Predictive factors for true bacteremia and clinical utility of blood cultures as a prognostic tool in patients with community-onset pneumonia

Abstract

Although blood cultures (BCs) are an important component of diagnostic practice for antibiotic management in patients with pneumonia, several studies have questioned whether they should be performed. The objective of this study was to evaluate the predictive factors of bacteremia and the role of BCs in patients with community-onset pneumonia (community-acquired pneumonia and healthcare-associated pneumonia).This study was retrospectively conducted in patients with community-onset pneumonia who were hospitalized at Jeju National University Hospital between January 2012 and December 2014. A true bacteremia (TB) group and a contaminants or negative bacteremia (CNB) group were classified according to the bacterial growth on the BC media and were investigated for the clinical relevance of the BCs.We enrolled 785 patients; the TB group and the CNB group contained 36 patients (4.5%) and 749 (95.4%) patients, respectively. Only 10 patients (1.2%) required a change in antibiotic therapy based on the BC results (3 patients with an escalation, 7 with a de-escalation). There was no significant difference between the community-acquired pneumonia and the healthcare-associated pneumonia groups with regard to the rate of antibiotic change due to the BC results (1.1% vs 1.4%; P = 0.751). Chronic liver disease (odds ratio [OR] 2.973, 95% confidence interval [CI] 1.099-8.037), a confusion, urea, respiratory rate, blood pressure, age ≥65 (CURB-65) score of 4 to 5 points (OR 3.484, 95% CI 1.304-9.307), and Pneumonia Severity Index (PSI) class V (OR 2.405, 95% CI 1.007-5.743) were independently associated with TB. In patients with PSI class V and a CURB-65 score of 4 to 5 points, the TB group tended to show a higher inhospital mortality rate than the CNB group (50.0% vs 29.4%; P = 0.060, 60.0% vs 42.5%; P = 0.480). The areas under the curve for PSI score and CURB-65 score for predicting TB revealed an increased tendency compared with that of C-reactive protein (0.72, 95% CI 0.630-0.809; and 0.72, 95% CI 0.622-0.819 vs 0.629, 95% CI 0.522-0.735, respectively).It seemed reasonable to selectively conduct BC in patients hospitalized with severe community-onset pneumonia based upon its low overall positive rate, its effects on antimicrobial modification, and the associations of TB with the severity indices of pneumonia.Abbreviations: ARP = antibiotic-resistant pathogens, AUC = area under the curve, BC = blood culture, CAP = communityacquired pneumonia, CI = confidence interval, CNB = contaminants or negative bacteremia, CO = community onset, CRP = Creactive protein, CURB-65 = confusion, urea, respiratory rate, blood pressure, age ≥65, HCAP = healthcare-associated pneumonia, MDR = multidrug-resistant, PSI = Pneumonia Severity Index, TB = true bacteremia.

The clinical significance of simultaneous detection of pathogens from bronchoalveolar lavage fluid and blood samples by metagenomic next-generation sequencing in patients with severe pneumonia

“…Microbiological diagnosis is challenging among immunocompromised patients susceptible not only to pathogens that often infect immunocompetent hosts, but also to numerous opportunistic pathogens that may be fastidious or non-cultivable. Multiple reports have demonstrated the advantages of NGS as a quick detection and accurate microbial detection method especially among immunocompromised patients [5,[11][12][13]. In this study, mNGS helped to identify the infectious aetiologies in the majority of the patients with severe pneumonia, which could potentially guide clinicians regarding antimicrobial treatment.…”

“…The disease progression of severe pneumonia is often accelerated by accompanying various complications, such as bloodstream infection, multiple organ failures and shock [3]. Bloodstream infection is one of the most common complications in patients with severe pneumonia and has been widely regarded as an independent predictor of worsening prognosis [3][4][5]. One of the biggest challenges for precise therapy of severe pneumonia is to rapidly and accurately identify the aetiological pathogens [6].…”

“…One of the biggest challenges for precise therapy of severe pneumonia is to rapidly and accurately identify the aetiological pathogens [6]. Moreover, multiple reports have demonstrated that bloodstream infection is a commonly OPEN ACCESS found complication in patients with severe pneumonia [4,5]. The rapid identification of bloodstream infections and determining their pathogens in this population will allow us to make precise choices of antimicrobial treatment.…”

“…In the clinic, conventional bacterial culture often fails to find the pathogen of bloodstream infection in patients with severe pneumonia, and therefore the majority of patients with severe pneumonia receive empirical treatment without reliable evidence of the pathogens [5,7]. Recently, multiple lines of evidence have demonstrated that a comprehensive spectrum of potential causes (virus, bacteria, fungus, parasite, etc.)…”

Blood Cultures and Blood Microbiota Analysis as Surrogates for Bronchoalveolar Lavage Fluid Analysis in Dogs With Bacterial Pneumonia

“…While there is admittedly potential with optimized collection protocols for detection of microbes in blood cultures, they are currently overall considered a low yield diagnostic test in people (7,8). However, advances using culture-independent methods of microbial identi cation, such as PCR and more recently, bacterial 16S rRNA gene sequencing, have allowed for higher sensitivity and speci city in the detection of organisms (9).…”