Nonresolving Pneumonia

Prediction of short-term progression of COVID-19 pneumonia based on chest CT artificial intelligence: during the Omicron epidemic

BACKGROUND AND PURPOSE

The persistent progression of pneumonia is a critical determinant of adverse outcomes in patients afflicted with COVID-19. This study aimed to predict personalized COVID-19 pneumonia progression between the duration of two weeks and 1 month after admission by integrating radiological and clinical features.

METHODS

A retrospective analysis, approved by the Institutional Review Board, encompassed patients diagnosed with COVID-19 pneumonia between December 2022 and February 2023. The cohort was divided into training and validation groups in a 7:3 ratio. A trained multi-task U-Net network was deployed to segment COVID-19 pneumonia and lung regions in CT images, from which quantitative features were extracted. The eXtreme Gradient Boosting (XGBoost) algorithm was employed to construct a radiological model. A clinical model was constructed by LASSO method and stepwise regression analysis, followed by the subsequent construction of the combined model. Model performance was assessed using ROC and decision curve analysis (DCA), while Shapley's Additive interpretation (SHAP) illustrated the importance of CT features.

RESULTS

A total of 214 patients were recruited in our study. Four clinical characteristics and four CT features were identified as pivotal components for constructing the clinical and radiological models. The final four clinical characteristics were incorporated as well as the RS_radiological model to construct the combined prediction model. SHAP analysis revealed that CT score difference exerted the most significant influence on the predictive performance of the radiological model. The training group's radiological, clinical, and combined models exhibited AUC values of 0.89, 0.72, and 0.92, respectively. Correspondingly, in the validation group, these values were observed to be 0.75, 0.72, and 0.81. The DCA curve showed that the combined model exhibited greater clinical utility than the clinical or radiological models.

CONCLUSION

Our novel combined model, fusing quantitative CT features with clinical characteristics, demonstrated effective prediction of COVID-19 pneumonia progression from 2 weeks to 1 month after admission. This comprehensive model can potentially serve as a valuable tool for clinicians to develop personalized treatment strategies and improve patient outcomes.

Treatment Failure and Clinical Stability in Severe Community-Acquired Pneumonia

Treatment failure and clinical stability are important outcomes in community-acquired pneumonia (CAP). It is essential to know the causes and risk factors for treatment failure and delay in reaching clinical stability in CAP. The study of both as well as the associated underlying mechanisms and host response are key to improving outcomes in pneumonia.

Primary lung adenocarcinoma mimicking recurrent pneumonia in a young adult

A man in his 20s with a history of tobacco use presented with recurrent shortness of breath. He was hospitalised three times within the past 4 months for similar symptoms despite completing several courses of antibiotic therapy. In this presentation, he was afebrile with rhonchi and decreased breath sounds over the right lung. Chest CT demonstrated large consolidations in the right middle and lower lobes, worsened compared with 4 months prior. Infectious workup including bronchoscopy with bronchoalveolar lavage did not identify a causative organism. Testing for immune disease was negative. Transbronchial biopsy ultimately identified well-differentiated stage 3b lung adenocarcinoma with a KRAS G12C mutation. The patient was referred to oncology for outpatient follow-up and has since initiated chemotherapy. This case highlights diagnostic biases encountered in young patients and the utility of bronchoscopic biopsy for definitive diagnosis in presumed community-acquired pneumonia when the clinical outcome is not improving as expected.

Peripheral Pulmonary Lesions in Confirmed Pulmonary Arterial Embolism: Follow-up Study of B-Mode Ultrasound and of Perfusion Patterns Using Contrast-Enhanced Ultrasound (CEUS)

PURPOSE

This retrospective study aimed to describe the B-mode lung ultrasound (B-LUS) and contrast-enhanced ultrasound (CEUS) follow-up patterns of peripheral pulmonary lesions (PPLs) in patients with confirmed pulmonary embolism (PE).

PATIENTS AND METHODS

Data from 27 patients with a confirmed diagnosis of PE and PPLs over 5 mm from October 2009 to November 2018 were included retrospectively in the study. The inclusion criteria were performance of a baseline CEUS examination, a short-term B-LUS and CEUS follow-up, and a long-term B-LUS follow-up of PPLs. The homogeneity of enhancement of PPLs (homogeneous/inhomogeneous/absent) on CEUS and the presence and size of PPLs on B-LUS were evaluated.

