title: A meta-analysis of prehospital airway control techniques part II: alternative airway devices and cricothyrotomy success rates.
abstract: BACKGROUND
  Airway management is a key component of prehospital care for seriously ill and injured patients. Oral endotracheal intubation (OETI) is the definitive airway of choice in most emergency medical services (EMS) systems. However, OETI may not be an approved skill for some clinicians or may prove problematic in certain patients because of anatomic abnormalities, trauma, or inadequate relaxation. In these situations alternative airways are frequently employed. However, the reported success rates for these devices vary widely, and established benchmarks are lacking.
  
  
  OBJECTIVE
  We sought to determine pooled estimates of the success rates of alternative airway devices (AADs) and needle cricothyrotomy (NCRIC) and surgical cricothyrotomy (SCRIC) placement through a meta-analysis of the literature.
  
  
  METHODS
  We performed a systematic literature search for all English-language articles reporting success rates for AADs, SCRIC, and NCRIC. Studies of field procedures performed by prehospital personnel from any nation were included. All titles were reviewed independently by two authors using prespecified inclusion criteria. Pooled estimates of success rates for each airway technique were calculated using a random-effects meta-analysis model.
  
  
  RESULTS
  Of 2,005 prehospital airway titles identified, 35 unique studies were retained for analysis of AAD success rates, encompassing a total of 10,172 prehospital patients. The success rates for SCRIC and NCRIC were analyzed across an additional 21 studies totaling 512 patients. The pooled estimates (and 95% confidence intervals [CIs]) for intervention success across all clinicians and patients were as follows: esophageal obturator airway-esophageal gastric tube airway (EOA-EGTA) 92.6% (90.1%-94.5%); pharyngeotracheal lumen airway (PTLA) 82.1% (74.0%-88.0%); esophageal-tracheal Combitube (ETC) 85.4% (77.3%-91.0%); laryngeal mask airway (LMA) 87.4% (79.0%-92.8%); King Laryngeal Tube airway (King LT) 96.5% (71.2%-99.7%); NCRIC 65.8% (42.3%-83.59%); and SCRIC 90.5% (84.8%-94.2%).
  
  
  CONCLUSIONS
  We provide pooled estimates for prehospital AAD, NCRIC, and SCRIC airway interventions. Of the AADs, the King LT demonstrated the highest insertion success rate (96.5%), although this estimate is based on limited data, and data regarding its ventilatory effectiveness are lacking; more data are available for the ETC and LMA. The ETC, LMA, and PTLA all had similar-but lower-success rates (82.1%-87.4%). NCRIC has a low rate of success (65.8%); SCRIC has a much higher success rate (90.5%) and should be considered the preferred percutaneous rescue airway.
authors.affiliation: Emergency Medical Care Program, 122 Moore Building, Western Carolina University, Cullowhee, NC 28723, USA. mhubble@email.wcu.edu
authors.forename: Michael W
authors.initials: MW
authors.lastname: Hubble
authors.forename: Denise A
authors.initials: DA
authors.lastname: Wilfong
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Brown
authors.forename: Attila
authors.initials: A
authors.lastname: Hertelendy
authors.forename: Randall W
authors.initials: RW
authors.lastname: Benner
mesh_terms: D000293:Adolescent; D058109:Airway Management / Q000379:methods*; D002648:Child; D003413:Cricoid Cartilage / Q000601:surgery*; D004632:Emergency Medical Services; D006801:Humans; D017063:Outcome Assessment, Health Care; D013957:Thyroid Cartilage / Q000601:surgery; D014140:Tracheotomy / Q000379:methods