Patient responses during rapid terminal weaning from mechanical ventilation

Abstract
Objective To describe and analyze patient responses to rapid terminal weaning from mechanical ventilation. Design A prospective, descriptive, correlational study. Setting An urban, university-affiliated, trauma/emergency hospital. Patients A convenience sample of 31 adult patients experiencing withdrawal of mechanical ventilation. Interventions None. Measurements and Main Results Physiologic (peripheral oxygen saturation, end-tidal CO2, heart rate, and respiratory rate) and comfort (electroencephalogram [EEG], Bizek Agitation Scale, and the COMFORT scale) measures were collected at baseline, during, and after the terminal weaning procedure. Clinical status was measured using the Acute Physiology and Chronic Health Evaluation score, Glasgow Coma Scale, and PaO2/FIO2. Duration of survival after the wean inversely correlated with illness severity but did not correlate with consciousness, use of analgesia/sedation, or pulmonary function. Respiratory rate and oxygen saturation changed significantly during the wean but not end-tidal CO2. Patients remained comfortable with little or no analgesia/sedation, in a predominantly comatose sample. Subjective measures of comfort strongly correlated with objective data from bispectral analysis of EEG. Conclusions Patients with altered consciousness or coma can be kept comfortable during a rapid terminal weaning procedure with morphine and benzodiazepines in low doses. Comfort can be reliably evaluated using subjective scales. (Crit Care Med 1999;27:73-77)