Preventing VAP

Three industry experts give us their views on the fight to eliminate ventilator-associated pneumonia from the US healthcare system.

“While VAP appears to be an impossible challenge to eliminate, the history of medicine shows that many healthcare breakthroughs have solved even greater problems.”
-Ernest Waaser

How common is ventilator-associated pneumonia within US hospitals? What are the circumstances that would result in a patient contracting VAP?

Ed Coombs. VAP is a leading cause of death associated with hospital-acquired infections. It is exceeding the rate of death due to central line infections, severe sepsis and respiratory tract infections in the non-intubated patient. Perhaps the most concerning aspect of VAP is the high associated mortality rate. Hospital mortality of ventilated patients who develop VAP is 46 percent compared to 32 percent for ventilated patients who do not develop VAP.

In addition, VAP prolongs time spent on the ventilator, length of ICU stay and length of hospital stay after discharge from the ICU. VAP adds an estimated cost of $40,000 to a typical hospital admission.

Ernest Waaser. The CDC and the Society for Healthcare Epidemiology (SHEA) cite VAP as the second most common hospital acquired infection in the United States. VAP is estimated to occur in 10 percent to 20 percent of mechanically assisted ventilated patients.

Many potentially harmful pathogens exist throughout the hospital, especially in ICUs. ICU patients tend to have compromised immune systems and are highly susceptible to infection through contact transmission from caregivers or equipment. Ventilated patients are at high risk for VAP because natural respiratory defenses are compromised and are often breached through the use of an indwelling device, like an endotracheal tube. Endotracheal tubes can act like superhighways for bacterial invasion into the sterile lower respiratory tract, which means VAP could be referred to as intubation associated pneumonia.

Stefano Nava. The incidence of VAP within US hospital varies according to the type of environment, the geographical location and also the prevention measures adopted by each specific hospital. Nationwide, a large retrospective survey was conducted in the late 1990s. According to that study, of the 9080 patients meeting study entry criteria, VAP developed in 842 patients (9.3 percent). The mean interval between intubation, admission to the ICU, hospital admission, and the identification of VAP was 3.3 days, 4.5 days, and 5.4 days, respectively.

Risk factors for VAP were also examined using crude and adjusted odds ratios. Identified independent risk factors for the development of VAP were: male gender, trauma admission, and intermediate deciles of underlying illness severity (on admission). Quite surprisingly, hospital mortality did not differ significantly between cases and matched control subjects, Nevertheless, patients with VAP had a significantly longer duration of mechanical ventilation and hospital stay. Other single-center or multicenter studies have also shown an association between VAP and mortality rate.

What are some of the strategies that hospitals can employ to prevent the occurrence of this type of pneumonia? What technologies are available to help achieve this?

EW. According to SHEA, strategies to prevent VAP in hospitals focus on controlling the main causes: aspiration of secretions into the lungs, colonization of bacteria in the aerodigestive tract and use of contaminated equipment. Many hospitals adopt a VAP bundle approach. Simple steps of hand washing, head-of-bed elevation and routine oral care, combined with the use of innovative medical devices and caregiver education have also been effective. Recognizing the value of this comprehensive approach, we at Teleflex Medical offer a suite of ventilation management products and programs designed to reduce the risk of VAP.

One promising technology is our ISIS HVT, the industry's first convertible endotracheal tube, which allows for subglottic secretion suctioning on demand with a separate suction line. Often, the endotracheal tube chosen for initial intubation doesn't allow for easy access for this valuable practice, which helps prevent aspiration of secretions into the lungs. The ISIS HVT solves that challenge.

The Teleflex Gibeck Humid-Flo Passive Humidification Kit is an integrated system that promotes best practices for VAP risk reduction. This product has been validated to remain in-line during the first 72 hours of mechanical ventilation, which minimizes ventilator circuit breaks and the resulting patient exposure to inadvertent contact transmission of harmful bacteria.

Teleflex's OSMO allows for maintenance free water removal from the expiratory limb of the breathing circuit; providing protection to the patient through reduced circuit manipulation and cross-contamination potential. OSMO further assists institutions with compliance to infection risk reduction strategies such as SHEA's recommendation to keep ventilator circuits closed during condensate removal.

We also offer a variety of non-invasive ventilation (NIV) products to help manage a patient's respiratory requirements without endotracheal intubation, including the ConchaTherm Neptune heated humidifier and the ResMed NIV masks.

