Kentaro Kajino

Effectiveness of Bystander-Initiated Cardiac-Only Resuscitation for Patients With Out-of-Hospital Cardiac Arrest

Background— Previous animal and clinical studies suggest that bystander-initiated cardiac-only resuscitation may be superior to conventional cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrests. Our hypothesis was that both cardiac-only bystander resuscitation and conventional bystander CPR would improve outcomes from out-of-hospital cardiac arrests of ≤15 minutes’ duration, whereas the addition of rescue breathing would improve outcomes for cardiac arrests lasting >15 minutes. Methods and Results— We carried out a prospective, population-based, observational study involving consecutive patients with emergency responder resuscitation attempts from May 1, 1998, through April 30, 2003. The primary outcome measure was 1-year survival with favorable neurological outcome. Multivariable logistic regression analysis was performed to evaluate the relationship between type of CPR and outcomes. Among the 4902 witnessed cardiac arrests, 783 received conventional CPR, and 544 received cardiac-only resuscitation. Excluding very-long-duration cardiac arrests (>15 minutes), the cardiac-only resuscitation yielded a higher rate of 1-year survival with favorable neurological outcome than no bystander CPR (4.3% versus 2.5%; odds ratio, 1.72; 95% CI, 1.01 to 2.95), and conventional CPR showed similar effectiveness (4.1%; odds ratio, 1.57; 95% CI, 0.95 to 2.60). For the very-long-duration arrests, neurologically favorable 1-year survival was greater in the conventional CPR group, but there were few survivors regardless of the type of bystander CPR (0.3% [2 of 624], 0% [0 of 92], and 2.2% [3 of 139] in the no bystander CPR, cardiac-only CPR, and conventional CPR groups, respectively; P<0.05). Conclusions— Bystander-initiated cardiac-only resuscitation and conventional CPR are similarly effective for most adult out-of-hospital cardiac arrests. For very prolonged cardiac arrests, the addition of rescue breathing may be of some help.

Continuous Improvements in “Chain of Survival” Increased Survival After Out-of-Hospital Cardiac Arrests A Large-Scale Population-Based Study

Background— The impact of ongoing efforts to improve the “chain of survival” for out-of-hospital cardiac arrest (OHCA) is unclear. The objective of this study was to evaluate the incremental effect of changes in prehospital emergency care on survival after OHCA. Methods and Results— This prospective, population-based observational study involved consecutive patients with OHCA from May 1998 through December 2006. The primary outcome measure was 1-month survival with favorable neurological outcome. Multiple logistic regression analysis was used to assess factors that were potentially associated with better neurological outcome. Among 42 873 resuscitation-attempted adult OHCAs, 8782 bystander-witnessed arrests of presumed cardiac origin were analyzed. The median time interval from collapse to call for medical help, first cardiopulmonary resuscitation, and first shock shortened from 4 (interquartile range [IQR] 2 to 11) to 2 (IQR 1 to 5) minutes, from 9 (IQR 5 to 13) to 7 (IQR 3 to 11) minutes, and from 19 (IQR 13 to 22) to 9 (IQR 7 to 12) minutes, respectively. Neurologically intact 1-month survival after witnessed ventricular fibrillation increased from 6% (6/96) to 16% (49/297; P<0.001). Among all witnessed OHCAs, earlier cardiopulmonary resuscitation (odds ratio per minute 0.89, 95% confidence interval 0.85 to 0.93) and earlier intubation (odds ratio per minute 0.96, 95% confidence interval 0.94 to 0.99) were associated with better neurological outcome. For ventricular fibrillation, only earlier shock was associated with better outcome (odds ratio 0.84, 95% confidence interval 0.80 to 0.88). Conclusions— Data from a large, population-based cohort demonstrate a continuous increase in OHCA survival with improvement in the chain of survival. The incremental benefit of early advanced care on OHCA survival is also suggested.

Cerebrospinal fluid concentrations of anti-inflammatory mediators in early-phase severe traumatic brain injury.

