Is observation for traumatic hemothorax safe?

Thoracic cavity irrigation prevents retained hemothorax and decreases surgical intervention in trauma patients

INTRODUCTION

Retained hemothorax (HTX) is a common complication following thoracic trauma. Small studies demonstrate the benefit of thoracic cavity irrigation at the time of tube thoracostomy (TT) for the prevention of retained HTX. We sought to assess the effectiveness of chest irrigation in preventing retained HTX leading to a secondary surgical intervention.

METHODS

We performed a single-center retrospective study from 2017 to 2021 at a Level I trauma center, comparing bedside thoracic cavity irrigation via TT versus no irrigation. Using the trauma registry, patients with traumatic HTX were identified. Exclusion criteria were TT placement at an outside hospital, no TT within 24 hours of admission, thoracotomy or video-assisted thoracoscopic surgery (VATS) prior to or within 6 hours after TT placement, VATS as part of rib fixation or diaphragmatic repair, and death within 96 hours of admission. Bivariate and multivariable analyses were conducted.

RESULTS

A total of 370 patients met the inclusion criteria, of whom 225 (61%) were irrigated. Patients who were irrigated were more likely to suffer a penetrating injury (41% vs. 30%, p = 0.03) and less likely to have a flail chest (10% vs. 21%, p = 0.01). On bivariate analysis, irrigation was associated with lower rates of VATS (6% vs. 19%, p < 0.001) and retained HTX (10% vs. 21%, p < 0.001). The irrigated cohort had a shorter TT duration (4 vs. 6 days, p < 0.001) and hospital length of stay (7 vs. 9 days, p = 0.04). On multivariable analysis, thoracic cavity irrigation had lower odds of VATS (adjusted odds ratio, 0.37; 95% confidence interval [CI], 0.30-0.54), retained HTX (adjusted odds ratio, 0.42; 95% CI, 0.25-0.74), and a shorter TT duration ( β = -1.58; 95% CI, -2.52 to -0.75).

CONCLUSION

Our 5-year experience with thoracic irrigation confirms findings from smaller studies that irrigation prevents retained HTX and decreases the need for surgical intervention.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level III.

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.

Small Hemothoraces Not Drained on Admission: Initial Volume Predicts Need for Intervention

BACKGROUND

Unlike large hemothoraces (HTX), small HTX after blunt trauma may be observed without drainage. We aimed to study if there were risk factors that would predict the need for intervention in initially observed small HTX.

METHODS

A retrospective review of patients with blunt traumatic HTX from 2016 to 2022 was performed. Patients with small HTX (pleural fluid volume <400 mL on admission chest computerized tomography [CT]) were included. Patients were considered as being "initially observed" if there was no intervention for the HTX within 48 hours after admission. Primary outcome was any HTX-related intervention (open, thoracoscopic or percutaneous procedures) occurring after 48 hours and up to 6 months after injury. Univariable and multivariable statistical analyses were employed. A P-value of <.05 was considered significant.

RESULTS

Of 335 patients with HTX, 188 (59.6%) met inclusion criteria. Median (interquartile range) HTX volume was 90 (36-134) ml. One hundred and twenty-seven (68%) were initially observed. Of these, 31 (24%) had the primary outcome. These patients had a larger HTX volume (median, 129 vs 68 mL, P = .0001), and number of rib fractures (median, 7 vs 4, P = .0002) compared to those without the primary outcome. Chest-related readmission occurred in 8 (6%) with a median of 20 days from injury. Of these, 7 required an HTX-related intervention. Logistic regression analysis found that both the number of rib fractures and HTX volume independently predicted the primary outcome.

CONCLUSION

For small HTX initially observed, number of rib fractures and initial volume predicted delayed HTX-related intervention.

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.

CT-based pleural effusion volume estimation formula demonstrates low accuracy and reproducibility for traumatic hemothorax

PURPOSE

We aimed to evaluate the accuracy and reproducibility of the CT-based volume estimation formula V = d2 * h, where d and h represent the maximum depth and height of the effusion, for acute traumatic hemothorax.

MATERIALS & METHODS

Prospectively identified patients with CT showing acute traumatic hemothorax were considered. Volumes were retrospectively estimated using d2 * h, then manually measured on axial images. Subgroup analysis was performed on borderline-sized hemothorax (200-400 mL). Measurements were repeated by three non-radiologists. Bland-Altman analysis was used to assess agreement between the two methods and agreement between raters for each method.

