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.     

Incidence and outcomes of out-of-hospital cardiac arrest with shock-resistant ventricular fibrillation: Data from a large population-based cohort

Background

The increasing survival rates after out-of-hospital cardiac arrests (OHCA) are due mainly to improvements in the first 3 steps of the chain of survival. The aim of this study was to describe the temporal trends of OHCA incidence and outcomes with shock-resistant ventricular fibrillation (VF) requiring advanced life support procedures.

Methods

All our subjects were persons aged 18 years or more who had suffered OHCA of presumed cardiac etiology, were witnessed by bystanders, treated by emergency medical service (EMS), and had VF as initial rhythm. Our study was conducted in Osaka Prefecture, Japan from May 1, 1998 through December 31, 2006. Data were collected by EMS personnel using an Utstein-style database. We evaluated the temporal trends of incidence and outcomes of shock-resistant VF.

Results

During the study period, there were 8782 witnessed OHCA cases of presumed cardiac etiology. Among them, 1733 had VF as an initial rhythm, 392 of whom were shock-resistant. While the age-adjusted annual incidence of witnessed VF increased from 2.0 to 3.3 per 100,000 inhabitants, that of shock-resistant VF underwent little change during the study period. The proportion of shock-resistant VF among witnessed VF decreased from 37.0% to 19.0%. Neurologically intact 1-month survival rates after shock-resistant VF remained low at 5.6% even in 2006.

Conclusion

The actual incidence of shock-resistant VF has remained unchanged, and their outcomes continue to be dismal. Further efforts are required to reduce the mortality rates of such shock-resistant VF to achieve improved survival after OHCA.     

Minimizing pre- and post-defibrillation pauses increases the likelihood of return of spontaneous circulation (ROSC)

Background

The three-phase model of ventricular fibrillation (VF) arrest suggests a period of compressions to “prime” the heart prior to defibrillation attempts. In addition, post-shock compressions may increase the likelihood of return of spontaneous circulation (ROSC). The optimal intervals for shock delivery following cessation of compressions (pre-shock interval) and resumption of compressions following a shock (post-shock interval) remain unclear.

Objective

To define optimal pre- and post-defibrillation compression pauses for out-of-hospital cardiac arrest (OOHCA).

Methods

All patients suffering OOHCA from VF were identified over a 1-month period. Defibrillator data were abstracted and analyzed using the combination of ECG, impedance, and audio recording. Receiver-operator curve (ROC) analysis was used to define the optimal pre- and post-shock compression intervals. Multiple logistic regression analysis was used to quantify the relationship between these intervals and ROSC. Covariates included cumulative number of defibrillation attempts, intubation status, and administration of epinephrine in the immediate pre-shock compression cycle. Cluster adjustment was performed due to the possibility of multiple defibrillation attempts for each patient.

Results

A total of 36 patients with 96 defibrillation attempts were included. The ROC analysis identified an optimal pre-shock interval of <3 s and an optimal post-shock interval of <6 s. Increased likelihood of ROSC was observed with a pre-shock interval <3 s (adjusted OR 6.7, 95% CI 2.0-22.3, p = 0.002) and a post-shock interval of <6 s (adjusted OR 10.7, 95% CI 2.8-41.4, p = 0.001). Likelihood of ROSC was substantially increased with the optimization of both pre- and post-shock intervals (adjusted OR 13.1, 95% CI 3.4-49.9, p < 0.001).

Conclusions

Decreasing pre- and post-shock compression intervals increases the likelihood of ROSC in OOHCA from VF.     

Clinical predictors of survival in patients treated with therapeutic hypothermia following cardiac arrest

Introduction

Therapeutic hypothermia has been shown to provide neuroprotection and improved survival in patients suffering a cardiac arrest. We report outcomes of consecutive patients receiving therapeutic hypothermia for cardiac arrest and describe predictors of short and long-term survival.

Methods

Eighty patients receiving therapeutic hypothermia between January 2005 and December 2008 were identified and categorized as those who survived and died. Outcomes and predictors of survival were determined.

