New Mass Spectrometer Will Aid In The Diagnosis And Treatment Of Pulmonary Disorders
(Philadelphia, PA) -- Scientists at the Center for Anesthesia Research at the University of Pennsylvania Medical Center have developed an unprecedented method to quickly and accurately assess lung function. In less than 10 minutes, this technique -- Micropore Membrane Inlet Mass Spectrometry (MMIMS) -- directly measures trace gas tensions in small blood and breath samples to determine if the lungs are working properly. The use of this novel mass spectrometry technique will be presented at the Shock Society of America's* 21st annual conference on Wednesday, June 17, in San Antonio, Texas.
Principal inventor James E. Baumgardner, MD, PhD, assistant professor of Anesthesia and Bioengineering, has designed a sensitive probe device that extends an existing method known as Multiple Inert Gas Elimination Technique (MIGET), a complex laboratory procedure for measuring lung and gas exchange efficiency. MIGET detects impaired gas exchange associated with such pulmonary disorders as acute respiratory distress syndrome, pneumonia, asthma, and emphysema. MMIMS uses polymer membranes designed specifically to carry out the MIGET method rapidly in a clinically-applicable and simplified way.
"We have known about the MIGET method and its contribution to the knowledge of lung function since 1974," explains Dr. Baumgardner. "However, the discovery of the sensitive probe device introduces a way to take this sophisticated technique out of the laboratory and into the clinical setting."
To function normally, the body relies on the lungs to obtain both a steady supply of oxygen and to eliminate carbon dioxide generated by metabolism. Abnormalities in the lungs cause unbalanced exchanges of oxygen and carbon dioxide, which result in pulmonary distress. Currently, clinical practice depends on chemical analysis of blood samples and observing a patient's breathing abilities to evaluate lung function, resulting in approximate diagnosis and treatment. Whether in outpatient clinics, hospital rooms, intensive care units, or in emergency rooms, there is a need to regularly and more accurately estimate patients' lung oxygen and carbon dioxide exchange in order to pinpoint the severity of the pulmonary disease, target correct therapy, and assess status of the patients' conditions.
MIGET is an established research tool for studying mechanisms of impaired pulmonary function. With MIGET, trace amounts of six inert gases are dissolved in saline and infused intravenously. Excreted and retained portions of these gases are then measured in breath and blood samples. Retention and excretion data for all six inert gases are translated into ventilation/perfusion ratio distributions using linear algebraic techniques. This allows for the calculation of lung efficiency in a sophisticated way and provides detailed information about the mechanisms of impaired gas exchange. Analysis is so complex and difficult, however, that it has previously been available only in the world's most advanced research laboratories. Application has also been limited by the large volume of blood needed for repeated analysis (approximately 20 - 40 milliliters, or one to three tablespoons, per analysis), as well as the amount of time required for each process (about four hours).
"The ability to measure lung function routinely -- with the detail of a research lab -- allows clinicians to provide pulmonary disease patients with more accurate diagnosis, precise drug or other treatment, and specific assessment of progress or effectiveness of previous therapies," says Bryan E. Marshall, MD, FRCP, co-inventor and Horatio C Wood Professor of Anesthesia at Penn.
To date, extensive research has been conducted on the pulmonary function of normal rabbits with the MMIMS/MIGET method using small blood sample volumes (about two milliliters, or one teaspoonful). This work has demonstrated the feasibility, precision, and reduction of analytic time and error provided with the use of the new sensitive probe device. In approximately eight to ten minutes, a mathematical description of each subject's lung function was obtained. Because both rabbits and humans have the same basic mammalian physiology, researchers are confident that the findings will translate into human application. Human trials are set to begin within the next month.
SpectruMedix Corporation of State College, PA, has recently begun a collaboration with Baumgardner and Marshall to develop and commercialize the MMIMS technique. SpectruMedix is a U.S. company with a strong focus on medical and scientific technologies and associated instrumentation. SpectruMedix is providing research support, and, has an exclusive worldwide license to develop a commercial instrument for clinical use.
Sources of research funding for this work include: the University of Pennsylvania Foundation; the Department of Anesthesia at the University of Pennsylvania Medical Center; SpectruMedix Corporation; and the National Institutes of Health's Small Business Technology Transfer Program (STTR). NIH's STTR program is designed to foster transfer of technology from academia to small businesses that results in products and devices that benefit society.
Editor's Notes: *The Shock Society of America is a specialized group of scientists and clinicians from an interdisciplinary mixture of fields, including surgery, anesthesia, physiology, and bioengineering. From June 15 - 17 , please contact Diane Giaccone to reach Dr. Baumgardner at the Shock Society conference in San Antonio. Dr. Marshall can be reached directly at (215) 662-3766. To contact SpectruMedix, call Bernard Sonnenschein at (814) 867-8600.
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