Lung abscesses: US examination and US-guided transthoracic aspiration

Implementing an interprofessional point-of-care ultrasound protocol for dyspneic patients in an emergency department as a blended learning concept-Feasibility of Employing Thoracic Ultrasound in Shortness of Breath

Objective

Dyspnea is a common symptom in the Emergency Department, with a wide variety of differential diagnoses. Previous research has demonstrated the diagnostic accuracy of Point-of-Care Ultrasound (POCUS) in this field of interest. Our goal was to better establish sonography in our emergency department with a practicable and time effective method. Therefore, we implemented a sonography protocol in an interprofessional emergency team using blended learning as a modern didactic approach and evaluated the learning and teaching success. We named the study FETUS, which stands for "Feasibility of Employing Thoracic Ultrasound in Shortness of Breath."

Methods

A demonstration of the POCUS protocol was given, followed by individual supervision during clinical routine. A written manual, a pocket card, and further materials for personal training supplemented the training. A post-training questionnaire measured several parameters regarding the training, e.g., subjective skill-acquisition or media use.

Results

32 medical and nursing staff participated in this study, 14 of whom completed the questionnaire. All training modalities offered were well received. A pre-post comparison of subjective sonographic competence shows a significant increase in both medical and nursing staff.The other items surveyed also indicate the success of the intervention undertaken.

Conclusion

The use of different media as a blended learning approach can support the implementation of new measures in the ongoing working routine within an interprofessional team.

The making of hypervirulent Klebsiella pneumoniae

Klebsiella pneumoniae is a notorious bacterium in clinical practice. Virulence, carbapenem-resistance and their convergence among K. pneumoniae are extensively discussed in this article. Hypervirulent K. pneumoniae (HvKP) has spread from the Asian Pacific Rim to the world, inducing various invasive infections, such as pyogenic liver abscess, endophthalmitis, and meningitis. Furthermore, HvKP has acquired more and more drug resistance. Among multidrug-resistant HvKP, hypervirulent carbapenem-resistant K. pneumoniae (Hv-CRKP), and carbapenem-resistant hypervirulent K. pneumoniae (CR-HvKP) are both devastating for their extreme drug resistance and virulence. The hypervirulence of HvKP is primarily attributed to hypercapsule, macromolecular exopolysaccharides, or excessive siderophores, although it has many other factors, for example, lipopolysaccharides, fimbriae, and porins. In contrast with classical determination of HvKP, that is, animal lethality test, molecular determination could be an optional and practical method after improvement. HvKP, including Hv-CRKP and CR-HvKP, has been progressing. R-M and CRISPR-Cas systems may play pivotal roles in such evolutions. Hv-CRKP and CR-HvKP, in particular the former, should be of severe concern due to their being more and more prevalent.

Genetic Homology between Bacteria Isolated from Pulmonary Abscesses or Pyothorax and Bacteria from the Oral Cavity

Pulmonary abscesses and pyothorax are bacterial infections believed to be caused primarily by oral microbes. However, past reports addressing such infections have not provided genetic evidence and lack accuracy, as they used samples that had passed through the oral cavity. The aim of this study was to determine whether genetically identical bacterial strains exist in both the oral microbiota and pus specimens that were obtained percutaneously from pulmonary abscesses and pyothorax, without oral contamination. First, bacteria isolated from pus were identified by 16S rRNA gene sequencing. It was then determined by quantitative PCR using bacterial-species-specific primers that DNA extracted from paired patient oral swab sample suspensions contained the same species. This demonstrated sufficient levels of bacterial DNA of the targeted species to use for further analysis in 8 of 31 strains. Therefore, the whole-genome sequences of these eight strains were subsequently determined and compared against an open database of the same species. Five strain-specific primers were synthesized for each of the eight strains. DNA extracted from the paired oral swab sample suspensions of the corresponding patients was PCR amplified using five strain-specific primers. The results provided strong evidence that certain pus-derived bacterial strains were of oral origin. Furthermore, this two-step identification process provides a novel method that will contribute to the study of certain pathogens of the microbiota.

