American Thoracic Society Journal news tips for January (second issue)

Pregnant women with an abnormal condition of pregnancy called pre-eclampsia, which raises blood pressure, showed significantly smaller upper airways than did either nonpregnant women or those with normal pregnancies. According to the authors of the British study, these results could explain why such patients have an increased upper airway resistance while sleeping and a resulting rise in blood pressure. The researchers measured the upper airway caliber in 137 women: 50 women in the third trimester of a normal pregnancy; 37 patients with pre-eclampsia; and 50 healthy, nonpregnant women. Pre-eclampsia, which develops in 5 percent of pregnancies, does not occur until the 20th week of gestation or later. The problem is characterized by hypertension, swelling from fluid in the face and hands, and the presence of protein in the urine. The investigators found that patients with pre-eclampsia had a significantly narrower upper airway when either seated or when lying on their back, as compared with nonpregnant women. The women with pre-eclampsia also had a significantly larger neck circumference than normal pregnant women. This difference was believed to be due to tissue edema. The study appears in the second issue for January 2003 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.

WORK STATUS IMPROVING IN ADULT CYSTIC FIBROSIS PATIENTS

Pulmonary function and exercise capacity testing have limited utility in predicting whether adult patients with cystic fibrosis (CF) can either work or go to school. CF is an inherited illness, usually diagnosed during childhood. It is characterized by glands in the pancreas, lungs, and intestines becoming clogged with thick mucus. However, despite the seriousness of the problem, the researchers point out that advances in diagnosis and treatment have led to substantial increases in survival. Yet, in light of the progressive nature of the disease, the question of disability always arises. The investigators said that educational and work accomplishments of their study patients were indicators of the overall improvements in the health status of adults with CF. (Fifty nine of 73 patients studied in the Canadian CF clinic were either working or going to school full- or part-time.) They observe that many patients and their families were determined to minimize the effects of the disease and to optimize the quality of life. The study appears in the second issue for January 2003 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.

FAMILIAL DYSAUTONOMIA CAN LEAD TO BLUNTED RESPIRATORY AND CARDIOVASCULAR RESPONSES

Hyperventilation, taking either too frequent or too deep breaths, can cause a person with familial dysautonomia (FD) to stop breathing temporarily (apnea), which can rapidly provoke low levels of oxygen in the blood, along with cardio-respiratory depression. If low blood pressure then develops, irreversible cardiovascular changes (and even death) can occur. FD is a recessive genetic disorder, showing up in childhood. It is seen exclusively in persons of Jewish extraction. The problem causes extensive central, peripheral, and autonomic disturbances that affect the cardiovascular and respiratory systems. According to researchers, individuals with FD are unable to mount appropriate cardiovascular and other responses to physical stress, including exercise. After evaluating 22 females with the condition (ages 11 to 46), along with 23 matched female controls, using a variety of cardio- respiratory tests, the investigators said that their ventilatory, cardiovascular, and cerebro-vascular responses to inadequate amounts of available oxygen in the blood were blunted, while their responses to excess carbon dioxide in the blood were preserved. They noted that responses to respiratory challenges were normal in persons with FD when they were performed under either normal or conditions of excess oxygen availability in the blood. However, when only inadequate amounts of oxygen were available in the blood, central cardio-respiratory depression developed quickly, leading to deficient ventilation, a slower heart rate, and low blood pressure. The study appears in the second issue for January 2003 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.

For the complete text of these articles, please see the American Thoracic Society Online Web Site at http://www.atsjournals.org. For either contact information or to request a complimentary journalist subscription to ATS journals online, or if you would like to add your name to the Society's twice monthly journal news mailing list, contact Cathy Carlomagno at 212-315-6442, or by e-mail at ccarlomagno@thoracic.org.

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