Lung abscess following ventilator-associated pneumonia during COVID-19: a retrospective multicenter cohort study

Heterogeneity in clinical patterns of adult lung abscess patients: an 8-year retrospective study in a tertiary hospital

BACKGROUND

The widespread use of broad-spectrum antibiotics has led to changes in both the microbiological and clinical characteristics of lung abscesses. It is necessary to re-evaluate the bacterial spectrum associated with these infections. As a novel method for pathogen detection, metagenomic next-generation sequencing (mNGS) is increasingly being applied in clinical practice. There is limited research evaluating the use of mNGS in patients with lung abscesses.

METHODS

A retrospective analysis was conducted on patients with lung abscess who were hospitalized between July 2015 and July 2023 at a teaching hospital in China. Patients who underwent both computerized tomography (CT) imaging and conventional pathogen testing were included in the study. The efficacy of pathogen detection using conventional methods was compared with that of mNGS. Additionally, the clinical and radiological features were analyzed to provide a comprehensive understanding of the disease patterns.

RESULTS

A total of 782 patients with lung abscess were included in the study and hematogenous abscess accounting for 7.16% (56/782) of cases. The overall hospital mortality rate was 1.53%. The mean age of the patients with lung abscess was 60 years, with a male predominance (80.2%). A significant proportion of patients had comorbid conditions, including diabetes (29.7%) and cardiovascular disease (18.2%). Lung abscesses were predominantly located in the right lung, and pleural effusion was more commonly observed in the deceased group. The detection rate of pathogen via conventional test was lower at 41.8% (327/782). Among patients with positive mNGS results, only 51.9% had pathogens identified through conventional testing methods. Klebsiella pneumoniae was the most frequently detected pathogen by conventional culture, while mNGS identified was Parvimonas micra. Infections caused solely by anaerobic bacteria or facultative anaerobes were associated with shorter hospital stays. Patient infected with Gram-negative bacilli (GNB) had a higher proportion of liver abscesses (11.8%).

CONCLUSION

Compared to conventional testing methods, mNGS demonstrates superior performance in detecting anaerobic and facultative anaerobic bacteria. The low detection rate of conventional tests may result in an underestimation of the clinical significance of anaerobic bacteria infections. In patients with lung abscess caused by GNB, hematogenous dissemination, liver abscess and diabetes were more commonly observed and these patients tended to have longer hospital stays.

Recovery of temperature to normal may indicate the best time for surgery in patients with lung cancer complicated by a lung abscess: A case report

In clinical practice, the management of a lung abscess (LA) usually initiates with antibiotic administration to address the infection. Nevertheless, for cases presenting with refractory pulmonary tumors complicated by a LA, surgical intervention stands as an essential therapeutic recourse. The current study presents case involving lung cancer complicated by a LA. Despite continuously elevated infection marker levels, surgical intervention was promptly performed following the normalization of the patient's temperature. Subsequent postoperative histopathological analysis and immunohistochemistry revealed a moderately differentiated squamous cell carcinoma located in the lower right lung, classified as T2aN0M0, Ib stage. Following a 2-year follow-up period, no cancer recurrence was observed and the patient exhibited a favorable prognosis. This case highlights the vital role of surgical timing in the management of lung cancer complicated by an acute LA. Early surgical intervention may play a crucial role in arresting the advancement of lung cancer, indicating that prompt surgery upon temperature normalization could serve as a significant treatment indication for these patients.

Management of COVID-19 Infection Associated Lung Abscess with Secondary Pleural Empyema Using Percutaneous Intracavitary Drainage: Case Series and Review of the Literature

Background/Objectives: COVID-19-related pulmonary complications, such as lung abscesses and pleural empyema, are rare but serious. This study presents a case series of three patients with COVID-19-associated lung abscesses complicated by pleural empyema, managed conservatively with percutaneous intracavitary drainage (ICD) and lavage. We assess the efficacy and safety of this treatment and compare our findings with the current literature. Methods: A retrospective analysis of three cases treated at the Clinic of Thoracic Surgery and Intensive Care Unit in Cluj-Napoca, Romania, was conducted. All patients developed severe lung involvement post-COVID-19, with abscesses rupturing into the pleural cavity. Conservative management included percutaneous ICD and daily lavage with isotonic saline, avoiding extensive surgery due to the patients' critical condition. Clinical, radiological, and functional outcomes were followed, and results were compared to similar cases in the literature. Results: Among 496 critically ill patients with COVID-19 infection, three patients (age 42-60) developed lung abscesses and bacterial superinfection. In all patients, the germs involved were identified (monomicrobial infection in 1, polymicrobial in 2 patients). The abscesses were treated with percutaneous ICD and lavage, leading to clinical improvement in all cases. Long-term drainage (94-290 days) was necessary to obtain healing, and none of the patients required lung resection or decortication. Serial CT scans showed resolution of the abscesses and empyema. All were successfully discharged, and long-term follow-up (30-32 months) revealed minor radiological sequelae and mild respiratory impairment. The literature review found three studies summarizing 45 patients with lung abscesses complicating COVID-19 infections, but only one study addressed the use of percutaneous ICD. The mortality reported in this group was high (50-65%). Conclusions: Conservative treatment with percutaneous ICD and lavage is effective in managing lung abscesses and pleural empyema in critically ill COVID-19 patients, offering a viable alternative to surgery in high-risk cases. This method may be beneficial in multidisciplinary care for non-surgical candidates.