Results

Forty-five patients (56%) survived to hospital discharge and were alive at 30 days and among survivors 41 (91%) were alive 1 year after discharge. Survivors were younger, were more likely to present with VF, required less epinephrine during resuscitation, were more likely to have preserved renal function, and were less likely to be taking beta-blockers and ACE inhibitors. Predictors of survival included VF on presentation (OR 14.9, CI 2.7-83.2, p = 0.002), pre-cardiac arrest aspirin use (OR 9.7, CI 1.6-61.1, p = 0.02), return of spontaneous circulation <20 min (OR 9.4, CI 2.2-41.1, p = 0.003), absence of coronary artery disease (OR 5.3, CI 1.1-24.7, p = 0.002) and preserved renal function.

Conclusion

Therapeutic hypothermia is useful in the treatment of patients suffering a cardiac arrest. Several clinical factors may aid in predicting patients who are likely to survive after a cardiac arrest.     

Survival rate and factors associated with 1-month survival of witnessed out-of-hospital cardiac arrest of cardiac origin with ventricular fibrillation and pulseless ventricular tachycardia: the Utstein Osaka project

OBJECTIVE: We reassessed 1-month survival of patients with witnessed out-of-hospital cardiac arrest (OHCA) of cardiac origin with ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) in Osaka, Japan, and identified factors associated with 1-month survival using updated data from 1998 to 2004 collected based on the Utstein Style. METHODS: Using the Utstein Osaka Project database, we analyzed 1028 cases which met the following criteria: (1) patient age 18 years or older; (2) presumed cardiac origin based on the definition of the Utstein Style; (3) witnessed by citizens; (4) VF or pulseless VT at the time of arrival of the ambulance. The main outcome measure was survival at 1 month after collapse. Variables to develop a predictive model for 1-month survival were selected by stepwise logistic regression. RESULTS: Survival at 1 month was 19.6%. Factors retained in the final logistic regression were age, sex, type of witness, and time interval from (a) ambulance call receipt to cardiopulmonary resuscitation (CPR) by the ambulance crew; (b) ambulance call to defibrillation; (c) CPR by the ambulance crew to hospital arrival. Area under the receiver-operating characteristic curve for the model developed with the six variables was 0.738 and Hosmer-Lemshow goodness-of-fit p-value was 0.94. CONCLUSION: We successfully developed a model to estimate the probability of 1-month survival using variables easy to collect in the early phase of resuscitation, and this model would help physicians and family members predict the likelihood of 1-month survival of OHCA patients on admission.     

A model of survival following pre-hospital cardiac arrest based on the Victorian Ambulance Cardiac Arrest Register

AIMS: This study describes the epidemiology of sudden cardiac arrest patients in Victoria, Australia, as captured via the Victorian Ambulance Cardiac Arrest Register (VACAR). We used the VACAR data to construct a new model of out-of-hospital cardiac arrest (OHCA), which was specified in accordance with observed trends. PATIENTS: All cases of cardiac arrest in Victoria that were attended by Victorian ambulance services during the period of 2002-2005. RESULTS: Overall survival to hospital discharge was 3.8% among 18,827 cases of OHCA. Survival was 15.7% among 1726 bystander witnessed, adult cardiac arrests of presumed cardiac aetiology, presenting in ventricular fibrillation or ventricular tachycardia (VF/VT), where resuscitation was attempted. In multivariate logistic regression analysis, bystander CPR, cardiac arrest (CA) location, response time, age and sex were predictors of VF/VT, which, in turn, was a strong predictor of survival. The same factors that affected VF/VT made an additional contribution to survival. However, for bystander CPR, CA location and response time this additional contribution was limited to VF/VT patients only. There was no detectable association between survival and age younger than 60 years or response time over 15min. CONCLUSION: The new model accounts for relationships among predictors of survival. These relationships indicate that interventions such as reduced response times and bystander CPR act in multiple ways to improve survival.     

The effects of changes to the ERC resuscitation guidelines on no flow time and cardiopulmonary resuscitation quality: a randomised controlled study on manikins

