Are Occult Pneumothoraces Truly Occult or Simply Missed?

Optimal diagnostic strategies for pleural diseases and identifying high-risk patients

INTRODUCTION

Pleural diseases encompass a broad range of conditions with diverse and heterogenous etiologies. Diagnostics in pleural diseases thus represents a challenging field with a wide array of available testing to distinguish between the numerous causes of pleural disease. Nonetheless, deploying best practice diagnostics in this area is essential in reducing both duration o the investigation pathway and symptom burden.

AREAS COVERED

This article critically appraises the optimal diagnostic strategies and pathway in patients with pleural disease, reviewing the latest evidence and key practice points in achieving a treatable diagnosis in patients with pleural disease. We also cover future and novel directions that are likely to influence pleural diagnostics in the near future. PubMed was searched for articles related to pleural diagnostics (search terms below), with the date ranges including June 2012 to June 2022.

EXPERT OPINION

No single test will ever be sufficient to provide a diagnosis in pleural conditions. The key to reducing procedure burden and duration to diagnosis lies in personalizing the investigation pathway to patients and deploying tests with the highest diagnostic yield early (such as pleural biopsy in infection and malignancy). Novel biomarkers may also allow earlier diagnostic precision in the near future.

Occult Pneumothorax Identification on Extended Focused Assessment with Sonography for Trauma Examination in Children

OBJECTIVE

Occult pneumothoraces (OPTXs) are defined by air within the pleural space that is not visible on conventional chest radiographs (CXR). The aim of this study was to understand how frequently the Extended Focused Assessment with Sonography for Trauma (eFAST) examination identifies occult PTX in a pediatric blunt trauma population as compared with a criterion standard of chest computed tomography (CCT).

METHODS

This study is a secondary analysis of blunt trauma patients younger than 18 years who underwent CCT at Los Angeles County +USC Medical Center Emergency Department from October 2015 to April 2017. The eFAST examination was performed and documented by an emergency medicine resident with attending oversight or by an emergency medicine attending for each trauma. The eFAST results were reviewed for patients diagnosed with small or trace pneumothoraces identified on CCT.

RESULTS

Of 168 pediatric trauma patients undergoing CCT, 16 had OPTXs not seen on CXR and 4 patients had a small/trace PTX without a corresponding CXR performed. None were identified on eFAST.

CONCLUSIONS

Although the sample size in this data set was small, our eFAST examinations identified none of 16 proven and 4 presumed OPTXs. The standard eFAST examination performed poorly in the detection of OPTXs in this single-center study of pediatric blunt trauma victims.

Introducing a Radiography-based Score in Children With Acute Respiratory Failure: A Cross-sectional Study

PURPOSE

Respiratory failure (RF) is one of the most common reasons for hospitalization in pediatric intensive care units (PICU). We propose a radiography-based severity score for the assessment of children with RF and investigate the possible associations with severity indices and outcome.

MATERIALS AND METHODS

Children with acute RF admitted in PICU were enrolled. Disease severity scores [Pediatric Risk of Mortality (PRISM) and Pediatric Logistic Organ Dysfunction (PELOD)], the ratio of partial pressure arterial oxygen and fraction of inspired oxygen (PaO2/FiO2) ratios, duration of ventilator support (DVS), length of PICU and hospital stay (LOS), and outcome were recorded. A 5-point radiography score that considered potential radiographic findings was derived through stepwise multivariable logistic regression analysis, and validated. Radiographs upon PICU admission and on the worst RF day (maximum respiratory support and worst oxygenation/ventilation parameters) were blindly reviewed and independently scored by 2 radiologists and 2 clinicians, following training.

RESULTS

We enrolled 104 children [median age 2.7 (interquartile range, 0.5 to 9.6) y, 65.4% boys]. Overall, 163 radiographs (PICU admission: 86, worst RF day: 77) were assessed. Radiography scores correlated positively with predicted mortality (PELOD, PRISM), DVS, LOS (all P<0.001) and inversely with PaO2/FiO2 (P<0.001). Scores differed among diagnostic categories (P<0.05); patients with acute respiratory distress syndrome, air-leaks, drowning, and pneumonia scored the highest (P<0.005). Radiography scoring trends indicating deterioration were associated with prolonged DVS, PICU, and hospital LOS (P<0.001). Agreement between all raters was good (κ=0.7, P<0.001).