Clinical characteristics of apical segment lung abscess: a 10-year retrospective study

Background

Lung abscess in the apical segment of the lung is not rare and is often underestimated in clinical practice. However, the clinical features of apical segment lung abscess (AL) have scarcely been reported. Hence, this study aimed to determine the clinical characteristics of AL and explore moderate therapeutic strategies.

Methods

This was a retrospective, single-center cohort study. We reviewed the medical records of consecutive patients who were admitted to Shanghai Pulmonary Hospital in Shanghai, China, from January 2009 to December 2018. This study collected information on patients with lung abscess, including demographics, symptoms, clinical findings, and treatment. The statistical methods used were descriptive statistics, Chi-squared test, Fisher's exact test, t-tests, and logistic regression analysis.

Results

Of 824 patients, 431 with lung abscess were finally eligible after a review of medical records. The patients were divided into two groups: the AL group (n=68) and the non-apical segment lung abscess (NAL) group (n=363). Compared with patients in the NAL group, those in the AL group had lower rates of chronic obstructive pulmonary disease (COPD) (5.9% vs. 17.4%, P=0.02), diabetes (14.7% vs. 32.2%, P=0.004) and hypoprealbuminemia (10.3% vs. 25.3%, P=0.007). Regarding clinical symptoms, patients in the AL group exhibited lower fever (38.2% vs. 58.4%, P=0.002) and less purulent sputum (32.4% vs. 45.5%, P=0.045). Moreover, regarding radiological features, the AL group had a lower proportion of air-fluid level on chest computed tomography (CT) (7.4% vs. 16.8%, P=0.047). In addition, the study demonstrated that the AL group had a shorter duration of intravenous antibiotic treatment [8 (7-8) vs. 10 (8-12) days, P <0.001]. Surprisingly, the AL group had a high rate of surgical treatment (36.8% vs. 15.4%, P<0.001). In multivariate analysis, surgical treatment occurred more frequently in patients with AL [odds ratio (OR): 2.58, 95% confidence interval (CI): 1.40-4.77, P=0.002], lower in patients who had fever (OR: 0.55, 95% CI: 0.31-0.98, P=0.04), and imaging features of liquefaction necrosis (OR: 0.32, 95% CI: 0.15-0.69, P=0.004).

Conclusions

Patients with AL presented with atypical and relatively mild clinical symptoms. However, the rate of surgical treatment was significantly higher. These data should be considered when managing the AL.

Lung abscess: an update on the current knowledge and call for future investigations

PURPOSE OF REVIEW

Lung abscess is a severe and complex respiratory infection. The purpose of this review is to discuss recent publications on lung abscess, covering topics such as epidemiology, clinical presentation, diagnosis, and treatment and prevention.

RECENT FINDINGS

Risk factors associated with lung abscess include structural lung disease, poor dental hygiene, and ventilator-associated pneumonia, while concerns are now raised regarding the potential of electronic cigarettes use as a risk factor. The complexity of lung abscess is reflected by the relative high number of case reports describing rare and complex cases. Early transthoracic drainage could improve in-hospital outcomes, while next-generation sequencing could become an important tool in diagnostics and future clinical studies.

SUMMARY

High-quality evidence and guidelines to support treatment of lung abscess are lacking. Despite advancements, we call for prospective studies to evaluate the use of invasive procedures and antibiotic treatment regimens.

Recurrent ventilator-associated pneumonia in severe Covid-19 ARDS patients requiring ECMO support

OBJECTIVE

To describe ventilator-associated pneumonia (VAP) recurrence in COVID-19 patients requiring extracorporeal membrane oxygenation (ECMO) support, and to evaluate the impact of antimicrobial treatment duration of the first VAP episode on VAP recurrence.

METHODS

Adult patients with COVID-19 severe pneumonia on ECMO admitted between March 2020 and January 2022 were retrospectively included. Primary outcome was incidence of VAP recurrence, and secondary outcome was the impact of duration of antimicrobial treatment on VAP recurrence.

RESULTS

Among the 252 included patients, 226 (90%) developed a first VAP. Sixteen had lung abscess and were excluded, leaving 210 patients. VAP recurrence occurred in 172 patients (82%), with a median (IQR) time from first VAP to recurrence of 10 (7-13) days. Pseudomonas aeruginosa and Enterobacteriaceae were respectively responsible for 28% and 52% of first VAP, and 51% and 62% of first recurrence episodes. Among the 210 patients with a first VAP, 158 (75%) received a short course of antibiotics [< 8 days, median (IQR) duration 6 (5-7) days] and 52 (25%) received a prolonged course of antibiotics [≥ 8 days, median (IQR) duration 9 (8-10) days]. Estimated cumulative incidence of VAP recurrence, taking into account death and extubation as competing risks, was not different in patients with short- and prolonged-antimicrobial treatment.

CONCLUSIONS

In patients with severe Covid-19-ARDS requiring ECMO support, VAP recurrence occurs frequently, with Enterobacteriaceae and Pseudomonas aeruginosa as predominant causative microorganisms. An antimicrobial treatment of ≥ 8 days for the treatment of first VAP episode did not reduce the risk of VAP recurrence, as compared to shorter duration.