"Noisy" Ventilators Are Better

Controlled variability enhances and protects lung function, according to a recent study published in the journal Nature.

Scientists at Boston University’s Department of Biomedical Engineering have reported a new model of ventilator-assisted lung function. In this model, the pressure of air delivered by the ventilator is varied by the addition of "noise," a random amount of additional air pressure that varies from breath to breath. Scientists believe the "noisy"ventilator has the potential to improve gas exchange in patients with lung injury and could minimize ventilator-related trauma.

To conduct the study, researchers used a computer model of a damaged lung that had large collapsed regions. They found that during inhalation, the collapsed regions tended to open in a burst, or avalanche, with large groups of airways and alveoli popping open simultaneously, suddenly increasing the alveolar surface area available for gas exchange. By varying the pressure of air delivered by the ventilator–adding "noise" to the base air pressure–this avalanche-like opening of the airways and alveoli was enhanced and gas exchange improved. Researchers also determined there was an optimal "noise" level; too much led to barotrauma, while too little had no impact. The model is currently being tested on animals.

Welcome to the Board

Catherine M. Foss MS, RRT, RPFT, did not always dream of being a part of the respiratory care industry when she graduated from the University of Michigan with a bachelor of science degree. She always wanted to work in a hospital setting, however. After 2 years of teaching kindergarten through 12th grade in "every subject but English,"Foss opted for a career in respiratory therapy. "

"I wanted a career in health care that would include patient contact and utilized my education experience. Asthma education, pulmonary rehab, and diagnostic testing were a good fit with my prior experience, so I signed up for a local respiratory therapy program," Foss says.

Currently a senior clinical technologist at The University of Michigan Medical Center, Foss supervises the adult blood gas laboratories and the outpatient diagnostic laboratory. In addition, she teaches clinical rotations for respiratory therapy students.

Foss also participates in research conducted at the medical center. Thanks to the facility’s advanced equipment, clinicians are able to perform studies that only few other medical centers can perform worldwide, putting Foss–and, in turn, RT–at the forefront of new research and therapies.

"The facility I work in performs unusual studies that may interest other centers in the field, and the advisory board," Foss says.

A study of importance to Foss is the National Emphysema Treatment Trial for lung-volume–reduction surgery, currently under way at the the University of Michigan Medical Center. Funded by the National Institutes of Health and the National Heart, Lung, and Blood Institute, the data from this research will provide insight on medical treatment for emphysema versus the surgery. In the future, Foss says she would like to expand her knowledge in neonatal diagnostics/pulmonary function in addition to completing her master’s degree in public health.

ALA Selects Vice President of Communication

Kent Wallace-Meggs has been named vice president of communication for the American Lung Association of Los Angeles County, and will be responsible for public/media relations, marketing, and public affairs. Wallace-Meggs has a strong background in public relations, marketing, and advertising for not-for-profit and for-profit organizations.

Obesity May Increase Asthma Risk

Two studies presented at the American Lung Association/American Thoracic Society International Conference this past April in Chicago suggest obesity may increase one’s asthma risk.

In one study, researchers using data from a study of more than 100,000 nurses found the more overweight a nurse was, the greater her risk of developing asthma in adulthood. The second study found the most overweight 26-year-olds were more likely to have asthma than the thinnest ones.

Previously, it was assumed that people with asthma may become overweight because their breathing problems limit their activity, according to Carlos A. Camargo, Jr, MD, DPH, of Harvard Medical School in Boston. However, "with proper treatment, people with asthma should not have activity limitations," says Camargo, who led the nurses study.

In the first study, Camargo and colleagues based their findings on data from the Harvard Nurses Health Study II, a prospective study of 116,678 nurses. Of these nurses, they tracked 89,061 who did not have asthma in 1991 and found that 1,652 developed asthma between 1991 and 1995. Those who were most obese in 1991 were three times as likely to develop asthma as those who were the least overweight.

In the second study, British researchers looked at the relationship of birthweight, weight, and height at age 26 to the prevalence of asthma in more than 8,000 people. They found the heaviest adults were 80 percent more likely to have asthma than the thinnest ones, according to researcher Seif O. Shaheen, PhD, of the United Medical and Dental Schools in London.

Although little research has been conducted to examine how obesity might lead to asthma, Camargo said it is possible being overweight somehow compresses the airways, making them smaller and, therefore, more reactive to cold and other asthma triggers.

Shaheen believes the type of diet obese people consume and a lack of exercise may put them at a higher asthma risk.

Outpatient Asthma Care Saves Money, Gets Results

Researchers at the University of Illinois in Chicago have found a more effective, less costly treatment for people suffering from severe asthma attacks, according to a study published in the April issue of the Journal of Medical Care.

