Ken Nagao

Nationwide public access defibrillation in Japan

BACKGROUND It is unclear whether dissemination of automated external defibrillators (AEDs) in public places can improve the rate of survival among patients who have had an out-of-hospital cardiac arrest. METHODS From January 1, 2005, through December 31, 2007, we conducted a prospective, population-based, observational study involving consecutive patients across Japan who had an out-of-hospital cardiac arrest and in whom resuscitation was attempted by emergency responders. We evaluated the effect of nationwide dissemination of public-access AEDs on the rate of survival after an out-of-hospital cardiac arrest. The primary outcome measure was the 1-month rate of survival with minimal neurologic impairment. A multivariate logistic-regression analysis was performed to assess factors associated with a good neurologic outcome. RESULTS A total of 312,319 adults who had an out-of-hospital cardiac arrest were included in the study; 12,631 of these patients had ventricular fibrillation and had an arrest that was of cardiac origin and that was witnessed by bystanders. In 462 of these patients (3.7%), shocks were administered by laypersons with the use of public-access AEDs, and the proportion increased, from 1.2% to 6.2%, as the number of public-access AEDs increased (P<0.001 for trend). Among all patients who had a bystander-witnessed arrest of cardiac origin and who had ventricular fibrillation, 14.4% were alive at 1 month with minimal neurologic impairment; among patients who received shocks from public-access AEDs, 31.6% were alive at 1 month with minimal neurologic impairment. Early defibrillation, regardless of the type of provider (bystander or emergency-medical-services personnel), was associated with a good neurologic outcome after a cardiac arrest with ventricular fibrillation (adjusted odds ratio per 1-minute increase in the time to administration of shock, 0.91; 95% confidence interval, 0.89 to 0.92; P<0.001). The mean time to shock was reduced from 3.7 to 2.2 minutes, and the annual number of patients per 10 million population who survived with minimal neurologic impairment increased from 2.4 to 8.9 as the number of public-access AEDs increased from fewer than 1 per square kilometer of inhabited area to 4 or more. CONCLUSIONS Nationwide dissemination of public-access AEDs in Japan resulted in earlier administration of shocks by laypersons and in an increase in the 1-month rate of survival with minimal neurologic impairment after an out-of-hospital cardiac arrest.

Conventional and chest-compression-only cardiopulmonary resuscitation by bystanders for children who have out-of-hospital cardiac arrests: a prospective, nationwide, population-based cohort study

BACKGROUND The American Heart Association recommends cardiopulmonary resuscitation (CPR) by bystanders with chest compression only for adults who have cardiac arrests, but not for children. We assessed the effect of CPR (conventional with rescue breathing or chest compression only) by bystanders on outcomes after out-of-hospital cardiac arrests in children. METHODS In a nationwide, prospective, population-based, observational study, we enrolled 5170 children aged 17 years and younger who had an out-of-hospital cardiac arrest from Jan 1, 2005, to Dec 31, 2007. Data collected included age, cause, and presence and type of CPR by bystander. The primary endpoint was favourable neurological outcome 1 month after an out-of-hospital cardiac arrest, defined as Glasgow-Pittsburgh cerebral performance category 1 or 2. FINDINGS 3675 (71%) children had arrests of non-cardiac causes and 1495 (29%) cardiac causes. 1551 (30%) received conventional CPR and 888 (17%) compression-only CPR. Data for type of CPR by bystander were not available for 12 children. Children who were given CPR by a bystander had a significantly higher rate of favourable neurological outcome than did those not given CPR (4.5% [110/2439] vs 1.9% [53/2719]; adjusted odds ratio [OR] 2.59, 95% CI 1.81-3.71). In children aged 1-17 years who had arrests of non-cardiac causes, favourable neurological outcome was more common after bystander CPR than no CPR (5.1% [51/1004] vs 1.5% [20/1293]; OR 4.17, 2.37-7.32). However, conventional CPR produced more favourable neurological outcome than did compression-only CPR (7.2% [45/624] vs 1.6% [six of 380]; OR 5.54, 2.52-16.99). In children aged 1-17 years who had arrests of cardiac causes, favourable neurological outcome was more common after bystander CPR than no CPR (9.5% [42/440] vs 4.1% [14/339]; OR 2.21, 1.08-4.54), and did not differ between conventional and compression-only CPR (9.9% [28/282] vs 8.9% [14/158]; OR 1.20, 0.55-2.66). In infants (aged <1 year), outcomes were uniformly poor (1.7% [36/2082] with favourable neurological outcome). INTERPRETATION For children who have out-of-hospital cardiac arrests from non-cardiac causes, conventional CPR (with rescue breathing) by bystander is the preferable approach to resuscitation. For arrests of cardiac causes, either conventional or compression-only CPR is similarly effective. FUNDING Fire and Disaster Management Agency and the Ministry of Education, Culture, Sports, Science and Technology (Japan).

