From the Guidelines
Hospital-acquired pneumonia (HAP) is defined as pneumonia that occurs 48 hours or more after admission to a hospital, which was not incubating at the time of admission 1. This definition is crucial in distinguishing HAP from community-acquired pneumonia and other types of infections.
Key Characteristics of HAP
- Develops 48 hours or more after hospital admission
- Not incubating at the time of admission
- Typically involves more resistant pathogens than community-acquired pneumonia
- Characterized by new lung infiltrates on chest imaging, along with clinical signs such as fever, purulent sputum, leukocytosis, and declining oxygenation
Causative Organisms
- Gram-negative bacteria like Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter species
- Gram-positive bacteria such as Staphylococcus aureus, including MRSA
Risk Factors
- Mechanical ventilation (which leads to ventilator-associated pneumonia, a subset of HAP)
- Prolonged hospitalization
- Recent antibiotic use
- Advanced age
- Immunosuppression
- Underlying lung disease
Prevention Strategies
- Hand hygiene
- Elevation of the head of the bed
- Oral care
- Minimizing sedation and mechanical ventilation duration when applicable As noted in the guidelines published by the European Respiratory Society (ERS) 1, HAP is a serious healthcare-associated infection that increases hospital length of stay, healthcare costs, and mortality rates.
Importance of Accurate Diagnosis and Treatment
- Avoid untreated or inadequately treated HAP
- Recognize the variability of bacteriology from one hospital to another
- Use this information to alter the selection of an appropriate antibiotic treatment regimen for any specific clinical setting
- Avoid the overuse of antibiotics by focusing on accurate diagnosis, tailoring therapy to the results of lower respiratory tract cultures, and shortening duration of therapy to the minimal effective period The ATS/IDSA guideline 1 also emphasizes the importance of individual clinical judgment in the management of HAP, as each patient's situation can be highly complex and requires a knowledgeable physician's assessment.
From the Research
Definition of Hospital-Acquired Pneumonia
Hospital-acquired pneumonia (HAP) is defined as pneumonia that develops 48 hours or more after hospital admission, in patients who were not incubating the infection at the time of admission 2.
Key Characteristics
- HAP is a common cause of nosocomial infection, morbidity, and mortality in hospitalized patients 3.
- It is especially challenging to diagnose promptly in the intensive care unit because a plethora of other causes can contribute to clinical decline in complex, critically ill patients 2.
- The pathogens responsible for HAP are frequently more virulent and have greater resistance to commonly used antimicrobials than other pathogens 3.
Causes and Risk Factors
- HAP can be caused by various bacteria, including Pseudomonas aeruginosa 4, 5.
- Risk-factor modification and inpatient prevention strategies can have a significant impact on the incidence of HAP 3.
- Patient- and disease-specific factors contribute to the pathophysiology of HAP, particularly in the surgical population 3.
Diagnosis and Management
- The best diagnostic strategy remains a subject of some debate, but prompt and appropriate antimicrobial therapy in patients suspected of having HAP has been shown to significantly decrease mortality 3.
- The diagnosis, management, and prevention of HAP and ventilator-associated pneumonia (VAP) are based on current guidelines and recent evidence 2.
- Clinicians must have knowledge of the resistance patterns at their institutions to choose appropriate therapy 3.