Resp Care
-
Historically, the relationship between the ventilator circuit and pulmonary infection was accepted as fact, without any scientific evidence. Hence the term, "ventilator"-associated pneumonia. Recent evidence, however, has demonstrated that the major sources of pneumonia in the ventilated patient are colonization of the gastrointestinal tract, with subsequent aspiration around the endotracheal tube cuff, and contamination by caregivers. ⋯ A number of clinical trials have demonstrated that routine changing of the ventilator circuit fails to impact the incidence of pneumonia in the ventilated patient. Additional studies evaluating the type of humidification device, type of suctioning device, and frequency of change of the devices have resulted in conflicting evidence. This paper reviews the role of the humidifier, ventilator circuit, and airway suctioning equipment on the pathogenesis and prevention of ventilator-associated pneumonia.
-
Ventilator management strategies can affect the risk for ventilator-associated pneumonia in 3 ways: the development of ventilator-induced lung injury; the need for potentially harmful tradeoffs in providing lung-protective ventilatory strategies; and the prolongation of the duration of mechanical ventilation from iatrogenic factors. Strategies to reduce ventilator-induced lung injury include a smaller tidal volume and careful attention to reducing the maximum pressures in the lung. ⋯ However, the weight of evidence suggests that beneficial outcomes from lung-protective strategies outweigh any potential harm from these tradeoffs. Finally, properly performed weaning protocols based on clinical evidence should reduce any iatrogenic delays in ventilator weaning and thereby minimize prolongation of unneeded mechanical ventilatory support.
-
Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in the intensive care unit and is associated with major morbidity and attributable mortality. Strategies to prevent VAP are likely to be successful only if based upon a sound understanding of pathogenesis and epidemiology. The major route for acquiring endemic VAP is oropharyngeal colonization by the endogenous flora or by pathogens acquired exogenously from the intensive care unit environment, especially the hands or apparel of health-care workers, contaminated respiratory equipment, hospital water, or air. ⋯ Measures to prevent epidemic VAP include rigorous disinfection of respiratory equipment and bronchoscopes, and infection-control measures to prevent contamination of medical aerosols. Hospital water should be Legionella-free, and high-risk patients, especially those with prolonged granulocytopenia or organ transplants, should be cared for in hospital units with high-efficiency-particulate-arrestor (HEPA) filtered air. Routine surveillance of VAP, to track endemic VAPs and facilitate early detection of outbreaks, is mandatory.
-
Ventilator-associated pneumonia (VAP) is a common complication of ventilatory support for patients with acute respiratory failure and is associated with increased morbidity, mortality, and costs. Awareness of the microbiology of VAP is essential for selecting optimal antibiotic therapy and improving these outcomes. The specific microbial causes of VAP are many and varied. ⋯ In conclusion, information about the microbiology of VAP serves to guide optimal antibiotic therapy. The risk of antibiotic-resistant pathogens can be estimated using simple clinical features and awareness of local microbiology patterns. The roles of atypical bacterial and nonbacterial pathogens in VAP are incompletely understood and should be investigated further.
-
There has long been a controversy about whether to use a clinical or microbiologic approach to diagnose ventilator-associated pneumonia (VAP) and about which approach to use in managing patients. Although the clinical approach has often been criticized, a number of recent studies have shown that it is possible to use such an approach to effectively manage patients. This approach involves using all available clinical data to define the presence of pneumonia and then to initiate empiric therapy in a timely fashion, based on therapy guidelines, modified by local microbiologic data. ⋯ Based on this assessment, in conjunction with the results of tracheal aspirate cultures, therapy can be either modified or continued. A number of studies have shown that the clinical approach leads to a large number of patients receiving adequate empiric therapy, while still permitting de-escalation of antibiotic regimens, along with short durations of therapy. Thus a clinical approach to management can be successful in allowing for effective management of VAP, without promoting the unnecessary use of broad-spectrum antimicrobial therapy.