Assessing the efficacy of the new protocol for chest compressions before definitive cardiac arrest in emergency medical service-witnessed adult out-of-hospital cardiac arrests.

Aims: Japanese emergency medical services (EMS) personnel providing advance life support confirm the absence of a carotid pulse before initiating chest compressions (CCs) in adult out-of-hospital cardiac arrest (OHCA). This study aims to investigate the efficacy of a new protocol facilitating early CCs before definitive cardiac arrest in enhancing the outcomes of OHCA.

Methods: The 2011 new protocol facilitated EMS to initiate CCs when the carotid pulse was weak and/or <50/min in comatose adult patients with respiratory arrest (apnoea or agonal breathing) and loss of the radial pulse.

Temporal variations in dispatcher-assisted and bystander-initiated resuscitation efforts.

Purpose: To investigate temporal variations in dispatcher-assisted and bystander-initiated resuscitation efforts and their association with survival after bystander-witnessed out-of-hospital cardiac arrests (OHCAs).

Methods: We retrospectively analyzed the neurologically favorable 1-month survival and the parameters related to dispatcher assisted cardiopulmonary resuscitation (DA-CPR) and bystander CPR (BCPR) for 227,524 OHCA patients between 2007 and 2013 in Japan. DA-CPR sensitivity for OHCAs, bystander's compliance to DA-CPR assessed by the proportion of bystanders who follow DA-CPR, and performance of BCPR measured by the rate of bystander-initiated CPR in patients without DA-CPR were calculated as indices of resuscitation efforts.

Poor outcomes of out-of-hospital cardiac arrest at dinnertime in the elderly: Diurnal and seasonal variations.

Purpose: To investigate differences in chronological variations in characteristics and outcomes of out-of-hospital cardiac arrests (OHCAs) between elderly and non-elderly patients.

Methods: We retrospectively analyzed bystander-witnessed OHCAs without prehospital involvement of physicians between January 2007 and December 2014 in Japan. We considered the following time periods: night-time (23:00-5:59) and non-night-time; we further divided non-night-time into dinnertime (18:00-20:29) and other non-night-time.

The impact of prehospital assessment and EMS transport of acute aortic syndrome patients.

Background: The quality of acute aortic syndrome (AAS) assessment by emergency medical service (EMS) and the incidence and prehospital factors associated with 1-month survival remain unclear.

Methods: We retrospectively analyzed the data collected for 94,468 patients with non-traumatic medical emergency excluding out-of-hospital cardiac arrest during the period of 2011-2014.

Results: Of these transported by EMS, 22,075 had any of the AAS-related symptoms, and 330 had an EMS-assessed risk for AAS; of these, 195 received an in-hospital AAS diagnosis.

Augmented survival of out-of-hospital cardiac arrest victims with the use of mobile phones for emergency communication under the DA-CPR protocol getting information from callers beside the victim.

Purpose: To investigate the impacts of emergency calls made using mobile phones on the quality of dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) and survival from out-of-hospital cardiac arrests (OHCAs) that were not witnessed by emergency medical service (EMS).

Methods: In this prospective study, we collected data for 2530 DA-CPR-attempted medical emergency cases (517 using mobile phones and 2013 using landline phones) and 2980 non-EMS-witnessed OHCAs (600 using mobile phones and 2380 using landline phones). Time factors and quality of DA-CPR, backgrounds of callers and outcomes of OHCAs were compared between mobile and landline phone groups.

Recruitments of trained citizen volunteering for conventional cardiopulmonary resuscitation are necessary to improve the outcome after out-of-hospital cardiac arrests in remote time-distance area: A nationwide population-based study.

Aims: To compare the factors associated with survival after out-of-hospital cardiac arrests (OHCAs) among three time-distance areas (defined as interquartile range of time for emergency medical services response to patient's side).

Methods: From a nationwide, prospectively collected data on 716,608 OHCAs between 2007 and 2012, this study analyzed 193,914 bystander-witnessed OHCAs without pre-hospital physician involvement.

Results: Overall neurologically favourable 1-month survival rates were 7.

Are regional variations in activity of dispatcher-assisted cardiopulmonary resuscitation associated with out-of-hospital cardiac arrests outcomes? A nation-wide population-based cohort study.

Aim: Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) impacts the rates of bystander CPR (BCPR) and survival after out-of-hospital cardiac arrests (OHCAs). This study aimed to elucidate whether regional variations in indexes for BCPR and emergency medical service (EMS) may be associated with OHCA outcomes.