In our previous study of patients with early-phase severe traumatic brain injury (TBI), the anti-inflammatory interleukin (IL)-10 concentration was lower in cerebrospinal fluid (CSF) than in serum, whereas proinflammatory IL-1β and tumor necrosis factor (TNF)-α concentrations were higher in CSF than in serum. To clarify the influence of additional injury on this disproportion between proinflammatory and anti-inflammatory mediators, we compared their CSF and serum concentrations in patients with severe TBI with and without additional injury. All 35 study patients (18 with and 17 without additional injury) had a Glasgow Coma Scale score of 8 or less upon admission. With the exception of additional injury, clinical characteristics did not differ significantly between groups. CSF and serum concentrations of two proinflammatory mediators (IL-1β and TNF-α,) and three anti-inflammatory mediators (IL-1 receptor antagonist [IL-1ra], soluble TNF receptor-I [sTNFr-I], and IL-10) were measured and compared at 6 h after injury. CSF concentrations of proinflammatory mediators were much higher than the corresponding serum concentrations in both patient groups (P < 0.001). In contrast, serum concentrations of anti-inflammatory mediators were much higher than the paired CSF concentrations in patients with additional injury (P < 0.001), but serum concentrations were lower than or equal to the corresponding CSF concentrations in patients without additional injury. CSF concentrations of IL-1β, IL-1ra, sTNFr-I, and IL-10 were significantly higher (P < 0.01 for all) in patients with high intracranial pressure (ICP; n = 11) than in patients with low ICP (n = 24), and were also significantly higher (P < 0.05 for all) in patients with an unfavorable outcome (n = 14) than in patients with a favorable outcome (n = 21). These findings indicate that increased serum concentrations of anti-inflammatory mediators after severe TBI are mainly due to additional extracranial injury. We conclude that anti-inflammatory mediators in CSF may be useful indicators of the severity of brain damage in terms of ICP as well as overall prognosis of patients with severe TBI.

Impact of transport to critical care medical centers on outcomes after out-of-hospital cardiac arrest ,

BACKGROUND Post-resuscitation care has emerged as an important predictor of survival from out-of-hospital cardiac arrest (OHCA). In Japan, selected hospitals are certified as Critical Care Medical Centers (CCMCs) based on their ability and expertise. HYPOTHESIS Outcome after OHCA is better in patients transported to a CCMC compared a non-critical care hospital (NCCH). MATERIALS AND METHODS Adults with OHCA of presumed cardiac etiology, treated by emergency medical services systems, and transported in Osaka from January 1, 2005 to December 31, 2007 were registered using a prospective Utstein style population cohort database. Primary outcome measure was 1 month neurologically favorable survival (CPC< or =2). Outcomes of patients transported to CCMC were compared with patients transported to NCCH using multiple logistic regressions and stratified on the basis of stratified field ROSC. RESULTS 10,383 cases were transported. Of these, 2881 were transported to CCMC and 7502 to NCCH. Neurologically favorable 1-month survival was greater in the CCMC group [6.7% versus 2.8%, P<0.001]. Among patients who were transported to hospital without field ROSC, neurologically favorable outcome was greater in the CCMC group than the NCCH group [1.7% versus 0.5%; adjusted odds ratio (OR), 3.39; 95% confidence interval (CI), 2.17-5.29; P<0.001]. In the presence of field ROSC, survival was similar between the groups [43% versus 41%; adjusted OR, 1.09; 95% CI, 0.82-1.45; P=0.554]. CONCLUSIONS Survival after OHCA of presumed cardiac etiology transported to CCMCs was better than those transported to NCCHs. For OHCA patients without field ROSC, transport to a CCMC was an independent predictor for a good neurological outcome.