Cardiopulmonary cerebral resuscitation using emergency cardiopulmonary bypass, coronary reperfusion therapy and mild hypothermia in patients with cardiac arrest outside the hospital

OBJECTIVES The purpose of this study was to evaluate the efficacy of an alternative cardiopulmonary cerebral resuscitation (CPCR) using emergency cardiopulmonary bypass (CPB), coronary reperfusion therapy and mild hypothermia. BACKGROUND Good recovery of patients with out-of-hospital cardiac arrest is still inadequate. An alternative therapeutic method for patients who do not respond to conventional CPCR is required. METHODS A prospective preliminary study was performed in 50 patients with out-of-hospital cardiac arrest meeting the inclusion criteria. Patients were treated with standard CPCR and, if there was no response, by emergency CPB plus intra-aortic balloon pumping. Immediate coronary angiography for coronary reperfusion therapy was performed in patients with suspected acute coronary syndrome. Subsequently, in patients with systolic blood pressure above 90 mm Hg and Glasgow coma scale score of 3 to 5, mild hypothermia (34 C for at least two days) was induced by coil cooling. Neurologic outcome was assessed by cerebral performance categories at hospital discharge. RESULTS Thirty-six of the 50 patients were treated with emergency CPB, and 30 of 39 patients who underwent angiography suffered acute coronary artery occlusion. Return of spontaneous circulation and successful coronary reperfusion were achieved in 92% and 87%, respectively. Mild hypothermia could be induced in 23 patients, and 12 (52%) of them showed good recovery. Factors related to a good recovery were cardiac index in hypothermia and the presence of serious complications with hypothermia or CPB. CONCLUSIONS The alternative CPCR demonstrated an improvement in the incidence of good recovery. Based upon these findings, randomized studies of this hypothermia are needed.

Nationwide Improvements in Survival From Out-of-Hospital Cardiac Arrest in Japan

Background—Little is known about the nationwide trend in the survival of out-of-hospital cardiac arrest (OHCA) in Japan and the differences in incidence and survival by age group and origin of arrest. Methods and Results—A nationwide, prospective, population-based observation covering the whole population of Japan and involving consecutive OHCA patients with resuscitation attempts was conducted from January 2005 to December 2009. The main outcome measure was 1-month survival with favorable neurological outcome. The nationwide trends in OHCA incidence and outcome by age and origin of arrest were assessed. Multiple logistic regression analysis for bystander-witnessed OHCA was used to adjust for factors that were potentially associated with favorable neurological outcome. During 5 years, 547 153 overall OHCAs and 169 360 bystander-witnessed OHCAs were enrolled. The annual incidence significantly increased among overall OHCAs and bystander-witnessed OHCAs. Neurologically favorable survival significantly increased from 1.6% (1676/102 737) in 2005 to 2.8% (3280/115 250) in 2009 (P<0.001), from 2.1% (638/30 556) to 4.3% (1558/36 361) (P<0.001), and from 9.8% (437/4461) to 20.6% (1215/5906) (P<0.001) among overall OHCA, bystander-witnessed OHCA, and bystander-witnessed ventricular fibrillation OHCA, respectively. Public-access automated external defibrillator use, either bystander-initiated chest compression–only cardiopulmonary resuscitation or conventional cardiopulmonary resuscitation, and earlier emergency medical services response time were associated with a better neurological outcome. Favorable neurological outcome among adult OHCA subjects significantly improved, but the outcome among younger children and very elderly subjects did not improve and was poor irrespective of origin of OHCA. Conclusions—Nationwide improvements of favorable neurological outcome from OHCA were observed in Japan and differed by age group and origin of OHCA.

Chest Compression-Only Cardiopulmonary Resuscitation for Out-of-Hospital Cardiac Arrest With Public-Access Defibrillation A Nationwide Cohort Study

Background—It remains unclear which is more effective to increase survival after out-of-hospital cardiac arrest in those with public-access defibrillation, bystander-initiated chest compression–only cardiopulmonary resuscitation (CPR) or conventional CPR with rescue breathing. Methods and Results—A nationwide, prospective, population-based observational study covering the whole population of Japan and involving consecutive out-of-hospital cardiac arrest patients with resuscitation attempts has been conducted since 2005. We enrolled all out-of-hospital cardiac arrests of presumed cardiac origin that were witnessed and received shocks with public-access automated external defibrillation (AEDs) by bystanders from January 1, 2005, to December 31, 2009. The main outcome measure was neurologically favorable 1-month survival. We compared outcomes by type of bystander-initiated CPR (chest compression–only CPR and conventional CPR with compressions and rescue breathing). Multivariable logistic regression was used to assess the relationship between the type of CPR and a better neurological outcome. During the 5 years, 1376 bystander-witnessed out-of-hospital cardiac arrests of cardiac origin in individuals who received CPR and shocks with public-access AEDs by bystanders were registered. Among them, 506 (36.8%) received chest compression–only CPR and 870 (63.2%) received conventional CPR. The chest compression–only CPR group (40.7%, 206 of 506) had a significantly higher rate of 1-month survival with favorable neurological outcome than the conventional CPR group (32.9%, 286 of 870; adjusted odds ratio, 1.33; 95% confidence interval, 1.03–1.70). Conclusions—Compression-only CPR is more effective than conventional CPR for patients in whom out-of-hospital cardiac arrest is witnessed and shocked with public-access defibrillation. Compression-only CPR is the most likely scenario in which lay rescuers can witness a sudden collapse and use public-access AEDs.