IMPORTANCE We present direct genetic evidence that some of the bacteria in pulmonary abscesses and pyothorax are derived from the oral flora. This is the first report describing the presence of genetically homologous strains both in pus from pulmonary abscesses and pyothorax and in swab samples from the mouth. We developed a new method incorporating quantitative PCR and next-generation sequencing and successfully prevented contamination of pus specimens with oral bacteria by percutaneous sample collection. The new genetic method would be useful for enabling investigations on other miscellaneous flora; for example, detection of pathogens from the intestinal flora at the strain level.

Ultrasound use in the ICU for interventional pulmonology procedures

Critical care ultrasound has shifted the paradigm of thoracic imaging by enabling the treating physician to acquire and interpret images essential for clinical decision-making, at the bedside, in real-time. Once considered impossible, lung ultrasound based on interpretation of artifacts along with true images, has gained momentum during the last decade, as an integral part of rapid evaluation algorithms for acute respiratory failure, shock and cardiac arrest. Procedural ultrasound image guidance is a standard of care for both common bedside procedures, and advanced procedures within interventional pulmonologist’s (IP’s) scope of practice. From IP’s perspective, the lung, pleural, and chest wall ultrasound expertise is a prerequisite for mastery in pleural drainage techniques and transthoracic biopsies. Another ultrasound application of interest to the IP in the intensive care unit (ICU) setting is during percutaneous dilatational tracheostomy (PDT). As ICU demographics shift towards older and sicker patients, the indications for closed pleural drainage procedures, bedside transthoracic biopsies, and percutaneous dilatational tracheostomies have dramatically increased. Although ultrasound expertise is considered an essential IP operator skill there is no validated curriculum developed to address this component. Further, there is a need for developing an educational tool that matches up with the curriculum and could be integrated real-time with ultrasound-guided procedures.

Effectiveness and Safety of Transthoracic Ultrasound in Guiding Percutaneous Needle Biopsy in the Lung and Comparison vs. CT Scan in Assessing Morphology of Subpleural Consolidations

(1) Background: The aim of this study was to conduct a prospective analysis on the diagnostic accuracy of transthoracic ultrasound-guided percutaneous needle biopsy (TUS-PNB) for the histological assessment of peripheral lung lesions and to assess the performance of transthoracic ultrasound (TUS) examination vs. chest CT (gold standard) in the differentiation between malignant and benign peripheral lung lesions. (2) Methods: A total of 961 consecutive patients with subpleural pulmonary lesions were enrolled. All the patients received a CT scan with contrast; 762 patients underwent TUS-PTNB for suspicion of malignancy, and the remaining 199 enrolled patients underwent only TUS examination as a part of routine follow-up for known non-malignant subpleural consolidations. (3) Results: Among the 762 TUS-guided biopsies, there were 627 (82.28%) malignant lesions, 82 (10.76%) benign lesions, and 53 (6.96%) indeterminate lesions. The overall diagnostic accuracy was 93.04%. The rates of pneumothorax not requiring chest-tube insertion and self-limited hemoptysis were 0.79 and 0.26%, respectively. Patients were divided into two groups based on the benign or malignant nature of the subpleural consolidations. On TUS, both malignant and benign lesions showed mostly irregular margins and a hypoechoic pattern, but no differences were assessed in terms of sonographic margins and pattern between the two groups. There was poor agreement between TUS and chest CT in assessing air bronchograms and necrotic areas. The only finding in the detection of which TUS showed superiority compared to chest-CT was pleural effusion. (4) Conclusions: TUS-PNB was confirmed to be an effective and safe diagnostic method for peripheral pulmonary consolidation, but their sonographic pattern did not allow to rule out a malignant nature. A pre-operative evaluation on CT images, combined with the possibility of performing additional immunohistochemical and cytological investigations and the experience of the medical staff, may improve the diagnostic yield of TUS-guided biopsies.

