Chika Nishiyama

Reduction in incidence and fatality of out-of-hospital cardiac arrest in females of the reproductive age

AIMS The aim of this study was to determine relative risk (RR) of incidence and fatality of out-of-hospital cardiac arrest (OHCA) by gender and oestrogen status. METHODS AND RESULTS In a prospective, population-based observational study from 1998 through 2007, incidence and neurologically intact 1-month survival after OHCA were compared by gender after grouping: 0-12 years, 13-49 years, and > or =50 years according to menarche and menopause age. Among 26 940 cardiac arrests, there were 11 179 females and 15 701 males. Age-adjusted RR of females for OHCA incidence compared with males was 0.72 [95% confidence interval (CI), 0.58-0.91] in age 0-12 years, 0.39 (95% CI, 0.37-0.43) in age 13-49 years, and 0.54 (95% CI, 0.52-0.55) in age > or =50 years. Females aged 13-49 years had a significantly higher good neurological outcome than males [adjusted odds ratio (OR), 2.00 (95% CI 1.21-3.32)]. This sex difference was larger than that in the other age groups [adjusted OR, 0.82 (95% CI, 0.06-12.02) in age 0-12 years and 1.23 (95% CI, 0.98-1.54) in age > or =50 years]. CONCLUSION Reproductive females had a lower incidence and a better outcome of OHCA than females of other ages and males, which might be explained by cardioprotective effects of endogenous oestrogen on OHCA.

Effectiveness of simplified chest compression-only CPR training for the general public: A randomized controlled trial

OBJECTIVES To compare the quality of resuscitation between those with a simplified chest compression-only cardiopulmonary resuscitation (CPR) program and those with a conventional CPR program. METHODS The participants were randomly assigned to either the 120-min training program of chest compressions (chest compression-only CPR) or the 180-min training program of chest compressions and ventilations (conventional CPR). Main outcome measures were the net number of appropriate chest compressions during the 2-min test period and the proportion of appropriate chest compressions over the theoretically attainable number one month after the training. RESULTS 223 participants were enrolled and 104 in each group completed this study. The 2-min number of appropriate chest compressions was 86.1+/-57.2 in the chest compression-only CPR group, which was significantly greater than 57.1+/-30.2 in the conventional CPR group (p<0.001). The proportion of appropriate chest compressions was higher in the chest compression-only CPR group than in the conventional CPR group (47.1+/-31.1% versus 38.1+/-20.1%, p=0.022). Time without chest compressions during conventional CPR reached 85.5+/-17.0 s out of 120 s, which was significantly longer than that during chest compression-only CPR (33.9+/-10.0 s, p<0.001). The total number of ventilations and the number of appropriate ventilations during 2 min was 2.5+/-3.0 and 0.9+/-1.6, respectively. CONCLUSIONS A simplified chest compression-only CPR program makes it possible for the general public to perform a greater number of appropriate chest compressions than the conventional CPR program (UMIN-CTR C0000000321).

Quality of chest compressions during continuous CPR; comparison between chest compression-only CPR and conventional CPR

OBJECTIVES This study aimed to compare the time-dependent deterioration of chest compressions between chest compression-only cardiopulmonary resuscitation (CPR) and conventional CPR. METHODS This study involved 106 and 107 participants randomly assigned to chest compression-only CPR training and conventional CPR training, respectively. Immediately after training, participants were asked to perform CPR for 2 min and the quality of their CPR skills were evaluated. The number of chest compressions in total and those with appropriate depth were counted every 20-s CPR period from the start of CPR. The primary outcome was the CPR quality index calculated as the proportion of chest compressions with appropriate depth among total chest compressions. RESULTS The total number of chest compressions remained stable over time both in the chest compression-only and the conventional CPR groups. The CPR quality index, however, decreased from 86.6+/-25.0 to 58.2+/-36.9 in the chest compression-only CPR group from 0-20 s through 61-80 s. The reduction was greater than in the conventional CPR group (85.9+/-25.5 to 74.3+/-34.0). The difference in the CPR quality index reached statistical significance (p=0.003) at 61-80 s period. CONCLUSIONS Chest compressions with appropriate depth decreased more rapidly during chest compression-only CPR than conventional CPR. We recommend that CPR providers change their roles every 1 min to maintain the quality of chest compressions during chest compression-only CPR. (UMIN-CTR C0000000321).