Researchers studied 113 patients at the Cook County Hospital emergency department. Roughly half the patients were treated with an accelerated treatment protocol, Emergency Department Observation Unit (EDOU). The rest received traditional treatment and inpatient care. EDOU resulted in higher quality of life outcomes post discharge and lower costs–$1,202 per patient versus $2,247 per patient for inpatient care, a 47 percent decrease, researchers found.

"As third-party payors come to realize the cost savings and higher patient satisfaction in emergency department outpatient units, they will serve as the preferred standard of care," says Robert Rydman, lead author and associate professor of health policy and administration at the University of Illinois’s School of Public Health.

"Travel Advisory" on the Information Superhighway

Parents seeking asthma information on the Internet should be aware that quantity, not quality, seems to be the rule of the road, researchers warn.

According to researchers, the accuracy and quality of information on the Internet vary widely. When it comes to accurate and balanced information, Web sites created by educational institutions, the government, and not-for-profit organizations are better resources, say researchers Madhumita Sinha, MD, and Chris Kennedy, MD, of the division of emergency medicine at Children’s Hospital Medical Center, in Akron, Ohio.

Sinha and Kennedy divided 40 Web sites with parent-oriented childhood asthma information into two groups–commercial and noncommercial (educational institution, government, and nongovernmental organizations). Nineteen sites were classified as commercial, 21 as noncommercial. The two groups were then analyzed for relevance, accuracy, and balance of content. When the content was compared with standard patient education information published by the National Institutes of Health, including asthma symptom identification, triggers, assessment of severity of an attack, drug information, home management, and prevention, noncommercial sites were found to be superior.

Although commercial and noncommercial Web sites were equally attractive in design, noncommercial sites provided more consistent, balanced, authentic information, researchers say.

"Definitive standards and regulations should be established for all Web sites providing medical information," Sinha said

Tricyclic Antidepressants Linked to Lung Disease

A study by researchers at City Hospital in Nottingham, United Kingdom, reveals that some older forms of antidepressants may cause idiopathic pulmonary fibrosis (IPF).

Researchers examined medication use of 141 people with IPF and 246 people of similar age and sex without the disease. The study, which looked at antidepressants, beta blockers, antibiotics, anticonvulsants, and nonsteroidal anti-inflammatory drugs, found IPF to be most strongly associated with exposure to several tricyclic antidepressant medications, particularly imipramine. The researchers estimated that 10 percent of IPF cases were caused by antidepressant exposure. No significant association was seen between IPF and the other drugs studied.

Gary Hunninghake, MD, director of the pulmonary division at University of Iowa Hospitals in Iowa City, said the new findings are interesting, but need to be confirmed. "For now, I would advise that patients taking tricyclic antidepressants not stop their medications," he said. They may want to discuss the study findings with their personal physician, he said.

Researchers Closer To Curing the Common Cold

Research by scientists at Purdue University, in Indiana, may help bring an end to one of the most troublesome and universal pathogens known to man: the common cold virus.

The researchers, led by Michael G. Rossmann, PhD, have unlocked the secrets of a cell receptor the common cold virus uses to enter and infect human cells. Rossmann and his team analyzed in atomic detail the three-dimensional structure of the part of the cellular receptor that binds to the virus that causes the majority of colds in humans. Knowing the structure will help scientists unravel the mystery of how cold viruses enter cells and may suggest ways to develop drugs that prevent the common cold and other illnesses caused by similar viral pathogens.

The receptor, ICAM-1, intercellular adhesion molecule one, is one of many types of adhesion molecules found in multicelled organisms. As the name implies, adhesion molecules play a role in binding cells to other molecules or cells. ICAM-1 normally functions to hold infection-fighting white blood cells in place in regions of the body that have been injured or damaged.

Fingerlike projections on ICAM-1 set it apart from other cellular adhesion molecules and make it a perfect complement to the rhinovirus structure, Rossmann says. "The shell of the rhinovirus has deep crevices or canyons capable of interacting with the fingerlike projections of the ICAM-1 receptor," Rossmann says.

The study shows that the rhinovirus bypasses the structure ICAM-1 uses to bind to white blood cells and binds instead to another part of the receptor to gain entry into the cell, says Jordi Bella, PhD, a post-doctoral researcher working on the study.

Because the virus attaches to a different site than the one used by white blood cells, it should be possible to develop ways to block the interaction, Bella says.

"If scientists could prevent that interaction . . . either by a drug or genetic engineering technique, we could eliminate a large percentage of colds in humans without interfering with the normal function of the ICAM-1 receptor," Bella says.

This would not mean an end to all colds. Rhinovirus 16, the cold virus used in the study, comes from a family responsible for 70 percent of colds. The remaining 30 percent are caused by viruses that use other means of infecting cells, Bella says.

