title: Accuracy and reliability of the self-inflating bulb to verify tracheal intubation in out-of-hospital cardiac arrest patients.
abstract: BACKGROUND
  To determine the sensitivity and specificity of the self-inflating bulb (SIB) to verify tracheal intubation in out-of-hospital cardiac arrest patients.
  
  
  METHODS
  Sixty-five consecutive adult patients with out-of-hospital cardiac arrest were enrolled. Patients were provided chest compression and ventilation by either ba-valve-mask or the esophageal tracheal double-lumen airway by ambulance crews when they arrived at the authors' department. Immediately after intubation in the emergency department, the endotracheal tube position was tested by the SIB and end-tidal carbon dioxide (ETCO2) monitor using an infrared carbon dioxide analyzer. We observed the SIB reinflating for 10 s, and full reinflation within 4 s was defined as a positive result (tracheal intubation).
  
  
  RESULTS
  Five esophageal intubations occurred, and the SIB correctly identified all esophageal intubations. Of the 65 tracheal intubations, the SIB correctly identified 47 tubes placed in the trachea (72.3%). Delayed but full reinflation occurred in one tracheal intubation during the 10-s observation period. Fifteen tracheal intubations had incomplete reinflation during the observation period, and two tracheal intubations did not achieve any reinflation. Thirty-nine tracheal intubations were identified by ETCO2 (60%). When the SIB test is combined with the ETCO2 detection, 59 tracheal intubations were identified with a 90.8% sensitivity.
  
  
  CONCLUSIONS
  The authors found a high incidence of false-negative results of the SIB in out-of-hospital cardiac arrest patients. Because no single test for verifying endotracheal tube position is reliable, all available modalities should be tested and used in conjunction with proper clinical judgment to verify tracheal intubation in cases of out-of-hospital cardiac arrest.
authors.affiliation: Department of Emergency and Critical Care Medicine, School of Medicine, Fukuoka University, Japan. tanigawa@fukuoka-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Tanigawa
authors.forename: T
authors.initials: T
authors.lastname: Takeda
authors.forename: E
authors.initials: E
authors.lastname: Goto
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D002245:Carbon Dioxide / Q000032:analysis; D004632:Emergency Medical Services / Q000379:methods*; D004947:Esophagus; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006323:Heart Arrest / Q000628:therapy*; D006801:Humans; D007440:Intubation; D007442:Intubation, Intratracheal / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D002245:Carbon Dioxide