CONCLUSIONS

This novel radiography score for children with RF, associated with clinical severity scores, mortality risk, duration of ventilatory support, and hospitalization, follows a simple structured approach and can be readily utilized by radiologists and pediatricians as a bedside tool for stratification of disease severity and prognosis.

Diagnostic accuracy of oblique chest radiograph for occult pneumothorax: comparison with ultrasonography

Backgraound

An occult pneumothorax is a pneumothorax that is not seen on a supine chest X-ray but is detected by computed tomography scanning. However, critical patients are difficult to transport to the computed tomography suite. We previously reported a method to detect occult pneumothorax using oblique chest radiography (OXR). Several authors have also reported that ultrasonography is an effective technique for detecting occult pneumothorax. The aim of this study was to evaluate the usefulness of OXR in the diagnosis of the occult pneumothorax and to compare OXR with ultrasonography.

Methods

All consecutive blunt chest trauma patients with clinically suspected pneumothorax on arrival at the emergency department were prospectively included at our tertiary-care center. The patients underwent OXR and ultrasonography, and underwent computed tomography scans as the gold standard. Occult pneumothorax size on computed tomography was classified as minuscule, anterior, or anterolateral.

Results

One hundred and fifty-nine patients were enrolled. Of the 70 occult pneumothoraces found in the 318 thoraces, 19 were minuscule, 32 were anterior, and 19 were anterolateral. The sensitivity and specificity of OXR for detecting occult pneumothorax was 61.4 % and 99.2 %, respectively. The sensitivity and specificity of lung ultrasonography was 62.9 % and 98.8 %, respectively. Among 27 occult pneumothoraces that could not be detected by OXR, 16 were minuscule and 21 could be conservatively managed without thoracostomy.

Conclusion

OXR appears to be as good method as lung ultrasonography in the detection of large occult pneumothorax. In trauma patients who are difficult to transfer to computed tomography scan, OXR may be effective at detecting occult pneumothorax with a risk of progression.

Occult pneumothoraces – red flag or red herring?

Pneumothorax is a relatively common complication following blunt chest trauma; however, the investigation and management of these injuries remains a contentious issue. Occult pneumothoraces are those not diagnosed by conventional radiographic imaging, but by subsequent computed tomography. This review examines the current evidence base behind the investigation and management of this condition. An anteroposterior chest x-ray should not be underestimated in its ability to provide sufficient radiological information to instigate an initial management plan in the trauma setting. Ultrasound has a high diagnostic rate for pneumothoraces; however, it is subjected to influence from other injuries, whilst failing to address other important injuries in trauma patients requiring computed tomography imaging. It is therefore best used in situations where computed tomography is unavailable or contraindicated. In the management of occult pneumothoraces, there is little difference in patient outcome between those managed conservatively or with a prophylactic chest drain. Clinicians must be wary of recommendations which in this area are often based on inadequate study size and they should continue to provide the best individual care on a case-by-case basis. Observation alone in patients that are haemodynamically stable can be considered, with a view to drainage of the pneumothorax should the clinical status of the patient deteriorate.

[Results of conservative treatment in patients with occult pneumothorax]

INTRODUCTION

An occult pneumothorax is found in 2-15% trauma patients. Observation (without tube thoracostomy) in these patients presents still some controversies in the clinical practice. The objective of the study is to evaluate the efficacy and the adverse effects when observation is performed.

METHODS

A retrospective observational study was undertaken in our center (university hospital level II). Data was obtained from a database with prospective registration. A total of 1087 trauma patients admitted in the intensive care unit from 2006 to 2013 were included.

RESULTS

In this period, 126 patients with occult pneumothorax were identified, 73 patients (58%) underwent immediate tube thoracostomy and 53 patients (42%) were observed. Nine patients (12%) failed observation and required tube thoracostomy for pneumothorax progression or hemothorax. No patient developed a tension pneumothorax or experienced another adverse event related to the absence of tube thoracostomy. Of the observed patients 16 were under positive pressure ventilation, in this group 3 patients (19%) failed observation. There were no differences in mortality, hospital length of stay or intensive care length of stay between the observed and non-observed group.

