In the article “Identifying Risk Factors for Ventilated Hospital-Acquired Pneumonia and Mortality through Machine Learning,” researchers conducted a retrospective cohort study to identify risk factors associated with the development and mortality of ventilated hospital-acquired pneumonia (vHABP) and evaluate antibiotic management. The study involved adult patients with nosocomial bacterial pneumonia admitted between 2014 and 2019. By utilizing machine learning techniques, the researchers identified key risk factors for progression to vHABP and pneumonia-associated mortality. The findings of this study provide clinicians with actionable data to recognize patients at risk for vHABP and guide antibiotic therapy selection, ultimately improving treatment outcomes.
Background
Study Objective
The objective of the study was to identify the risk factors associated with the development of ventilated hospital-acquired pneumonia (vHABP) and pneumonia-associated mortality. Additionally, the study aimed to evaluate antibiotic management in these cases.
Methods
A multicenter retrospective cohort study was conducted on adult patients admitted with hospital-acquired bacterial pneumonia (HABP) between the years 2014 and 2019. The patients were stratified into three groups: vHABP, nvHABP, and VABP (ventilator-associated bacterial pneumonia). Demographics, clinical characteristics, treatment, and outcomes were compared among the groups. Machine learning models were used to generate multivariable models for identifying the risk factors for the progression of vHABP and pneumonia-associated mortality.
Results
A total of 457 patients were evaluated, with 32% in the nvHABP group, 37% in the vHABP group, and 31% in the VABP group. The vHABP and nvHABP groups had similar median ages (66.4 years) and a high prevalence of multiple comorbidities (77%). However, the vHABP group had higher rates of liver disease (18.2% vs. 7.7%, p=0.005), alcohol use disorder (27% vs. 7.1%, p<0.0001), and recent hospitalization within the past 30 days (30.4% vs. 19.5%, p=0.02). Approximately 70% of vHABP patients required immediate ventilatory support upon diagnosis. The mortality rate was highest in the vHABP group, followed by the VABP and nvHABP groups (44.6% vs. 36% vs. 14.3%, p<0.0001). The vHABP group had a high incidence of positive cultures (96%), primarily Gram-negative pathogens (58.8%), with 33.0% of them showing resistance to extended-spectrum beta-lactams (ESBLs), ceftriaxone (17.5%), fluoroquinolones (20.6%), and carbapenem (12.4%). Ineffective empiric regimens were observed in up to 50% of vHABP patients with ESBL-Enterobacterales or Pseudomonas aeruginosa. Delayed initiation of effective therapy beyond the day of pneumonia diagnosis resulted in over a 50% increase in mortality rate.
Conclusions
The study’s findings provide actionable data for clinicians to identify patients at risk for vHABP at the start of pneumonia and to target antimicrobial stewardship efforts. This knowledge can help improve treatment success by ensuring appropriate antibiotic therapy selection.
Study Objective
Identify risk factors associated with ventilated hospital-acquired pneumonia
The first objective of the study was to identify the risk factors associated with the development of ventilated hospital-acquired pneumonia (vHABP). By understanding these risk factors, clinicians can be better equipped to identify patients who are at a higher risk of developing vHABP.
Identify risk factors for pneumonia-associated mortality
The second objective of the study was to identify risk factors associated with mortality in patients with hospital-acquired pneumonia. By recognizing these risk factors, clinicians can identify patients who may require more aggressive treatment and monitoring to improve outcomes.
Evaluate antibiotic management
The third objective of the study was to evaluate antibiotic management in patients with hospital-acquired pneumonia. This evaluation aimed to identify areas for improvement in antibiotic therapy selection to optimize treatment success and reduce the emergence of antibiotic resistance.
Methods
Multicenter retrospective cohort study
The study employed a multicenter retrospective cohort design. This approach allowed for the collection of data from multiple hospitals, increasing the sample size and diversity of patient populations.
Study period and patient population
The study included adult patients admitted with hospital-acquired bacterial pneumonia between the years 2014 and 2019. This broad time range allowed for a comprehensive evaluation of risk factors and outcomes over multiple years.
Group stratification
The patients were stratified into three groups: vHABP, nvHABP, and VABP. This stratification enabled the comparison of different types of hospital-acquired pneumonia and their respective risk factors and outcomes.
Data collection
Data on demographics, clinical characteristics, treatment, and outcomes were collected from patient records. This comprehensive data collection allowed for a thorough evaluation of the factors associated with vHABP and pneumonia-associated mortality.
Machine learning models
Machine learning models were utilized to generate multivariable models for identifying the risk factors for the progression of vHABP and pneumonia-associated mortality. Machine learning algorithms can analyze large datasets and identify complex relationships between variables, providing valuable insights into potential risk factors.
Results
Evaluation of patients
A total of 457 patients were evaluated, with representation from the vHABP, nvHABP, and VABP groups. This comprehensive evaluation allowed for a detailed analysis of the risk factors and outcomes associated with different types of hospital-acquired pneumonia.
