Chest
Clinical Investigations: AsthmaRespiratory Mechanics in Status Asthmaticus: Effects of Inhalational Anesthesia
Section snippets
Subjects
Three patients (two male, one female) with status asthmaticus refractory to conventional medical treatment were studied in the medical intensive care units of three McGill University teaching hospitals. In each case, the diagnosis of asthma had been previously established by the medical history and the presence of reversible airway obstruction.3 Each patient had severe bronchospasm associated with marked respiratory distress and acute respiratory acidosis necessitating urgent endotracheal
Results
Individual values for Rmax, Rmin, and Crs before and during isoflurane anesthesia are provided in Figure 1. Baseline values of Rmax and Rmin were markedly elevated and decreased considerably with isoflurane. Crs was variably reduced and did not change significantly with isoflurane. In patient 2, a dose-response curve of isoflurane was obtained. As can be seen in Figure 2, the lowest isoflurane concentration used reduced Rmax and Rmin with further improvement at the higher concentrations while
Discussion
This study shows the severity of abnormalities in respiratory function that occur in status asthmaticus and the effects of isoflurane on various indices of respiratory system mechanics in this setting. Previous reports have described a number of abnormalities in respiratory mechanics in ventilated patients with status asthmaticus.14, 15, 16 These include increases in inspiratory and expiratory resistance as well as the development of dynamic hyperinflation with PEEPi. However, to our knowledge,
ACKNOWLEDGMENTS
The authors wish to thank Dr. Andrew Scott and the staff of the Montreal General Hospital, the Royal Victoria Hospital, and the Montreal Chest Hospital Centre for their help and cooperation.
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Cited by (0)
Supported in part by the Medical Research Council of Canada, the Respiratory Health Network of Centres of Excellence, the Canadian Cystic Fibrosis Foundation, and the J.T. Costello Memorial Research Fund
Presented in part at the Annual Meeting of the American Thoracic Society, Miami, May 17, 1992.
Recipient of research fellowship awards from the Canadian Lung Association and the Fonds de la Recherche en Sante du Quebec.
Medical Research Scholar of the Fonds de la Recherche en Sante du Quebec.