[Management of Adult Community-Acquired Pneumonia and Prevention - Update 2021 - Guideline of the German Respiratory Society (DGP), the Paul-Ehrlich-Society for Chemotherapy (PEG), the German Society for Infectious Diseases (DGI), the German Society of Medical Intensive Care and Emergency Medicine (DGIIN), the German Viological Society (DGV), the Competence Network CAPNETZ, the German College of General Practitioneers and Family Physicians (DEGAM), the German Society for Geriatric Medicine (DGG), the German Palliative Society (DGP), the Austrian Society of Pneumology Society (ÖGP), the Austrian Society for Infectious and Tropical Diseases (ÖGIT), the Swiss Respiratory Society (SGP) and the Swiss Society for Infectious Diseases Society (SSI)]

The present guideline provides a new and updated concept of the management of adult patients with community-acquired pneumonia. It replaces the previous guideline dating from 2016.The guideline was worked out and agreed on following the standards of methodology of a S3-guideline. This includes a systematic literature search and grading, a structured discussion of recommendations supported by the literature as well as the declaration and assessment of potential conflicts of interests.The guideline has a focus on specific clinical circumstances, an update on severity assessment, and includes recommendations for an individualized selection of antimicrobial treatment.The recommendations aim at the same time at a structured assessment of risk for adverse outcome as well as an early determination of treatment goals in order to reduce mortality in patients with curative treatment goal and to provide palliation for patients with treatment restrictions.

ACR Appropriateness Criteria® Pneumonia in the Immunocompetent Child

Pneumonia is one of the most common acute infections and the single greatest infectious cause of death in children worldwide. In uncomplicated, community-acquired pneumonia in immunocompetent patients, the diagnosis is clinical and imaging has no role. The first role of imaging is to identify complications associated with pneumonia such as pleural effusion, pulmonary abscess, and bronchopleural fistula. Radiographs are recommended for screening for these complications and ultrasound and CT are recommended for confirmation. The second role of imaging is to identify underlying anatomic conditions that may predispose patients to recurrent pneumonia. CT with intravenously administered contrast is recommended for this evaluation. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Thoracic ultrasonography: a narrative review

This narrative review focuses on thoracic ultrasonography (lung and pleural) with the aim of outlining its utility for the critical care clinician. The article summarizes the applications of thoracic ultrasonography for the evaluation and management of pneumothorax, pleural effusion, acute dyspnea, pulmonary edema, pulmonary embolism, pneumonia, interstitial processes, and the patient on mechanical ventilatory support. Mastery of lung and pleural ultrasonography allows the intensivist to rapidly diagnose and guide the management of a wide variety of disease processes that are common features of critical illness. Its ease of use, rapidity, repeatability, and reliability make thoracic ultrasonography the "go to" modality for imaging the lung and pleura in an efficient, cost effective, and safe manner, such that it can largely replace chest imaging in critical care practice. It is best used in conjunction with other components of critical care ultrasonography to yield a comprehensive evaluation of the critically ill patient at point of care.

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.

[Lung abscess: Diagnosis and management]

Lung abscesses are necrotic cavitary lesions of the lung parenchyma. They are usually caused by anaerobic bacteria or mixed flora and typically occur after aspiration. Primary lung abscesses occur in previously healthy patients with no underlying medical disorders and are usually solitary. Secondary lung abscesses occur in patients with underlying or predisposing conditions and may be multiple. The initial diagnosis is usually made by chest radiography showing a lung cavity with an air-fluid level. Typically, the cavity wall is thick and irregular, and a surrounding pulmonary infiltrate is often present. The differential diagnosis of pulmonary cavitation is wide, including different types of possible infections, neoplasia and malformations of the bronchial tree. Management is usually based on prolonged antibiotic treatment. Failure of conservative management, manifested by the persistence of sepsis and/or other abscess complications, may necessitate drainage with invasive techniques (percutaneous, endoscopic or surgical) or open surgical removal of the lung lesion in patients with good performance status and sufficient respiratory reserve.