AIM OF THE STUDY: The European Resuscitation Council (ERC) guidelines changed in 2005. We investigated the impact of these changes on no flow time and on the quality of cardiopulmonary resuscitation (CPR). MATERIALS AND METHODS: Simulated cardiac arrest (CA) scenarios were managed randomly in manikins using ERC 2000 or 2005 guidelines. Pairs of paramedics/paramedic students treated 34 scenarios with 10min of continuous ventricular fibrillation. The rhythm was analysed and defibrillation shocks were delivered with a semi-automatic defibrillator, and breathing was assisted with a bag-valve-mask; no intravenous medication was given. Time factors related to human intervention and time factors related to device, rhythm analysis, charging and defibrillation were analysed for their contribution to no flow time (time without chest compression). Chest compression quality was also analysed. RESULTS: No flow time (mean+/-S.D.) was 66+/-3% of CA time with ERC 2000 and 32+/-4% with ERC 2005 guidelines (P<0.001). Human factor interventions occupied 114+/-4s (ERC 2000) versus 107+/-4s (ERC 2005) during 600-s scenarios (P=0.237). Device factor interventions took longer using ERC 2000 guidelines: 290+/-19s versus 92+/-15s (P<0.001). The total number of chest compressions was higher with ERC 2005 guidelines (808+/-92s versus 458+/-90s, P<0.001), but the quality of CPR did not differ between the groups. CONCLUSIONS: The use of a single shock sequence with guidelines 2005 has decreased the no flow time during CPR when compared with guidelines 2000 with multiple shocks.     

Recurrent ventricular fibrillation during advanced life support care of patients with prehospital cardiac arrest

AIM OF THE STUDY: The response of recurrent episodes of ventricular fibrillation (VF) to defibrillation shocks has not been systematically studied. We analyzed outcomes from countershocks delivered for VF during advanced life support (ALS) care of patients with out-of-hospital cardiac arrest. METHODS: Cohort of patients with prehospital cardiac arrest presenting with VF, treated by ALS ambulance staff following ERC Guidelines 2000. Biphasic defibrillators provided shocks increasing from 200 to 360J. Recorded signals were analyzed to determine, for each shock, if VF was terminated and if a sustained organized rhythm was restored within 60s. RESULTS: In 465 of the 467 patients enrolled, the initial VF episode was terminated within three shocks: 92%, 61%, and 83% responded to 200J first, 200J second and 360J third shocks, respectively. VF recurred in 48% of patients within 2min of the first episode, and in 74% sometime during prehospital care. In the 175 patients experiencing five or more VF episodes, single shock VF termination dropped from the first to the fifth episode (90-80%, p<0.001) without change in transthoracic impedance, yet the proportion returning to organized rhythms increased (11-42%, p<0.0001). CONCLUSIONS: Repeated refibrillation is common in patients with VF cardiac arrest. The likelihood of countershocks to terminate VF declines for repeated episodes of VF, yet shocks that terminate these episodes result increasingly in a sustained organized rhythm.     

基于乌斯坦因模式的心肺复苏研究报告

目的 心肺复苏Utstein评价模式已被许多国家广泛用于心肺复苏评价研究.本文以心肺复苏结果Utstein评价模式设计心肺复苏注册登记表,以评价中国海南海南省人民医院心搏骤停患者流行病学特征、心肺复苏效果与影响因素.方法 应用心肺复苏Utstein模式注册登记表,对海南省人民医院急诊科511例心肺复苏患者进行前瞻性观察研究,评价本组患者心搏骤停流行病学特征及心肺复苏结果.结果 注册登记的511例心肺复苏患者纳入研究.本研究患者以40 ～ 70岁等年龄段心搏骤停发生率较高.既往史中,心血管系统疾病(190例,37.2％)、脑血管疾病(48例,9.4％)及呼吸系统疾病(39例,7.6％)等慢性疾病较为常见.173例(33.9％)为心源性心搏骤停,其中109例(21.3％)为急性心肌梗死.80例(15.7％)患者首次监测心律为心室纤颤.院内心搏骤停患者自主循环恢复率及成活出院率分别为47.0％和13.5％,院外心搏骤停患者为16.7％和4.7％.结论 本研究表明心血管系统疾病、脑血管疾病及呼吸系统疾病为最常见慢性疾病.急性心肌梗死、中风及创伤为最常见心搏骤停病因.院内心搏骤停组自主循环恢复率及成活出院率均高于院外心搏骤停组,两组差异具有统计学意义.     

Post-resuscitative clinical features in the first hour after achieving sustained ROSC predict the duration of survival in children with non-traumatic out-of-hospital cardiac arrest

Aim of the study

Although sustained return of spontaneous circulation (ROSC) can be initially established after resuscitation from non-traumatic out-of-hospital cardiac arrest (OHCA) in some children, many of the children lose spontaneous circulation during hospital stay and do not survive to discharge. The aim of this study was to determine the clinical features during the first hour after ROSC that may predict survival to hospital discharge.