Methods: We conducted a population-based observational study involving 157,093 bystander-witnessed, resuscitation-attempted OHCAs without physician involvement between 2007 and 2011.

Advantage of CPR-first over call-first actions for out-of-hospital cardiac arrests in nonelderly patients and of noncardiac aetiology.

Aim: To assess the benefit of immediate call or cardiopulmonary resuscitation (CPR) for survival from out-of-hospital cardiac arrests (OHCAs).

Methods: Of 952,288 OHCAs in 2005-2012, 41,734 were bystander-witnessed cases without prehospital involvement of physicians but with bystander CPR (BCPR) on bystander's own initiative. From those OHCAs, we finally extracted the following three call/BCPR groups: immediate Call+CPR (N=10,195, emergency call/BCPR initiated at 0 or 1 min after witness, absolute call-BCPR time interval=0 or 1 min), immediate Call-First (N=1820, emergency call placed at 0 or 1 min after witness, call-to-BCPR interval=2-4 min), immediate CPR-First (N=5446, BCPR initiated at 0 or 1 min after witness, BCPR-to-call interval=2-4 min).

Impact of bystander-performed ventilation on functional outcomes after cardiac arrest and factors associated with ventilation-only cardiopulmonary resuscitation: A large observational study.

Aim: To determine the effectiveness of ventilations in bystander cardiopulmonary resuscitation (BCPR) and to identify the factors associated with ventilation-only BCPR.

Methods: From out-of-hospital cardiac arrest (OHCA) data prospectively collected from 2005 to 2011 in Japan, we extracted data for 210,134 bystander-witnessed OHCAs with complete datasets but no prehospital involvement of physician [no BCPR, 115,733; ventilation-only, 2093; compression-only, 61,075; and conventional (compressions+ventilations) BCPR, 31,233] and determined the factors associated with 1-month neurologically favourable survival using simple and multivariable logistic regression analyses. In 91,885 patients with known BCPR durations, we determined the factors associated with ventilation-only BCPR.

Do early emergency calls before patient collapse improve survival after out-of-hospital cardiac arrests?

Aim: Some out-of-hospital cardiac arrests (OHCAs) are witnessed after emergency calls. This study aimed to confirm the benefit of early emergency calls before patient collapse on survival after OHCAs witnessed by bystanders and/or emergency medical technicians (EMTs).

Methods: We analysed 278,310 witnessed OHCAs [EMT-witnessed cases (n=54,172), bystander-witnessed cases (n=224,138)] without pre-hospital physician involvement from all Japanese OHCA data prospectively collected between 2006 and 2012.

Improper bystander-performed basic life support in cardiac arrests managed with public automated external defibrillators.

Aim: The aim of the study was to determine the quality of basic life support (BLS) in out-of-hospital cardiac arrests (OHCAs) receiving bystander cardiopulmonary resuscitation (CPR) and public automated external defibrillator (AED) application.

Methods: From January 2006 to December 2012, data were prospectively collected from OHCA) and impending cardiac arrests treated with and without public AED before emergency medical technician (EMT) arrival. Basic life support actions and outcomes were compared between cases with and without public AED application.

Potential association of bystander-patient relationship with bystander response and patient survival in daytime out-of-hospital cardiac arrest.

Aim: To investigate whether the bystander-patient relationship affects bystander response to out-of-hospital cardiac arrest (OHCA) and patient outcomes depending on the time of day.

Methods: This population-based observational study in Japan involving 139,265 bystander-witnessed OHCAs (90,426 family members, 10,479 friends/colleagues, and 38,360 others) without prehospital physician involvement was conducted from 2005 to 2009. Factors associated with better bystander response [early emergency call and bystander cardiopulmonary resuscitation (BCPR)] and 1-month neurologically favourable survival were assessed.

Factors associated with quality of bystander CPR: the presence of multiple rescuers and bystander-initiated CPR without instruction.

Aims: To identify the factors associated with good-quality bystander cardiopulmonary resuscitation (BCPR).

Methods: Data were prospectively collected from 553 out-of-hospital cardiac arrests (OHCAs) managed with BCPR in the absence of emergency medical technicians (EMT) during 2012. The quality of BCPR was evaluated by EMTs at the scene and was assessed according to the standard recommendations for chest compressions, including proper hand positions, rates and depths.