Education is also critically important, and Teleflex sponsors several caregiver educational initiatives focused on improving patient outcomes and facilitating VAP risk reduction as well. From the Clinical Foundations Newsletter (www.clinicalfoundations.org) to the Advances in Respiratory Care speaker series, we are proud to partner with leading respiratory care clinicians to deliver world-class education. We also sponsor www.firstdonoharm.com, a website dedicated to helping healthcare practitioners and executives reduce the human and financial toll exacted by hospital-acquired conditions.

SN. There are several clinician-developed guidelines for avoiding the occurrence of VAP which are based on the criteria of evidence-based medicine. Obviously, the single best way to prevent VAP is to limit the amount of time a patient is on mechanical ventilation.

The guidelines call for using noninvasive positive-pressure ventilation instead of intubation whenever possible. If this is not possible, remove a patient's ET tube as soon as possible and avoid re-intubation.

The use of a particular type of ET tube with an additional lumen that ends with an evacuation port just above the cuff - making it possible to remove secretions from above the cuff - may also be employed. Orotracheal rather than nasotracheal intubation is recommended, together with proper patient positioning (i.e. elevation of 30-40 degrees) to avoid gastric reflux. Tubing and other disposables changes are advised only when the equipment is visibly soiled or malfunctioning.

Oral care (i.e. chlorhexidine gluconate (0.12 percent) oral rinse) should also be performed especially in post-surgical patients. Finally, avoiding cross-contamination (i.e. preventing the transmission of microorganisms from healthcare workers to patients) through proper personal hygiene is probably the oldest but most effective preventive measure one can take.

EC.Reducing mortality due to ventilator-associated pneumonia requires an organized process that ensures early recognition of pneumonia and consistent application of the best evidence-based practices. A multi-disciplinary approach involving all bedside caregivers is essential to reducing the incidence of VAP.

The Institute for Health Care Improvement's 'Ventilator Bundle' is a series of interventions related to ventilator care that, when implemented together, should achieve significantly better outcomes than when implemented individually.

The key components of the Ventilator Bundle include elevation of the head of the bed. While it is not immediately clear whether this intervention facilitates the prevention of ventilator-associated pneumonia by decreasing the risk of aspiration of gastrointestinal contents or oropharyngeal and nasopharyngeal secretions, this was the ostensible reason for the initial recommendation.

Another reason that the intervention was suggested was to improve patients' ventilation. For example, patients in the supine position will have lower spontaneous tidal volumes on pressure support ventilation than those seated in an upright position. Although a variety of ventilator strategies may be applied, the improvement in patient positioning may aid ventilatory efforts and minimize risk of atelectasis.

Daily 'sedation vacations' and assessment of readiness to extubate are also key components of the Bundle. It appears that lightening sedation decreases the amount of time spent on mechanical ventilation and therefore the risk of ventilator-acquired pneumonia. In addition, weaning patients from ventilators becomes easier when patients are able to assist themselves at extubation with coughing and control of secretions.

Sedation vacations are not without risks, however. Patients who are not sedated as deeply have an increased potential for self-extubation. Therefore, the maneuver must be conducted in a careful manner. In addition, there may be an increased potential for pain and anxiety associated with light sedation. Lastly, decreased muscle tone and poor synchrony with the ventilator during the maneuver may risk episodes of desaturation.

The final two components are peptic ulcer disease prophylaxis and deep venous thrombosis prophylaxis. With peptic ulcer disease prophylaxis, critically ill intubated patients lack the ability to defend their airway. Esophageal reflux and aspiration of gastric contents along the endotracheal tube may lead to endobronchial colonization and pneumonia or may precipitate pneumonia due to the decreased bacterial killing in the low-acid environment.

Applying deep venous thrombosis prophylaxis is an appropriate intervention in all patients who are sedentary, however the higher incidence of deep venous thrombosis in critical illness justifies greater vigilance. The risk of venous thromboembolism is reduced if prophylaxis is consistently applied.

In addition to the IHI's ventilator bundle, new technologies in mechanical ventilation employ closed-loop systems to automate weaning protocols such as Draeger's SmartCare/PS which is available on the Evita XL and Evita Infinity V500. SmartCare/PS utilizes patient values such as ETCO2, tidal volume and respiratory rate to evaluate and automate weaning through knowledge-based guidelines.

How does VAP fit into the broader issue of post-operative pulmonary complications?

SN. Independent of surgical complications, such as infections and bleeding, there are three major types of medical risks that accompany major surgery. These include: cardiac risks, the formation of blood clots and pulmonary complications. The closer the surgery is to the diaphragm - any thoracic, upper abdominal, gallbladder or aortic surgery for example - the greater the risk of complications.