Basic Insights of Lung Ultrasonography in Critical Care Setting

Lung ultrasonography has a tailored diagnostic and therapeutic approach in the critical care setting. Lung ultrasonography in critically ill (LUCI) is a helpful modality for the early detection and assessment of various lung pathologies and guides the management protocol for the same. The aim of this review was to highlight the basics of an ultrasound machine, the fundamentals of a lung ultrasound and the importance of lung artifacts in detecting the anatomy and pathology of the lung disease. In addition, we have also discussed regarding the effective approach to lung ultrasonography through the two protocols: the Bedside Lung Ultrasound in Emergency (BLUE) protocol and the Fluid Administration Limited by Lung Sonography (FALLS) protocol.

Lung ultrasound for diagnosis and monitoring of ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) is the most frequent nosocomial infection in intensive care units (ICU) and is associated with increased mortality, use of antimicrobials, longer mechanical ventilation, and higher healthcare costs. Lung ultrasonography (LUS) can be used at the bedside and gained widespread acceptance in ICU. Although the visualization of a single LUS sign cannot be considered specific for a diagnosis, clinically-driven LUS examination in particular setting and clinical conditions allow ruling in or out quickly and accurately several causes of acute respiratory failure. This article reviews LUS signs for VAP diagnosis and summarizes the studies testing LUS for VAP diagnosis and monitoring. Many VAP occurs in already injured regions, thus presence of lobar consolidation is not enough to affirm VAP. However, a linear/arborescent air-bronchogram confirms the diagnosis of VAP with a good specificity, a normal LUS rules out the diagnosis of VAP (in experimented hands). LUS, thanks to its bedside ready availability, has the potential to become a key tool in early VAP diagnosis. LUS could ideally represent the decision-making tool for antimicrobial therapy administration in the timeframe of the technical time required for bronchoalveolar lavage analysis. A systematic approach for diagnosis and monitoring of VAP with LUS is also proposed in this review. But specific data on LUS specificity and sensitivity for the diagnosis of VAP are still lacking and should be investigated.

Lung Infections

A review of pulmonary infections of all types with diagnostic and morphological features.

Understanding the Lung Abscess Microbiome: Outcomes of Percutaneous Lung Parenchymal Abscess Drainage with Microbiologic Correlation

INTRODUCTION

Lung parenchymal abscesses represent an uncommon pathology with high mortality if untreated. Although most respond well to antibiotics, the optimal therapy for persistent abscesses is unknown. The purpose of this study was to review the outcomes of percutaneous lung parenchymal abscess catheter drainage after broad-spectrum antibiotic therapy failure and correlate with patient microbiologic samples.

MATERIALS AND METHODS

Retrospective review of patients who underwent percutaneous lung abscess drainage at a tertiary hospital system from 2005 to 2015 was performed. In total, 19 procedures were identified on 16 different patients; six females and ten males. Mean patient age was 55 years (range 22-81). Median follow-up time was 7 months (range <1-78).

RESULTS

Technical success was 100%. There was one major complication, a pneumothorax. Follow-up was until tube removal or death in 100% of patients. Catheters were removed with resolution of the abscess cavity in 58% (11/19) or with non-draining abscess cavities in 21% (4/19) for a clinical success rate of 79%. Blood cultures demonstrated no growth in all cases, while 21% (4/19) of sputum or bronchoscopic cultures demonstrated growth. In comparison, the specimens from initial catheter placement isolated a causative organism in 95% (18/19) of case (p < 0.0001).

CONCLUSION

In cases of persistent lung abscess after broad-spectrum antibiotics, percutaneous abscess drainage is highly sensitive for microbiologic sampling compared to sputum/bronchoscopic or blood cultures. Additionally, percutaneous drainage of lung parenchymal abscess cavities may promote resolution of the abscess with high rates of therapeutic success and low complications.

Pleuro-Pulmonary Aspergillosis

We reviewed the US findings and the diagnostic yield of fine-needle aspiration biopsy (FNAB) for cytologic and microbiologic samples in 4 patients with pulmonary or pleural aspergillosis. All 3 apical Aspergillus abscesses were round, hypoechoic with irregular margins and one contained echo-densities with shadowing consistent with air. One pleural empyema was oval and hypoechoic. Cytology suggested inflammation in all cases and Aspergillus hyphae were detected in 2 of 4 aspirates. Culture of the aspirate was positive for Aspergillus in 3 of 4 cases, while one diagnosis was made after surgery. No complications occurred. Apico-pleural Aspergillus lesions are suitable targets for US-guided FNAB, thus avoiding more invasive methods. Our results suggest wider use of this procedure.

