Among the factors contributing to contracting HAP are mechanical ventilation (ventilator-associated pneumonia), old age, decreased filtration of inspired air, intrinsic respiratory, neurologic, or other disease states that result in respiratory tract obstruction, trauma, (abdominal) surgery, medications, diminished lung volumes, or decreased clearance of secretions may diminish the defenses of the lung.
Among the factors contributing to contracting HAP are mechanical ventilation, old age, reduced air filtration, and various underlying conditions such as respiratory, neurological, or other diseases that cause respiratory tract obstruction, trauma, surgery, medications, diminished lung capacity, or impaired secretion clearance. These factors can weaken the defenses of the lungs.