Potential repercussions related to the development of ventilator-associated pneumonia (VAP), which include death, dictate the need for uniform industry recommendations.
Ventilator-associated pneumonia (VAP) has long been the subject of much discussion around the creation of standardized definitions, assessment tools and treatment options. Potential repercussions related to the development of VAP, which include death, dictate the need for uniform industry recommendations.
A 2012 study1 reported that VAP “…is the most common nosocomial infection in patients receiving mechanical ventilation, and it accounts for about half of all antibiotics given in the intensive care unit (ICU).” How frequently VAP occurs depends on the case mix, how long the patient is on mechanical ventilation and what type of criteria the hospital or unit uses to diagnose the condition. The study also noted that VAP develops in nine to 27% of mechanically ventilated patients and is related to increased length of stay in the ICU and in the hospital.
According to the Institute for Healthcare Improvement (IHI), the mortality rate for hospitalized patients on ventilators who develop ventilator-associated pneumonia (VAP) is 46%; inpatients who do not develop VAP while on a vent have a mortality rate of 32%. In an effort to reduce the incidence of VAP, in 2006 IHI launched the 100,000 Lives Campaign,2 which suggested taking a “series of interdependent, scientifically grounded steps” to address the problem.
Key Ventilator Features
When creating a VAP prevention protocol, hospitals need to consider the type of ventilator to use, according to Paul Garbarini, MS, RRT, vice president, Product Research and Development, Hamilton Medical Inc. “Depending on the preferred ventilator used by the institution, certain components of VAP prevention may require the use of external devices not associated with the ventilator. The more external devices utilized in these protocols, the higher the potential incidence of device-related technical failures or patient cross-contamination, if the device is shared among other patients,” Garbarini said.
“One example is artificial airway cuff pressure management. Traditional cuff pressure management involves the healthcare provider manually measuring cuff pressure using a portable device, such as a handheld, manual cuff filling system on a scheduled basis, commonly once or twice a shift, and is often shared between patients,” Garbarini continued. “Disposable devices are available and minimize cross contamination. However, they do not provide continuous monitoring and/or adjustment of cuff pressure in the absence of the healthcare provider.”
Garbarini pointed out that Hamilton Medical’s IntelliCuff continuous cuff pressure controller, which can be a standalone portable unit or integrated into the Hamilton-G5 ventilator, provides servo-regulated cuff pressure adjustment, monitoring and alarms on a continuous basis. “When integrated into the Hamilton-G5 ventilator, the cuff pressure can be visually displayed and adjusted on the Hamilton-G5 ventilator interface,” he added.
Furthermore, the more user-friendly the device, the better the outcome. According to Garbarini, Hamilton Medical’s ventilators are equipped with an intuitive interface that minimizes the complexity of operation. “[Ventilation Cockpit] provides a standardized display of patient data using ‘Intelligent Panels,’ including lung mechanics and the level of support or weaning status. The Ventilation Cockpit is operated the same way whether the device is in use in the ICU, MR suite or during transport,” he said. “This streamlined approach makes VAP detection, such as trending changes in oxygenation support, and prevention much easier and timely due to the standardized display of numeric and graphical values. Hamilton Medical’s Ventilation Cockpit provides user-configured Intelligent Panels that allow display of past and present patient data. This data can be trended over time in a variety of time frames and formats.”
Patient Analysis Tools
Another useful tool in reducing/preventing the development of VAP in ventilated patients is adaptive support ventilation, a closed loop mode that “…automatically adjusts tidal volume and respiratory rate combinations to minimize patient work of breathing, ventilator induced lung injury (VILI), and ventilator induced diaphragmatic dysfunction (VIDD),” Garbarini said. “Preventing these harmful occurrences from happening has been shown to contribute to a reduction in ventilator duration, therefore contributing to prevention and minimizing of risk factors associated with VAP development.”
Other recent advances in ventilator technology can alert the end user of physiologic changes related to VAP development, Garbarini added. “These include breath-to-breath analysis of the respiratory time constant, which can be displayed in a pictorial format to enhance identification of changes in pulmonary mechanics associated with VAP,” he said. “One example is Hamilton Medical’s Dynamic Lung, which provides a breath-by-breath, graphical, color display of lungs and tracheobronchial tree that change shape and color when significant changes in pulmonary mechanics have occurred.”
Admittedly, the best option for preventing VAP is to use noninvasive ventilation (NIV). Garbarini explained that NIV and heated high flow oxygen administration aims to eliminate the need of an artificial airway. He noted that some of today’s devices combine traditional ventilation with NIV.
These combination models have the necessary algorithm adjustments to ensure effective NIV, according to Garbarini. “All Hamilton Medical ventilators incorporate a variety of NIV modes to streamline transition from invasive ventilation to NIV, eliminating the need for separate NIV devices and circuitry. The variety of NIV options allows the clinicians to select an NIV mode and individualize settings to provide adequate support for the patient,” he said. “Additionally, Hamilton Medical’s ‘IntelliTrigger’ automatic leak compensation system enhances patient-ventilator synchrony, which is critical to successful application of NIV.”