Comparison of supraglottic airway versus endotracheal intubation for the pre-hospital treatment of out-of-hospital cardiac arrest

IntroductionBoth supraglottic airway devices (SGA) and endotracheal intubation (ETI) have been used by emergency life-saving technicians (ELST) in Japan to treat out-of-hospital cardiac arrests (OHCAs). Despite traditional emphasis on airway management during cardiac arrest, its impact on survival from OHCA and time dependent effectiveness remains unclear.MethodsAll adults with witnessed, non-traumatic OHCA, from 1 January 2005 to 31 December 2008, treated by the emergency medical services (EMS) with an advanced airway in Osaka, Japan were studied in a prospective Utstein-style population cohort database. The primary outcome measure was one-month survival with neurologically favorable outcome. The association between type of advanced airway (ETI/SGA), timing of device placement and neurological outcome was assessed by multiple logistic regression.ResultsOf 7,517 witnessed non-traumatic OHCAs, 5,377 cases were treated with advanced airways. Of these, 1,679 were ETI while 3,698 were SGA. Favorable neurological outcome was similar between ETI and SGA (3.6% versus 3.6%, P = 0.95). The time interval from collapse to ETI placement was significantly longer than for SGA (17.2 minutes versus 15.8 minutes, P < 0.001). From multivariate analysis, early placement of an advanced airway was significantly associated with better neurological outcome (Adjusted Odds Ratio (AOR) for one minute delay, 0.91, 95% confidence interval (CI) 0.88 to 0.95). ETI was not a significant predictor (AOR 0.71, 95% CI 0.39 to 1.30) but the presence of an ETI certified ELST (AOR, 1.86, 95% CI 1.04 to 3.34) was a significant predictor for favorable neurological outcome.ConclusionsThere was no difference in neurologically favorable outcome from witnessed OHCA for ETI versus SGA. Early airway management with advanced airway regardless of type and rhythm was associated with improved outcomes.

Pan‐Asian Resuscitation Outcomes Study (PAROS): Rationale, Methodology, and Implementation

Disease-based registries can form the basis of comparative research to improve and inform policy for optimizing outcomes, for example, in out-of-hospital cardiac arrest (OHCA). Such registries are often lacking in resource-limited countries and settings. Anecdotally, survival rates for OHCA in Asia are low compared to those in North America or Europe, and a regional registry is needed. The Pan-Asian Resuscitation Outcomes Study (PAROS) network of hospitals was established in 2009 as an international, multicenter, prospective registry of OHCA across the Asia-Pacific region, to date representing a population base of 89 million in nine countries. The networks goal is to provide benchmarking against established registries and to generate best practice protocols for Asian emergency medical services (EMS) systems, to impact community awareness of prehospital emergency care, and ultimately to improve OHCA survival. Data are collected from emergency dispatch, ambulance providers, emergency departments, and in-hospital collaborators using standard protocols. To date (March 2011), there are a total of 9,302 patients in the database. The authors expect to achieve a sample size of 13,500 cases over the next 2 years of data collection. The PAROS network is an example of a low-cost, self-funded model of an Asia-Pacific collaborative research network with potential for international comparisons to inform OHCA policies and practices. The model can be applied across similar resource-limited settings.

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.

Prognostic indicators and outcome prediction model for patients with return of spontaneous circulation from cardiopulmonary arrest: The Utstein Osaka Project

OBJECTIVE To determine the most important indicators of prognosis in patients with return of spontaneous circulation (ROSC) following out-of-hospital cardiopulmonary arrest (OHCA) and to develop a best outcome prediction model. DESIGN AND PATIENTS All patients were prospectively recorded based on the Utstein Style in Osaka over a period of 3 years (2005-2007). Criteria for inclusion were a witnessed cardiac arrest, age greater than 17 years, presumed cardiac origin of the arrest, and successful ROSC. Multivariate logistic regression (MLR) analysis was used to develop the best prediction model. The dependent variables were favourable outcome (cerebral-performance category [CPC]: 1-2) and poor outcome (CPC: 3-5) at 1 month after the event. Eight explanatory pre-hospital variables were used concerning patient characteristics and resuscitation. External validation was performed on an independent set of Utstein data in 2007. RESULTS Subjects comprised 285 patients in VF and 577 patients with pulseless electrical activity (PEA)/asystole. The percentage of favourable outcomes was 31.9% (91/285) in VF and 5.7% (33/577) in PEA/asystole. The most important prognostic indicators of favourable outcome found by MLR were age (p=0.10), time from collapse to ROSC (TROSC) (p<0.01), and presence of pre-hospital ROSC (PROSC) (p=0.15) for VF and age (p=0.03), TROSC (p<0.01), PROSC (p<0.01), and conversion to VF (p=0.01) for PEA/asystole. For external validation data, areas under the receiver-operating characteristic curve were 0.867 for VF and 0.873 for PEA/asystole. CONCLUSIONS A model based on four selected indicators showed a high predictive value for favourable outcome in OHCA patients with ROSC.