Out-of-hospital cardiac arrest due to drowning among children and adults from the Utstein Osaka Project

BACKGROUND Children have better outcomes after out-of-hospital cardiac arrest (OHCA) than adults. However, little is known about the difference in outcomes between children and adults after OHCA due to drowning. OBJECTIVES The aim of this study is to assess the outcome after OHCA due to drowning between children and adults. Our hypothesis is that outcomes after OHCA due to drowning would be in better among children (<18 years old) compared with adults (≥18 years old). METHOD This prospective population-based, observational study included all emergency medical service-treated OHCA due to drowning in Osaka, Japan, between 1999 and 2010 (excluding 2004). Outcomes were evaluated between younger children (0-4 years old), older children (5-17 years old), and adults (≥18 years old). Major outcome measures were one-month survival and neurologically favorable one-month survival defined as cerebral performance category 1 or 2. Multivariate logistic regression analyses were used to account for potential confounders. RESULTS During the study period, 66,716 OHCAs were documented, and resuscitation was attempted for 62,048 patients (1300 children [2%] and 60,748 adults [98%]). Among these OHCAs, 1737 (3% of OHCAs) were due to drowning (36 younger children [2%], 32 older children [2%], and 1669 adults [96%]). The odds of one-month survival were significantly higher for younger children (28% [10/36]; adjusted odds ratio [AOR], 20.20 [95% confidence interval {CI} 7.45-54.78]) and older children (9% [3/32]; AOR, 4.47 [95% CI 1.04-19.27]) when compared with adults (2% [28/1669]). However, younger children (6% [2/36]; AOR, 5.23 [95% CI 0.52-51.73]) and older children (3% [1/32]; AOR, 2.53 [95% CI 0.19-34.07]) did not have a higher odds of neurologically favorable outcome than adults (1% [11/1669]). CONCLUSION In this large OHCA registry, children had better one-month survival rates after OHCA due to drowning compared with adults. Most survivors in all groups had unfavorable neurological outcomes.

Trends in survival among elderly patients with out-of-hospital cardiac arrest: a prospective, population-based observation from 1999 to 2011 in Osaka.

BACKGROUND Little is known about the improvement in out-of-hospital cardiac arrest (OHCA) survival among elderly patients. The aim of this study was to evaluate the trends in the survival after bystander-witnessed OHCA of cardiac origin in this age group. METHODS This prospective, population-based, observation of the whole population of Osaka, Japan included consecutive OHCA patients aged ≥65 years with emergency responder resuscitation attempts from January 1999 to December 2011. The primary outcome measure was one-month survival with neurologically favorable outcome, and the trends in the outcome from OHCA were evaluated by location. Multiple logistic regression analysis was used to assess factors that were potentially associated with neurologically favorable outcome. RESULTS During the study period, a total of 10,876 bystander-witnessed OHCA of cardiac origin were eligible for our analyses. In whole arrests, the proportion of one-month survival with neurologically favorable outcome improved from 1.4% in 1999 to 4.8% in 2011 (P for trend <0.001). The proportion of neurologically favorable outcome in homes and public places improved from 0.7% in 1999 to 3.2% in 2011 (P for trend <0.001) and from 4.2% in 1999 to 20.9% in 2011 (P for trend <0.001), respectively, whereas, in nursing homes, the proportion of neurologically favorable outcome did not improve. In a multivariate analysis, bystander-initiated cardiopulmonary resuscitation and emergency response time were significant predictors for neurologically favorable outcome. CONCLUSIONS In this population, survival from OHCA among elderly patients significantly improved during the study period, but the trends differed by the OHCA location.

