Thoracic Ultrasound: What Non-radiologists Need to Know

Urban thoracic trauma: diagnosis and initial treatment of non-cardiac injuries in adults

This comprehensive review aims to delineate the prevailing non-cardiac thoracic injuries occurring in urban environments following initial on-site treatment and subsequent admission to hospital emergency departments. Our study involved a rigorous search within the PubMed database, employing key phrases and their combinations, including "thoracic injury," "thoracic trauma," "haemothorax," "lung contusion," "traumatic pneumothorax," "rib fractures," and "flail chest." We focused on original research articles and reviews. Non-cardiac thoracic injuries exhibit a high prevalence, often affecting poly-trauma patients, and contributing to up to 35% of polytrauma-related fatalities. Furthermore, severe thoracic injuries can result in a substantial 5% mortality rate. This review provides insights into clinical entities such as lung contusion, traumatic haemothorax, pneumothorax, rib fractures, and sternal fractures. Thoracic injuries represent a frequent and significant clinical concern for emergency department physicians and thoracic surgeons, warranting thorough understanding and timely intervention.

Thoracic Ultrasound Utility in Pulmonary Pathologies Following Blunt Chest Trauma: A Cross-Sectional Study From Barcelona, Venezuela

Background The thoracic ultrasound (TUS) is a monitoring tool that has gained worldwide popularity in various scenarios, offering the opportunity for dynamic, bedside evaluations. Recent studies indicate that the use of TUS enables the diagnosis of pathologies resulting from blunt chest trauma (BCT), yielding favorable outcomes. This study aimed to compare the utility of TUS versus chest radiography (CXR) in diagnosing pulmonary pathologies resulting from closed-chest traumas. Methodology A prospective cross-sectional study was conducted with a sample of 58 patients diagnosed with BCT who sought emergency care at the "Dr. Luis Razetti" University Hospital in Barcelona, Venezuela, from November 2023 to January 2024. Results Of the patients, 75.9% (n = 44) were male, with an average age of 37.8 years (standard deviation = 18.4 years). Injuries were reported in 8.6% (n = 5) of the patients, including 60% (n = 3) pneumothorax and 40% (n = 2) hemothorax. Ultrasound results coincided with CXR in 94.8% (n = 55) of the cases, with a Cohen's kappa coefficient of 0.9 (95% confidence interval (CI) = 0.642-1.0). TUS demonstrated higher sensitivity than CXR (100% vs. 60%) for detecting hemothorax and pneumothorax in patients with BCT, with an area under the receiver operating characteristic curve of 0.991 (95% CI = 0.968-1.013). Conclusions BCT predominantly occurred in young males, resulting primarily in pneumothorax and hemothorax lesions, detectable with higher sensitivity through TUS compared to CXR. The use of TUS should be considered an essential component of the initial assessment for individuals with BCT.

Quantitative Assessment of Lung Ultrasound Grayscale Images Based on Shannon Entropy for the Detection of Pulmonary Aeration: An Animal Study

OBJECTIVE

Lung ultrasound (LUS) is a radiation-free, affordable, and bedside monitoring method that can detect changes in pulmonary aeration before hypoxic damage. However, visual scoring methods of LUS only enable subjective diagnosis. Therefore, quantitative analysis of LUS is necessary for obtaining objective information on pulmonary aeration. Because raw data are not always available in conventional ultrasound systems, Shannon entropy (ShanEn) of information theory without the requirement of raw data is valuable. In this study, we explored the feasibility of ShanEn estimated through grayscale histogram (GSH) analysis of LUS images for the quantification of pulmonary aeration.

METHODS

Different degrees of pulmonary aeration caused by edema was induced in 32 male New Zealand rabbits intravenously injected with 0.1 mL/kg saline (the control group) and 0.025, 0.05, and 0.1 mL/kg oleic acid (mild, moderate, and severe groups, respectively). In vivo grayscale LUS images were acquired using a commercial point-of-care ultrasound system for estimation of GSH and corresponding ShanEn. Both lungs of each rabbit were dissected, weighed, and dried to determine the wet weight-to-dry weight ratio (W/D) through gravimetry.

RESULTS

The determination coefficients of linear correlations between ShanEn and W/D increased from 0.0487 to 0.7477 with gain and dynamic range (DR). In contrast to visual scoring methods of pulmonary aeration that use median gain and low DR, ShanEn for quantifying pulmonary aeration requires high gain and DR.

CONCLUSION

The current findings indicate that ShanEn estimated through GSH analysis of LUS images acquired using conventional ultrasonic imaging systems has great potential to provide objective information on pulmonary aeration.

