Ventilator-associated pneumonia

Concept

• Ventilator-associated pneumonia is a type of pneumonia that occurs > 48 hours after a patient undergoes endotracheal intubation and mechanical ventilation.
• It is a severe and common infectious disease in Intensive Care Units, occurring in 9% to 25% of patients who are intubated for ≥ 48 hours.
• The causative agents of ventilator-associated pneumonia have high antibiotic resistance rates, leading to a high mortality rate. If the patient experiences shock, renal failure, etc., the mortality rate ranges from 24% to 50%.
• Ventilator-associated pneumonia is a contributing factor to increased hospital stay duration, treatment costs, and mortality rates among patients treated in Intensive Care Units.

Risk Factors

Patient's underlying condition:

• Elderly patients with multiple accompanying underlying diseases.
• Severe malnutrition, immunodeficiency.

Factors related to treatment measures:

• Endotracheal intubation and mechanical ventilation.
• Prolonged use of sedatives and muscle relaxants.
• Aspiration of pharyngeal secretions or gastric reflux.
• Poor sterility in the care of mechanically ventilated patients.

Diagnosis

Patients on mechanical ventilation for > 48 hours due to previously non-infectious causes who develop the following signs:

• Fever, the degree of fever may vary depending on the patient.
• Increased respiratory rate, increased quantity of sputum secretions, yellow sputum, cloudy sputum.
• Decreased blood oxygen saturation, requiring increased ventilator settings.
• Lung auscultation revealing numerous crackles/secretion sounds.
• Blood tests: elevated infection indices.
• Chest X-ray: newly appeared infiltration lesions on the imaging.
• Specimen culture: bronchial fluid, sputum, blood cultures, etc., can identify the pathogen in about 40% of cases.

Diagnosis criteria:

Occurring > 48 hours after endotracheal intubation and mechanical ventilation with the presence of:

• Fever
• Increased sputum production, tachypnea
• Blood tests showing elevated infection indices
• Chest X-ray: new infiltrates, new consolidation
• Pathogenic microorganisms found in specimen samples such as bronchial fluid, sputum, blood, etc.

Pathogens

Common pathogens: mostly bacteria, rarely viruses or fungi.

Treatment

- Causal treatment:

• Empirical antibiotic treatment during the period when the pathogenic microorganism has not yet been identified.
• Once the pathogen is identified, antibiotic selection will be based on the antibiogram results.

- Treatment of accompanying organ damage: renal failure, heart failure, etc.

- Supportive treatment: respiratory physical therapy, aggressive sputum suctioning.

Prevention

General strategy:

• Medical staff must comply with hospital hand hygiene and asepsis procedures.
• Training medical staff on the care procedures for mechanically ventilated patients.
• Prioritizing the use of non-invasive ventilation.
• Early specimen culturing to use antibiotics according to the antibiogram.
• Early weaning from mechanical ventilation, limiting the use of sedatives and muscle relaxants during mechanical ventilation.

Prevention of pulmonary aspiration:

• Elevating the head of the bed to 30–45 degrees.
• Preventing overly full stomachs by dividing meals into smaller portions throughout the day.
• Avoiding patient transport unless necessary.

Prevention of bacterial colonization:

• Daily oral care.
• Performing oral endotracheal intubation instead of the nasal route.

Minimizing contamination of ventilation equipment:

• Proper disinfection and washing of equipment according to procedures.
• Cleaning the ventilator and removing impurities in the ventilator tubing.

“The information above is for reference purposes only and is not intended as medical advice. Please contact your doctor for detailed medical consultation.”