CONCLUSION

Observation is a safe treatment in occult pneumothorax, even in pressure positive ventilated patients.

Semi-quantification of pneumothorax volume by lung ultrasound

BACKGROUND

Lung ultrasound (LUS) may accurately diagnose pneumothorax. However, there is uncertainty about its usefulness in the quantification of pneumothorax size. To determine the ability of LUS in the semi-quantification of pneumothorax volume, we compared the projection of the lung point (LP) with the pneumothorax volume measured by computerized tomography (CT) and the interpleural distance on chest radiography (CXR).

METHODS

We performed LUS in patients with pneumothorax and all the LP located on the chest wall were compared to CXR and CT studies. The primary outcome of the study was the ability of LP to grade pneumothorax volumes measured by CT. The secondary outcome was the accuracy of LP to predict small and large pneumothorax according to the societal guidelines based on CXR reading.

RESULTS

A total of 124 patients with pneumothorax were enrolled (76 spontaneous, 20 traumatic and 28 post-procedural). Ninety-four CXR and 58 CT were available for the analysis. An LP posterior to the mid axillary line corresponded to three different CXR criteria for large pneumothorax with sensitivity from 81.4 to 88.2 % and specificity from 64.7 to 72.6 %. The mid axillary line also represented the limit for predicting greater than 15 % of lung collapse when volume is measured at CT, with sensitivity 83.3 % and specificity 82.4 %.

CONCLUSIONS

LUS-targeted assessment of LP was a useful predictor of pneumothorax volume in this research study setting. LUS reliably classified pneumothorax size when compared to criteria based on CXR reading, particularly the small sized pneumothorax. However, LUS greatly outperformed conventional CXR reading for a graded quantification of the percentage of lung collapse.

Can cervical spine computed tomography assist in detecting occult pneumothoraces?

INTRODUCTION

Screening CT often detects posttraumatic pneumothoraces that were not diagnosed on a preceding supine anteroposterior chest radiograph (occult pneumothoraces (OPTXs)). Because abdominal CT imaging misses OPTXs in the upper thorax, the objective of this study was to evaluate the utility of cervical spine (C-spine) CT screening for diagnosing OPTXs.

METHODS

A dual-institution (Foothills Medical Centre and Grady Memorial Hospital) retrospective review of consecutive OPTXs was performed. The accuracy of various CT screening protocols in detecting OPTXs was compared.

RESULTS

OPTXs were detected in 75 patients. Patient demographics and injury characteristics were similar between centres (65% male; 97% blunt mechanism; 29% hemodynamically unstable; mean ISS=27; mean length of stay=22 days; mortality=9%)(p>0.05). Patients received either abdominal (41%) or thoraco-abdominal (59%) CT imaging. Most patients (89%) also underwent C-spine CT imaging. OPTXs were evident on thoracic CT in 100% (44/44), abdominal CT in 83% (62/75), and C-spine CT in 82% (55/67) of cases. All patients with OPTXs identified solely on thoracic CT (i.e. not abdominal) who also underwent imaging of their C-spine could have had their OTPXs diagnosed by using the pulmonary windows setting of their C-spine CT series. Combining C-spine and abdominal CT screening diagnosed all OPTXs (67/67) detected on thoracic CT, for patients who also underwent these investigations.

CONCLUSIONS

OPTXs were evident on thoracic (and not abdominal) CT in 17% of severely injured patients. For patients who also underwent C-spine imaging, all OPTXs isolated to thoracic CT could be diagnosed by using the pulmonary windows setting of their C-spine CT imaging protocol. All OPTXs, regardless of intra-thoracic location, could also be detected by combining C-spine and abdominal CT screening.