Methods

We retrospectively evaluated the medical records of 228 children who presented to the emergency department without spontaneous circulation following non-traumatic OHCA during the period January 1996 to December 2008. Among these children, 80 achieved sustained ROSC for at least 20 min. The post-resuscitative clinical features during the first hour after achieving sustained ROSC that correlated with survival, median duration of survival, and death were analyzed.

Results

Among the 80 children who achieved sustained ROSC for at least 20 min, 28 survived to hospital discharge and 6 had good neurologic outcomes (PCPC scale = 1 or 2). Post-resuscitative clinical features associated with survival included sinus cardiac rhythm (p = 0.012), normal heart rate (p = 0.008), normal blood pressure (p < 0.001), urine output > 1 ml/kg/h (p = 0.002), normal skin color (p = 0.016), lack of cardiopulmonary resuscitation (CPR)-induced rib fracture (p = 0.044), initial Glasgow Coma Scale score > 7 (p < 0.001), and duration of in-hospital CPR ≤ 10 min (p < 0.001). Furthermore, these variables were also significantly associated with the duration of survival (all p < 0.05).

Conclusions

The most important predictors of survival to hospital discharge in children with OHCA who achieve sustained ROSC are a normal heart rate, normal blood pressure, and an initial urine output > 1 ml/kg/h.     

A model of survival from out-of-hospital cardiac arrest using the Boston EMS arrest registry

Objectives

To characterize the survival rate for out-of-hospital arrests of cardiac aetiology and predictor variables associated with survival in Boston, MA, and to develop a composite multivariate logistic regression model for projecting survival rates.

Methods

This is a retrospective analysis of all arrests of presumed cardiac aetiology (from January 1, 2004 to December 31, 2007) where resuscitation was attempted (n = 1156) by 911 emergency responders.

Results

The survival-at-hospital discharge rate was 11% (vs. 1-10% often reported). The coefficients and odds ratios in the first equation of the model show that joint presence of presenting rhythm of ventricular fibrillation/tachycardia (VF/VT) and return of spontaneous circulation in the pre-hospital setting (ROSC) is a substantial direct predictor of survival (e.g., 54% of such cases survive). Response time, public location, witnessed, and age are significant but less sizable direct predictors of survival. A second equation shows that these four variables make an additional indirect contribution to survival by affecting the probability of joint presence of VF/VT and ROSC; bystander CPR also makes such an indirect contribution but no significant direct one as shown in the first equation. The projected survival rate if cases had always experienced bystander CPR and rapid response time of less than four minutes is 21%.

Conclusions

The unique model describes the major contribution of VF/VT and ROSC, and key relationships among predictors of survival. These connections may have otherwise gone underreported using standard approaches and should be considered when allocating scarce resources to impact cardiac arrest survival.     

Rapid induction of mild therapeutic hypothermia by extracorporeal veno-venous blood cooling in humans

Aim

Mild therapeutic hypothermia is beneficial in patients successfully resuscitated from non-traumatic out-of-hospital cardiac arrest. The effect of fast induction of hypothermia in these patients remains to be investigated. The aim of this study was to evaluate the efficacy and safety of extracorporeal veno-venous blood cooling in humans successfully resuscitated from cardiac arrest.

Methods

We performed an interventional study in patients after successful resuscitation from cardiac arrest admitted to the emergency department of a tertiary care centre. The extracorporeal veno-venous circulation was established via a percutaneously introduced double lumen dialysis catheter in the femoral vein, and a tubing circuit and heat exchanger. A paediatric cardiopulmonary bypass roller pump and a heater-cooler system were used to circulate the blood. Main outcome measures were feasibility, efficacy, and safety.

Results

We included eight consecutive cardiac arrest patients with a median oesophageal temperature of 35.9 °C (interquartile range 34.9–37.0). A median time of 8 min elapsed (interquartile range 5–15 min) to reach oesophageal temperatures below 34 °C, which reflects a cooling rate of 12.2 °C/h (interquartile range 10.8 °C/h to 14.1 °C/h). The predefined target temperature of 33.0 °C was reached after 14 min (interquartile range 8–21 min). No device or method related adverse events were reported.

