The first published study to examine the understanding of patients, doctors, and family members about living wills shows that substantial differences in interpretation exist about what the document mandates and under what circumstances it is appropriately executed. The researchers studied 151 hospitalized patients (70 men and 81 women), ranging in age from 29 to 91 (mean age 71), who had living wills. Of 4,800 patients admitted to the hospital during the study period, only 206 (4.3 percent) were identified with living wills. Fifty-five were excluded from the study for various reasons. In addition to the patients, the investigators also questioned 70 physicians who cared for 120 of the individuals, plus 108 family members. Through their personally administered questionnaires, the investigators placed special emphasis on endotrachael intubation and cardiopulmonary resuscitation (CPR) procedures. In their living wills, all study patients either had specifically checked or stipulated that they did not want CPR or intubation if they were suffering from a terminal illness. Of the 140 patients admitted to the general hospital wards, 17 persons (12.1 percent) wanted their living wills to preclude intubation/mechanical ventilation under any circumstances, even if there was the possibility of recovery. In addition, 12 patients of the 140 did not want CPR under any circumstances (including nine that did not want intubation). Among the responses from 70 physicians, seven said that they would not either intubate or perform CPR on their patients with living wills under any circumstances. Yet three of the patients wanted intubation and CPR if there was a chance of recovery. Also, two physicians would have administered a trial intubation and/or CPR even if they thought that the patient had no chance of recovery. The study appears in the first issue for December 2002 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.
Ventilator mode affects sleep quality in critically ill
In the first study to assess whether critically ill patients develop central apneas while receiving mechanical ventilation, investigators have shown that selecting a ventilator mode has a marked influence on the quality of such patients' sleep. The investigators studied 11 critically ill patients who were randomized to receive at least two hours each of three ventilator modes: assist-control ventilation, pressure support alone, and pressure support with dead space. The investigators demonstrated that, although patients receiving mechanical ventilation often have severely fragmented sleep, one mode, pressure support, might further aggravate this fragmentation in susceptible patients. However, another mode, assist-control ventilation, did not cause central apneas that can worsen sleep fragmentation. The researchers noted that, unlike pressure support, assist-control ventilation delivers a fixed tidal volume on every breath, and can be set to deliver breaths when a patient fails to make an effort. They believe the backup rate can prevent the development of apneas (temporary stoppage of breathing) and perhaps decrease arousals. Apneas occurred in the pressure support mode in six patients. The investigators found that sleep fragmentation, as measured by the number of arousals and awakenings in the 11 patients, was greater, on average, in the pressure support mode by 24 events per hour. The study appears in the first issue for December 2002 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.
Inspiratory muscle training tested
In the first controlled study of its type, researchers have discovered that respiratory muscle training in patients with severe chronic obstructive pulmonary disease (COPD) can produce functional improvement through structural adaptation within the respiratory muscles. Spanish investigators studied 14 male patients with COPD in a randomized, placebo-control trial of an inspiratory muscle training protocol. Half of the patients, who were about age 66, received sham treatment. The other seven participants underwent supervised breathing using a threshold inspiratory device for 30 minutes per day, five times a week, for five consecutive weeks. The researchers found that respiratory muscle strength as well as respiratory endurance were significantly increased after inspiratory muscle training. However, the investigators were unable to detect any changes in either walking distance or maximal oxygen uptake. The study appears in the first issue for December 2002 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 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 (please select either postal or electronic delivery), contact Cathy Carlomagno at (212) 315-6442, or by e-mail at ccarlomagno@thoracic.org.
Journal
American Journal of Respiratory and Critical Care Medicine