Adam Seiver, chief medical officer, Philips Patient Care and Monitoring Solutions, emphasized that the features of an invasive ventilator are not per se central to the development of VAP; rather, the endotracheal tube that is integral to invasive ventilation is the problem. He reported that recent literature more often makes reference to “endotracheal-tube associated pneumonia,” rather than “ventilator associated pneumonia.” “While the term VAP is still commonly used, the mechanism underlying the infection appears to be the presence of the tube in the trachea, which is required by invasive ventilation,” he said. “In fact, an important hospital-based VAP prevention initiation is propagating the use of NIV as an alternative for invasive ventilation in appropriate patients.”
Whenever endotracheal tube placement is necessary, caution should be executed to ensure no foreign bodies are present, Seiver noted. The environment should be sterile and the trachea should be kept clear from interference with normal cough and swallowing activities, he added. “There is also some research that suggests there may be both abnormal local and system inflammation from the endotracheal tube as a foreign body.”
Multiple randomized trials show that VAP rates are lower with appropriate use of NIV, according to Seiver. “There is strong clinical evidence for the use of NIV in respiratory dysfunction with exacerbations of COPD, congestive heart failure and immune-compromised hosts. Use for other conditions is constantly being evaluated and it is likely that what is considered appropriate use will continue to expand,” he said. “In fact, it is interesting to think about NIV being the treatment for shortness of breath, with progression to invasive ventilation only occurring for patients who are likely to fail NIV.”
Technology and Training
Seiver reported that Philips has supported expanding the practice of NIV into the broader clinical space by eliminating the endotracheal tube and substituting a mask as the interface between the machine and the patient. “As the market leader in dedicated noninvasive ventilation in the hospital setting, we provide ventilators that allow patients with respiratory dysfunction, particularly those with exacerbations of COPD, to be treated without invasive ventilation. By avoiding the endotracheal tube there is a reduction in incidence of pneumonia and length of ventilation. There is also a mortality benefit. Studies suggest that for every five to ten patients treated with noninvasive ventilation, one life is saved.”
Additionally, preventing and reducing the incidence of VAP relies on appropriate use of technology, Seiver asserted. Ease of use for basic operation and “…training programs that help users know when and how to use NIV, including how to fit masks properly…” are key to obtaining the benefits of current technology. “Philips is also developing software and other tools that can enhance clinician bedside decision-making and decision implementation related to NIV use,” he added.
In general, Seiver advocates for measures based on anecdotal and clinical evidence. “Prevention measures, which have various levels of supporting clinical evidence, include clinician hand-washing and expediting removal of the endotracheal tube as soon as risks of continued invasive ventilation outweigh risks of its discontinuance,” he said. “Other tactics include avoiding micro-aspiration of gastric contents through upright positioning of the patient and the use of silver-coated endotracheal tubes.”
Prevention in Practice
These recommendations comprise part of the ventilation bundle that IHI promoted in its 5 Million Lives Campaign, which took place between 2006 and 2008. In a review article3 that discusses the possibility of a zero VAP rate, Michael Klompas noted that more than 2,000 hospitals have adopted VAP prevention bundles in response to the 5 Million and 100,000 Lives campaign promotions. In some cases, these measures are meeting with success.
For instance, the adult critical care unit at Mercy Medical Center in Baltimore, Maryland, experienced no VAP incidents for 1149 days (as of March 31, 2017), according to Crystal Barnes, RRT, manager, Respiratory and Pulmonary Department. “We do not have a formal VAP protocol. However, we have a lot of prevention strategies in place,” she said.
For example, ventilator circuits in the unit are not routinely changed. “Ventilator circuits should be checked every four hours and changed if visibly soiled,” Barnes said. “We maintain head-of-bed elevation to 30 degrees and endotracheal tube cuff pressure is checked every shift to maintain pressure of 25 to 30.” She noted that a Hi-Lo endotracheal tube is used on every patient and every intubated patient has closed in-line suction. Moreover, Mercy Medical Center uses heated ventilator circuits and nurses regularly perform oral care to prevent bacteria from accumulating in the mouth. “We are currently working on a spontaneous awakening and spontaneous breathing trial, so that we can increase extubation and decrease ventilator days.”
Klompas suggested that devising an objective definition for VAP might prove to be a better tool “…to monitor quality of care for ventilated patients, identify possible areas for improvement, and assess the impact of prevention initiatives.” RT
Phyllis Hanlon is a contributing writer to RT. For more information contact [email protected]
- Hunter JD. “Ventilator associated pneumonia.” BMJ 2012, 344: e3325. 10.1136/bmj.e3325.
- Berwick DM; Calkins DR; McCannon CJ; Hackbarth AD. “The 100,000 lives campaign: setting a goal and a deadline for improving health care quality.” 2006 Jan 18;295(3):324-7.
- Klompas M. “Is a ventilator-associated pneumonia rate of zero really possible?” Curr Opin Infect Dis 2012, 25:000-000. Doi: 10.1097/QCO.0bO13e3283502437.