RESULTS

A total of 46 patients (median age 34; 36 men) with hemothorax volume 23-1622 mL (median 191 mL, IQR 99-324 mL) were evaluated. Limits of agreement between estimates and measured volumes were -718 - +842 mL (± 202 mL). Borderline-sized hemothorax (n = 13) limits of agreement were -300 - +121 mL (± 114 mL). Of all hemothorax, 85 % (n = 39/46) were correctly stratified as over or under 300 mL, and of borderline-sized hemothorax, 54 % (n = 7/13). Inter-rater limits of agreement were -251 - +350, -694 - +1019, and -696 - +957 for the estimation formula, respectively, and -124 - +190, -97 - +111, and -96 - +46 for the measured volume.

DISCUSSION

An estimation formula varies with actual hemothorax volume by hundreds of mL. There is low accuracy in stratifying hemothorax volumes close to 300 mL. Variability between raters was substantially higher with the estimation formula than with manual measurements.

Predictors of initial management failure in traumatic hemothorax: A prospective multicenter cohort analysis

BACKGROUND

Traumatic hemothorax is common, and management failure leads to worse outcomes. We sought to determine predictive factors and understand the role of trauma center performance in hemothorax management failure.

METHODS

We prospectively examined initial hemothorax management (observation, pleural drainage, surgery) and failure requiring secondary intervention in 17 trauma centers. We defined hemothorax management failure requiring secondary intervention as thrombolytic administration, tube thoracostomy, image-guided drainage, or surgery after failure of the initial management strategy at the discretion of the treating trauma surgeon. Patient-level predictors of hemothorax management failure requiring secondary intervention were identified for 2 subgroups: initial observation and immediate pleural drainage. Trauma centers were divided into quartiles by hemothorax management failure requiring secondary intervention rate and hierarchical logistic regression quantified variation.

RESULTS

Of 995 hemothoraces in 967 patients, 186 (19%) developed hemothorax management failure requiring secondary intervention. The frequency of hemothorax management failure requiring secondary intervention increased from observation to pleural drainage to surgical intervention (12%, 22%, and 35%, respectively). The number of ribs fractured (odds ratio 1.12 per fracture; 95% confidence interval 1.00-1.26) and pulmonary contusion (odds ratio 2.25, 95% confidence interval 1.03-4.91) predicted hemothorax management failure requiring secondary intervention in the observation subgroup, whereas chest injury severity (odds ratio 1.58; 95% confidence interval 1.17-2.12) and initial hemothorax volume evacuated (odds ratio 1.10 per 100 mL; 95% confidence interval 1.05-1.16) predicted hemothorax management failure requiring secondary intervention after pleural drainage. After adjusting for patient characteristics in the logistic regression model for hemothorax management failure requiring secondary intervention, patients treated at high hemothorax management failure requiring secondary intervention trauma centers were 6 times more likely to undergo an intervention after initial hemothorax management failure than patients treated in low hemothorax management failure requiring secondary intervention trauma centers (odds ratio 6.18, 95% confidence interval 3.41-11.21).

CONCLUSION

Failure of initial management of traumatic hemothorax is common and highly variable across trauma centers. Assessing patient selection for a given management strategy and center-level practices represent opportunities to improve outcomes from traumatic hemothorax.

[Occult and Retained Haemothorax - Recommendations of the Interdisciplinary Thoracic Trauma Task Group of the German Trauma Society (DGU - Section NIS) and the German Society for Thoracic Surgery (DGT)]

The management of occult and retained haemothorax is challenging for all involved in the care of polytrauma patients in terms of diagnosis and treatment. The focus of decision making is preventing sequelae such as pleural empyema and avoiding a trapped lung. An interdisciplinary task force of the German Society for Thoracic Surgery (DGT) and the German Trauma Society (DGU) on thoracic trauma offers recommendations for post-trauma care of patients with occult and/or retained haemothorax, as based on a comprehensive literature review.

A pilot study of deep learning-based CT volumetry for traumatic hemothorax

PURPOSE

We employ nnU-Net, a state-of-the-art self-configuring deep learning-based semantic segmentation method for quantitative visualization of hemothorax (HTX) in trauma patients, and assess performance using a combination of overlap and volume-based metrics. The accuracy of hemothorax volumes for predicting a composite of hemorrhage-related outcomes - massive transfusion (MT) and in-hospital mortality (IHM) not related to traumatic brain injury - is assessed and compared to subjective expert consensus grading by an experienced chest and emergency radiologist.

