title: The experience of dyspnea during weaning.
abstract: OBJECTIVE
  To compare the degree of dyspnea experienced by ventilator-dependent patients receiving synchronized intermittent mandatory ventilation (SIMV) versus T-piece or pressure support ventilation (PSV) weaning. The relationship between self-reported perceptions of dyspnea and physiologic variables observed during weaning trials was examined. Variables included heart rate, respiratory rate, minute ventilation, and oxygen saturation as measured by a pulse oximeter.
  
  
  METHODS
  Quasi-experimental, counterbalanced design with repeated measures.
  
  
  METHODS
  Medical intensive care unit of a large university-affiliated medical center.
  
  
  METHODS
  Nine mechanically ventilated patients diagnosed with chronic obstructive lung disease. The patients were admitted for respiratory failure between May 1990 to November 1990. Six tolerated SIMV 4 versus T-piece trials; three were placed in the SIMV 8 versus PSV trials.
  
  
  METHODS
  Each patient's perception of dyspnea was measured using a visual analog scale (VAS) at the initiation and at 5-minute intervals of 20-minute weaning trials. Physiologic indicators were noted simultaneously with VAS ratings of dyspnea.
  
  
  RESULTS
  Findings indicated no difference in the degree of dyspnea experienced between weaning methods compared. Within-subject regression analysis on VAS scores revealed individual differences in the relationship between physiologic indicators and perceptions of dyspnea.
  
  
  CONCLUSIONS
  The patient's experience of dyspnea during the weaning process can be a valuable guide to observe the patient's progress. The VAS serves as a reliable, easy-to-use tool for quantifying the patient's perception of dyspnea.
authors.affiliation: Surgical Intensive Care Unit, Yale New Haven Hospital, CT 06510.
authors.forename: G H
authors.initials: GH
authors.lastname: Bouley
authors.forename: R
authors.initials: R
authors.lastname: Froman
authors.forename: H
authors.initials: H
authors.lastname: Shah
mesh_terms: D000368:Aged; D001784:Blood Gas Analysis; D015400:Clinical Nursing Research; D004417:Dyspnea / Q000209:etiology / Q000451:nursing / Q000523:psychology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000592:standards*; D009730:Nursing Assessment / Q000592:standards*; D010092:Oximetry; D010358:Patient Participation; D012119:Respiration; D015300:Ventilator Weaning / Q000379:methods / Q000523:psychology* / Q000592:standards