Emergency extracorporeal life support and ongoing resuscitation: a retrospective comparison for refractory out-of-hospital cardiac arrest.

BACKGROUND: In refractory cardiac arrest, with cardiopulmonary resuscitation (CPR) for more than 30 min, chances of survival are small. Extracorporeal cardiopulmonary resuscitation (ECPR) is an option for certain patients with cardiac arrest. The aim of this study was to evaluate characteristics of patients selected for ECPR. METHODS: Anonymised data of adult patients suffering refractory cardiac arrest, transported with ongoing CPR to an ED of a tertiary care centre between 2002 and 2012 were analysed. Outcome measure was the selection for ECPR. Secondary outcome was 180 days survival in good neurological condition. RESULTS: Overall, 239 patients fulfilled the inclusion criteria. ECPR was initiated in seven patients. Patients treated with ECPR were younger (46 vs 60 years; p=0.04), had shorter intervals before CPR was started (0 vs 1 min; p=0.013), faster admissions at the ED (38 vs 56 min; p=0.31) and lower blood glucose levels on admission (14 vs 21 mmol/L; p=0.018). Survival to discharge in good neurological condition was achieved in 14 (6%) of all patients. One patient in the ECPR group survived in excellent neurological condition. Age was independently associated with the selection for ECPR (OR 0.07; 95% CI 0.01 to 0.85; p=0.037). CONCLUSIONS: Emergency extracorporeal life support was used for a highly selected group of patients in refractory cardiac arrest. Several parameters were associated with the decision, but only age was independently associated with the selection for ECPR. The patient selection resulting in a survival of one patient out of seven treated seems reasonable. Randomised controlled trials evaluating the age limit as selection criteria are urgently needed to confirm these findings.

Chest compression duration influences outcome between integrated load-distributing band and manual CPR during cardiac arrest.

BACKGROUND: The Circulation Improving Resuscitation Care (CIRC) Trial found equivalent survival in adult out-of-hospital cardiac arrest (OHCA) patients who received integrated load-distributing band CPR (iA-CPR) compared to manual CPR (M-CPR). We hypothesized that as chest compression duration increased, iA-CPR provided a survival benefit when compared to M-CPR. METHODS: A pre-planned secondary analysis of OHCA of presumed cardiac etiology from the randomized CIRC trial. Chest compressions duration was defined as the total number of minutes spent on compressions during resuscitation and identified from transthoracic impedance and accelerometer data recorded by the EMS defibrillator. Logistic regression was used to model the interaction between treatment and duration of chest compressions and was covariate-adjusted for trial site, patient age, witnessed arrest, and initial shockable rhythm. Primary outcome was survival to hospital discharge. RESULTS: We enrolled 4231 subjects and of those, 2012 iA-CPR and 2002 M-CPR had complete outcome and duration of chest compressions data. While covariate-adjusted odds ratio for survival to hospital discharge was 1.86 in favor of iA-CPR (95% CI 1.16-3.0), there was an interaction between duration and study arm. When this was factored into the multivariate equation, the odds ratio for survival to hospital discharge showed a significant benefit for iA-CPR vs. M-CPR for chest compression duration greater than 16.5 min. CONCLUSION: After adjusting for compression duration and duration-treatment interaction, iA-CPR showed a significant benefit for survival to hospital discharge vs. M-CPR in patients with OHCA if chest compression duration was longer than 16.5 min.

Cerebral and Peripheral Metabolism to Predict Successful Reperfusion After Cardiac Arrest in Rats: A Microdialysis Study.

BACKGROUND: In clinical practice, monitoring of the efficacy of resuscitation can be challenging. The prediction of cerebral and overall outcome in particular is an unmet medical need. Microdialysis is a minimally invasive technique for the continuous determination of metabolic parameters in vivo. Using this technique, we set out to establish a model allowing for concomitant determination of cerebral and peripheral metabolism in a cardiac arrest setting in rodents. METHODS: Microdialysis settings were optimized in vitro and then used in male Sprague-Dawley rats. Probes were implanted into the CA1 region of the right hippocampus and the right femoral vein. With a time interval of 8 min, glucose, lactate, pyruvate, and glutamate levels were determined during baseline conditions, untreated ventricular fibrillation cardiac arrest, cardiopulmonary resuscitation (CPR), reperfusion, and death. RESULTS: In 16 rodents, restoration of spontaneous circulation was achieved in seven animals. Characteristic metabolic changes were evident during cardiac arrest and reperfusion with both probes. Ischemic patterns in peripheral compartments were delayed and more variable compared to the changes in cerebral metabolism highlighting the importance of cerebral metabolic monitoring. Microdialysis allowed distinguishing between survivors and non-survivors 8 min after termination of CPR. Cerebral glutamate showed a trend toward higher levels in non-survivors during CPR. CONCLUSIONS: We established a new rodent model for research in hypoxic ischemic encephalopathy. This setting allows to investigate the impact of resuscitation methods on cerebral and peripheral metabolism simultaneously. The present model may be used to evaluate different resuscitation strategies in order to optimize brain survival in future studies.