Feasibility and efficacy of lung ultrasound to investigate pulmonary complications in patients who developed postoperative Hypoxaemia-a prospective study

Background

Postoperative pulmonary complications (PPCs) and hypoxaemia are associated with morbidity and mortality. We aimed to evaluate the feasibility and efficacy of lung ultrasound (LUS) to diagnose PPCs in patients suffering from hypoxaemia after general anaesthesia and compare the results to those of thoracic computed tomography (CT).

Methods

Adult patients who received general anaesthesia and suffered from hypoxaemia in the postanaesthesia care unit (PACU) were analysed. Hypoxaemia was defined as an oxygen saturation measured by pulse oximetry (SPO₂) less than 92% for more than 30 s under ambient air conditions. LUS was performed by two trained anaesthesiologists once hypoxaemia occurred. After LUS examination, each patient was transported to the radiology department for thoracic CT scan within 1 h before returning to the ward.

Results

From January 2019 to May 2019, 113 patients (61 men) undergoing abdominal surgery (45 patients, 39.8%), video-assisted thoracic surgery (31 patients, 27.4%), major orthopaedic surgery (17 patients, 15.0%), neurosurgery (10 patients, 8.8%) or other surgery (10 patients, 8.8%) were included. CT diagnosed 327 of 1356 lung zones as atelectasis, while LUS revealed atelectasis in 311 of the CT-confirmed zones. Pneumothorax was detected by CT scan in 75 quadrants, 72 of which were detected by LUS. Pleural effusion was diagnosed in 144 zones on CT scan, and LUS detected 131 of these zones. LUS was reliable in diagnosing atelectasis (sensitivity 98.0%, specificity 96.7% and diagnostic accuracy 97.2%), pneumothorax (sensitivity 90.0%, specificity 98.9% and diagnostic accuracy 96.7%) and pleural effusion (sensitivity 92.9%, specificity 96.0% and diagnostic accuracy 95.1%).

Conclusions

Lung ultrasound is feasible, efficient and accurate in diagnosing different aetiologies of postoperative hypoxia in healthy-weight patients in the PACU.

Trial registration

Current Controlled Trials NCT03802175, 2018/12/05, www.ClinicalTrials.gov

Ultrasonido pulmonar en Medicina, su utilidad en la práctica clínica

Lung ultrasound has become increasingly important in the evaluation of the thorax and its pathologies. It has proved to be very useful in the evaluation of hospitalized patients, allowing doctors to evaluate and make quick decisions, as well as providing guidance for diagnostic and therapeutic procedures. Ultrasound has many advantages over other studies since it can avoid transferring patients, and it is harmless, accessible and fast. In this article we will review basic concepts of lung ultrasound and its use in the diagnosis of pathologies. Key words: Pulmonary ultrasound; pleura; pneumothorax; pleural effusion.

Outcomes of an initiative to improve inpatient safety of small bore thoracostomy tube insertion

Background

Intercostal chest catheter (ICC) insertion is a common hospital procedure with attendant risks including life‐threatening complications such as pneumothorax and visceral damage.

Aim

To investigate the effect of a quality improvement (QI) initiative on complications associated with inpatient thoracostomy tube insertion.

Methods

Following an audit of ICC complications in inpatients over a 2‐year period we implemented a comprehensive QI programme. This involved formal training in and mandatory use of thoracic ultrasound, standardisation of the procedure and documentation, a dedicated procedure room with nurses trained in assisting ICC insertion and senior supervision for medical staff. An audit over 2 years post‐implementation of the QI protocol was compared with pre‐implementation results.

Results

A total of 103 cases were reviewed pre‐implementation and 105 cases were reviewed post‐implementation of the QI programme. All procedures following the QI initiative were image guided compared to 23.3% of cases pre‐implementation. The rate of developing a pneumothorax requiring intervention post‐implementation was less than pre‐implementation (1.9% vs 5.8% (P = 0.023). Post‐implementation, there were no instances of dry taps, viscera perforation, clinically significant bleeding or wrong side ICC insertion and documentation improved.

Conclusion

QI initiative applied to thoracostomy tube insertion in hospital inpatients can reduce complications and improve procedure documentation.

Relevance of lung ultrasound in the diagnostic algorithm of respiratory diseases in a real-life setting: A multicentre prospective study

BACKGROUND AND OBJECTIVE

The aim of this study was to assess the role of lung ultrasound (LUS) in a diagnostic algorithm of respiratory diseases, and to establish the accuracy of LUS compared with chest radiography (CXR).