Conclusion

Extracorporeal veno-venous blood cooling is a feasible, safe, and very fast approach for induction of mild therapeutic hypothermia in patients successfully resuscitated from cardiac arrest.     

Chest compression quality variables influencing the temporal development of ROSC-predictors calculated from the ECG during VF

Background

Predictive measures that reflect the probability of return of spontaneous circulation (ROSC) if the patient is defibrillated can be calculated from the electrocardiogram during ventricular fibrillation (VF) and ventricular tachycardia (VT). It has not been studied how the quality of chest compressions affect the development of such ROSC predictors.

Materials and methods

We have formulated a model for the effect of chest compressions on the ROSC predictor median-slope (MS). For untreated VF/VT MS is assumed to decay with time and increases in MS are attributed to the effect of chest compressions. The model correlates observed trends in MS with compression quality variables derived from measurements of compression depth and force recorded during out-of-hospital cardiac arrest. Among the quality variables tested were compression rate, depth, duty cycle, leaning depth, force, work and a novel quality indicator termed residual heart force. The model was first developed on an exploration dataset and thereafter validated against independent data.

Results

When testing the indicators one by one, residual heart force (p < 0.0001), force (p < 0.0001) and work (p = 0.0210) were significantly correlated to MS development. In multivariate analysis, residual heart force (p < 0.0001) was the most significant indicator. Adjusting for residual heart force, there was a tendency that increased depth was associated with smaller effect of compressions (p = 0.0330).

Conclusion

Using MS as an indicator of the state of the myocardium, force-based compression quality variables are better indicators of efficient CPR than compression depth. A novel indicator termed residual heart force gives the best correlation with observed trends in MS.     

海南省多中心心肺复苏Utstien模式注册研究

目的 本研究以心肺复苏乌斯坦因(Utstein)评估模式评价海南省13家医院心搏骤停患者流行病学特征、心肺复苏结果及其影响因素。方法 在Utstein指南基础上设计“海南省心肺复苏Utstein注册登记表”,在2007年1月1日至2010年12月31日期间对海南省13家医院急诊科心搏骤停心肺复苏患者实施注册登记。通过方差分析等统计学方法,对心肺复苏患者实施前瞻性描述性研究。结果 1125例心搏骤停患者男性占73.8％,女性26.2％,年龄为(53.9±13.1)岁,既往病史以冠心病最为多见,其次为高血压病;自主循环恢复率为23.8％,成活出院为7.4％。自主循环恢复和成活出院的患者中发病l min内获得心肺复苏患者所占比例分别为41.8％和49.4％。院内心搏骤停(IHCA)患者和院外心搏骤停(OHCA)患者ROSC率分别为36.3％,11.6％,成活出院率分别为11.5％,3.3％。心室纤颤/无脉性室性心动过速患者188例(16.7％),其自主循环恢复率及成活出院率分别为58.0％,21.8％。心源性心搏骤停448例(39.8％);其中院内与院外心搏骤停患者自主循环恢复率分别为36.3％,11.6％,成活出院率分别为11.5％,3.3％。非心源性心搏骤停677例(60.2％)。三级医院和二级医院自主循环恢复率分别为69.8％和30.2％,成活出院率分别为7.4％和7.3％。结论 心搏骤停更常见于男性。慢性疾病在本组患者中普遍存在,其中以冠心病和高血压病最为多见。院内心搏骤停患者自主循环恢复和成活出院率均明显高于院外心搏骤停患者。心室纤颤/无脉室性心动过速患者心肺复苏自主循环恢复及成活出院率高于其他类型初始心律的患者。缩短心肺复苏启动时间有助于提高自主循环恢复率及成活出院率。     