Occult pneumothorax, revisited

Pneumothorax is a recognized cause of preventable death following chest wall trauma where a simple intervention can be life saving. In cases of trauma patients where cervical spine immobilization is mandatory, supine AP chest radiograph is the most practical initial study. It is however not as sensitive as CT chest for early detection of a pneumothorax. "Occult" pneumothorax is an accepted definition of an existing but usually a clinically and radiologically silent disturbance that in most patients can be tolerated while other more urgent trauma needs are attended to. However, in certain patients, especially those on mechanical ventilation (with subsequent increase of intrapleural air with positive pressure ventilation), missing the diagnosis of pneumothorax can be deleterious with fatal consequences. This review will discuss the occult pneumothorax in the context of 3 radiological examples, which will further emphasize the entity. Because a negative AP chest radiograph can dangerously delay its recognition, we recommend that any trauma victim presenting to the emergency department with symptoms of respiratory distress should be screened with either thoracic ultrasonography or chest CT scan to avoid missing a pneumothorax.

A method to detect occult pneumothorax with chest radiography

Small pneumothoraces are often not visible on supine screening chest radiographs because they develop anteriorly to the lung. These pneumothoraces are termed occult. Occult pneumothoraces account for an astonishingly high 52% to 63% of all traumatic pneumothoraces. A 19-year-old obese woman was involved in a head-on car accident. The admission anteroposterior chest radiographs were unremarkable. Because of the presence of right chest tenderness and an abrasion, we suspected the presence of a pneumothorax. Thus, we decided to take a supine oblique chest radiograph of the right side of the thorax, which clearly revealed a visceral pleural line, consistent with a diagnosis of traumatic pneumothorax. A pneumothorax may be present when a supine chest radiograph reveals either an apparent deepening of the costophrenic angle (the "deep sulcus sign") or the presence of 2 diaphragm-lung interfaces (the "double diaphragm sign"). However, in practice, supine chest radiographs have poor sensitivity for occult pneumothoraces. Oblique chest radiograph is a useful and fast screening tool that should be considered for cases of blunt chest trauma, especially when transport of critically ill patients to the computed tomographic suite is dangerous or when imminent transfer to another hospital is being arranged and early diagnosis of an occult pneumothorax is essential.

Opening Pandora’s box: the potential benefit of the expanded FAST exam is partially confounded by the unknowns regarding the significance of the occult pneumothorax

Introduction

Point of care (POC) ultrasound brings another powerful dimension to the physical examination of the critically ill. A contemporary challenge for all care providers, however, is how to best incorporate ultrasound into contemporary algorithms of care. When POC ultrasound corroborates pre-examination clinical suspicion, incorporation of the findings into decision-making is easier. When POC ultrasound generates new or unexpected findings, decision-making may be more difficult, especially with conditions that were previously not appreciated with older diagnostic technologies. Pneumothoraces (PTXs), previously seen only on computed tomography and not on supine chest radiographs known as occult pneumothoraces (OPTXs), which are now increasingly appreciated on POC ultrasound, are such an example.

Methods

The relevant literature concerning POC ultrasound and PTXs was reviewed after an electronic search using PubMed supplemented by ongoing research by the Canadian Trauma Trials Collaborative of the Trauma Association of Canada.

Results

OPTXs are frequently encountered in the critically injured who often require mechanical ventilation with positive pressure breathing (PPB). Standard recommendations for post-traumatic PTXs and the setting of PPB mandate chest drainage, recognizing a significant rate of complications related to this procedure itself. Whether these standard recommendations generated in response to obvious overt PTXs apply to these more subtle OPTXs is currently unknown, and evidence-based recommendations regarding appropriate therapy are impossible due to the lack of clinical studies.

Conclusions

OPTXs are a condition that illustrates how incorporation of POC ultrasound findings brings further responsibilities to critically appraise the significance of these findings in terms of patient outcomes and overall care. Adequately powered and adequately followed-up clinical trials addressing the treatment are required.

Pleural ultrasound compared with chest radiographic detection of pneumothorax resolution after drainage

BACKGROUND

Pleural ultrasonography (PU) is more sensitive than chest radiograph (CXR) for diagnosing pneumothorax and could be useful for detecting resolution of pneumothorax after drainage. The aim of this prospective double-blind observational study was to assess PU accuracy during pneumothorax follow-up after drainage.

METHODS

All patients hospitalized with pneumothorax requiring drainage were eligible. After drainage, residual pneumothorax was assessed by CXR and PU (1) 24 h after bubbling in the aspiration device had stopped, (2) 6 h after clamping the pleural catheter, and (3) 6 h after removing the pleural catheter. Pneumothorax indicated by PU but not CXR was confirmed by CT scan or by aspiration of > 10 mL of air.