The Diagnostic Role of Ultrasound in the Chest

Although the plain radiograph and computed tomography remain undoubtedly the primary imaging modalities in the investigation of chest pathology, ultrasound can play an important complementary role, both in the diagnostic workup of a patient and in their subsequent management. Its lack of ionizing radiation, bedside availability and dynamic imaging capacity afford ultrasound certain advantages over other techniques; particularly in the critical care setting where conventional radiography is often suboptimal. This article reviews the technique and diagnostic application of ultrasound in the assessment of pathologies of the diaphragm, pleura, lung, mediastinum and chest wall.

Ultrasound for the Pulmonary Consultant

Bedside ultrasonographic assessment of the lung and pleura provides rapid, noninvasive, and essential information in diagnosis and management of various pulmonary conditions. Ultrasonography helps in diagnosing common conditions, including consolidation, interstitial syndrome, pleural effusions and masses, pneumothorax, and diaphragmatic dysfunction. It provides procedural guidance for various pulmonary procedures, including thoracentesis, chest tube insertion, transthoracic aspiration, and biopsies. This article describes major applications of ultrasonography for the pulmonary consultant along with illustrative figures and videos.

Klebsiella pneumoniae: Going on the Offense with a Strong Defense

Klebsiella pneumoniae causes a wide range of infections, including pneumonias, urinary tract infections, bacteremias, and liver abscesses. Historically, K. pneumoniae has caused serious infection primarily in immunocompromised individuals, but the recent emergence and spread of hypervirulent strains have broadened the number of people susceptible to infections to include those who are healthy and immunosufficient. Furthermore, K. pneumoniae strains have become increasingly resistant to antibiotics, rendering infection by these strains very challenging to treat. The emergence of hypervirulent and antibiotic-resistant strains has driven a number of recent studies. Work has described the worldwide spread of one drug-resistant strain and a host defense axis, interleukin-17 (IL-17), that is important for controlling infection. Four factors, capsule, lipopolysaccharide, fimbriae, and siderophores, have been well studied and are important for virulence in at least one infection model. Several other factors have been less well characterized but are also important in at least one infection model. However, there is a significant amount of heterogeneity in K. pneumoniae strains, and not every factor plays the same critical role in all virulent Klebsiella strains. Recent studies have identified additional K. pneumoniae virulence factors and led to more insights about factors important for the growth of this pathogen at a variety of tissue sites. Many of these genes encode proteins that function in metabolism and the regulation of transcription. However, much work is left to be done in characterizing these newly discovered factors, understanding how infections differ between healthy and immunocompromised patients, and identifying attractive bacterial or host targets for treating these infections.

An update on the drainage of pyogenic lung abscesses

Most lung abscesses (80-90%) are now successfully treated with antibiotics; however, this conservative approach may occasionally fail. When medical treatment fails, pulmonary resection is usually advised. Alternatively, percutaneous transthoracic tube drainage or endoscopic drainage can be considered, though both remain controversial. In this communication, the medical literature focusing on percutaneous tube drainage efficacy, indications, techniques, complications, and mortality, as well as available data regarding endoscopic drainage are reviewed.

