One of the biggest concerns of hospitals caring for patients on ventilators is the increased risk those patients have of developing what is known as “hospital-acquired pneumonia.” “The patients in our trauma ICU are there because they’ve been injured in car wrecks, accidents at home or at work, or shootings or other assaults,” explains Wood. “They often have to be on a mechanical ventilator, and that puts them at high risk of getting pneumonia or infection in their lungs.”

When a patient exhibits a trio of symptoms – fever, high white blood cell count, and an abnormal chest x-ray – the assumption is that pneumonia has developed. The patient is immediately placed on antibiotics until a culture can be performed and the results come back confirming the infection, a process that can take 3 to 4 days.

“But only 40% of these patients actually have pneumonia,” says Wood. “The rest are exhibiting those symptoms due to their trauma. So the problem is that 60% of these patients are placed on antibiotics when they don’t need to be – putting them at risk for side effects, developing resistance to antibiotics, and incurring unnecessary cost. We wanted to find a way to identify as quickly as possible those who don’t have pneumonia.”

Wood and his team decided to use bronchoalveolar lavage, a procedure which involves inserting a tube into the bronchi and alveoli of the lungs to collect mucous to test for the presence of microorganism concentrations that indicate pneumonia. The preliminary culture results from bronchoalveolar lavage, which are usually available within 24 hours, were compared to the final results. The team discovered that the preliminary results were correct over 90% of the time.

Over the course of the next 15 months, the team used the preliminary results as their guide. If a patient’s preliminary result came back negative, antibiotic use was discontinued, usually within 1 to 1 ½ days. False negatives occurred in only four patients, and none of these was negatively affected by the discontinuation of medications.

“The cumulative effect of decreasing antibiotic usage is huge,” states Wood. “Ventilator-associated pneumonia accounts for half of all antibiotic usage in the hospital. We administer hundreds of courses a year. In this study, we decreased the duration of antibiotics in people who didn’t need them by one half, and we have benefited from a cost standpoint as well. Antibiotics are a huge chunk of a hospital’s budget, and so money is saved for the pharmacy as well as the patient and his or her insurance company. We also think that limiting antibiotic therapy is a reason why we continue to have low levels of bacterial resistance in our ICU.”

Wood presented his findings at the 2006 Society of Critical Care Medicine Meeting and at the 2006 ASHP Midyear Clinical Meeting. He hopes that his study will convince others to consider faster discontinuation of antibiotics. “We’re trying to encourage health care professionals to follow the current pneumonia guidelines more closely,” he explains. “The experts agree that antibiotic usage can be discontinued upon a negative culture in many patients. We not only are doing that – we are doing it more rapidly than others and have shown that this is a safe and effective way to decrease antibiotic usage. I hope our study affects the way patients on ventilators are treated in the future.”