Ventilator-Associated Events

Abstract

H ealth care-associated infections (HAIs) are a global problem that result in an increase in patient morbidity and mortality. 1,2 Multiple efforts to decrease the occurrence of these complications have taken place, thus improving patient outcome. Recognizing that health careassociated complications are a patient safety issue and a public health threat, the United States, through the Centers for Disease Control and Prevention (CDC), has emphasized the importance of eliminating these complications. 3,4 Techniques to prevent HAI have involved the development of surveillance methods to detect both endogenous and exogenous sources of infection, as well as data-reporting systems to aid in identifying both causative and modifiable risk factors for HAI. A variety of strategies has resulted from these techniques. One impact of these initiatives has resulted in health care providers in all fields, including anesthesia, becoming engaged in the process of using various avoidance strategies with the goal of preventing and ultimately eradicating HAI. This review will focus on the prevention of complications associated with mechanical ventilation through the use of "care bundles" and discussion of the new definitions and their implications.Ventilator-associated pneumonia (VAP) is one example of an area in which specific guidelines have been created in an attempt to reduce the incidence of health care-associated complications, by implementing a group of evidence-based care interventions. Loosely termed care bundles, these care interventions are designed to decrease the rate of the targeted complications. In the case of VAP, the targeted rate initially set by the CDC and the Institute for Healthcare Improvement (IHI) was zero. The care bundle preventative strategies for VAP, including its applied rationale based on the evidence, will be discussed, as well as its limitations and shortcomings. VAP CARE BUNDLEIn 2001, the IHI recognized care of the ventilated patient as a top priority and identified the most significant complications associated with mechanically ventilated patients as VAP, venous thromboembolism, and stress-induced gastrointestinal bleeding. Four elements of care were identified as key factors in reducing these complications, with a fifth element added in 2010. The current IHI care bundle therefore consists of 5 interventions targeted to improve outcomes in mechanically ventilated patients. These include (1) head of bed (HOB) elevation, (2) daily sedation holiday with assessment for possible extubation, (3) daily oral care with chlorhexidine, (4) deep venous thrombosis prophylaxis, and (5) peptic ulcer prophylaxis. a The first 3 elements are the components that have been examined for the prevention of VAP (Table 1); the remaining 2 have been studied to reduce overall morbidity and mortality in patients who are mechanically ventilated and are not associated with a decrease in the incidence of VAP.The IHI VAP bundle has some recognized limitations and has been criticized by a number of authors. 5,6 These criticisms in...

Shifting the Paradigm: Preventing More Than Infection

“…The new algorithm broadly identifies Ventilator-associated events (VAEs) under which several subcategories exist, including: ventilator-associated conditions (VACs), infection-related ventilator-associated conditions (IVACs), and probable ventilator-associated pneumonia (PVAPs). [1][2][3][4][5][6][7][8][9][10][11][12] Historically, infection prevention programs have used one of several bundled care programs as a strategy to prevent VAP. However, demonstrating consistent efficacy of such bundled care has been severely limited by the subjective nature of the VAP definition.…”

“…13 With the implementation of the new definitions, the standard bundle is inadequate because the prevention initiatives must now include a broad scope of respiratory complications beyond infections. 1,3,6,7,12,[14][15][16][17][18] Ventilator-associated events are more objective and can be automated for detection because they are determined by specific changes in the fraction of inspired oxygen (FiO 2 ) and positive end expiratory pressure (PEEP). Therefore, many other noninfectious conditions associated with mechanical ventilation may trigger a VAE: atelectasis, acute respiratory distress syndrome (ARDS), fluid overload resulting in pulmonary edema or pleural effusions, transfusion-related lung injury, traumatic injury to the chest, barotrauma or volume-related trauma from the ventilator, pneumothorax and pulmonary emboli, among others.…”

“…Therefore, many other noninfectious conditions associated with mechanical ventilation may trigger a VAE: atelectasis, acute respiratory distress syndrome (ARDS), fluid overload resulting in pulmonary edema or pleural effusions, transfusion-related lung injury, traumatic injury to the chest, barotrauma or volume-related trauma from the ventilator, pneumothorax and pulmonary emboli, among others. [1][2][3][4][5][6][7]9,11,12,15,[17][18][19][20] The inclusion of the noninfectious causes has resulted in much scrutiny of the new definitions. Ventilator-associated events are associated with increased costs, duration of mechanical ventilation, ICU length of stay and mortality; however, there are discrepancies between the new and old definitions in the detection of VAP.…”

“…Ventilator-associated events are associated with increased costs, duration of mechanical ventilation, ICU length of stay and mortality; however, there are discrepancies between the new and old definitions in the detection of VAP. [2][3][4][5][6][7][8][9][10][11][12][14][15][16]18,19 Whether or not the VAE algorithm identifies VAP as well as the old remains controversial, particularly because PVAP comprises only~10%-30% of VAE cases. 2,3,[9][10][11][12]15,[17][18][19] If definitions of VAP were poor to start with, comparisons will be fraught with variability: the data are only as good as the initial definition of a case.…”

“…However, many of the best practices regarding prevention of the noninfectious etiologies also decrease VAP through shorter durations of intubation, improved clinical status, and decreased risk factors for development of pneumonia. 6,7,12,13,16,17 Notably, management by intensivists has also been associated with improvement in VAP rates. 20 For decades, research has focused on refining the definition of ARDS and treating ARDS; however, pharmacologic options have failed to result in significant improvement in ARDS.…”