Long-Term Prognosis and Causes of Death After Pleural Infections

Risk factors influencing postoperative pleural empyema in patients with pleural mesothelioma: a retrospective single-centre analysis

OBJECTIVES

Postoperative empyema is a severe, potentially lethal complication also present, but poorly studied in patients undergoing surgery for pleural mesothelioma. We aimed to analyse which perioperative characteristics might be associated with an increased risk for postoperative empyema.

METHODS

From September 1999 to February 2023 a retrospective analysis of consecutive patients undergoing surgery for pleural mesothelioma at the University Hospital of Zurich was performed. Uni- and multivariable logistic regression was used to identify associated risk factors of postoperative empyema after surgery.

RESULTS

A total of 400 PM patients were included in the analysis, of which n = 50 patients developed empyema after surgery (12.5%). Baseline demographics were comparable between patients with (Eyes) and without empyema (Eno). 39% (n = 156) patients underwent extrapleural pneumonectomy (EPP), of whom 22% (n = 35) developed postoperative pleural empyema; 6% (n = 15) of the remaining 244 patients undergoing pleurectomy and decortication (n = 46), extended pleurectomy and decortication (n = 114), partial pleurectomy (n = 54) or explorative thoracotomy (n = 30) resulted in postoperative empyema. In multivariable logistic regression analysis, EPP (odds ratio 2.8, 95% confidence interval 1.5-5.4, P = 0.002) emerged as the only risk factor associated with postoperative empyema when controlled for smoking status. Median overall survival was significantly worse for Eyes (16 months, interquartile range 5-27 months) than for Eno (18 months, interquartile range 8-35 months).

CONCLUSIONS

Patients undergoing EPP had a significantly higher risk of developing postoperative pleural empyema compared to patients undergoing other surgery types. Survival of patients with empyema was significantly shorter.

ERS/ESTS statement on the management of pleural infection in adults

Pleural infection is a common condition encountered by respiratory physicians and thoracic surgeons alike. The European Respiratory Society (ERS) and European Society of Thoracic Surgeons (ESTS) established a multidisciplinary collaboration of clinicians with expertise in managing pleural infection with the aim of producing a comprehensive review of the scientific literature. Six areas of interest were identified: 1) epidemiology of pleural infection, 2) optimal antibiotic strategy, 3) diagnostic parameters for chest tube drainage, 4) status of intrapleural therapies, 5) role of surgery and 6) current place of outcome prediction in management. The literature revealed that recently updated epidemiological data continue to show an overall upwards trend in incidence, but there is an urgent need for a more comprehensive characterisation of the burden of pleural infection in specific populations such as immunocompromised hosts. There is a sparsity of regular analyses and documentation of microbiological patterns at a local level to inform geographical variation, and ongoing research efforts are needed to improve antibiotic stewardship. The evidence remains in favour of a small-bore chest tube optimally placed under image guidance as an appropriate initial intervention for most cases of pleural infection. With a growing body of data suggesting delays to treatment are key contributors to poor outcomes, this suggests that earlier consideration of combination intrapleural enzyme therapy (IET) with concurrent surgical consultation should remain a priority. Since publication of the MIST-2 study, there has been considerable data supporting safety and efficacy of IET, but further studies are needed to optimise dosing using individualised biomarkers of treatment failure. Pending further prospective evaluation, the MIST-2 regimen remains the most evidence based. Several studies have externally validated the RAPID score, but it requires incorporating into prospective intervention studies prior to adopting into clinical practice.

Considerations on Baseline Generation for Imaging AI Studies Illustrated on the CT-Based Prediction of Empyema and Outcome Assessment

For AI-based classification tasks in computed tomography (CT), a reference standard for evaluating the clinical diagnostic accuracy of individual classes is essential. To enable the implementation of an AI tool in clinical practice, the raw data should be drawn from clinical routine data using state-of-the-art scanners, evaluated in a blinded manner and verified with a reference test. Three hundred and thirty-five consecutive CTs, performed between 1 January 2016 and 1 January 2021 with reported pleural effusion and pathology reports from thoracocentesis or biopsy within 7 days of the CT were retrospectively included. Two radiologists (4 and 10 PGY) blindly assessed the chest CTs for pleural CT features. If needed, consensus was achieved using an experienced radiologist’s opinion (29 PGY). In addition, diagnoses were extracted from written radiological reports. We analyzed these findings for a possible correlation with the following patient outcomes: mortality and median hospital stay. For AI prediction, we used an approach consisting of nnU-Net segmentation, PyRadiomics features and a random forest model. Specificity and sensitivity for CT-based detection of empyema (n = 81 of n = 335 patients) were 90.94 (95%-CI: 86.55–94.05) and 72.84 (95%-CI: 61.63–81.85%) in all effusions, with moderate to almost perfect interrater agreement for all pleural findings associated with empyema (Cohen’s kappa = 0.41–0.82). Highest accuracies were found for pleural enhancement or thickening with 87.02% and 81.49%, respectively. For empyema prediction, AI achieved a specificity and sensitivity of 74.41% (95% CI: 68.50–79.57) and 77.78% (95% CI: 66.91–85.96), respectively. Empyema was associated with a longer hospital stay (median = 20 versus 14 days), and findings consistent with pleural carcinomatosis impacted mortality.