RESULTS

Forty-four unilateral pneumothoraces were studied (primary spontaneous: 70.5%), and 162 pairs of examinations (CXR and PU) were performed. Twenty residual pneumothoraces were detected by both CXR and PU. Furthermore, PU suspected 14 pneumothoraces that were not identified by CXR; 13 were confirmed. All of these pneumothoraces resulted in therapeutic intervention. Thus, 39% (13/33) of the confirmed residual pneumothoraces were missed by CXR. In patients with primary spontaneous pneumothorax, the positive predictive value of PU for residual pneumothorax diagnosis was 100%; for other pneumothoraces, this value ranged from 90% in the absence of a lung point to 100% when a lung point was observed. PU results were obtained faster than results from CXR (35 +/- 34 min vs 71 +/- 56 min, P < .0001).

CONCLUSIONS

The accuracy of PU is excellent for detecting residual pneumothorax during pneumothorax follow-up after drainage.

Utility of Thoracic Computed Tomography after Blunt Trauma: When is Chest Radiograph Enough?

The purpose of this study was to identify the utility of thoracic computed tomography (TCT) in blunt trauma patients with a normal admission chest radiograph (CXR). A retrospective study was performed of 200 consecutive blunt trauma patients who received both CXR and TCT. One hundred and forty-three patients had a normal screening CXR; 36 of these patients (25%) had an abnormal TCT. TCT changed the management in only nine of these patients (6%): two required serial CXR for occult pneumothorax, four received additional imaging of the spine, and three were admitted to a monitored bed. Fifty-seven patients had an abnormal initial CXR. Of these, 41 (81%) had an abnormal TCT. TCT changed management in 21 (37%) of these patients: two aortic injuries identified, 12 aortic injuries excluded, two chest tubes placed, one patient taken to the Operating Room, and four patients required further diagnostic evaluation. TCT was significantly more likely to alter management in patients with an abnormal admission CXR (6% vs 37%, P < 0.001). TCT is of limited utility in patients with a normal admission CXR. A diagnostic strategy of obtaining TCT only in patients with abnormal CXR or high-risk mechanism of injury can result in significant cost savings without adversely affecting patient outcomes.

Clinical predictors of occult pneumothoraces in severely injured blunt polytrauma patients: A prospective observational study

INTRODUCTION

The supine antero-posterior (AP) chest radiograph (CXR) is an insensitive test for detecting post-traumatic pneumothoraces (PTXs). Computed tomography (CT) often identifies occult pneumothoraces (OPTXs) that were not diagnosed on CXR. The purpose of this study was to prospectively determine the incidence, and validate previously identified clinical predictors, of OPTXs after blunt trauma.

METHODS

All severe blunt injured patients (injury severity score (ISS)>or=12) presenting to a level 1 trauma centre over a 17-month period were prospectively evaluated. Thoracoabdominal CT scans and corresponding CXRs were reviewed at the time of admission. Patients with OPTXs were compared to those with overt PTXs regarding incidence and previously identified predictive risk factors (subcutaneous emphysema, rib fractures, female sex and pulmonary contusion).

RESULTS

CT imaging was performed concurrent to CXR in 405 blunt trauma patients (ISS>or=12) during the study period. PTXs were identified in 107 (26%) of the 405 patients. Eighty-one (76%) of these were occult when CXRs were interpreted by the trauma team. Concurrent chest trauma predictive of OPTXs was limited to subcutaneous emphysema (p=0.003). Rib fractures, pulmonary contusions and female sex were not predictive.

CONCLUSIONS

OPTXs were missed in up to 76% of all seriously injured patients when CXRs were interpreted by the trauma team. This is higher than previously reported in retrospective studies and is likely based on the difficult conditions in which the trauma team functions. Subcutaneous emphysema remains a strong clinical predictor for concurrent OPTXs.

Delayed pneumothorax after stab wound to thorax and upper abdomen: Truth or myth?

BACKGROUND

Stab wounds to the thorax and upper abdomen have the potential to cause pneumothorax (PTX). When a CXR (CXR) obtained during initial resuscitation is negative, a second CXR (CXR-2) is commonly performed with the goal of identifying delayed PTX.

