% (95% CI 82.0-87.5) for the inspiratory radiographs and 91.9% (95% CI 88.2-95.6) for the expiratory radiographs, a mean absolute difference of 7.1% (95% CI 2.2-12.1, P = 0.025) in favour of expiratory radiographs.

CONCLUSIONS

When reviewed by emergency physicians the present study found expiratory radiographs confer an increase in sensitivity for the diagnosis of pneumothorax compared with inspiratory radiographs. In certain patients where the clinical suspicion for pneumothorax is high performing an expiratory radiograph may increase the likelihood of the diagnosis being made in the ED.

Blunt chest trauma in the elderly: an expert practice review

Trauma in the elderly (>65 years) is an increasingly common presentation to the ED. A fall from standing height is the most common mechanism after which such patients present, and rib fracture is the most common non-spinal fracture. Thoracic injury in patients aged over 65 is associated with significant morbidity and mortality. There are currently no universally applied guidelines for assessment, investigation and management of such patients. In this expert practice review, we discuss the evidence base and options for clinical management in this vulnerable patient group.