title: Effect of using a laryngeal tube on the no-flow time in a simulated, single-rescuer, basic life support setting with inexperienced users.
abstract: BACKGROUND
  The laryngeal tube (LT) is a recommended alternative to endotracheal intubation during advanced life support (ALS). Its insertion is relatively simple; therefore, it may also serve as an alternative to bag mask ventilation (BMV) for untrained personnel performing basic life support (BLS). Data support the influence of LT on the no-flow time (NFT) compared with BMV during ALS in manikin studies.
  
  
  METHODS
  We performed a manikin study to investigate the effect of using the LT for ventilation instead of BMV on the NFT during BLS in a prospective, randomized, single-rescuer study. All 209 participants were trained in BMV, but were inexperienced in using LT; each participant performed BLS during a 4-min time period.
  
  
  RESULTS
  No significant difference in total NFT (LT: mean 81.1 ± 22.7 s; BMV: mean 83.2 ± 13.1 s, p = 0.414) was found; however, significant differences in the later periods of the scenario were identified. While ventilating with the LT, the proportion of chest compressions increased significantly from 67.2 to 73.2%, whereas the proportion of chest compressions increased only marginally when performing BMV. The quality of the chest compressions and the associated ventilation rate did not differ significantly. The mean tidal volume and mean minute volume were significantly lower when performing BMV.
  
  
  CONCLUSIONS
  The NFT was significantly shorter in the later periods in a single-rescuer, cardiac arrest scenario when using an LT without previous training compared with BMV with previous training. A possible explanation for this result may be the complexity and workload of alternating tasks (e.g., time loss when reclining the head and positioning the mask for each ventilation during BMV).
authors.affiliation: Institute for Emergency Medicine and Management in Medicine - INM, Klinikum der Universität München, Schillerstr. 53, 80336, Munich, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Meyer
authors.affiliation: Department of Anesthesiology, University Hospital of the Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle/Saale, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Bucher
authors.affiliation: Department of Medicine III, University Hospital of the Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle/Saale, Germany. jochen.schroeder@uk-halle.de.
authors.forename: J
authors.initials: J
authors.lastname: Schröder
mesh_terms: D000328:Adult; D022561:Advanced Cardiac Life Support; D016887:Cardiopulmonary Resuscitation / Q000193:education* / Q000295:instrumentation* / Q000379:methods; D002983:Clinical Competence; D006801:Humans; D007442:Intubation, Intratracheal; D008348:Manikins; D011446:Prospective Studies; D012121:Respiration, Artificial; D013337:Students, Medical; D013990:Tidal Volume; D055815:Young Adult
keywords: Bag mask ventilation; Basic life support; Cardiopulmonary resuscitation; Laryngeal tube; No-flow time