American Thoracic Society Journal news tips for July 2003 (second issue)

In a prospective study of 499 infants during their first year, researchers demonstrated a strong relationship between high levels of fungus in the household and an increased incidence of doctor-diagnosed lower respiratory tract illnesses, including croup, pneumonia, bronchitis, and bronchiolitis. (Fungi constitute a group of simple plantlike organisms, including yeast, some of which can cause disease.) The investigators found that of the 492 homes surveyed 324 residences had a high level of at least one type of fungi. According to the authors, children in environments with more than the 90th percentile for one or more fungi had an 86 percent increased risk of developing a lower respiratory illness during their first year of life. Of the 499 infants studied, 107 (21 percent) had a report of one doctor-diagnosed lower respiratory illness on one questionnaire during their first year. Twenty (4 percent) had a second illness reported. To obtain the study data, a trained technician visited each child's home to determine household and socioeconomic characteristics, as well as to conduct air and dust sampling. Particular emphasis was placed on the bedroom where the child usually slept. At 2 months of age, a follow-up questionnaire was given to the child's primary care-giver. Every two months thereafter, follow-up phone calls were made. The study appears in the second issue for July 2003 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.

Septic shock mortality decreases while frequency increases

Although the crude mortality rate for septic shock is decreasing, its frequency is increasing with more multi-resistant bacterial strains involved, according to a large study by French biomedical scientists of 100,544 intensive care unit (ICU) admissions from 22 hospitals over 8 years, from 1993 to 2000. The investigators point out that the annual frequency of septic shock increased from 7 patients per 100 ICU admissions in 1993 to 9.7 patients per 100 admissions in 2000. In addition, the crude mortality rate decreased over the 8-year period from 62.1 percent in 1993 to 55.9 percent in 2000. (In certain cases, sepsis, a severe infection of the bloodstream, leads to septic shock in which the patient's blood pressure falls to low levels considered life-threatening.) The ratio of lung infection-related septic shock in patients significantly increased from 1993 to 2000, but the percentage of shock due to urinary tract infection significantly decreased. Also, by 2000, the proportion of antibiotic-resistant organisms increased to approximately one-fourth of the cases seen. Among the septic shock cases studied, vasopressor therapy to cause vasoconstriction and raise blood pressure was used in over 85 percent of the cases, mechanical ventilation in about 81 percent, and renal replacement therapy in slightly over 25 percent. The study appears in the second issue for July 2003 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.

New oral appliance significantly aids obstructive sleep apnea patients in small study

A research team demonstrated that a new oral appliance called a mandibular advancement splint, when used during sleep, reduces upper airway collapsibility in obstructive sleep apnea patients, lowering the number of temporary pauses in breathing for 10 seconds or more from an average of 25 per hour per patient to less than 5. The investigators tested the mandibular advancement splint on 9 men and 1 woman who had proven obstructive sleep apnea. (The mandible is a large bone that makes up the lower jaw.) Apnea occurs when a sleeping person repeatedly stops breathing long enough (10 seconds or longer) to decrease the amount of oxygen in the blood and brain and to increase the amount of carbon monoxide. After some seconds, the individual usually awakens enough to resume breathing. Chronic sleep apnea can result in headaches, severe daytime sleepiness, slowed mental activity, and pulmonary insufficiency. Obstructive sleep apnea is caused by a blockage in the throat or upper airway. The new splint resulted in a "complete response" in 5 patients and a "partial response" in 2 patients. A "complete response" was defined as a resolution of symptoms and a reduction in the mean number of breathing pauses (apneas) from 25 to less than 5 per hour. A "partial response" was defined as improved symptoms, plus a reduction of 50 percent in the number of breathing pauses. "Treatment failure" occurred in 3 patients and resulted from a less than a 50 percent reduction in the breathing pauses. The study was published in the second issue for July 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 e-mail list, contact Cathy Carlomagno at 212-315-6442, or by e-mail at ccarlomagno@thoracic.org.

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