Surface vs. aortic flush cooling during cardiac arrest in pigs.

BACKGROUND: To investigate the feasibility and efficacy of earlier induction of hypothermia already during the 'no-flow' period of cardiac arrest with non-invasive surface cooling or invasive aortic flush cooling. METHODS: This was a prospective randomized experimental study that included 14 pigs, Large White breed (30-38 kg), with ventricular fibrillation cardiac arrest plus blanket surface and an invasive cold saline flush cooling. The endpoint was a decline in brain temperature (T(br)) at 35 min after cardiac arrest. RESULTS: With surface cooling, T(br) decreased from 38.7+/-0.2 degrees C to 37.4+/-0.8 degrees C (P=0.02) and with invasive cooling T(br) decreased from 38.8+/-0.13 degrees C to 19.0+/-2.8 degrees C within 216+/-23 s (P=0.02) and increased back to 33.0+/-0.6 degrees C at 35 min of cardiac arrest (P=0.02 vs. T(br) at 15 min, P=0.002 vs. T(br) at 35 min in the surface cooling groups). CONCLUSION: Invasive cooling by aortic flush with cold saline rapidly induces deep cerebral hypothermia, whereas non-invasive surface cooling only marginally decreases brain temperature.

Imbalance between plasma double-stranded DNA and deoxyribonuclease activity predicts mortality after out-of-hospital cardiac arrest.

AIM: Despite an increased rate of return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest (OHCA) patients, almost half of patients do not survive up to hospital discharge. Understanding pathophysiological mechanisms of post-cardiac arrest syndrome is essential for developing novel therapeutic strategies. During systemic inflammatory responses and concomitant cell death, double-stranded (ds) DNA is released into circulation, exerting pro-inflammatory effects. Deoxyribonuclease (DNase) degrades dsDNA. The role of DNase activity in OHCA survivors and impact on clinical outcome has not been analyzed yet. METHODS: In a prospective, single-center study, dsDNA and DNase activity were determined at hospital admission (acute phase) and 24 h (subacute phase) after ROSC. The ratio between dsDNA levels and DNase activity was calculated to determine the extent of dsDNA release in relation to the patients' capacity of degradation. Thirty-day mortality was defined as study end point. RESULTS: We enrolled 64 OHCA survivors, of whom 26.6% (n = 17) died within 30 days. A peak of circulating dsDNA was observed at admission which decreased within 24 h. DNase activity did not differ between acute and subacute phase, while dsDNA load per DNase activity significantly decreased. The ratio between dsDNA levels and DNase activity in the subacute phase was the strongest predictor of 30-day mortality with an adjusted HR per 1 SD of 3.59 (95% CI, 1.80-7.18, p < 0.001). CONCLUSION: Disproportionally increased dsDNA levels uncompensated by DNase activity are a strong predictor of mortality in OHCA survivors. This pilot study points to a potentially protective effect of DNase activity in patients undergoing cardiac arrest.

Time of out-of-hospital cardiac arrest is not associated with outcome in a metropolitan area: A multicenter cohort study.

AIM: Whether time of day influences survival after out-of-hospital cardiac arrest (OHCA) remains controversial. We compared outcomes after OHCA between day and night and explored whether characteristics of pre-hospital advanced life support (ALS)-quality varied by time of day. METHODS: We conducted a prospective cohort study of individuals that suffered a non-traumatic OHCA in the city of Vienna between August 2013 and August 2015 and who received resuscitative efforts by EMS. We compared clinical outcomes between day and night, defined as 7:00 pm-7:00 am based on EMS shift time including rates of sustained return of spontaneous circulation (ROSC), 30-day survival and favourable neurologic outcome (cerebral performance category 1 or 2). ALS quality measures included time to first medical contact, time to first shock, total dose of epinephrine, and multiple ALS performance measures. RESULTS: We included 1811 patients (37% female) with a mean age of 67 ± 16 years in our analyses. Rates of ROSC and 30-day survival with favourable neurological outcome did not differ between day or night (30% vs 28%, p =  0.33; 12% vs. 11%, p =  0.51, respectively). These results remained unchanged after multivariate adjustment for ROSC (RR, 1.1; 95% CI, 1.0-1.3, p = 0.19) and 30-day survival with favourable neurological outcome (RR, 1.2; 95% CI, 1.0-1.5, p =  0.10). The quality of ALS did not differ between day and night. CONCLUSIONS: In contrast to previous studies, there was no significant difference in sustained ROSC rates and 30-day survival with favourable neurological outcome after OHCA between day and night in the city of Vienna. This is likely due to nearly identical high bystander CPR rates and identical ALS performance provided by EMS personnel irrespective of time of the day.