Bystander-Initiated Rescue Breathing for Out-of-Hospital Cardiac Arrests of Noncardiac Origin

Background— Although chest compression–only cardiopulmonary resuscitation (CPR) is effective for adult out-of-hospital cardiac arrest (OHCA) of cardiac origin, it remains uncertain whether bystander-initiated rescue breathing has an incremental benefit for OHCA of noncardiac origin. Methods and Results— A nationwide, prospective, population-based, observational study covering the whole population of Japan and involving consecutive OHCA patients with emergency responder resuscitation attempts was conducted from January 2005 through December 2007. The primary outcome was neurologically intact 1-month survival. Multiple logistic regression analysis was used to assess the contribution of bystander-initiated CPR to better neurological outcomes. Among a total of 43 246 bystander-witnessed OHCAs of noncardiac origin, 8878 (20.5%) received chest compression–only CPR, and 7474 (17.3%) received conventional CPR with rescue breathing. The conventional CPR group (1.8%) had a higher rate of better neurological outcome than both the no CPR group (1.4%; odds ratio, 1.58; 95% confidence interval, 1.28 to 1.96) and the compression-only CPR group (1.5%; odds ratio, 1.32; 95% confidence interval, 1.03 to 1.69). However, the compression-only CPR group did not produce better neurological outcome than the no CPR group (odds ratio, 1.19; 95% confidence interval, 0.96 to 1.47). The number of OHCAs needed to treat with conventional CPR versus compression-only CPR to save a life with favorable neurological outcome after OHCA was 290. Conclusions— This nationwide observational study indicates that rescue breathing has an incremental benefit for OHCAs of noncardiac origin, but the impact on the overall survival after OHCA was small.

Reduced effectiveness of vasopressin in repeated doses for patients undergoing prolonged cardiopulmonary resuscitation

INTRODUCTION The efficacy of repeated administration of vasopressin alone during prolonged cardiopulmonary resuscitation (CPR) remains unconfirmed. This study was conducted to estimate the effectiveness of the repeated administration of vasopressin vs. epinephrine for cardiopulmonary arrest (CPA) patients receiving prolonged CPR. METHODS We conducted a prospective randomized controlled study on patients who experienced out-of-hospital CPA. The patients were randomly assigned to receive a maximum of four injections of either 40IU of vasopressin (vasopressin group) or 1mg of epinephrine (epinephrine group) immediately after emergency room (ER) admission. Patients who received vasopressors before ER admission or suffered non-cardiogenic CPA were excluded after randomization. RESULTS In total, 336 patients were enrolled (vasopressin group, n=137; epinephrine group, n=118). No differences were found between these groups (vasopressin group vs. epinephrine group) in the rates of return of spontaneous circulation (ROSC) (28.7% vs. 26.6%), 24-h survival (16.9% vs. 20.3%), or survival to hospital discharge (5.6% vs. 3.8%). In a subgroup analysis by the Fishers exact test, the rate of ROSC was higher in the vasopressin group than in the epinephrine group, among the patients whose arrests were witnessed (48.1% vs. 27.8%, p=0.010) or who received bystander CPR (68.0% vs. 38.5%, p=0.033). When the independent predictors of ROSC were calculated in the subgroup analysis, however, vasopressin administration (Odds ratio: 0.87-0.28) did not affect the outcome. CONCLUSIONS This is the first report of a possible vasopressin-alone resuscitation without additional epinephrine. However, repeated injections of either vasopressin or epinephrine during prolonged advanced cardiac life support resulted in comparable survival.