METHODS

Over a period of 2 years, 509 consecutive patients admitted for respiratory-related symptoms to both emergency and general medicine wards were enrolled and evaluated using LUS and CXR. LUS was conducted by expert operators who were blinded to the medical history and laboratory data. Computed tomography (CT) of the chest was performed in case of discordance between the CXR and LUS, suspected lung cancer and an inconclusive diagnosis. Diagnosis made by CT was considered the gold standard.

RESULTS

The difference in sensitivity and specificity between LUS and CXR as demonstrated by ROC curve analyses (LUS-AUROC: 0.853; specificity: 81.6%; sensitivity: 93.9% vs CXR-AUROC: 0.763; specificity: 57.4%; sensitivity: 96.3%) was significant (P = 0.001). Final diagnosis included 240 cases (47.2%) of pneumonia, 44 patients with cancer (8.6%), 20 patients with chronic obstructive pulmonary disease (COPD, 3.9%), 24 patients with heart failure (4.7%) and others (6.1%). In 108 patients (21.2%) with any lung pathology, a CT scan was performed with a positive diagnosis in 96 cases (88.9%); we found that CXR and LUS detected no abnormality in 24 (25%) and 5 (5.2%) cases, respectively. LUS was concordant with the final diagnosis (P < 0.0001), and in healthy patients, there was a low percentage of false positives (5.9%).

CONCLUSION

The results support the routine use of LUS in the clinical context.

Application of Lung Ultrasound in Critical Care Setting: A Review

This article reviews the use of thoracic ultrasound in the intensive care unit (ICU). The focus of this article is to review the basic terminology and clinical applications of thoracic ultrasound. The diagnostic approach to a breathless patient, the blue protocol, is presented in a simplified flow chart. The diagnostic application of thoracic ultrasound in lung parenchymal and pleural diseases, role in bedside procedures, diaphragmatic assessment, and lung recruitment are described. Recent updates discussed in this review help support its increasingly indispensable role in the emergent and critical care setting.

Diagnostic Performance of 6-Point Lung Ultrasound in ICU Patients: A Comparison with Chest X-Ray and CT Thorax

Objective

To evaluate the diagnostic performance of a rapid bedside 6-point lung ultrasonography (LUS) performed by an intensive care unit (ICU) physician for detection of four common pathological conditions of the lung, such as alveolar consolidation, pleural effusion, interstitial syndrome and pneumothorax, in critically ill patients and its comparison with bedside chest X-ray (CXR) and high-resolution computed tomography (CT) scan of the thorax. Volume of pleural effusion measured by LUS and CT thorax was also compared.

Methods

This was a cross-sectional, observational study of 90 adult patients with an acute lung injury score of ≥1 admitted to the medical-surgical ICU. They were examined by CXR and 6-point LUS as per BLUE protocol at bedside, followed by CT thorax in the radiology department.

Results

The sensitivity of 6-point LUS for detecting alveolar consolidation, pleural effusion, interstitial syndrome and pneumothorax was 76%, 88%, 83% and 89%, respectively, which was remarkably higher than that of CXR. The specificity of LUS was 100% for all pathologies, which was again notably higher than that of CXR except for interstitial syndrome for which it was 88.5%. Measurement of volume of pleural effusion by LUS was comparable and had a strong absolute agreement with CT thorax.

Conclusion

6-Point LUS can be a useful diagnostic tool and is better than CXR in diagnosing respiratory pathologies in critically ill patients. Owing to the comparable diagnostic performance of LUS and CT scan and with increasing evidence in favour of LUS, the requirement of CT thorax can be reduced. Radiation hazards associated with CXR and CT, as well as potentially risky transfer of patients to CT room, can also be minimised.

Agreement between chest ultrasonography and chest X-ray in patients who have undergone thoracic surgery: preliminary results

Background

Chest Ultrasonography (chest US) has shown good sensibility in detecting pneumothorax, pleural effusions and peripheral consolidations and it can be performed bedside.

Objectives

The aim of the study was to analyze agreement between chest US and chest X-ray in patients who have undergone thoracic surgery and discuss cases of discordance.

Methods

Patients undergoing thoracic surgery were retrospectively selected. Patients underwent routinely Chest X-ray (CXR) during the first 48 h after surgery. Chest US have been routinely performed in all selected patients in the same date of CXR. Chest US operators were blind to both reports and images of CXR. Ultrasonographic findings regarding pneumothorax (PNX), subcutaneous emphysema (SCE), lung consolidations (LC), pleural effusions (PE) and hemi-diaphragm position were collected and compared to corresponding CXR findings. Inter-rater agreement between two techniques was determined by Cohen's kappa-coefficient.