Overcrowding May Play Bigger Factor Than Race in TB

A new study suggests social and economic factors that lead to overcrowded housing may play a bigger role in TB than race.

The Centers for Disease Control and Prevention (CDC) study found that people in lower income groups are more likely to be exposed to the TB virus because they share airspace in crowded living conditions.

In 1997, the TB case rate among Hispanics, blacks, and Asian/Pacific Islanders were 6, 8, and 16 times greater, respectively, than among whites.

"This study shows that socioeconomic factors are strong predictors for tuberculosis," says Lee Reichman, MD, MPH, former ALA president and executive director of the New Jersey Medical School National Tuberculosis Center, in Newark. "However, one needs to remember that TB is a transmissible disease that can be spread to individuals of any race or ethnic group," he says.

Companies Support ASAA

The American Sleep Apnea Association has announced that National Sleep Technologies has joined the ASAA Industry Roundtable as a contributor ( supports are defined as sponsors, benefactors, patrons, investors, and contributors).

In addition to National Sleep Technologies, other Industry Roundtable members include, in descending order of support, Nellcor Puritan Bennett and Respironics (sponsors), ResMed (investor), and AirSep Corporation and Sunrise Medical (contributors).

The ASAA Roundtable helps support the association’s work by making unrestricted tax-deductible contributions to the ASAA–whose mission is to reduce injuries, disabilities, and death caused by sleep apnea.

Flu 911

The influenza virus strain that dominated last winter’s flu season will be included in next season’s vaccine, according to the Centers for Disease Control and Prevention (CDC). The influenza A/Sydney strain, first seen in Australia and New Zealand, will be included in the new vaccine. The strain has been linked to up to 90 percent of flu cases reported to the CDC during the last flu season, which peaked in late January/early February. Health officials estimate that flu is associated with 20,000 deaths a year. Flu vaccines are up to 90 percent effective in preventing flu in healthy adults, according to the CDC.

The Ride of His Life

Board-certified internist, pulmonologist, and critical care specialist Thomas Dailey, MD, is about to embark on what may be his most challenging–and greatest–feat yet: a cross-country bike race.

Dailey, an asthmatic, will be among 1,000 cyclists participating in the GTE Big Ride Across America, a cross-country trip to raise money for the American Lung Association.

"I look forward to the physical challenge of riding across America," says Dailey of the 45-day, 3,000-mile trip. "I’m also trying to show that asthma doesn’t have to restrict physical activity. With aggressive treatment, asthma is a controllable condition, and exercise is an important part of any program designed to improve breathing," he says.

Dailey, chief of member services at Kaiser Permanente Santa Clara Medical Center, hopes to raise $6,000. Those who wish to contribute may contact Dailey care of Kaiser Permanente, 900 Kiely Blvd, Santa Clara, CA 95051.

Some People "Born to Smoke," Study Shows

For years, researchers have pondered why some teens who experiment with tobacco become lifetime smokers. Research at the University of Michigan Medical School, in Ann Arbor, may provide the answer.

According to a University of Michigan study, some individuals are more susceptible to nicotine’s pleasurable effects, making them more likely to become smokers. The study, conducted by Ovide Pomerleau, MS, PhD, and colleagues at the Nicotine Research Laboratory in the University of Michigan Behavioral Medicine Program, could have a bearing on cigarette advertising, Pomerleau says. The study suggests that one in three children who sample a cigarette will become lifetime smokers. For this reason, it is important to prevent teens from trying a cigarette in the first place, Pomerleau says.

Previous studies have indicated that smoking addiction is genetically transmitted, even more so than alcoholism. The University of Michigan study goes a step further, offering clues about precisely what trait is being inherited–the tendency for some individuals to experience a pleasurable “buzz” when they smoke. Researchers believe these findings may help them eventually develop a test for biological sensitivity to nicotine that will identify children at high risk of becoming smokers and make preventive measures possible, Pomerleau says.

Ultrasound Endotracheal Tube Could Save Lives

Experts in emergency medicine and ultrasound at the University of Rochester have teamed up to improve an important lifesaving tool: the endotracheal tube.

Experts estimate that each year, 2 percent to 5 percent of patients are intubated incorrectly, resulting in insufficient ventilation, stomach rupture, airway trauma, and, in some cases, death.

The new device, soon to receive a US patent, takes advantage of ultrasound technology. The new tube is equipped with ultrasound transducers smaller than a pencil eraser. These transducers, which are attached to the lower end of the foot-long tubes, emit ultrasonic pulses detected by a small receiver on the front of the patient’s neck only if the device is correctly inserted.

Researchers believe the transducer-equipped tubes will sell for slightly more than the current ones. The system’s battery unit would be an additional one-time cost of $50 to $100 for an ambulance squad or hospital.