Risk factor-based analysis of community-acquired pneumonia, healthcare-associated pneumonia and hospital-acquired pneumonia: Microbiological distribution, antibiotic resistance, and clinical outcomes

Bacterial profile, and independent predictors for healthcare-associated pneumonia persistently caused by multidrug-resistant Gram-negative bacteria for patients with the preceding multidrug-resistant Gram-negative pneumonia in Taiwan

OBJECTIVES

To understand the microbial profile and investigate the independent predictors for healthcare-associated pneumonia (HCAP) pertinaciously caused by isolates of multidrug-resistant (MDR) Gram-negative bacteria (GNB).

METHODS

Multicenter ICU patients who received appropriate antibiotic treatments for preceding pneumonia due to MDR GNB isolates and subsequently developed HCAP caused by either MDR GNB (n = 126) or non-MDR GNB (n = 40) isolates in Taiwan between 2018 and 2023 were enrolled. Between the groups of patients with HCAP due to MDR GNB and non-MDR GNB, the proportions of the following variables, including demographic characteristics, important co-morbidities, nursing home residence, physiological severity, intervals between two hospitalizations, steroid use, the tracheostomy tube use alone, ventilator support, and the predominant GNB species involving HCAP, were analyzed using the chi-square test. Logistic regression was employed to explore the independent predictors for HCAP persistently caused by MDR GNB in the aforementioned variables with a P-value of <0.15 in the univariate analysis.

RESULTS

MDR-Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii complex were the three predominant species causing HCAP. Chronic structural lung disorders, diabetes mellitus, intervals of ≤30 days between two hospitalizations, use of the tracheostomy tube alone, and prior pneumonia caused by MDR A. baumannii complex were shown to independently predict the HCAP tenaciously caused by MDR GNB. Conversely, the preceding pneumonia caused by MDR P. aeruginosa was a negative predictor.

CONCLUSION

Identifying predictors for HCAP persistently caused by MDR GNB is crucial for prescribing appropriate antibiotics.

Predictors of hospital mortality and multidrug-resistant pathogens in hospitalized pneumonia patients residing in the community

Background and objective

The 2019 ATS/ADSA guidelines for adult community-acquired pneumonia (CAP) eliminated healthcare-associated pneumonia (HCAP) and considered it to be a form of CAP. This concept, however, was based on studies with relatively small sample sizes.

Methods

We investigated the risk factors of 30-day mortality, and methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa infections in patients with pneumonia coming from the community using the Diagnosis Procedure Combination database, a nationwide discharge database of acute care hospitals. Furthermore, we compared these factors between CAP and HCAP.

Results

A total of 272,337 patients aged ≥20 years with pneumonia were grouped into 145,082 CAP patients and 127,255 HCAP patients. The 30-day mortality rate (8.9 % vs.3.3 %), MRSA infection (2.4 % vs. 1.4 %), and Pseudomonas aeruginosa infection (1.6 % vs. 1.0 %) were significantly higher in HCAP than in CAP patients. Multivariable logistic regression analysis showed that 12 of 13 identified predictors of mortality (i.e., high age, male, underweight, non-ambulatory status, bedsore, dehydration, respiratory failure, consciousness disturbance, hypotension, admitted in critical care, comorbidity of heart failure, and chronic obstructive pulmonary disease) were identical in CAP and HCAP patients. Similarly, five of six distinct risk factors for MRSA infection, and three of three for Pseudomonas aeruginosa infection were identical between the patients.

Conclusion

The risk factors for mortality and MRSA or Pseudomonas aeruginosa infection were almost identical in patients with CAP and HCAP. The assessment of individual risk factors for mortality and MRSA or Pseudomonas aeruginosa infection in CAP and abandoning categorization as HCAP can improve and simplify empiric therapy.

Ten Issues for Updating in Community-Acquired Pneumonia: An Expert Review

Community-acquired pneumonia represents the third-highest cause of mortality in industrialized countries and the first due to infection. Although guidelines for the approach to this infection model are widely implemented in international health schemes, information continually emerges that generates controversy or requires updating its management. This paper reviews the most important issues in the approach to this process, such as an aetiologic update using new molecular platforms or imaging techniques, including the diagnostic stewardship in different clinical settings. It also reviews both the Intensive Care Unit admission criteria and those of clinical stability to discharge. An update in antibiotic, in oxygen, or steroidal therapy is presented. It also analyzes the management out-of-hospital in CAP requiring hospitalization, the main factors for readmission, and an approach to therapeutic failure or rescue. Finally, the main strategies for prevention and vaccination in both immunocompetent and immunocompromised hosts are reviewed.

Gram-negative pulmonary infections - advances in epidemiology and diagnosis

PURPOSE OF REVIEW

Pulmonary infections due to Gram-negative organisms are increasing worldwide and traditional assumptions that these are limited to hospital and ventilator-acquired pneumonia are rapidly falling away. Accordingly, empiric antibiotic guidelines have to follow suit with ever broader spectrum choices in order to remain 'safe', as the Global prevalence of extensively resistant Gram-negative organisms inexorably increases. Rapid, multiplex PCR-based detection of a wide variety of potential pathogens offers the opportunity to replace empiric antibiotic choices with targeted, evidence-based therapy in clinically actionable timeframes.

RECENT FINDINGS

Here, we describe the data underpinning both the increasing global prevalence of Gram-negative pulmonary infections and their increasing antibiotic resistance. We also describe the performance, characteristics and early emerging clinical impact of already available rapid molecular diagnostic platforms and how they might best be deployed.

SUMMARY

It seems will likely be advantageous to replace the current trend for empiric prescription of increasingly broad-spectrum antibiotics with 'same day' evidence-based, targeted therapy using high performance, rapid molecular diagnostic solutions. Several challenges remain be overcome, however, to fully realize their clear potential for better, focussed deployment of antibiotics, improved patient outcomes and antibiotic stewardship.