Pneumonia in the immunocompetent patient

Pneumonia is an acute inflammation of the lower respiratory tract. Lower respiratory tract infection is a major cause of mortality worldwide. Pneumonia is most common at the extremes of life. Predisposing factors in children include an under-developed immune system together with other factors, such as malnutrition and over-crowding. In adults, tobacco smoking is the single most important preventable risk factor. The commonest infecting organisms in children are respiratory viruses and Streptoccocus pneumoniae. In adults, pneumonia can be broadly classified, on the basis of chest radiographic appearance, into lobar pneumonia, bronchopneumonia and pneumonia producing an interstitial pattern. Lobar pneumonia is most commonly associated with community acquired pneumonia, bronchopneumonia with hospital acquired infection and an interstitial pattern with the so called atypical pneumonias, which can be caused by viruses or organisms such as Mycoplasma pneumoniae. Most cases of pneumonia can be managed with chest radiographs as the only form of imaging, but CT can detect pneumonia not visible on the chest radiograph and may be of value, particularly in the hospital setting. Complications of pneumonia include pleural effusion, empyema and lung abscess. The chest radiograph may initially indicate an effusion but ultrasound is more sensitive, allows characterisation in some cases and can guide catheter placement for drainage. CT can also be used to characterise and estimate the extent of pleural disease. Most lung abscesses respond to medical therapy, with surgery and image guided catheter drainage serving as options for those cases who do not respond.

Lung ultrasound in acute respiratory distress syndrome and acute lung injury

PURPOSE OF REVIEW

Lung ultrasound at the bedside can provide accurate information on lung status in critically ill patients with acute respiratory distress syndrome.

RECENT FINDINGS

Lung ultrasound can replace bedside chest radiography and lung computed tomography for assessment of pleural effusion, pneumothorax, alveolar-interstitial syndrome, lung consolidation, pulmonary abscess and lung recruitment/de-recruitment. It can also accurately determine the type of lung morphology at the bedside (focal or diffuse aeration loss), and therefore it is useful for optimizing positive end-expiratory pressure. The learning curve is brief, so most intensive care physicians will be able to use it after a few weeks of training.

SUMMARY

Lung ultrasound is noninvasive, easily repeatable and allows assessment of changes in lung aeration induced by the various therapies. It is among the most promising bedside techniques for monitoring patients with acute respiratory distress syndrome.

Point-of-care ultrasound: Infection control in the intensive care unit

Ultrasound provides a diagnostic modality that allows a whole-body approach at the bedside of a critically ill patient in the search for infectious foci. Both common sites of infection, such as the lung and pleura, central veins, and maxillary sinuses, and also less common sites, such as gastrointestinal perforation, sepsis due to mesenteric ischemia, or even meningitis, provide characteristic ultrasound patterns. Optimal use of ultrasound also combines bedside diagnosis with subsequent interventional procedures that can decrease the need for transfer to other imaging and interventional suites. Experience has shown that fevers of unknown origin in the critical care unit often have ultrasound equivalents. Thus, if a comprehensive ultrasound examination is negative, it is now appropriate to speak of fever of unknown sonographic origin.

Clinical review: Bedside lung ultrasound in critical care practice

Lung ultrasound can be routinely performed at the bedside by intensive care unit physicians and may provide accurate information on lung status with diagnostic and therapeutic relevance. This article reviews the performance of bedside lung ultrasound for diagnosing pleural effusion, pneumothorax, alveolar-interstitial syndrome, lung consolidation, pulmonary abscess and lung recruitment/derecruitment in critically ill patients with acute lung injury.

Pediatric chest ultrasound

Ultrasound examination of the thorax can be quite rewarding in children, because their unique thoracic anatomy provides many acoustic windows into the chest. With only a modest effort, chest ultrasonography can provide many clinically relevant answers, without the radiation exposure from CT, or the need for sedation sometimes required for CT and MR imaging.

Changing bacteriology of adult community-acquired lung abscess in Taiwan: Klebsiella pneumoniae versus anaerobes

BACKGROUND

Most literature regarding lung abscess focuses on anaerobic bacterial lung abscess, and aerobic gram-negative bacillary infection is less frequently discussed. This study was conducted to investigate the bacteriology of community-acquired lung abscess and to improve the empirical therapeutic strategy for adults with community-acquired lung abscess.

METHODS

We reviewed and analyzed data on 90 consecutive adult cases of bacteriologically confirmed community-acquired lung abscess treated during 1995-2003 at a tertiary university hospital in Taiwan.