OBJECTIVES

To assess the diagnostic yield of the CXR-2 in identifying delayed PTX.

METHODS

Prospective observational study of patients (age >or=13 years) with stab wounds to the thorax (chest/back) and upper abdomen with suspected PTX, in a level 1 trauma centre. Patients were included if they had a negative initial CXR followed by a repeat CXR 3-6h after the initial one.

EXCLUSION CRITERIA

patients who died, were transferred out of the ED, or received chest tubes before the second CXR. The outcome of interest was delayed PTX. All CXR were read by an attending radiologist. To test the inter-observer agreement, another blinded radiologist reviewed 20% of CXR. Continuous data is presented as mean+/-standard deviation and categorical data as percentages with 95% confidence interval (CI). Kappa statistics were used to measure the inter-observer agreement between radiologists.

RESULTS

Between January 2003 and December 2006 a total of 185 patients qualified for the enrollment (mean age: 28+/-10 years, age range: 13-65, 94% male). Only 2 patients (1.1%, 95% CI, 0.4- 4.1%) had PTX on the CXR-2. Both patients received chest tubes. The inter-observer agreement for radiology reports was high (kappa: 0.79).

CONCLUSION

Occurrence of delayed PTX in patients with stab wounds to the thorax and upper abdomen and negative triage CXR is rare.

Follow-up after asymptomatic penetrating thoracic injury: 3 hours is enough

BACKGROUND

Patients with asymptomatic penetrating thoracic injuries routinely undergo chest radiographs (CXRs) upon emergency department (ED) arrival, and then 6 hours later to exclude delayed pneumothorax (PTX) or hemothorax (HTX). Although previous reports indicate that up to 12% (mean, 3%) of asymptomatic penetrating thoracic injuries are complicated by delayed PTX or HTX, we hypothesized that these events would be detectable after only 3 hours of observation. The purpose of this study was to compare the incidence of delayed thoracic injury at 3 hours and 6 hours using standard CXR.

METHODS

A prospective trial of asymptomatic patients with penetrating thoracic injuries was conducted during 36 months. CXRs were performed upon arrival (supine, AP), and at 3 hours (upright, PA/lateral) and 6 hours (upright, PA/lateral). Patients with either injuries detected on initial CXR or cardiopulmonary symptoms were excluded. Findings from 3 hour and 6 hour CXRs were compared. Assuming a delayed PTX or HTX rate of 3%, the probability of detecting at least one delayed event between 3 hours and 6 hours in 100 patients is 95.25%.

RESULTS

Of 648 patients with penetrating thoracic injuries, 100 patients both met inclusion criteria and completed the study. Patients were predominantly young (32.5 years +/- 13.3 years [mean +/- SD]) men (75% men) with stab wounds (75% stab wounds, 25% gunshot wounds). The mean length of stay for patients discharged from the ED was 8.8 hours +/- 2.6 hours. Although two patients developed a PTX between arrival and 3 hours, none developed after 3 hours. Patient charges, hospital costs, and radiation exposure were calculated for patients in our proposed study protocol, totaling $2802, $189, and 0.08 mSv, respectively.

CONCLUSIONS

No patient in our study population developed a delayed PTX or HTX after 3 hours. Our results suggest that shortening the observation period after asymptomatic penetrating thoracic injuries to 3 hours is safe, cost-effective, minimizes radiation exposure, and may help relieve congested urban EDs.

Successful Management of Occult Pneumothorax without Tube Thoracostomy despite Positive Pressure Ventilation

The objective of this study was to determine whether tube thoracostomy can be safely avoided in a subset of patients with blunt occult pneumothorax. A retrospective review was performed. Management without tube thoracostomy was attempted for 59 occult pneumothoraces and was successful in 51 (86%). Observation was successful in 16 of 20 occult pneumothoraces (80%) exposed to positive pressure ventilation within 72 hours of admission. Eight delayed tube thoracostomies were required an average of 19.7 hours post admission. Patients who failed observant management had more significant physiologic derangement on admission (revised trauma score 6.96 vs 7.66, P = 0.04), were more likely to have significant multisystem trauma (88% vs 37%, P = 0.007), but were not more likely to require positive pressure ventilation (PPV) (50% vs 31%, P = 0.31). This study demonstrates that a subset of patients with blunt occult pneumothorax requiring positive pressure ventilation may be safely managed without tube thoracostomy.