Transport with ongoing cardiopulmonary resuscitation may not be futile.

BACKGROUND: Despite it being generally regarded as futile, patients are regularly brought to the emergency department with ongoing cardiopulmonary resuscitation (CPR). METHODS: Long-term outcome and its predictors in patients who were transported during ongoing CPR were evaluated in an observational study. Adult patients with non-traumatic cardiac arrest admitted to the Department of Emergency Medicine of a tertiary-care facility after transport with ongoing chest compression were retrospectively analysed. Multivariate analysis of epidemiological variables, treatment, blood gas values on admission, cause of arrest, and location of arrest was performed to find factors that were predictive for favourable long-term outcome (6-month survival, best cerebral performance category 1 or 2). RESULTS: Over 15 yr (1991-2006), a total of 2643 patients were treated after cardiac arrest. Of these, 327 patients received chest compressions during transport and were analysed (out-of-hospital cardiac arrest: n=244, in-hospital: n=83; the remaining 2316 patients were either stabilized before transport or suffered their arrest in our department). Return of spontaneous circulation was achieved in 31% of patients (n=102). Of these, 19 (19%) had favourable long-term outcome (6% of total). Independent predictors of good outcome were age, witnessed arrest, amount of epinephrine, and initial shockable rhythm. Among the patients with cardiac origin of arrest, 11 out of 197 patients (6%) survived; pulmonary origin, 4 out of 46 patients (9%); hypothermic arrest, 1 of 10 patients (10%); and intoxications, one out of nine patients (11%). CONCLUSIONS: Post-resuscitation care in patients who receive CPR during transport is not futile. Once restoration of spontaneous circulation is established, one out of five patients will have good long-term outcome.

Regional cerebral oxygen saturation during cardiopulmonary resuscitation as a predictor of return of spontaneous circulation and favourable neurological outcome - A review of the current literature.

INTRODUCTION: Regional cerebral oxygen saturation (rSO2) can be measured non-invasively even at no- or low-flow states. It thus allows assessment of brain oxygenation during CPR. Certain rSO2 values had been associated with return of spontaneous circulation (ROSC) and neurological outcome in the past. Clear-cut thresholds for the prediction of beneficial outcome, however, are still lacking. METHODS: We conducted a database search to extract all available investigations on rSO2 measurement during CPR. Mean, median, and ΔrSO2 values were either taken from the studies or calculated. Thresholds for the outcome "ROSC" and "neurological outcome" were sought. RESULTS: We retrieved 26 publications for the final review. The averaged mean rSO2 for patients achieving ROSC was 41 ±â€¯12% vs. 30 ±â€¯12% for non-ROSC (p = .009). ROSC was not observed when mean rSO2 remained <26%. In ROSC patients, ΔrSO2 was 22 ±â€¯16% vs. 7 ±â€¯10% in non-ROSC patients (p = .009). A rSO2 threshold of 36% predicted ROSC with a sensitivity of 67% and specificity of 69% while ΔrSO2 of 7% showed a sensitivity of 100% and a specificity of 86% (AUC = 0.733 and 0.893, respectively). Mean rSO2 of 47 ±â€¯11% was associated with favourable and 38 ±â€¯12% with poor neurological outcome. There was, however, a great overlap between groups due to scarce data. CONCLUSION: Higher rSO2 consistently correlated with increased rates of ROSC. The discriminatory power of rSO2 to prognosticate favourable neurological outcome remains unclear. Measuring rSO2 during CPR could potentially facilitate clinical decision-making.

Added value of the DIC score and of D-dimer to predict outcome after successfully resuscitated out-of-hospital cardiac arrest.

BACKGROUND: Recent Korean data suggest a high prevalence of overt disseminated intravascular coagulation (DIC) and a good predictive performance of the ISTH DIC score in successfully resuscitated out-of-hospital cardiac arrest. OBJECTIVES: We hypothesised that in a European cohort of resuscitated out-of-hospital cardiac arrest patients the prevalence of DIC is substantially lower. Furthermore, the determination of D-dimer levels at admission, but not the DIC score, could improve mortality prediction above traditional predictors. PATIENTS/METHODS: Data were extracted from a prospective cardiac arrest registry including patients admitted between 2006 and 2015, who achieved return of spontaneous circulation and had parameters for DIC score calculation available. The primary outcome was the prevalence of overt DIC at admission. Secondary outcomes included the association of overt DIC with 30-day mortality and the contribution of the DIC score and D-dimer levels to 30-day mortality prediction using logistic regression. Three stepwise models were evaluated by receiver-operating-characteristic analysis. RESULTS: Out of 1179 patients 388 were included in the study. Overt DIC was present in 8% of patients and associated with substantial 30-day mortality (83% vs. 39%). The AUC for model 1, including traditional mortality predictors, was 0.83. The inclusion of D-dimer levels significantly improved prognostication above traditional predictors (model 3, AUC 0.89), whereas the inclusion of the DIC Score had no effect on mortality prediction (model 2, AUC 0.83). CONCLUSION: Overt DIC was rare in a European cohort of out-of-hospital cardiac arrest patients. D-dimer levels improved 30-day mortality prediction and provided added value to assess early mortality risk after successful resuscitation.