Time-dependent effectiveness of chest compression-only and conventional cardiopulmonary resuscitation for out-of-hospital cardiac arrest of cardiac origin

BACKGROUND Little is known about the effect of the type of bystander-initiated cardiopulmonary resuscitation (CPR) for prolonged out-of-hospital cardiac arrest (OHCA). OBJECTIVES To evaluate the time-dependent effectiveness of chest compression-only and conventional CPR with rescue breathing for witnessed adult OHCA of cardiac origin. METHODS A nationwide, prospective, population-based, observational study of the whole population of Japan included consecutive OHCA patients with emergency responder resuscitation attempts from 1 January 2005 to 31 December 2007. Multiple logistic regression analysis was performed to assess the contribution of the bystander-initiated CPR technique to favourable neurological outcomes. RESULTS Among 55014 bystander-witnessed OHCA of cardiac origin, 12165 (22.1%) received chest compression-only CPR and 10851 (19.7%) received conventional CPR. For short-duration OHCA (0-15min after collapse), compression-only CPR had a higher rate of survival with favourable neurological outcome than no CPR (6.4% vs. 3.8%; adjusted odds ratio (OR), 1.55; 95% confidence interval (CI), 1.38-1.74), and conventional CPR showed similar effectiveness (7.1% vs. 3.8%; adjusted OR, 1.78; 95% CI, 1.58-2.01). For the long-duration arrests (>15min), conventional CPR showed a significantly higher rate of survival with favourable neurological outcome than both no CPR (2.0% vs. 0.7%; adjusted OR, 1.93; 95% CI, 1.27-2.93) and compression-only CPR (2.0% vs. 1.3%; adjusted OR, 1.56; 95% CI, 1.02-2.44). CONCLUSIONS For prolonged OHCA of cardiac origin, conventional CPR with rescue breathing provided incremental benefit compared with either no CPR or compression-only CPR, but the absolute survival was low regardless of type of CPR.

Duration of Prehospital Resuscitation Efforts After Out-of-Hospital Cardiac Arrest.

Background— During out-of-hospital cardiac arrest, it is unclear how long prehospital resuscitation efforts should be continued to maximize lives saved. Methods and Results— Between 2005 and 2012, we enrolled 282 183 adult patients with bystander-witnessed out-of-hospital cardiac arrest from the All-Japan Utstein Registry. Prehospital resuscitation duration was calculated as the time interval from call receipt to return of spontaneous circulation in cases achieving prehospital return of spontaneous circulation or from call receipt to hospital arrival in cases not achieving prehospital return of spontaneous circulation. In each of 4 groups stratified by initial cardiac arrest rhythm (shockable versus nonshockable) and bystander resuscitation (presence versus absence), we calculated minimum prehospital resuscitation duration, defined as the length of resuscitation efforts in minutes required to achieve ≥99% sensitivity for the primary end point, favorable 30-day neurological outcome after out-of-hospital cardiac arrest. Prehospital resuscitation duration to achieve prehospital return of spontaneous circulation ranged from 1 to 60 minutes. Longer prehospital resuscitation duration reduced the likelihood of favorable neurological outcome (adjusted odds ratio, 0.84; 95% confidence interval, 0.838–0.844). Although the frequency of favorable neurological outcome was significantly different among the 4 groups, ranging from 20.0% (shockable/bystander resuscitation group) to 0.9% (nonshockable/bystander resuscitation group; P<0.001), minimum prehospital resuscitation duration did not differ widely among the 4 groups (40 minutes in the shockable/bystander resuscitation group and the shockable/no bystander resuscitation group, 44 minutes in the nonshockable/bystander resuscitation group, and 45 minutes in the nonshockable/no bystander resuscitation group). Conclusions— On the basis of time intervals from the shockable arrest groups, prehospital resuscitation efforts should be continued for at least 40 minutes in all adults with bystander-witnessed out-of-hospital cardiac arrest. Clinical Trial Registration— URL: http://www.umin.ac.jp/ctr/. Unique identifier: 000009918.

Significance of imbalance in the ratio of serum n-3 to n-6 polyunsaturated fatty acids in patients with acute coronary syndrome.

This study aimed to assess the balance of serum n-3 to n-6 polyunsaturated fatty acids (PUFAs) in patients with acute coronary syndrome (ACS). We enrolled 1,119 patients who were treated and in whom serum PUFA level was evaluated in 5 divisions of cardiology in a metropolitan area in Japan. Serum levels of PUFAs, including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA), were compared between patients with and without ACS. We also evaluated the balance of serum n-3 to n-6 PUFAs, including EPA/AA and DHA/AA ratios. EPA/AA values were 0.46 ± 0.32 and 0.50 ± 0.32 in the ACS and non-ACS groups, respectively. DHA/AA values were 0.95 ± 0.37 and 0.96 ± 0.41 in the ACS and non-ACS groups, respectively. Next, we divided the patients into 3 groups based on the tertiles of EPA/AA or tertiles of DHA/AA to determine the independent risk factors for ACS. According to multivariate logistic regression analysis, the group with the lowest EPA/AA (≤0.33) had a greater probability of ACS (odds ratio 3.14, 95% confidence interval 1.16 to 8.49), but this was not true for DHA/AA. In conclusion, an imbalance in the ratio of serum EPA to AA, but not in the ratio of DHA to AA, was significantly associated with ACS.