Epidemiology and outcome of adult out-of-hospital cardiac arrest of non-cardiac origin in Osaka: a population-based study

Objectives To evaluate epidemiological characteristics of out-of-hospital cardiac arrests (OHCAs) by detailed non-cardiac cause and factors associated with the outcomes after OHCAs of non-cardiac origin. Design A prospective, population-based observational study. Setting The Utstein Osaka Project. Participants 14 164 adult patients aged ≥20 years old with OHCAs due to non-cardiac origin who were resuscitated by emergency-medical-service personnel or bystanders, and then were transported to medical institutions from January 2005 to December 2011. Primary outcome measures One-month survival after OHCA. Multiple logistic regression analysis was used to assess factors that were potentially associated with the outcome. Results During the study period, the 1-month survival rate was 5.3% (755/14 164). The proportion of 1-month survival was 6.2% (510/8239) in external causes, 6.5% (94/1148) in respiratory diseases, 0.8% (11/1309) in malignant tumours, 4.9% (55/1114) in strokes and 4.1% (85/2054) in others. As for external causes, the proportion of 1-month survival was 14.3% (382/2670) in asphyxia, 4.2% (84/1999) in hanging, 0.7% (9/1300) in fall, 1.1% (12/1062) in drowning, 1.6% (12/765) in traffic injury, 3.7% (7/187) in drug overuse and 1.6% (4/256) in unclassified external causes. In a multivariate analysis, adults aged <65 years old with arrests witnessed by bystanders, with normal activities of daily living before the arrests, having ventricular fibrillation arrests, having arrests in public places, intravenous fluid levels and early Emergency Medical Service response time were significant predictors for 1-month outcome after OHCAs of non-cardiac origin. The proportion of 1-month survival of all OHCAs of non-cardiac origin did not significantly increase (from 4.3% (86/2023) in 2005 to 4.9% (105/2126) in 2011) and the adjusted OR for one-increment of year was 1.01 (95% CI 0.97 to 1.06). Conclusions From a large OHCA registry in Osaka, we demonstrated that 1-month survival after OHCAs of non-cardiac origin was poor and stable.

Effectiveness of simplified chest compression-only CPR training program with or without preparatory self-learning video: a randomized controlled trial.

OBJECTIVES To evaluate the effectiveness of 1-h practical chest compression-only cardiopulmonary resuscitation (CPR) training with or without a preparatory self-learning video. METHODS Participants were randomly assigned to either a control group or a video group who received a self-learning video before attending the 1-h chest compression-only CPR training program. The primary outcome measure was the total number of chest compressions during a 2-min test period. RESULTS 214 participants were enrolled, 183 of whom completed this study. In a simulation test just before practical training began, 88 (92.6%) of the video group attempted chest compressions, while only 58 (64.4%) of the control group (p<0.001) did so. The total number of chest compressions was significantly greater in the video group than in the control group (100.5+/-61.5 versus 74.4+/-55.5, p=0.012). The proportion of those who attempted to use an automated external defibrillator (AED) was significantly greater in the video group (74.7% versus 28.7%, p<0.001). After the 1-h practical training, the number of total chest compressions markedly increased regardless of the type of CPR training program and inter-group differences had almost disappeared (161.0+/-31.8 in the video group and 159.0+/-35.7 in the control group, p=0.628). CONCLUSIONS 1-h chest compression-only CPR training makes it possible for the general public to perform satisfactory chest compressions. Although a self-learning video encouraged people to perform CPR, their performance levels were not sufficient, confirming that practical training as well is essential. (UMIN000001046).

Impact of the number of on-scene emergency life-saving technicians and outcomes from out-of-hospital cardiac arrest in Osaka City

BACKGROUNDS In Japan, ambulance staffing for cardiac arrest responses consists of a 3-person unit with at least one emergency life-saving technician (ELST). Recently, the number of ELSTs on ambulances has increased since it is believed that this improves the quality of on-scene care leading to better outcomes from out-of-hospital cardiac arrest (OHCA). The objective of this study was to evaluate the association between the number of on-scene ELSTs and OHCA outcome. METHODS This was a prospective cohort study of all bystander-witnessed OHCA patients aged ≥ 18 years in Osaka City from January 2005 to December 2007 using on an Utstein-style database. The primary outcome measure was one-month survival with favorable neurological outcome defined as a cerebral performance category ≤ 2. Multivariable logistic regression model were used to assess the contribution of the number of on-scene ELSTs to the outcome after adjusting for confounders. RESULTS Of the 2408 bystander-witnessed OHCA patients, one ELST group was present in 639 (26.5%), two ELST were present in 1357 (56.4%), and three ELST group in 412 (17.1%). The three ELST group had a significantly higher rate of one-month survival with favorable neurological outcome compared with the one ELST group (8.0% versus 4.5%, adjusted OR 2.26, 95% CI 1.27-4.04), while the two ELST group did not (5.4% versus 4.5%, adjusted OR 1.34, 95% CI 0.82-2.19). CONCLUSIONS Compared with the one on-scene ELST group, the three on-scene ELST group was associated with the improved one-month survival with favorable neurological outcome from OHCA in Osaka City.