RESULTS

We found that a high proportion (21%) of cases of lung abscess were due to Klebsiella pneumoniae infection, which differs from the findings of previous studies. Lung abscess due to K. pneumoniae was associated with underlying diabetes mellitus (odds ratio [OR], 4.3; 95% confidence interval [CI], 1.0-18.4; P = .039) and negatively correlated with a time from onset of symptoms to diagnosis of >30 days (OR, 0.2; 95% CI, 0.1-0.7; P = .008). A higher percentage of patients with K. pneumoniae lung abscess had concomitant bacteremia (OR, 9.4; 95% CI, 1.1-81.9; P = .032), delayed defervesence (OR, 9.2; 95% CI, 1.8-47.8; P = .004), and multiple cavities noted on radiographs (OR, 11.0; 95% CI, 1.3-94.9; P = .015), compared with patients with anaerobic bacterial lung abscess. The rate of nonsusceptibility to clindamycin and penicillin among anaerobes and Streptococcus milleri group isolates increased.

CONCLUSION

K. pneumoniae has become a more common cause of lung abscess than before, and a high proportion of anaerobes and S. milleri strains have become resistant to penicillin and clindamycin. A beta-lactam/beta-lactamase inhibitor or second- or third-generation cephalosporin with clindamycin or metronidazole is suggested as empirical antibiotic therapy for community-acquired lung abscess.

Differentiating Pyopneumothorax and Peripheral Lung Abscess: Chest Ultrasonography

BACKGROUND

Differentiation between pyopneumothorax and lung abscess can be difficult but has important therapeutic consequences. The role of chest ultrasonography in this issue remains undetermined. Sonographic features of hydropneumothorax and/or pyopneumothorax are characteristic and not difficult to recognize. In this study, the authors evaluate the usefulness of a panel of sonographic findings characteristic of hydropneumothorax in distinguishing pyopneumothorax from lung abscess.

METHODS

This series included 16 patients with lung abscess and 19 with pyopneumothorax. A diagnosis of lung abscess or pyopneumothorax was based on the following criteria: pus aspiration from the lesion, appropriate clinical setting, thoracic computed tomographic findings, serial follow-up of chest radiograms, and consistent clinical course. The panel of sonographic features suggestive of hydropneumothorax, including the presence of air-fluid level, the curtain sign, loss of gliding sign above the air-fluid level, and the suspended microbubble sign, were recorded and analyzed by a consensus of blinded readers. In addition, sonographic features used to differentiate empyema and lung abscess were also evaluated.

RESULTS

The results indicated that the presence of air-fluid level, the curtain sign, loss of gliding sign above the air-fluid level, and the suspended microbubble sign were valuable in distinguishing pyopneumothorax from lung abscess. All four sonographic findings were observed in 17 of 19 patients with pyopneumothorax. In contrast, two or fewer sonographic findings were seen in 16 patients with lung abscess. Our results confirmed that the wall characteristics, shape of the lesion, chest wall angle, and pleural separation were also useful.

CONCLUSIONS

The panel of sonographic findings is of considerable value in differentiating pyopneumothorax and lung abscess.

Ultrasound diagnosis of alveolar consolidation in the critically ill

OBJECTIVE

Alveolar consolidation is a basic concern in critically ill patients. Radiography is not a precise tool, and referral to CT raises problems (transport, irradiation). The aim of this study was to assess the utility of ultrasound in the diagnosis of alveolar consolidation.

DESIGN

Prospective clinical study.

SETTING

The medical ICU of a university-affiliated teaching hospital.

PATIENTS

A total of 65 cases of alveolar consolidation proven on CT were compared to 53 CT controls.

MEASUREMENTS

Alveolar consolidation was defined as a tissue-like pattern visible at the chest wall, arising from the pleural line and devoid of centrifugal inspiratory dynamics.

RESULTS

Feasibility was 99%. In 65 cases of alveolar consolidation, ultrasound was positive in 59 and negative in 6. In 52 analyzable controls, ultrasound was negative in 51 and positive in 1. Sensitivity of ultrasound was 90% and specificity 98%. A concordance test showed a Kappa coefficient of 0.89. Among 62 posterior locations on CT, ultrasound showed posterior consolidation patterns in 56 cases and was negative in 6. Ultrasound showed anterior involvement in all 3 cases of whole lung consolidation.