MATERIALS AND METHODS

The study included manually labeled admission chest CTs from 77 consecutive adult patients with non-negligible (≥ 50 mL) traumatic HTX between 2016 and 2018 from one trauma center. DL results of ensembled nnU-Net were determined from fivefold cross-validation and compared to individual 2D, 3D, and cascaded 3D nnU-Net results using the Dice similarity coefficient (DSC) and volume similarity index. Pearson's r, intraclass correlation coefficient (ICC), and mean bias were also determined for the best performing model. Manual and automated hemothorax volumes and subjective hemothorax volume grades were analyzed as predictors of MT and IHM using AUC comparison. Volume cut-offs yielding sensitivity or specificity ≥ 90% were determined from ROC analysis.

RESULTS

Ensembled nnU-Net achieved a mean DSC of 0.75 (SD: ± 0.12), and mean volume similarity of 0.91 (SD: ± 0.10), Pearson r of 0.93, and ICC of 0.92. Mean overmeasurement bias was only 1.7 mL despite a range of manual HTX volumes from 35 to 1503 mL (median: 178 mL). AUC of automated volumes for the composite outcome was 0.74 (95%CI: 0.58-0.91), compared to 0.76 (95%CI: 0.58-0.93) for manual volumes, and 0.76 (95%CI: 0.62-0.90) for consensus expert grading (p = 0.93). Automated volume cut-offs of 77 mL and 334 mL predicted the outcome with 93% sensitivity and 90% specificity respectively.

CONCLUSION

Automated HTX volumetry had high method validity, yielded interpretable visual results, and had similar performance for the hemorrhage-related outcomes assessed compared to manual volumes and expert consensus grading. The results suggest promising avenues for automated HTX volumetry in research and clinical care.

Readmission for pleural space complications after chest wall injury: Who is at risk?

BACKGROUND

Little is known about patient characteristics predicting postdischarge pleural space complications (PDPSCs) after thoracic trauma. We sought to analyze the patient population who required unplanned hospital readmission for PDPSC.

METHODS

Retrospective review of adult patients admitted to a Level I Trauma Center with a chest Abbreviated Injury Scale (AIS) score of 2 or greater between January 2015 and August 2020. Those readmitted within 30 days of index hospitalization discharge for PDPSC were compared with those not readmitted. Demographics, injury characteristics, surgical procedures, imaging, and readmission data were retrieved.

RESULTS

Out of 17,192 trauma evaluations, 3,412 (19.8%) suffered a chest AIS score of 2 or greater injury and 155 experienced an unplanned 30-day hospital readmission. Of those, 49 (1.4%) were readmitted for the management of PDPSC (readmit PDPSC) and were compared with patients who were not readmitted (no readmit, n = 3,257). The readmit PDPSC group was significantly older age, heavier, comprised of fewer men, and suffered a higher mean chest AIS score. The readmit PDPSC group had a significantly higher incidence of rib fractures, flail chest, pneumothorax, hemothorax, scapula fractures, and a higher rate of tube thoracostomy placement during index admission. The discharge chest X-ray in the readmit PDPSC group demonstrated a pleural space abnormality in 36 (73%) of patients. Mean time to readmission was 10.2 (7.2) days, and hospital length of stay on readmission was 5.8 (3.7) days. Pleural effusion was the most common readmission diagnosis (44 [90%]), and 42 (86%) required tube thoracostomy.

CONCLUSION

We describe the subset of chest wall injury patients who require hospital readmission for PDPSC. Characteristics from index hospitalization associated with PDPSC include older age, female sex, heavier weight, presence of rib fractures, pleural space abnormality, scapular fracture, and chest tube placement. Further studies are needed to characterize this at-risk chest wall injury population, and to determine what interventions can facilitate outpatient management of postdischarge pleural space complications and mitigate readmission risk.

LEVEL OF EVIDENCE

Prognostic and epidemiologic, Level IV; Care management, Level V.

Scoping review of traumatic hemothorax: Evidence and knowledge gaps, from diagnosis to chest tube removal

BACKGROUND

Traumatic hemothorax is a common injury that invites diagnostic and management strategy debates. Evidence-based management has been associated with improved care efficiency. However, the literature abounds with long-debated, re-emerging, and new questions. We aimed to consolidate up-to-date evidence on traumatic hemothoraces, focusing on clinical conundra debated in literature.

METHODS

We conducted a scoping review of 21 clinical conundra in traumatic hemothorax diagnosis and management according to PRISMA-ScR guidelines. Experimental and observational studies evaluating patients (aged ≥18 years) with traumatic hemothoraces were identified through database searches (PubMed, EMBASE, Web of Science, Cochrane Library; database inception to Sep, 26 2020) and bibliography reviews of selected articles. Three reviewers screened and selected articles using standardized forms.