Results

Twenty-four patients were selected. Inter-rater agreement showed a moderate magnitude for PNX (Cohen's Kappa 0.5), a slight/fair magnitude for SCE (Cohen's Kappa 0.21), a fair magnitude for PE (Cohen's Kappa 0.39), no agreement for LCs (Cohen's Kappa 0.06), high levels of agreement for position of hemi-diaphragm (Cohen's Kappa 0.7).

Conclusion

Analysis of agreement between chest X-ray and chest US showed that ultrasonography is able to detect important findings for surgeons. Limitations and advantages have been found for both chest X-ray and chest US. Knowing the limits of each one is important to really justify and optimize the use of ionizing radiations.

New insights in the use of pleural ultrasonography for diagnosis and treatment of pleural disease

The use of transthoracic ultrasound (US) has acquired a wide consensus among respiratory physicians during the last few years. The development of portable devices promotes patient's bedside evaluation providing rapid, real-time and low-cost diagnostic information. The different acoustic impedance between different tissues and organs produces artifacts known as A lines, B lines, sliding sign, lung point, etc. The identification of such artifacts is essential to discriminate normal pleural appearance from the presence of pleural effusion, pneumothorax, thickenings and tumors. Ultrasounds are also a valuable tool during interventional procedures, such as thoracentesis, chest tube insertion and transcutaneous biopsy. Its use is recommended before medical thoracoscopy in order to assess the best site of trocar insertion according to presence, quantity and characteristics of pleural effusion. The aim of this review is to provide practical tips on chest ultrasound in clinical and interventional respiratory practice.

Lung ultrasound as a monitoring tool in lung transplantation in rodents: a feasibility study

Background

Orthotopic lung transplantation in rats has been developed as a model to study organ dysfunction, but available tools for monitoring the graft function are limited. In this study, lung ultrasound (LUS) is proposed as a new non-invasive monitoring tool in awake rodents.

Methods

LUS was applied to native and graft lung of six rats after left orthotopic transplantation. Rats were monitored with LUS while awake, patterns identified, images evaluated with a scoring system, intra- and inter-rater agreement was assessed and examination times analyzed.

Results

A total of 78 clips were recorded. The median quality score of LUS was 3.66/4 for left hemithorax and 3.71/4 for native right side. The intra-rater agreement was 0.53 and 0.65 and the inter-rater agreement was 0.61 (P<0.01). Median time to complete the examination was 233.0 seconds (IQR 142) for both lungs, lowered from 254.0 seconds (IQR 129.5) (first trimester of study) to 205.5 seconds (IQR 88.5) (second trimester of the study). Significant findings on LUS were confirmed on pathological examination.

Conclusions

LUS in awake rodents without shaving has been shown to be both feasible and safe and the images collected were of good quality and comparable to those obtained in anesthetized rats without bristles.

Point-of-care ultrasound versus auscultation in determining the position of double-lumen tube

This study was designed to assess the accuracy of point-of-care ultrasound in determining the position of double-lumen tubes (DLTs).A total of 103 patients who required DLT intubation were enrolled into the study. After DLTs were tracheal intubated in the supine position, an auscultation researcher and ultrasound researcher were sequentially invited in the operating room to conduct their evaluation of the DLT. After the end of their evaluation, fiberscope researchers (FRs) were invited in the operating room to evaluate the position of DLT using a fiberscope. After the patients were changed to the lateral position, the same evaluation process was repeated. These 3 researchers were blind to each other when they made their conclusions. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were obtained by statistical analysis.When left DLTs (LDLTs) were used, the accuracy of ultrasound (84.2% [72.1%, 92.5%]) was higher than the accuracy of auscultation (59.7% [45.8%, 72.4%]) (P < .01). When right DLTs (RDLTs) were used, the accuracy of ultrasound (89.1% [76.4%, 96.4%]) was higher than the accuracy of auscultation (67.4% [52.0%, 80.5%]) (P < .01). When LDLTs were used in the lateral position, the accuracy of ultrasound (75.4% [62.2%, 85.9%]) was higher than the accuracy of auscultation (54.4% [40.7%, 67.6%]) (P < .05). When RDLT were used, the accuracy of ultrasound (73.9% [58.9%, 85.7%]) was higher than the accuracy of auscultation (47.8% [32.9%, 63.1%]) (P < .05).Assessment via point-of-care ultrasound is superior to auscultation in determining the position of DLTs.