Current termination of resuscitation (TOR) guidelines predict neurologically favorable outcome in Japan

BACKGROUND It is unclear whether the basic life support (BLS) and advanced life support (ALS) pre-hospital termination of resuscitation (TOR) rules developed in North America can be applied successfully to patients with out-of-hospital cardiac arrest (OHCA) in other countries. OBJECTIVES To assess the performance of the BLS and ALS TOR in Japan. METHODS Retrospective nationwide, population-based, observational cohort study of consecutive OHCA patients with emergency responder resuscitation attempts from 1 January 2005 to 31 December 2009 in Japan. The BLS TOR rule has 3 criteria whereas the ALS TOR rule includes 2 additional criteria. We extracted OHCA patients meeting all criteria for each TOR rule, and calculated the specificity and positive predictive value (PPV) of each TOR rule for identifying OHCA patients who did not have neurologically favorable one-month survival. RESULTS During the study-period, 151,152 cases were available to evaluate the BLS TOR rule, and 137,986 cases to evaluate the ALS TOR rule. Of 113,140 patients that satisfied all three criteria for the BLS TOR rule, 193 (0.2%) had a neurologically favorable one-month survival. The specificity of BLS TOR rule was 0.968 (95% CI: 0.963-0.972), and the PPV was 0.998 (95% CI: 0.998-0.999) for predicting lack of neurologically favorable one-month survival. Of 41,030 patients that satisfied all five criteria for the ALS TOR rule, just 37 (0.1%) had a neurologically favorable one-month survival. The specificity of ALS TOR rule was 0.981 (95% CI: 0.973-0.986), and the PPV was 0.999 (95% CI: 0.998-0.999) for predicting lack of neurologically favorable one-month survival. CONCLUSIONS The prehospital BLS and ALS TOR rules performed well in Japan with high specificity and PPV for predicting lack of neurologically favorable one-month survival in Japan. However, the specificity and PPV were not 1000 and we have to develop more specific TOR rules.

Effectiveness of the new ‘Mobile AED Map’ to find and retrieve an AED: A randomised controlled trial☆☆☆

BACKGROUND Although early shock with an automated external defibrillator (AED) is one of the several key elements to save out-of-hospital cardiac arrest (OHCA) victims, it is not always easy to find and retrieve a nearby AED in emergency settings. We developed a cell phone web system, the Mobile AED Map, displaying nearby AEDs located anywhere. The simulation trial in the present study aims to compare the time and travel distance required to access an AED and retrieve it with and without the Mobile AED Map. METHODS DESIGN Randomised controlled trial. SETTING Two fields where it was estimated to take 2min (120-170m) to access the nearest AED. Participants were randomly assigned to either the Mobile AED Map group or the control group. We provided each participant in both groups with an OHCA scenario, and measured the time and travel distance to find and retrieve a nearby AED. RESULTS Forty-three volunteers were enrolled and completed the protocol. The time to access and retrieve an AED was not significantly different between the Mobile AED Map group (400±238s) and the control group (407±256s, p=0.92). The travel distance was significantly shorter in the Mobile AED Map group (606m vs. 891m, p=0.019). Trial field conditions affected the results differently. CONCLUSIONS Although the new Mobile AED Map reduced the travel distance to access and retrieve the AED, it failed to shorten the time. Further technological improvements of the system are needed to increase its usefulness in emergency settings (UMIN000002043).