Demographics and clinical characteristics
The study found that the vHABP and nvHABP groups had similar median ages and a high prevalence of multiple comorbidities. However, the vHABP group had higher rates of specific risk factors, such as liver disease, alcohol use disorder, and recent hospitalization.
Treatment and outcomes
The study analyzed the treatment and outcomes of patients with vHABP, nvHABP, and VABP. It found that ventilatory support was immediately required in a high percentage of vHABP patients upon diagnosis. Mortality rates were highest in the vHABP group, followed by the VABP and nvHABP groups.
Comparison of vHABP, nvHABP, and VABP groups
The study compared the vHABP, nvHABP, and VABP groups to identify differences in demographics, clinical characteristics, treatment, and outcomes. These comparisons provided insight into the unique factors associated with each type of hospital-acquired pneumonia.
Positive cultures and resistance patterns
The study found a high incidence of positive cultures in the vHABP group, with a significant proportion attributable to Gram-negative pathogens. Furthermore, a considerable percentage of these pathogens showed resistance to multiple antibiotics, emphasizing the importance of appropriate empiric therapy selection.
Effect of empiric regimen on mortality rate
The study demonstrated a significant increase in mortality rate when effective therapy was not initiated promptly after the diagnosis of vHABP. This finding underscores the importance of timely and appropriate antibiotic management in reducing mortality.
Conclusions
Actionable data for clinicians
The study’s findings provide actionable data for clinicians to help identify patients at risk for vHABP at the onset of pneumonia. This knowledge can guide early interventions and individualized management strategies to improve patient outcomes.
Identifying patients at risk for vHABP
By identifying the risk factors associated with vHABP development, clinicians can proactively assess patients for these factors and initiate appropriate interventions and preventive measures.
Targeting antimicrobial stewardship efforts
The study’s findings highlight the importance of targeted antimicrobial stewardship efforts to optimize treatment success and reduce the emergence of antibiotic resistance. Clinicians can utilize this information to improve their antibiotic therapy selection practices and promote responsible antibiotic use.
Risk Factors for vHABP Development
Alcohol use disorder
The study identified alcohol use disorder as a risk factor for the development of ventilated hospital-acquired pneumonia. Clinicians should be aware of this association and consider it when assessing patients with pneumonia and a history of alcohol use disorder.
APACHE II score
The study found that higher APACHE II scores were associated with an increased risk of vHABP development. The APACHE II score is a validated tool for assessing the severity of disease in critically ill patients and can help clinicians evaluate the risk of vHABP in these individuals.
Vasopressor therapy prior to infection
The study identified vasopressor therapy prior to infection as a risk factor for the development of ventilated hospital-acquired pneumonia. Clinicians should consider this factor when evaluating patients receiving vasopressor therapy and monitor them closely for signs of infection.
Culture positive for ESBL-Enterobacterales
The study found that a positive culture for ESBL-Enterobacterales was associated with an increased risk of vHABP development. Clinicians should be vigilant in identifying patients with positive cultures for ESBL-Enterobacterales and consider appropriate interventions to prevent the progression to ventilated hospital-acquired pneumonia.
Risk Factors for vHABP-associated Mortality
History of hospitalization in the past 30 days
The study identified a history of hospitalization in the past 30 days as a risk factor for mortality in patients with ventilated hospital-acquired pneumonia. Clinicians should be aware of this risk factor and closely monitor patients with recent hospitalizations for signs of deterioration.
Active malignancy
The study found that patients with active malignancy had a higher risk of mortality in the setting of vHABP. Clinicians should consider the presence of active malignancy when evaluating patients with ventilated hospital-acquired pneumonia and tailor their treatment and monitoring accordingly.
Isolation of ceftriaxone-resistant pathogens or Pseudomonas aeruginosa
The study identified the isolation of ceftriaxone-resistant pathogens or Pseudomonas aeruginosa as a risk factor for mortality in vHABP patients. Clinicians should prioritize appropriate empiric therapy selection and actively monitor patients with these pathogens for signs of clinical deterioration.
Vasopressor therapy
The study found that the use of vasopressor therapy was associated with an increased risk of mortality in patients with ventilated hospital-acquired pneumonia. Clinicians should carefully assess the need for vasopressor therapy and closely monitor these patients for signs of worsening clinical outcomes.
Implications for Antibiotic Therapy Selection
Improving treatment success
The study’s findings highlight the importance of appropriate antibiotic therapy selection in improving treatment success in patients with ventilated hospital-acquired pneumonia. Clinicians should consider the identified risk factors and resistance patterns when choosing empiric therapy and make timely adjustments based on culture results.
Targeting antimicrobial stewardship efforts
The study emphasizes the need for targeted antimicrobial stewardship efforts to prevent the emergence of multidrug resistance. Clinicians should review local resistance patterns and implement evidence-based guidelines to guide antibiotic therapy selection and promote responsible antibiotic use.