title: Comparison of breathing comfort during weaning with two ventilatory modes.
abstract: In twenty-one patients ventilated for > or = 3 days, we compared similar levels of partial support provided by synchronized intermittent mandatory ventilation (SIMV) and pressure support ventilation (PSV) in terms of breathing comfort. On a single day, eligible subjects experienced, in random order, both SIMV and PSV weaning protocols (sequential 20% reductions in support at timed intervals) separated by a 1 to 3 h rest. Breathing comfort was defined by subjective ratings of dyspnea and anxiety. Subjects reported significant levels of preweaning dyspnea and anxiety despite resting for at least 6 h. Dyspnea and anxiety were not significantly different between the two methods at any level of support. Our findings suggest that dyspnea and anxiety are higher than expected on "full" ventilator support, and that comfort may not differ between PSV and SIMV during active withdrawal of machine support.
authors.affiliation: Department of Physiological Nursing, University of California, San Francisco.
authors.forename: A R
authors.initials: AR
authors.lastname: Knebel
authors.forename: S L
authors.initials: SL
authors.lastname: Janson-Bjerklie
authors.forename: J D
authors.initials: JD
authors.lastname: Malley
authors.forename: A G
authors.initials: AG
authors.lastname: Wilson
authors.forename: J J
authors.initials: JJ
authors.lastname: Marini
mesh_terms: D000328:Adult; D000368:Aged; D000403:Airway Resistance; D000704:Analysis of Variance; D001007:Anxiety / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D002985:Clinical Protocols; D004417:Dyspnea / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration / Q000009:adverse effects / Q000379:methods*; D012131:Respiratory Insufficiency / Q000209:etiology / Q000628:therapy*; D015300:Ventilator Weaning / Q000009:adverse effects* / Q000379:methods*; D014939:Work of Breathing