RESULTS

We screened 1,440 articles for eligibility, of which 71 met criteria for synthesis. The review comprises 6 sections: (1) Presumptive antibiotics before tube thoracostomy; (2) Initial diagnostic and intervention decisions; (3) Chest tubes; (4) Retained hemothoraces; (5) Delayed hemothoraces; and (6) Chest tube removal). The 21 conundra across these sections follow the format of a question, our recommendation based on interpretation of available evidence, and succinct rationale. Rationale sections detail knowledge gaps and opportunities for future research.

CONCLUSION

Even practices engrained into surgical dogma, such as obtaining chest x-rays after inserting or removing chest tubes and mandating operation for patients who develop chest tube output above a certain threshold, deserve re-evaluation. Some knowledge gaps require rigorous future investigation; sound clinical judgment can likely supplement others.

Predictors of retained hemothorax in trauma: Results of an Eastern Association for the Surgery of Trauma multi-institutional trial

BACKGROUND

The natural history of traumatic hemothorax (HTX) remains unclear. We aimed to describe outcomes of HTX following tube thoracostomy drainage and to delineate factors that predict progression to a retained hemothorax (RH). We hypothesized that initial large-volume HTX predicts the development of an RH.

METHODS

We conducted a prospective, observational, multi-institutional study of adult trauma patients diagnosed with an HTX identified on computed tomography (CT) scan with volumes calculated at time of diagnosis. All patients were managed with tube thoracostomy drainage within 24 hours of presentation. Retained hemothorax was defined as blood-density fluid identified on follow-up CT scan or need for additional intervention after initial tube thoracostomy placement for HTX.

RESULTS

A total of 369 patients who presented with an HTX initially managed with tube thoracostomy drainage were enrolled from 17 trauma centers. Retained hemothorax was identified in 106 patients (28.7%). Patients with RH had a larger median (interquartile range) HTX volume on initial CT compared with no RH (191 [48-431] mL vs. 88 [35-245] mL, p = 0.013) and were more likely to be older with a higher burden of thoracic injury. After controlling for significant differences between groups, RH was independently associated with a larger HTX on presentation, with a 15% increase in risk of RH for each additional 100 mL of HTX on initial CT imaging (odds ratio, 1.15; 95% confidence interval, 1.08-1.21; p < 0.001). Patients with an RH also had higher rates of pneumonia and longer hospital length of stay than those with successful initial management. Retained hemothorax was also associated with worse functional outcomes at discharge and first outpatient follow-up.

CONCLUSION

Larger initial HTX volumes are independently associated with RH, and unsuccessful initial management with tube thoracostomy is associated with worse patient outcomes. Future studies should use this experience to assess a range of options for reducing the risk of unsuccessful initial management.

LEVEL OF EVIDENCE

Therapeutic/care management study, level III.

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.

Hemothorax: A Review of the Literature

Hemothorax is a collection of blood in the pleural cavity usually from traumatic injury. Chest X-ray has historically been the imaging modality of choice upon arrival to the hospital. The sensitivity and specificity of point-of-care ultrasound, specifically through the Extended Focal Assessment with Sonography in Trauma (eFAST) protocol has been significant enough to warrant inclusion in most Level 1 trauma centers as an adjunct to radiographs.^1,2 If the size or severity of a hemothorax warrants intervention, tube thoracostomy has been and still remains the treatment of choice. Most cases of hemothorax will resolve with tube thoracostomy. If residual blood remains within the pleural cavity after tube thoracostomy, it is then considered to be a retained hemothorax, with significant risks for developing late complications such as empyema and fibrothorax. Once late complications occur, morbidity and mortality increase dramatically and the only definitive treatment is surgery. In order to avoid surgery, research has been focused on removing a retained hemothorax before it progresses pathologically. The most promising therapy consists of fibrinolytics which are infused into the pleural space, disrupting the hemothorax, allowing for further drainage. While significant progress has been made, additional trials are needed to further define the dosing and pharmacokinetics of fibrinolytics in this setting. If medical therapy and early procedures fail to resolve the retained hemothorax, surgery is usually indicated. Surgery historically consisted solely of thoracotomy, but has been largely replaced in non-emergent situations by video-assisted thoracoscopy (VATS), a minimally invasive technique that shows considerable improvement in the patients' recovery and pain post-operatively. Should all prior attempts to resolve the hemothorax fail, then open thoracotomy may be indicated.