CONCLUSIONS

Ultrasound provides a reliable non-invasive, bedside method for accurate detection and location of alveolar consolidation in critically ill patients.

[Lung abscess in infancy--a rare disease. Clinical cases]

Lung abscess is a rare entity in childhood, but leads to high morbidity and long length of hospitalisation. It appears commonly in children with risk factors or other disease, have a good response to antibiotic therapy and it is rarely necessary the use of invasive techniques. Authors present two cases of lung abscess in children, one of them with risk factors to aspiration, that improved with antibiotic therapy and make a revision about this entity in infancy.

Percutaneous drainage of pyogenic lung abscess

Although lung abscesses are successfully treated with antibiotics in 80-90% of cases, this conservative approach may occasionally fail. In cases of failure, pulmonary resection is usually advised. Although it remains controversial, an alternative therapy in such situations is percutaneous transthoracic tube drainage (PTTD). Herein we review the medical literature on PTTD from the last 25 y, focusing on its efficacy, indications, technique, complications and mortality. We conclude that PTTD is a safe, simple and efficacious tool for the management of refractory lung abscess. Complications relating to the procedure occurred in 9.7% of cases and included catheter occlusion, chest pain, pneumothorax and hemothorax. The overall mortality rate secondary to lung abscess was acceptable (4.8%).

Real-time chest ultrasonography: a comprehensive review for the pulmonologist

This review discusses real-time pulmonary ultrasonography (US) for the practicing pulmonologist. US supplements chest radiography and chest CT scanning. Major advantages include bedside availability, absence of radiation, and guided aspiration of fluid-filled areas and solid tumors. Pulmonary vessels and vascular supply of consolidations may be visualized without contrast. US may help to diagnose conditions such as pneumothorax, hemothorax, pleural or pericardial effusion, pneumonia, and pulmonary embolism in the critically ill patient who is in need of bedside diagnostic testing. The technique of US, which is cost-effective compared to CT scanning and MRI, may be learned relatively easily by the pulmonologist.

Transthoracic US of the chest: clinical uses and applications

Transthoracic ultrasound (US) of the chest is useful in the evaluation of a wide range of peripheral parenchymal, pleural, and chest wall diseases. Furthermore, it is increasingly used to guide interventional procedures of the chest and pleural space. The technique lends itself to bedside use in the intensive care unit, where suboptimal radiography may mask or mimic clinically significant abnormalities. The authors discuss the uses, techniques and applications of US of the chest. The sonographic appearances of pleural diseases (pleural effusion, pneumothorax, pleural mass, and mesothelioma), parenchymal diseases (pneumonia, neoplasms, heart failure, infarct, and rounded atelectasis), chest wall abnormalities (chest wall tumor and rib fracture), and diaphragmatic paralysis are discussed. The use of US in guiding biopsy, thoracocentesis, and other interventional procedures of the lung, pleural space, and mediastinum are also reviewed.

Imaging guided thoracic interventions

Interventional Radiology is a technique based medical specialty, using all available imaging modalities (fluoroscopy, ultrasound, computed tomography, magnetic resonance, angiography) for guidance of interventional techniques for diagnostic or therapeutic purposes. Actual, percutaneous transthoracic needle biopsy includes core needle biopsy besides fine needle aspiration. Any pleural, pulmonary or mediastinal fluid or gas collection is amenable to percutaneous pulmonary catheter drainage. Treatment of haemoptysis of the bronchial artery or pulmonary artery origin, transcatheter embolization of pulmonary arteriovenous malformations and pseudoaneurysms, angioplasty and stenting of the superior vena caval system and percutaneous foreign body retrieval are well established routine procedures, precluding unnecessary surgery. These techniques are safe and effective in experienced hands. Computed tomography is helpful in pre- and postoperative imaging of patients being considered for endobronchial stenting. Many procedures can be performed on an outpatient basis, thus increasing the cost-effectiveness of radiologically guided interventions in the thorax.