Results from two randomized clinical trials demonstrated that when given within the first few weeks of life, inhaled nitric oxide (iNO) helps prevent chronic lung disease in some low-birth-weight premature infants. Also, when used within 48 hours after birth, treatment appears to protect some premature newborns from brain injury.
The two independent studies involved nearly 1,400 low-birth-weight premature infants treated at 37 medical centers. Supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH), the results of the studies are published in the July 27, 2006 issue of the New England Journal of Medicine (Haland et al., 2006).
In 2004, more than one-half million babies in the United States (about 12.5%) were born prematurely (less than 37 weeks of pregnancy). This is the highest number reported since comparable national data have been available, according to the Centers for Disease Control and Prevention (Martin et al., 2006). Costs associated with the premature births in the United States last year were approximately $26.2 billion, which equates to $51,500 per infant, according to a report released on July 13 by an independent panel convened by the Institute of Medicine of the National Academies (Behrman et al., 2006). Because their lungs are not fully developed, breathing problems at birth are common among premature infants and those with low birth weights less than 3 lb. Oxygen is used on these infants to help them breathe and for protection of the brain, heart, liver, and kidneys. High levels of extra oxygen or prolonged use of ventilators can damage the lungs and interrupt normal development, causing a chronic lung disease known as bronchopulmonary dysplasia (BPD). Infants born weighing less than 3 lb are at high risk of BPD even if they do not require a ventilator. In the United States, more than 10,000 babies develop BPD each year.
The use of iNO has proven beneficial in full-term newborns with severe respiratory failure and helps them survive without the need for treatment with a heart-lung machine. This treatment has lowered the risk of these infants developing BPD and other long-term complications. Benefits and risks of the use of nitric oxide in premature and low-birth-weight babies have been uncertain.
"When given within the first 48 hours of life, low-dose inhaled nitric oxide reduced the risk of brain injury in very low-birth-weight premature newborns who required mechanical ventilation after birth," said John P. Kinsella, MD, lead author of one of the studies (NHLBI, 2006). Kinsella is a neonatologist with the Pediatric Heart Lung Center at Children's Hospital in Denver and professor of pediatrics in the School of Medicine at the University of Colorado at Denver and Health Sciences Center. Kinsella and his colleagues will continue to follow these participants for another 4.5 years to better understand the long-term effects of the treatment.
Roberta A. Ballard, MD, professor of pediatrics and obstetrics and gynecology, and formerly chief of the Neonatology Division at the Children's Hospital of Philadelphia and the University of Pennsylvania, stated, "in addition to improving the rate of survival without BPD in these premature infants, we found that inhaled nitric oxide was associated with less severe lung disease among the treated infants who did develop BPD." Ballard is the lead author of the other study (NHLBI, 2006).
"Medical science has dramatically improved our ability to help very small and premature babies survive. But as the rate of premature births continues to rise, it is even more critical that we develop ways to prevent many of the complications related to prematurity so that these children can lead healthy, robust lives," NIH Director Elias A. Zerhouni, MD, says (NHLBI, 2006).
If you want more information on BPD, log on to http://www.nhlbi.nih.gov/health/dci/Diseases/Bpd/Bpd_WhatIs.html.
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