Ventricular fibrillation in Rochester, Minnesota: Experience over 18 years

ObjectiveSurvival following out-of-hospital cardiac arrest (OHCA) continues to be disappointingly low world-wide, despite advances in technology and international guidelines for resuscitation. Few cities or emergency medical service (EMS) agencies report patient outcomes after OHCA. Among those who do, survival from witnessed VF ranges from 7.7% to 39.9%, with only a few cities reporting rates higher than this. We report outcomes and incidence of VF OHCA over 18 years in a medium-sized city incorporating an aggressive approach to OHCA.MethodsThe city, which increased in population over the study period from 70,000 to 100,000 persons, utilizes an emergency response system which dispatches defibrillator-equipped police, fire-rescue and ambulance personnel simultaneously. Police and fire-rescue personnel are equipped with automated external defibrillators (AEDs). Advanced life-support is provided as needed by paramedics.ResultsThere were 454 arrests during the study period attributed to a cardiac cause. Of 271 bystander-witnessed arrests, 203 (74.9%) were in VF and 94 (46.3%) were discharged. Average time from 9-1-1 call to shock was relatively short: mean 6.5 min (S.D. 2.5 min). In a multivariable model, the interval from call to shock was strongly associated with neurologically intact survival (OR 0.72, 95% CI: 0.61–0.84 for each additional minute). The age- and sex-adjusted incidence of EMS-treated VF OHCA significantly (p < 0.001) declined over the study period: 1991–1999: 37.9/100,000 (95% CI: 31.8–44.0), 2000–2008: 17.8/100,000 (95% CI: 14.4–21.2).ConclusionsHigh survival from witnessed VF OHCA (46.3%) was achieved during the study period. Rapid response, and therefore rapid defibrillation, was the major contributor to survival.     

Cardiac arrest survivors with moderate elevated body mass index may have a better neurological outcome: a cohort study

Aim

Body mass index (BMI) may influence the quality of cardiopulmonary resuscitation and may influence prognosis after cardiac arrest. To review the direct effect of obesity on outcome after cardiac arrest, the following cohort study was conducted.

Methods

This study based on a cardiac arrest registry comprising all adult patients with cardiac arrest of non-traumatic origin and restoration of spontaneous circulation (ROSC) admitted to the department of emergency medicine of a tertiary-care facility. Data were collected between January 1992 and December 2007 according to the Utstein criteria. We assessed the association between BMI according to the WHO classification (underweight, BMI < 18.5; normal weight, 18.5-24.9; overweight, 25.0-29.9; obese ≥ 30), six-month survival and neurological recovery.

Results

Analysis was carried out on a total of 1915 adult patients (32% female). Patients had a median age of 59 years (interquartile range [IQR] 49-70) and a median BMI of 26.0 (IQR 23.9-29.1). Survival to six months was 50%. There was no significant difference in survival between the BMI groups (underweight 46%, normal weight 47%, overweight 52%, obese 51%). In a multivariate analysis neurological outcome was better in overweight patients as compared to subjects with normal BMI (odds ratio 1.35; 95% confidence interval 1.02-1.79).

Conclusion

Body mass index may have no direct influence on six-month survival after cardiac arrest, but patients with moderately elevated BMI may have a better neurological prognosis.     

A pilot study examining the role of regional cerebral oxygen saturation monitoring as a marker of return of spontaneous circulation in shockable (VF/VT) and non-shockable (PEA/Asystole) causes of cardiac arrest

Background

Non-invasive monitoring of cerebral perfusion and oxygen delivery during cardiac arrest is not routinely utilized during cardiac arrest resuscitation. The objective of this study was to investigate the feasibility of using cerebral oximetry during cardiac arrest and to determine the relationship between regional cerebral oxygen saturation (rSO2) with return of spontaneous circulation (ROSC) in shockable (VF/VT) and non-shockable (PEA/asystole) types of cardiac arrest.

Methods

Cerebral oximetry was applied to 50 in-hospital and out-of-hospital cardiac arrest patients.

Results

Overall, 52% (n = 26) achieved ROSC and 48% (n = 24) did not achieve ROSC. There was a significant difference in mean ± SD rSO2% in patients who achieved ROSC compared to those who did not (47.2 ± 10.7% vs. 31.7 ± 12.8%, p < 0.0001). This difference was observed during asystole (median rSO2 (IQR) ROSC versus no ROSC: 45.0% (35.1–48.8) vs. 24.9% (20.5–32.9), p < 0.002) and PEA (50.6% (46.7–57.5) vs. 31.6% (18.8–43.3), p = 0.02), but not in the VF/VT subgroup (43.7% (41.1–54.7) vs. 42.8% (34.9–45.0), p = 0.63). Furthermore, it was noted that no subjects with a mean rSO2 < 30% achieved ROSC.

