Analysis of clinical characteristics of elderly patients with blood culture-positive bacterial liver abscess

Abstract

Objective: To analyze the clinical features of elderly patients with blood culture-positive bacterial liver abscess (BLA) and improve diagnostic and treatment strategies.

Methods: Elderly BLA patients admitted to our hospital from December 2018 to December 2023 were included in the study. Diagnostic tests included routine blood analysis, biochemistry, C-reactive protein (CRP), procalcitonin (PCT), imaging, and cultures of blood or pus. Treatments involved anti-infective therapy, ultrasound-guided abscess drainage, and supportive care.

Results: (1) Elderly patients with blood culture-positive BLA had higher rates of prolonged hospital stays (≥2 weeks), ICU admission, biliary system diseases, hepatitis B infection, maximum body temperature ≥ 39°C, and qSOFA scores ≥2 compared to controls (p < 0.05)0. (2) Laboratory findings showed higher levels of total bilirubin (≥34.2 μmol/L), ALT (≥50 U/L), serum creatinine (≥80 μmol/L), PCT (≥5 ng/mL), and lower platelet counts (≤100 × 10⁹/L) in the research group (p < 0.05). ESBL-positive cases and liver abscesses ≤5 cm were more common in the research group (p < 0.05). (3) Complications such as pleural effusion, ascites, pulmonary infections, and extrahepatic abscesses were significantly more frequent in the blood culture-positive group (p < 0.05). (4) Microbiological analysis indicated that Klebsiella pneumoniae was the leading pathogen (87.93%), followed by Escherichia coli. For ESBL-positive infections, E. coli was dominant (75.76%), especially in patients with biliary diseases (75.56%). (5) Logistic regression identified prolonged hospital stay, hepatitis B infection, biliary system diseases, temperature ≥ 39°C, PCT ≥5, and abscess size ≤5 cm as independent risk factors for blood culture-positive BLA. (6) The combined diagnostic indicator showed good predictive ability (AUC = 0.840, sensitivity 76.6%, specificity 72.2%).

Conclusion: Elderly patients with biliary diseases, hepatitis B, high PCT levels (≥5 ng/mL), small abscesses (≤5 cm), and fever (≥39°C) are at higher risk for blood culture-positive BLA. Klebsiella pneumoniae remains the predominant pathogen (87.93%), highlighting the need for prompt empirical antibiotic therapy. The combined diagnostic model offers reliable predictive value for this condition. We developed a predictive model aimed at assisting clinicians in identifying high-risk patients prone to bloodstream infections secondary to BLA. This model provides valuable guidance for clinicians in formulating more rational and individualized treatment strategies.

Keywords: Klebsiella pneumoniae; bacterial liver abscess; blood culture-positive; clinical characteristics; elderly.

Figure 1

Receiver operating characteristic (ROC) curve of factors affecting the occurrence of positive blood cultures in patients with bacterial liver abscess.