RESULTS

A total of n = 25/27 (92.6%) lesions showed absent or inhomogeneous enhancement during baseline examination or short-term follow-up, indicating impaired perfusion. On short-term CEUS follow-up, 9/27 cases (33.3%) showed a pattern shift. On B-LUS long-term follow-up, 26/27 lesions (96.3%) were detectable for an average of 10 weeks (range 3-32 weeks). The size of reference lesions was significantly reduced at the time of the final follow-up examination (P < .05).

CONCLUSION

B-LUS follow-up showed that, in patients with confirmed PE, PPLs had a delayed regression. On CEUS follow-up examination, various perfusion patterns of PPLs were observed, indicating the different ages and the variable reparative processes of pulmonary infarction. In PPLs independent of the underlying signs and symptoms, follow-up B-LUS and CEUS examinations may be helpful for a possible retrospective diagnosis of peripheral pulmonary infarction suggestive of PE.

Nonresolving pneumonia in the setting of malignancy

PURPOSE OF REVIEW

This article reviews recent literature and experience in the diagnosis of nonresolving and slowly resolving pneumonia as it pertains to malignancy.

RECENT FINDINGS

Malignancy must be considered as an important cause of pneumonia that resolves slowly or has incomplete resolution. Airway obstruction is more common than malignant infiltration as a cause of pneumonia that does not resolve appropriately. Infection due to resistant or unusual organisms must also be considered in the differential diagnosis.

SUMMARY

Nonresolving pneumonia remains an important clinical challenge. Bronchoscopic evaluation in conjunction with computed tomography and PET scanning is still the most important technique for diagnosis.

Lung Infections

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

Risk factors for slowly resolving pneumonia in the intensive care unit

BACKGROUND

Slowly resolving pneumonia (SRP) poses early challenges for identification and medical expense for clinicians in intensive care units (ICUs); to date, the literature has been very limited in this regard.

METHODS

This was a retrospective and cohort-based study in the ICU of a university-affiliated hospital in Shanghai. Medical records of pneumonia patients in the ICU between April 2008 and February 2011were reviewed retrospectively to evaluate the risk factors for SRP.

RESULTS

In all, 106 pneumonia patients in the ICU were identified as immune-competent with a diagnosis of bacterial pneumonia. There were 62 (58.49%) patients who showed SRP and their radiographic infiltrations were completely resolved between 5 weeks and 8 weeks. Multivariate logistic regression analysis demonstrated that initial treatment with an inappropriate antibiotic, multilobar infiltration, and a high CURB-65 score were independent risk factors for SRP, with odds ratio (OR) values of 8.338 [95% confidence interval (CI) 2.117-32.848], 11.184 (95% CI 2.526-49.514), and 2.329 (95% CI 1.172-4.626), respectively. The length of the ICU stay in the SRP group was twice as long as that of the normally resolving pneumonia (NRP) group (62.27 ± 73.73 vs. 32.25 ± 23, p = 0.002). The 28-day and 60-day mortality rates in the SRP group were 17.74% and 25.81%, respectively. In addition, the 60-day mortality rate was significantly higher in the SRP group than the NRP group (25.81% vs. 6.82%, respectively; p = 0.012). Moreover, SRP was an independent risk factor for 60-day mortality (OR 5.687, 95% CI 1.334-24.240).

CONCLUSION

Treatment with an inappropriate antibiotic, multilobar infiltration, and a high CURB-65 score were independent risk factors for SRP.

Outcome of recommendations for radiographic follow-up of pneumonia on outpatient chest radiography

OBJECTIVE

Follow-up chest radiographs are frequently recommended by radiologists to document the clearing of radiographically suspected pneumonia. However, the clinical utility of follow-up radiography is not well understood. The purpose of this study was to examine the incidence of important pulmonary pathology revealed during follow-up imaging of suspected pneumonia on outpatient chest radiography.

MATERIALS AND METHODS

Reports of 29,138 outpatient chest radiography examinations performed at an academic medical center in 2008 were searched to identify cases in which the radiologist recommended follow-up chest radiography for presumed community-acquired pneumonia (n = 618). Descriptions of index radiographic abnormalities were recorded. Reports of follow-up imaging (radiography and CT) performed during the period from January 2008 to January 2010 were reviewed to assess the outcome of the index abnormality. Clinical history, demographics, microbiology, and pathology reports were reviewed and recorded.

RESULTS

Compliance with follow-up imaging recommendations was 76.7%. In nine of 618 cases (1.5%), a newly diagnosed malignancy corresponded to the abnormality on chest radiography initially suspected to be pneumonia. In 23 of 618 cases (3.7%), an alternative nonmalignant disease corresponded with the abnormality on chest radiography initially suspected to be pneumonia. Therefore, in 32 of 618 patients (5.2%), significant new pulmonary diagnoses were established during follow-up imaging of suspected pneumonia.