Prodromal symptoms of out-of-hospital cardiac arrests: a report from a large-scale population-based cohort study.

OBJECTIVE Little is known about which symptoms are manifested before out-of-hospital cardiac arrest (OHCA). The objective of this study is to describe the prodromal symptoms of OHCA focusing on the onset of the symptom in relation of etiology of cardiac arrests, and to analyze the association between those symptoms and their outcomes after OHCA. METHODS This prospective, population-based cohort study enrolled all persons aged 18 years or older who had experienced OHCA of presumed cardiac and non-cardiac origin that were witnessed by bystanders or emergency medical system (EMS) personnel in Osaka from 2003 through 2004. RESULTS There were 1042 were presumed to be of cardiac origin and 424 of non-cardiac. Patients with non-cardiac origin were more likely to have prodromal symptoms than those with cardiac etiology (70.0% vs. 61.8%, p=0.003). Over 40% of OHCA regardless of etiology had displayed symptoms at least several minutes before their arrest (40.2% [259/644] in those of cardiac origin and 45.5% [135/297] in those of non-cardiac origin). As to cardiac origin, the most frequent prodromal symptom was dyspnea (27.6%), followed by chest pain (20.7%) and syncope (12.7%). For non-cardiac origin, the most frequent symptom was also dyspnea (40.7%), but chest pain was rarely presented (3.4%). Although, prodromal symptoms themselves were not associated with better neurological outcomes (adjusted odds ratio [AOR], 2.03; 95% confidence interval [CI], 1.00-4.13), earlier contact to a patient yielded better neurological outcomes (AOR per every one-minute increase, 0.90; 95% CI, 0.82-0.99). CONCLUSIONS Many of OHCA regardless of etiology have prodromal symptoms before arrest. Prodromal symptoms induced early activation of the EMS system, and may thus improve outcomes after OHCA.

Epidemiological characteristics of sudden cardiac arrest in schools.

AIMS The present study aimed to clarify the incidence and outcomes of sudden cardiac arrests in schools and the clinically relevant characteristics of individuals who experienced sudden cardiac arrests. METHODS AND RESULTS We obtained data on sudden cardiac arrests that occurred in schools between January 1, 2005 and December 31, 2009 from the database of the Utstein Osaka Project, a population-based observational study on out-of-hospital cardiac arrests in Osaka, Japan. The data were analyzed to show the epidemiological features of sudden cardiac arrests in schools in conjunction with prehospital documentation. In total, 44 cases were registered as sudden cardiac arrests in schools during the study period. Of these, 34 cases had nontraumatic cardiac arrests. Twenty-one cases (62%) had pre-existing cardiac diseases and/or collapsed during physical exercise. Twenty-three cases (68%) presented with ventricular fibrillation or pulseless ventricular tachycardia, with cases of survival 1 month after cardiac arrest and those having favourable neurological outcome (Cerebral Performance Category 1 or 2) being 12 (52%) and 10 (43%), respectively. The incidence of sudden cardiac arrests in students was 0.23 per 100,000 persons per year, ranging from 0.08 in junior high school to 0.64 in high school. The incidence of sudden cardiac arrests in school faculty and staff was 0.51 per 100,000 persons per year, a rate approximately 2 times of that observed in the students. CONCLUSIONS Although sudden cardiac arrests in schools is rare, they majorly occurred in individuals with cardiac diseases and/or during physical exercise and presented as ventricular fibrillation or pulseless ventricular tachycardia observed initially as cardiac arrhythmia.