title: Measurement of a baseline minute ventilation for the calculation of minute ventilation recovery time: is a subjective method reliable?
abstract: BACKGROUND
  Minute ventilation recovery time is a new predictor of extubation outcome that uses a subjective method for the determination of baseline minute ventilation (V(E)) during its measurement. The purpose of the current study is to evaluate the inter-rater reliability of this subjective method for determining baseline V(E).
  
  
  METHODS
  Three critical-care physicians served as independent readers. Each was trained with 5 practice V(E) trends, using the published method for determining baseline V(E), defined as the lowest, stable nadir lasting 15-30 min prior to the final weaning trial before extubation. Readers then determined baseline V(E) prospectively from an 8-hour V(E) trend for 19 patients who were weaning from mechanical ventilation in the surgical intensive care unit of a tertiary care hospital. Each V(E) trend was an objective recording of V(E) every 15 min for 8 hours, immediately prior to the final weaning trial before extubation.
  
  
  RESULTS
  There was excellent inter-rater reliability between trained readers for determination of a subjective V(E) baseline. Baseline V(E) was within 1 L/min for 15/19 patients (79%). Intra-class correlation across the 3 readers was 0.92 (p < 0.01). Tukey's test revealed no significant variability between readers (p > 0.5), and Spearman correlations between all reader pairs were significant (p < 0.01).
  
  
  CONCLUSIONS
  After minimal training, readers can reliably determine a subjective baseline V(E). This study validates the original methodology for determining baseline V(E), an essential step in the measurement of minute ventilation recovery time.
authors.affiliation: Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA 19104-4283, USA.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Seymour
authors.forename: Jason D
authors.initials: JD
authors.lastname: Christie
authors.forename: Christina
authors.initials: C
authors.lastname: Gaughan
authors.forename: Barry D
authors.initials: BD
authors.lastname: Fuchs
mesh_terms: D000368:Aged; D020878:Device Removal / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D011446:Prospective Studies; D012123:Pulmonary Ventilation; D020127:Recovery of Function; D012016:Reference Values; D015300:Ventilator Weaning / Q000379:methods* / Q000592:standards*