CONCLUSION

Follow-up imaging of radiographically suspected pneumonia leads to a small number of new diagnoses of malignancy and important nonmalignant diseases, which may alter patient management.

A study on non-resolving pneumonia with special reference to role of fiberoptic bronchoscopy

Context:

Non-resolving pneumonia is often an area of concern for pulmonologists. Fiber optic bronchoscopy (FOB) may have a special role in etiologic evaluation of non-resolving pneumonias. There is paucity of recent studies in this field.

Aims:

This study aimed to assess the patients of non-resolving or slowly resolving pneumonia with special emphasis on efficacy of FOB and computed tomography (CT)-guided fine needle aspiration cytology (FNAC) in diagnosis.

Settings and Design:

Prospective, observational study conducted in a tertiary care institute over a period of one year.

Materials and Methods:

After fulfilling the definition of non-resolving pneumonia by clinical and radiological parameters, patients were evaluated by FOB with relevant microbiological, cytological, histopathological investigations and CT scan of thorax. CT-guided FNAC was done in selected cases where FOB was inconclusive.

Results:

Sixty patients were enrolled in the study. Mean age was 51.33 ± 1.71 years with male to female ratio 2:1. Right lung was more commonly involved (65%), and right upper lobe was the commonest site (25%). Pyogenic infection was the commonest etiology (53.3%), bronchogenic carcinoma and tuberculosis accounted for 26.7% and 16.7% cases, respectively. Both, FOB (85.7%) and CT-guided FNAC (91.67%) were very useful for etiological diagnosis of non-resolving pneumonia. Both the procedures were safe, and no major complication was observed.

Conclusions:

Because of the high yield of FOB, it is very useful and safe diagnostic tool for evaluation of non-resolving pneumonia. CT-guided FNAC also gives good yield when cases are properly selected.

Bronchoalveolar carcinoma (adenocarcinoma) mimicking recurrent bacterial community-acquired pneumonia (CAP)

Depending on the community-acquired pneumonia (CAP) pathogen, host factors, and immune status, CAPs resolve on chest x-rays at different rates. CAPs that resolve more slowly than expected, or not at all, are termed "slowly or non-resolving CAPs." In contrast, recurrent CAPs may be due to host defense defects (eg, multiple myelomas) or post-obstructive bronchogenic carcinomas. There are a variety of noninfectious disorders that may mimic CAPs on chest x-ray: alveolar hemorrhage, pulmonary drug reactions, radiation pneumonitis, Wegener's granulomatosis, bronchiolitis obliterans organizing pneumonia, bronchogenic carcinomas, and lymphomas. Noninfectious mimics of recurrent CAPs include congestive heart failure, pulmonary emboli, infarctions, sarcoidosis, and systemic lupus erythematosus pneumonitis. We present the case of a middle-aged man who presented with recurrent right middle lobe and right lower lobe CAPs. Diagnostic bronchoscopy showed no bronchial obstruction, but open lung biopsy showed bronchoalveolar carcinoma (well-differentiated adenocarcinoma). Bronchoalveolar carcinomas presenting as post-obstructive or recurrent CAPs are rare because the spread is along tissue planes and not endobronchially. The case described demonstrates a rare cause of bronchogenic carcinoma mimicking recurrent CAP.

Brazilian guidelines for community-acquired pneumonia in immunocompetent adults - 2009

Community-acquired pneumonia continues to be the acute infectious disease that has the greatest medical and social impact regarding morbidity and treatment costs. Children and the elderly are more susceptible to severe complications, thereby justifying the fact that the prevention measures adopted have focused on these age brackets. Despite the advances in the knowledge of etiology and physiopathology, as well as the improvement in preliminary clinical and therapeutic methods, various questions merit further investigation. This is due to the clinical, social, demographical and structural diversity, which cannot be fully predicted. Consequently, guidelines are published in order to compile the most recent knowledge in a systematic way and to promote the rational use of that knowledge in medical practice. Therefore, guidelines are not a rigid set of rules that must be followed, but first and foremost a tool to be used in a critical way, bearing in mind the variability of biological and human responses within their individual and social contexts. This document represents the conclusion of a detailed discussion among the members of the Scientific Board and Respiratory Infection Committee of the Brazilian Thoracic Association. The objective of the work group was to present relevant topics in order to update the previous guidelines. We attempted to avoid the repetition of consensual concepts. The principal objective of creating this document was to present a compilation of the recent advances published in the literature and, consequently, to contribute to improving the quality of the medical care provided to immunocompetent adult patients with community-acquired pneumonia.