title: The usefulness of design of experimentation in defining the effect difficult airway factors and training have on simulator oral-tracheal intubation success rates in novice intubators.
abstract: OBJECTIVE
  This exploratory study examined novice intubators and the effect difficult airway factors have on pre- and posttraining oral-tracheal simulation intubation success rates.
  
  
  METHODS
  Using a two-level, full-factorial design of experimentation (DOE) involving a combination of six airway factors (curved vs. straight laryngoscope blade, trismus, tongue edema, laryngeal spasm, pharyngeal obstruction, or cervical immobilization), 64 airway scenarios were prospectively randomized to 12 critical care nurses to evaluate pre- and posttraining first-pass intubation success rates on a simulator. Scenario variables and intubation outcomes were analyzed using a generalized linear mixed-effects model to determine two-way main and interactive effects.
  
  
  RESULTS
  Interactive effects between the six study factors were nonsignificant (p = 0.69). For both pre- and posttraining, main effects showed the straight blade (p = 0.006), tongue edema (p = 0.0001), and laryngeal spasm (p = 0.004) significantly reduced success rates, while trismus (p = 0.358), pharyngeal obstruction (p = 0.078), and cervical immobilization did not significantly change the success rate. First-pass intubation success rate on the simulator significantly improved (p = 0.005) from pre- (19%) to posttraining (36%).
  
  
  CONCLUSIONS
  Design of experimentation is useful in analyzing the effect difficult airway factors and training have on simulator intubation success rates. Future quality improvement DOE simulator research studies should be performed to help clarify the relationship between simulator factors and patient intubation rates.
authors.affiliation: Intermountain Life Flight, Intermountain Healthcare, Division of Pulmonary and Critical Care Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA. frank.thomas@imail.org
authors.forename: Frank
authors.initials: F
authors.lastname: Thomas
authors.forename: Judi
authors.initials: J
authors.lastname: Carpenter
authors.forename: Carol
authors.initials: C
authors.lastname: Rhoades
authors.forename: Renee
authors.initials: R
authors.lastname: Holleran
authors.forename: Gregory
authors.initials: G
authors.lastname: Snow
mesh_terms: D000328:Adult; D000402:Airway Obstruction / Q000473:pathology / Q000628:therapy*; D000488:Allied Health Personnel / Q000193:education; D002983:Clinical Competence; D016001:Confidence Intervals; D004521:Educational Measurement; D004634:Emergency Medical Technicians / Q000193:education*; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal / Q000295:instrumentation / Q000379:methods*; D007828:Laryngoscopy; D008297:Male; D008348:Manikins; D008875:Middle Aged; D016017:Odds Ratio; D011336:Probability