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| Vol. 23, No. 8 |
| May 1, 2001 |
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Nurse Researchers `Vent' their Expertise By PAMELA LEWIS The University of Texas Health Science Center at Houston Ever had trouble breathing - such trouble that your life was in danger? Did a mechanical ventilator, also known as a respirator, do your breathing for you? Did you develop a love-hate relationship with the machine that was keeping you alive? "A person who's been on a respirator, if he or she remembers the experience at all, describes it as one of the most devastating, uncomfortable, and scary experiences of her or his entire life," says Dr. Sandra K. Hanneman, associate dean for nursing research and evaluation at The University of Texas School of Nursing at Houston. If people only have to be on the ventilator a short time, she explains, they typically are sedated, which blocks their memory and their suffering during the experience. "If they have to be on it longer, we can't keep them sedated to the same extent. Then the awareness comes in and the interaction between patient and ventilator can increase the chance of complications in these situations." Patients' anxiety has to do with their lack of control while on a respirator. "They can't control how much of a breath they get or when they take a breath. If something goes wrong, they can't fix it themselves," says Dr. Hanneman. "Nobody cites being on the respirator as a positive experience. When something alters your breathing and you can't control it yourself, it looms larger than life," says the nurse-researcher, whose current work focuses on continuous monitoring technology to provide detailed chronobiologic (biorhythmic) indicators for successful weaning of acutely ill people from mechanical ventilators and back to breathing on their own. In addition to the patient control issue, being on a respirator is fraught with the possibility of complications, says Dr. Hanneman. Respirator dependency is almost always associated with a critical illness, with patients being thought of as "the sickest people." Being on a ventilator puts one at risk of infection, getting holes in the lung, or inhaling vomit and developing pneumonia, Dr. Hanneman says. Her current study, "Biorhythms During Mechanical Ventilation and Weaning," is supported by a National Institutes of Health R15 grant. Her co-investigators are Dr. Michael H. Smolensky, professor in UT-Houston School of Public Health's Environmental Sciences Department, and Dr. Robert F. Lodato, associate professor in UT-Houston Medical School's Department of Internal Medicine, Division of Pulmonary & Critical Care. The specific aims of the study are to:
"Anything we can do to keep people off the ventilator or get them off quickly, reduces exponentially the length of time they are in intensive care, the cost of their hospitalization, and the pain they suffer," says Dr. Hanneman. The work she is doing with circadian rhythms is not currently used to monitor patients. "If we are able to identify rhythms and how those rhythms change over time, we have the potential to predict how critically ill adults will do in the short-term - survive, develop complications or be on the road to recovery." Two other nurse-researchers at the School of Nursing also are conducting research on monitoring ventilator use to predict patient outcomes, says Dr. Hanneman. Dr. Mara Baun, the Lee and Joseph D. Jamail Distinguished Professor in the Department of Acute and Continuing Care, has conducted extensive research - much of it NIH-funded - on patients who need mechanical ventilation. "When people are mechanically ventilated, they always have secretions in their lungs that they cannot remove. I am looking at various ways to remove those secretions safely and minimize the need for prolonged mechanical ventilation. We are looking at various combinations of oxygenation and inflation that would decrease the negative consequences of endotrachial suctioning," says Dr. Baun. It's very difficult at present to decide who will do the best in terms of getting off a respirator, says the researcher. In her study, "Factors Affecting Weaning from Mechanical Ventilation," she says, "We are looking at a number of physiological factors as well as some psychological ones, because the individual's psyche may play a part in the readiness for weaning. Psychological variables generally have not been included in previous studies of predictors of readiness for weaning from the ventilator." Dr. Baun is eager to make new endotracheal suctioning clinical protocols readily available to health care professionals at the bedside. "Despite all the research on endotracheal suctioning, the information is still not being used universally at the bedside," she says. "Hospital administrators want one protocol to fit all patients, but they need to remember that each patient is different, that one protocol doesn't necessarily work for every person." Dr. Pamela K. Shiao, associate professor in the Department of Nursing for Target Populations, also is looking at oxygen saturation, but her research focuses on neonates. "These babies are as early as 26 weeks with an average weight of 800 grams," says Shiao. "We also have approval to study babies weighing 600 grams (born at 24 weeks gestation), or six months of pregnancy." Maintaining adequate oxygenation for neonates who need ventilator support is essential for optimal health outcomes in this vulnerable group. To avoid oxygen toxicity (poisoning), neonates are aggressively weaned from the ventilator. When these tiny babies are on ventilators, they are more sensitive to stimuli. They frequently develop desaturation of oxygen episodes, may have short-term cessation of breathing, and slow heart action. They are at greater risk of deficiency in blood oxygen, in part because of their high fetal hemoglobin level. Accurate and continuous oxygen saturation status is crucial. Dr. Shiao's research includes using fiber optic umbilical catheters to monitor arterial and venous oxygen saturation levels in these neonates. "Current routine monitors used in neonatal intensive care are based on adult hemoglobin levels and designed for adults. These preterm babies have lots of jittery, hyperactive body movements. The sensors are put on their extremities, mostly the foot, and they get shaken off a lot. More than 50 percent of the time, continuous measurement is broken by the loss of the sensor detection," she says. The aims of this NIH-supported RO1 study are to:
Using a computerized coding system, a data collector along with a video camera will continuously record bedside care events including each ventilator-weaning attempt. "The study will determine whether arterial and venous oxygen saturation monitoring will improve the success of ventilator weaning and reduce oxygenation complications," says Dr. Shiao. "In addition, the study will examine oxygen utilization and hemodynamic function when neonates adapt to extrauterine life during ventilatory support." This neonatal research is important because kids are the future of society, says Dr. Shiao. "Taking care of the sickest newborns and preventing all these complications has benefits for society as a whole. These are the sickest babies we are talking about." The world of technology is evolving to the point that smaller, younger neonates are living, despite a tenuous time in utero and during birth. "These kids are eventually going to be part of society with 99.3 percent of them surviving now. But how they survive, with or without developmental problems from the ventilator and other factors, is key to our research," concludes Dr. Shiao.
©2006 Texas Medical Center E-Mail: tmcinfo@texmedctr.tmc.edu URL: http://www.tmc.edu/tmcnews/05_01_01/page_21.html |