Diagnostic techniques in thoracic trauma

Diagnosis of thoracic injury begins with a history of events and examination of the patient. Appropriate radiographic studies will be dictated by the findings on history and physical. Procedural examinations, such as endoscopy or angiography, may also be needed for accurate diagnosis.

Diagnostic Dilemmas and Current Controversies in Blunt Chest Trauma

Blunt chest injuries are common encounters in the emergency department. Instead of a comprehensive review of the management of all chest injuries, this review focuses on injuries that can be difficult to diagnose and manage, including blunt aortic injury, cardiac contusion, and blunt diaphragmatic injury. This review also discusses some recent controversies in the literature regarding the use of prophylactic antibiotics for tube thoracostomy and the optimal management of occult pneumothorax. The article concludes with a discussion of the management of rib fractures in the elderly.

The accuracy of thoracic ultrasound for detection of pneumothorax is not sustained over time: a preliminary study

BACKGROUND

Ultrasound has proven to be very accurate in the diagnosis of pneumothorax in the trauma suite. It is unknown whether this accuracy is maintained over time in patients with a thoracostomy (TT) in place.

METHODS

Hospitalized patients with a TT placed to treat a traumatic pneumothorax underwent serial daily bedside surgeon-performed ultrasound by 1 of 2 experienced surgeon sonographers who were unaware of concomitant X-ray findings. Results were compared with daily chest X-ray films. Data collected included size and day of placement of the chest tube, as well as the results of the serial ultrasounds and the comparative X-ray films.

RESULTS

Fourteen patients (78% men, mean age 33 years) sustained traumatic pneumothorax. The causes included stab wound (9), gunshot wound (3), and rib fracture (2). They underwent 126 (median 7) ultrasound evaluations and were followed between 4 and 26 (median 7) days after injury. Of these exams, 95 had a concomitant chest X-ray film within 1 hour of the ultrasound, thus 190 hemithoraces could be analyzed. Eighty-two ultrasounds were performed for hemithoraces that had no injury or TT in place and all 82 revealed normal pleural sliding. No pneumothoraces were noted on concomitant chest X-ray films (100% accuracy). One hundred eight ultrasounds were performed for hemithoraces that had a TT in place. For the first 24 hours, accuracy remained 100%. After 24 hours, however, sensitivity of ultrasound diagnosis of pneumothorax fell to 55%, specificity fell to 70%, positive predictive value to 43%, and negative predictive value to 79%. This led to an overall accuracy rate for ultrasound examination after 24 hours of 65%.

CONCLUSIONS

Ultrasound evaluation for pneumothorax is very accurate for the first 24 hours after insertion of a TT, but the accuracy, especially the positive predictive value, is not sustained over time, possibly as a result of the formation of intrapleural adhesions.

Advanced Trauma Life Support. ABCDE from a radiological point of view

Accidents are the primary cause of death in patients aged 45 years or younger. In many countries, Advanced Trauma Life Support® (ATLS®) is the foundation on which trauma care is based. We will summarize the principles and the radiological aspects of the ATLS®, and we will discuss discrepancies with day to day practice and the radiological literature. Because the ATLS® is neither thorough nor up-to-date concerning several parts of radiology in trauma, it should not be adopted without serious attention to defining the indications and limitations pertaining to diagnostic imaging.

Critical care issues in the early management of severe trauma

Violent trauma and road traffic injuries kill more than 2.5 million people in the world every year, for a combined mortality of 48 deaths per 100,000 population per year. Most trauma deaths occur at the scene or in the first hour after trauma, with a proportion from 34% to 50% occurring in hospitals. Preventability of trauma deaths has been reported as high as 76% and as low as 1% in mature trauma systems. Critical care errors may occur in a half of hospital trauma deaths, in most of the cases contributing to the death. The most common critical care errors are related to airway and respiratory management, fluid resuscitation, neurotrauma diagnosis and support, and delayed diagnosis of critical lesions. A systematic approach to the trauma patient in the critical care unit would avoid errors and preventable deaths.