New System May Allow Xenon Use to Protect Brain in Critically Ill Newborns

Newswise — Breathing xenon gas can help protect the infant brain from damage caused by oxygen deprivation, but the xenon's high cost and scarcity has precluded its widespread use. A newly developed "closed circuit system" may make xenon feasible, safe, and cost efficient for use in protecting the brains of critically ill infants, according to a study in the August issue of Anesthesia & Analgesia, official journal of the International Anesthesia Research Society (IARS). The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health, a leading provider of information and business intelligence for students, professionals, and institutions in medicine, nursing, allied health, pharmacy and the pharmaceutical industry.

Led by Dr. John Dingley of University of Wales, Swansea, a U.K. research team introduces a new method of giving xenon to newborn infants with birth defects and other life-threatening conditions requiring surgery and anesthesia. The usual reason for newborns to undergo surgery is a critical problem with the infants' breathing or circulation that prevents their tissues from getting enough oxygen. This lack of oxygen is particularly damaging to the brain, with long-term consequences for the child.

Although it is chemically considered an inert gas, xenon has profound biological effects—in high concentrations, it can induce unconsciousness. For several years, researchers have known that xenon provides protection against some forms of low-oxygen injury to the brain. However, because xenon is extremely expensive, its use is currently limited to a few experimental centers.

Closed-Circuit System Allows Xenon to Be Given for $2 per Hour

To address this problem, Dr. Dingley and colleagues designed a closed-circuit xenon delivery system. The system takes advantage of the fact that uptake of xenon by the lung is very low—when a given amount of xenon is breathed in, almost all of it is breathed out. The new system, fitted to a conventional newborn ventilator, essentially recaptures the exhaled xenon so that the infant can re-breathe it. The system adds precise amounts of oxygen and other gases as needed.

The researchers tested their closed-circuit xenon delivery system on newborn pigs. They found that they could precisely control the depth of anesthesia, while delivering exactly the right amount of oxygen. The piglets had stable vital signs and recovered without any complications. The xenon system could be used with our without cooling of body temperature (hypothermia)—previously the only technique known to protect the brain in infants with low-oxygen injury.

Using the closed circuit system, the researchers estimate that xenon could be used for surgery in critically ill newborns for as little as $2 per hour. This would allow "responsible use of a restricted global xenon supply in the maximum number of clinical cases per year," according to Dr. Dingley and colleagues. They believe that the simple design and operational cost of the system should make the delivery of xenon—once considered prohibitively expensive for routine medical use—safe and inexpensive for newborns requiring surgery and anesthesia for life-threatening birth defects.

About the IARS

The International Anesthesia Research Society is a nonpolitical, not-for-profit medical society founded in 1922 to encourage, stimulate, and fund ongoing anesthesia-related research and projects that will enhance and advance the anesthesiology specialty. The IARS has a worldwide membership of 15,000 physicians, physician residents, and others with doctoral degrees, as well as health professionals in anesthesia-related practice. In additional to publishing the monthly scientific journal Anesthesia & Analgesia, the IARS sponsors an annual clinical and scientific meeting, funds anesthesia-related research, and sponsors the SAFEKIDS research initiative in conjunction with the FDA. Additional information about the society and the journal may be found at www.iars.org and www.anesthesia-analgesia.org.

About Lippincott Williams & Wilkins

Lippincott Williams & Wilkins (LWW) is a leading international publisher for healthcare professionals and students with nearly 300 periodicals and 1,500 books in more than 100 disciplines publishing under the LWW brand, as well as content-based sites and online corporate and customer services. LWW is part of Wolters Kluwer Health, a leading provider of information and business intelligence for students, professionals and institutions in medicine, nursing, allied health, pharmacy and the pharmaceutical industry.

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