Protocol for supraglottic airways placementIf there are indications for authorized action (indication: the cause of death, patient’s status, the distance to the receiving hospital, and so on) Vorinostat structure and ELST is permitted by on-line medical control, the ELST is able to do SGA placement. Placement time is within 10 seconds/attempt. There are no restrictions on the number of attempts. After SGA placement, non-synchronized CPR is possible.Protocol for endotracheal intubationThe protocol for endotracheal intubation of cardiac arrest patients who have both lack of pulse and apnea is as follows. 1. The patient meets the indications for endotracheal intubation. 2. It is impossible to maintain the patient’s airway with SGA, because of (1) asphyxia due to foreign-body airway obstruction, (2) or in cases in which the medical control doctor judges ETI to be required.

3. Patients are ineligible for endotracheal intubation, because there is: (1) suspected cervical spine injury, (2) head-tilt difficulty, (3) trismus, (4) difficulty with laryngoscope insertion, (5) difficulty with larynx expansion after laryngoscope insertion, (6) difficulty in visualizing the vocal chords, (7) prolonged unsuccessful attempts, (8) the ELST on the scene is not certified to perform endotracheal intubation, and (9) rapid sequence intubation (paralysis and sedation) is not used for ETI as it is only indicated for cardiac arrest.Selection of participantsFrom 1 January 2005 through 31 December 2008, this study enrolled all persons in Osaka Prefecture, Japan, aged 18 years or older who suffered from adult-witnessed non-traumatic OHCA, and who were treated with an advanced airway by ELSTs.

Participants were enrolled from a prospective Utstein-Style population cohort database.Data collection and processingData were prospectively collected using a data collection tool designed by the project steering committee. Included were all core data elements recommended in the Utstein style for OHCA [11,12], including age, gender, etiology, first documented rhythm, resuscitation time-course, bystander-initiated CPR, location, ELST status, final device type of advanced airway, epinephrine administration, return of spontaneous circulation (ROSC), hospital admission, one-month survival and neurological status at one month after the event. The data sheet was filled out by the EMS personnel in cooperation with the physicians in charge of the patient.

It was then transferred to the Information Center for Emergency Medical Services of Osaka and reviewed by the investigators. If the information provided on the data sheet was unclear or incomplete, it was returned to the appropriate EMS personnel for completion. All survivors were followed GSK-3 for up to one month after the event, and the neurological outcomes were obtained by the responsible EMS personnel with the cooperation of the Osaka Medical Association and medical institutions in this area.