Practical strategies in the prevention of ventilator-associated pneumonia

Abstract

Intubation and mechanical ventilation are associated with a 4- to 21- fold increase in pneumonia, which occurs in 10% to 65% of patients on mechanical ventilation, depending on the population studied. Patients on mechanical ventilation are at particular risk of pneumonia because of various factors that impair host defense and/or increase exposure to microorganisms. Preventive strategies should target risk factors that are important in the pathogenesis of ventilator-associated pneumonia. Effective and practical measures include the following: (1) infection control measures- the importance of simple measures in the prevention and spread of nosocomial infection cannot be overemphasized: proper hand washing between handling of patients; changing of ventilator circuits no more than every 48 hours; aseptic techniques in instrumentation including tracheal suction; careful drainage of tubing condensate; proper disinfection of ventilator circuits, nebulizers, resuscitation bags, and other equipment; isolation of patients infected with resistant/highly infectious organisms with the use of disposable gloves and gowns, and, where available, isolation rooms; additional isolation measures in relevant cases such as air filters for aspergillosis in high-risk patients; prompt detection of infectious reservoirs through a bacterial surveillance program and institution of relevant control measures; (2) prevention of aspiration by adoption of semierect position and careful oropharyngeal suction to decrease the amount of secretions pooling above the inflated cuff; (3) prevention of gastric colonization by careful choice of stress ulcer prophylaxis; enteral feeding with orogastric and nasogastric routes of tube placement, use of small-bore tube if there is no requirement for larger size, and avoidance of large- volume feeds with rate adjustment according to any evidence of retention; (4) enhancement of host-clearance mechanisms by proper pain control, chest physiotherapy, breathing exercises, frequent turning for postural drainage, and early ambulation; (5) prevention of bacterial colonization by pathogenic bacteria by judicious use of antibiotics, preferably propagated through a hospital policy; and (6) expedient removal of invasive instrumentation when no longer needed.