Diagnostic Accuracy of Imaging Findings in Pleural Empyema: Systematic Review and Meta-Analysis

Computed tomography (CT) diagnosis of empyema is challenging because current literature features multiple overlapping pleural findings. We aimed to identify informative findings for structured reporting. The screening according to inclusion criteria (P: Pleural empyema, I: CT C: culture/gram-stain/pathology/pus, O: Diagnostic accuracy measures), data extraction, and risk of bias assessment of studies published between 01-1980 and 10-2021 on Pubmed, Embase, and Web of Science (WOS) were performed independently by two reviewers. CT findings with pooled diagnostic odds ratios (DOR) with 95% confidence intervals, not including 1, were considered as informative. Summary estimates of diagnostic accuracy for CT findings were calculated by using a bivariate random-effects model and heterogeneity sources were evaluated. Ten studies with a total of 252 patients with and 846 without empyema were included. From 119 overlapping descriptors, five informative CT findings were identified: Pleural enhancement, thickening, loculation, fat thickening, and fat stranding with an AUC of 0.80 (hierarchical summary receiver operating characteristic, HSROC). Potential sources of heterogeneity were different thresholds, empyema prevalence, and study year.

Pleural infection-an indicator of morbidity and increased burden on health care

OBJECTIVES

Patients with pleural infections frequently have several comorbidities and inferior long-term survival. We hypothesized that these patients represent a vulnerable cohort with high rates of hospitalization and frequent use of healthcare services. This study aims to ascertain the need for and causes of treatment episodes after pleural infections during long-term follow-up.

METHODS

Patients treated for pleural infections at Tampere University Hospital between January 2000 and December 2008 (n = 191, 81% males, median age 58 years) were included and compared to a demographically matched population-based random sample of 1910 controls. Seventy percent of the pleural infections were caused by pneumonias and 80% of the patients underwent surgery. Information regarding later in-hospital periods and emergency room and out-patient clinic visits, as well as survival data, was obtained from national registries and compared between patients and controls.

RESULTS

Patients treated for pleural infections had significantly higher rates of hospitalizations (8.19 vs 2.19), in-hospital days (88.5 vs 26.6), emergency room admissions (3.18 vs 1.45), out-patient clinic visits (41.1 vs 11.8) and procedures performed (1.26 vs 0.55) per 100 patient-months when compared to controls during 5-year follow-up, in addition to having increased mortality (30% vs 11%), P-value <0.00001 each. Particularly, episodes due to respiratory and digestive diseases, malignancies and mental disorders were more frequent. The patients' comorbidities, such as alcoholism or chronic pulmonary disease, were associated with more frequent use of healthcare services.

CONCLUSIONS

Patients treated for pleural infections have high rates of hospitalizations, emergency room admissions and out-patient clinic visits during follow-up.

The Intrapleural Bridge Connection is One of the Reasons for Unknown Localized Pleural Adhesion

Background

Simple signs of local pleural adhesion are often found in people during a physical examination. In the present study, we aimed to clarify whether the merely localized pleural adhesion was just caused by previous pleural inflammation or physiological variation.

Materials and Methods

Chest X-ray image materials were collected to analyze the incidence of simple pleural adhesions. Moreover, the causes of these simple pleural adhesions were further analyzed using thoracoscopy under direct vision and biopsy data.

Results

In all 2218 chest X-ray images, 68 cases were found to have pleural lesions (3.07%), including 15 cases of localized pleural adhesion only. Subsequently, we analyzed the characteristics of 70 cases of pleural lesions using thoracoscopy. In two lung cancer patients with pleural metastasis, we found an unusual pleural junction. This connective strip was smooth and free of inflammation, resembling the normal pleura.

Conclusion

Some of these purely localized pleural adhesions might be attributed to previous inflammation. However, there was still at least a possibility that there must be a physiological pleural junction, which could be the cause of the purely localized pleural adhesion shown in the chest radiograph.

High Occurrence of Thrombo-Embolic Complications During Long-Term Follow-up After Pleural Infections-A Single-Center Experience with 536 Consecutive Patients Over 17 Years

Purpose

Pleural infections are associated with significant inflammation, long hospitalizations, frequent comorbidities, and are often treated operatively—all of which are consequential risk factors for thrombo-embolic complications. However, their occurrence following the treatment of pleural infection is still unknown. The aim of the study was to ascertain the early and long-term occurrence of thrombo-embolic events in patients treated for pleural infections.

Methods

The study included all patients that were treated for pleural infections in Tampere University Hospital between January 2000 and December 2016. Data regarding later treatment episodes due to pulmonary embolisms and/or deep vein thromboses as well as survival data were requested from national registries. The rates were also compared to a demographically matched reference population adjusted for age, sex, and the location of residence.