Additionally, emergency surgery or surgery lasting more than three hours also increases the likelihood that patients will develop postoperative pneumonia. Patients at risk are mainly those with advanced age (patients over 70 have a four-fold to six-fold increased risk of developing pneumonia), preexisting COPD, functional dependence (patients' inability to care for themselves), congestive heart failure, obstructive sleep apnea (OSA), pulmonary hypertension and a history of smoking.

The incidence of pulmonary complications (2.7 percent) is highly comparable to that of cardiac complications (2.5 percent). The development of postoperative respiratory failure (often defined as the need for ventilation for more than 48 hours after surgery) is an extremely morbid event, since it carries a mortality rate of greater than 25 percent.

EC. Post-operative ventilator care in the recovery room or ICU can range from short-term to long-term use of mechanical ventilation, depending on the nature of the illness or injury and duration of anesthesia. In both cases, it is essential to maintain proper airway care and utilize a protective ventilation strategy to reduce the risks of ventilator-induced lung injury. Reduction of ventilation time is paramount in the prevention of post-operative pulmonary complications.

EW.VAP significantly increases morbidity, mortality and health-care costs in post-operative patients, and research shows VAP is the most frequent ICU-acquired infection among patients receiving mechanical ventilation.

Continuous aspiration of subglottic secretions, as facilitated by the Teleflex ISIS HVT, has been identified as a VAP preventive measure. Other measures include limiting breathing circuit changes, spontaneous breathing trials and implementation of VAP bundles. Lung expansion intervention post-extubation may also decrease post-operative pulmonary complications. Teleflex's ventilator disposables with extended change-out protocols and incentive breathing spirometers support these strategies.

What is the likelihood of VAP being eliminated from the US hospital system in the future?

EW. While VAP appears to be an impossible challenge to eliminate, the history of medicine shows that many healthcare breakthroughs have solved even greater problems. The elimination of VAP is an ambitious and often-debated goal that the healthcare community, including its industry partners, must continue to strive to achieve. Education, increasing caregiver and public scrutiny and ongoing innovation are the tools that will help us meet that goal.

SN. This is a very difficult question to answer. Several studies have shown a significant and sustained reduction in VAP rates after the implementation of protocols aimed at preventive measures. However, most of these measures (e.g. hygiene, positioning, oral ET) are not related to any direct improvements in technology. Therefore, there remains a need for new technologies to help the clinicians avoid the development of VAP.

Right now, the only 'space' I see is for improving and expanding the use of NIV and ET tube with an additional lumen. NIV has been shown to significantly reduce the rate of VAP compared to ETI, so much so that some authors have suggested the name be changed from ventilator-associated pneumonia to intubation-associated pneumonia. Clinicians, however, should be aware of any absolute or relative contra-indications for NIV.

EC. While VAP may not be completely eliminated from mechanically ventilated patients, many facilities have been successful in significantly reducing or eliminating VAP through evidence-based practices. The Institute for Health Care Improvement (www.ihi.org) website is a powerful resource. The IHI model has been used very successfully by hundreds of health care organizations in the US and many countries to improve many different health care processes resulting in improved outcomes. The Model for Improvement has been combined with the concept of 'bundles of changes' to simplify the very complex processes of the care of critically ill patients.

Biography

Ed Coombs is Regional Director of Marketing - Respiratory Care Systems, Draeger-North America. Coombx is a graduate of SUNY Upstate Medical Center in Syracuse New York, earning his respiratory care credentials. He has served as a respiratory therapist, shift supervisor and clinical instructor for Stony Brook University Hospital and other Long Island community hospitals for approximately 18 years, prior to becoming involved in the medical device industry.

Dr. Stefano Nava is the Chief of the Respiratory Critical Care unit at the Istituto Scientifico di Pavia in Italy and a specialist in respiratory medicine and intensive care Medicine. He has published over 120 papers in peer-reviewed journals. Nava was elected chairman of the Intensive Care assembly at the European Respiratory Society. 

Ernest Waaser, President, Teleflex Medical, has over 20 years of experience in the medical device industry, leading multinational businesses, including as President/CEO of Hill-Rom, President of Agfa Medical Imaging and COO of Sterling Diagnostic Imaging. He holds a BS degree in Nuclear Engineering from Mississippi State University and an ME degree in Mechanical Engineering from the University of South Carolina.