Conclusions

Cerebral oximetry may have a role as a real-time, non-invasive predictor of ROSC during cardiac arrest. The main utility of rSO2 in determining ROSC appears to apply to asystole and PEA subgroups of cardiac arrest, rather than VF/VT. This observation may reflect the different physiological factors involved in recovery from PEA/asytole compared to VF/VT. Whereas in VF/VT, successful defibrillation is of prime importance, however in PEA and asytole achieving ROSC is more likely to be related to the quality of oxygen delivery. Furthermore, a persistently low rSO2 <30% in spite of optimal resuscitation methods may indicate futility of resuscitation efforts.     

Managing cardiac arrest with refractory ventricular fibrillation in the emergency department: Conventional cardiopulmonary resuscitation versus extracorporeal cardiopulmonary resuscitation

AimRefractory ventricular fibrillation, resistant to conventional cardiopulmonary resuscitation (CPR), is a life threatening rhythm encountered in the emergency department. Although previous reports suggest the use of extracorporeal CPR can improve the clinical outcomes in patients with prolonged cardiac arrest, the effectiveness of this novel strategy for refractory ventricular fibrillation is not known. We aimed to compare the clinical outcomes of patients with refractory ventricular fibrillation managed with conventional CPR or extracorporeal CPR in our institution.MethodThis is a retrospective chart review study from an emergency department in a tertiary referral medical center. We identified 209 patients presenting with cardiac arrest due to ventricular fibrillation between September 2011 and September 2013. Of these, 60 patients were enrolled with ventricular fibrillation refractory to resuscitation for more than 10 min. The clinical outcome of patients with ventricular fibrillation received either conventional CPR, including defibrillation, chest compression, and resuscitative medication (C-CPR, n = 40) or CPR plus extracorporeal CPR (E-CPR, n = 20) were compared.ResultsThe overall survival rate was 35%, and 18.3% of patients were discharged with good neurological function. The mean duration of CPR was longer in the E-CPR group than in the C-CPR group (69.90 ± 49.6 min vs 34.3 ± 17.7 min, p = 0.0001). Patients receiving E-CPR had significantly higher rates of sustained return of spontaneous circulation (95.0% vs 47.5%, p = 0.0009), and good neurological function at discharge (40.0% vs 7.5%, p = 0.0067). The survival rate in the E-CPR group was higher (50% vs 27.5%, p = 0.1512) at discharge and (50% vs 20%, p = 0. 0998) at 1 year after discharge.ConclusionsThe management of refractory ventricular fibrillation in the emergency department remains challenging, as evidenced by an overall survival rate of 35% in this study. Patients with refractory ventricular fibrillation receiving E-CPR had a trend toward higher survival rates and significantly improved neurological outcomes than those receiving C-CPR.     

Improving outcome after out-of-hospital cardiac arrest by strengthening weak links of the local Chain of Survival; quality of advanced life support and post-resuscitation care

Background

Survival after out-of-hospital cardiac arrest (OHCA) depends on a well functioning Chain of Survival. We wanted to assess if targeted attempts to strengthen the weak links of our local chain; quality of advanced life support (ALS) and post-resuscitation care, would improve outcome.

Materials and methods

Utstein data from all OHCAs in Oslo during three distinct 2-year time periods 1996-1998, 2001-2003 and 2004-2005 were collected. Before the second period the local ALS guidelines changed with increased focus on good quality chest compressions with minimal pauses, while standardized post-resuscitation care including goal directed therapy with therapeutic hypothermia and percutaneous coronary intervention was added in the third period. Additional a priori sub-group analyses of arrests with cardiac aetiology as well as bystander witnessed ventricular fibrillation/tachycardia (VF/VT) arrests with cardiac aetiology were performed.

Results

ALS was attempted in 454, 449, and 417 patients with OHCA in the first, second and last time period, respectively. From the first to the third period VF/VT arrests declined (40% vs. 33%, p = 0.039) and fewer arrests were witnessed (80% vs. 72%, p = 0.022) and response intervals increased (7 ± 4 to 9 ± 4 min, p < 0.001). Overall survival increased from 7% (first period) to 13% (last period), p = 0.002, and survival in the sub-group of bystander witnessed VF/VT arrests with cardiac aetiology increased from 15% (first period) to 35% (last period), p = 0.001.

Conclusions

Survival after OHCA was increased after improving weak links of our local Chain of Survival, quality of ALS and post-resuscitation care.