Results

The final study population comprised 536 patients and 5318 controls (median age 60, 78% men). The most common etiology for pleural infection was pneumonia (73%) and 85% underwent surgical treatment for pleural infection. The occurrence of thrombo-embolic complications in patients and controls was 3.8% vs 0.1% at three months, 5.0% vs 0.4% at one year, 8.8% vs 1.0% at three years, and 12.4% vs 1.8% at five years, respectively, p < 0.001 each. Female sex, advanced age, chronic lung disease, immunosuppression, video-assisted surgery, and non-pneumonic etiology were associated with a higher incidence of thrombo-embolism.

Conclusions

The occurrence of thrombo-embolic events—particularly pulmonary embolism but also deep vein thrombosis—was significant in patients treated for pleural infections, both initially and during long-term follow-up.

The Occurrence of Lung Cancer and Non-Pulmonary Malignancies After Pleural Infections

BACKGROUND AND AIMS

Patients who develop infections of the pleura have several risk factors for malignancies, particularly lung cancer, and the infections might even be caused by undiagnosed intra-thoracic neoplasms. The aim of the study was to compare the occurrence of lung cancer and other malignancies between patients treated for pleural infections and controls during long-term follow-up.

MATERIALS AND METHODS

All consecutive patients treated for pleural infections between January 2000 and June 2016 at the Tampere University Hospital were included. Ten matched controls and data regarding later cancer diagnoses were requested from national registries. The cancer types and rates, the diagnostic delays, as well as survival were compared between patients and controls.

RESULTS

The material comprised 506 patients and 5022 controls (78% was male and median age was 60 years in both groups) with a median follow-up time of 69 months. In total, 74% of pleural infections were related to pneumonia. The occurrence of lung cancer during follow-up was 3.0% in all patients, 2.2% in pneumonia-related cases, and 0.6% in controls, p < 0.001 when compared with controls. The overall rate of non-pulmonary malignancies did not differ. Lung cancer was diagnosed within 3 months in 73% of patients versus in 6.9% of controls, p < 0.001. The survival in patients with later lung cancers or other malignancies was inferior to that of controls with similar neoplasms.

CONCLUSION

The rate of lung cancer diagnoses was significantly increased in patients treated for pleural infections when compared with matched controls and the prognosis of patients with subsequent malignancies was impacted.

Streptococcus gordonii Empyema: A Rare Presentation of Streptococcus gordonii Infection

Empyema is often caused by Streptococcus pneumoniae, Staphylococcus aureus, and a variety of gram-negative organisms as well as anaerobes. Streptococcus gordonii (S. gordonii) is among some of the initial colonizers of the periodontal environment that is recognized to cause bacterial endocarditis. However, there are only a few case reports of S. gordonii causing empyema in the literature. We report the case of a 75-year-old male who presented with coughing up blood-tinged sputum. Physical examination revealed decreased breath sounds in the right lung base. Chest X-ray demonstrated a lower, right-sided, loculated pleural effusion. He underwent ultrasound-guided chest tube placement. The pleural fluid culture grew S. gordonii. He was started on ampicillin/ sulbactam. The follow-up computed tomography (CT) scan showed no significant improvement. Given his inability to improve with antibiotics and chest tube drainage, he was referred to an advanced care center for decortication of lung tissue.

Trends in the Incidence, Etiology, Treatment, and Outcomes of Pleural Infections in Adults Over a Decade in a Finnish University Hospital

BACKGROUND AND AIMS

The aim of the study was to ascertain changes in the incidence, etiology, treatment, and outcomes of pleural infections over a decade in a Finnish University Hospital.

MATERIALS AND METHODS

All patients treated for pleural infections in Tampere University Hospital during 2000-2008 and 2012-2016 were included. The incidence rates and the epidemiologic data and medical history of patients, etiology of infection, and treatment trends and outcomes were compared between the cohorts.

RESULTS

The incidence of pleural infections increased from 4.4 during 2000-2008 to 9.9 during 2012-2016 per 100.000 patient-years, p < 0.001. The patients in the latter group were older, 63 versus 57 years, p = 0.001, and the prevalence of chronic lung disease, hypertension, heart failure, dyslipidemia, and immunosuppressive medication were higher. The causes of infection remained similar and pneumonia accounted for 70% of all cases. The identification rate of the microbe pathogens increased from 49% to 64%, p = 0.002, while the distribution of identified pathogens was unchanged. More patients in the latter cohort were treated operatively, 88.3% versus 80.9%, p = 0.005, and, in these, the proportion of thoracoscopic surgery was higher, 57.4% versus 8.0%, p < 0.001, and the delay to surgery shorter, 5 versus 7 days, p < 0.001. Radiologic outcomes were similar. The 30-day mortality rate was 3.1% during 2000-2008 and 5.1% during 2012-2016, p = 0.293.

CONCLUSION

The overall incidence of pleural infections has increased significantly while the causes of pleural infections and the distribution of pathogens remain unchanged. Contemporary patients are older with higher prevalence of comorbidities and more frequently undergo thoracoscopic surgery.