Purpose: To identify the autonomic and emotional behaviors that occurs in response to an asphyxial threat.
Conceptual framework: Nociceptive responses activated by an asphyxial threat are evolutionarily ancient and produce measurable behaviors activated in subcortical brain areas. Some patients with respiratory distress are unable to self-report due to illness severity or cognitive impairment. Recognition of behavioral correlates of respiratory distress is postulated to have clinical and research utility.
Subjects: A convenience sample of 12 adult men and women patients were recruited from the medical intensive care unit in one urban medical center. Subjects were scheduled to experience a weaning trial from mechanical ventilation and were at risk for weaning failure and respiratory distress.
Method: Subjects were monitored with a capnograph/oximeter and videotaped continuously for a baseline interval and up to 30 minutes during weaning. Measures included heart rate, respiratory rate, peripheral oxygen saturation, end-tidal carbon dioxide, accessory muscle use, paradoxical breathing pattern, nasal flaring, and a fearful facial expression. At the end of the trial subjects were asked to identify any primal emotion experienced during the wean by pointing to a photo array that corresponded to the subject’s race and gender. Other variables collected included age, gender, race, cognitive state, and primary diagnosis.
Results: The subjects were women (58%) and African-American (83%) who were experiencing acute (50%) vs. chronic (50%) respiratory failure. Subjects were cognitively intact (50%) vs. impaired (50%). An array of respiratory distress behaviors were displayed in response to hypercarbia and hypoxemia including signs of autonomic responsiveness and fear. Hypercarbia predicted fear. Behaviors did not differ by cognitive state. Subjects with acute failure displayed fear more frequently than subjects with chronic respiratory disease.
Conclusions: Subjects experiencing an asphyxial threat display similar behaviors arising from subcortical brain areas. Fear conditioning may contribute to differences displayed by chronic disease subjects.
Session #1192 - Acute Care
The 29th Annual MNRS Research Conference (April 1-4, 2005)