Creatine kinase-mb fraction and cardiac troponin T to diagnose acute myocardial infarction after cardiopulmonary resuscitation.

OBJECTIVES: This study sought to evaluate the diagnostic value of the biochemical markers creatine kinase (CK), creatine kinase-MB fraction (CK-MB) and cardiac troponin T (cTNT) to diagnose acute myocardial infarction (AMI) after cardiopulmonary resuscitation (CPR). BACKGROUND: Elevations of CK and CK-MB after CPR are a frequent finding and might be associated with ischemic myocardial injury, as well as physical trauma to the chest. METHODS: Patients who had cardiac arrest and primary successful resuscitation were included in the study. The diagnosis of AMI was confirmed or ruled out by means of typical electrocardiographic findings, thallium-201 myocardial scintigraphy or autopsy, if death occurred during the hospital period, in 39 primary survivors of sudden cardiac death. In 24 patients (62%) the diagnosis of AMI was established. Serum cTNT, CK and CK-MB were measured, and the CK-MB/CK ratio was calculated on admission and after 12 h. RESULTS: On admission all markers of myocardial injury proved to be weak methods for the diagnosis of AMI. After 12 h cTNT as well as CK-MB exhibited a similar diagnostic performance; CK and the CK-MB/CK ratio proved to be worthless. Sensitivity and specificity for a cTNT cutoff value of 0.6 ng/ml, 12 h after cardiac arrest, were 96% and 80%, respectively. For a CK-MB cutoff value of 26 U/liter, sensitivity was 96% and specificity was 73%. CONCLUSIONS: Cardiac TNT and CK-MB are valuable tools in detecting AMI as the cause of sudden cardiac death. However, there is a considerable lack of sensitivity and specificity. Cardiac injury is probably caused not only by AMI, but also by myocardial damage related to CPR efforts.

Pulmonary embolism as a cause of cardiac arrest: presentation and outcome.

BACKGROUND: Pulmonary embolism (PE) is a possible noncardiac cause of cardiac arrest. Mortality is very high, and often diagnosis is established only by autopsy. METHODS: In a retrospective study, we analyzed clinical presentation, diagnosis, therapy, and outcome of patients with cardiac arrest after PE admitted to the emergency department of an urban tertiary care hospital. RESULTS: Within 8 years, PE was found as the cause in 60 (4.8%) of 1246 cardiac arrest victims. The initial rhythm diagnosis was pulseless electrical activity in 38 (63%), asystole in 19 (32%), and ventricular fibrillation in 3 (5%) of the patients. Pronounced metabolic acidosis (median pH, 6.95, and lactate level, 16 mmol/L) was found in most patients. In 18 patients (30%), the diagnosis of PE was established only postmortem. In 42 (70%) it was diagnosed clinically, in 24 of them the diagnosis of PE was confirmed by echocardiography. In 21 patients, 100 mg of recombinant tissue-type plasminogen activator was administered as thrombolytic treatment, and 2 (10%) of these patients survived to hospital discharge. Comparison of patients of the thrombolysis group (n = 21) with those of the nonthrombolysis group (n = 21) showed a significantly higher rate of return of spontaneous circulation (81% vs 43%) in the thrombolysis group (P=.03). CONCLUSIONS: Mortality related to cardiac arrest caused by PE is high. Echocardiography is supportive in determining PE as the cause of cardiac arrest. In view of the poor prognosis, thrombolysis should be attempted to achieve return of spontaneous circulation and probably better outcome.

Hyperthermia after cardiac arrest is associated with an unfavorable neurologic outcome.

BACKGROUND: Moderate elevation of brain temperature, when present during or after ischemia, may markedly worsen the resulting injury. OBJECTIVE: To evaluate the impact of body temperature on neurologic outcome after successful cardiopulmonary resuscitation. METHODS: In patients who experienced a witnessed cardiac arrest of presumed cardiac cause, the temperature was recorded on admission to the emergency department and after 2, 4, 6, 12, 18, 24, 36, and 48 hours. The lowest temperature within 4 hours and the highest temperature during the first 48 hours after restoration of spontaneous circulation were recorded and correlated to the best-achieved cerebral performance categories' score within 6 months. RESULTS: Over 43 months, of 698 patients, 151 were included. The median age was 60 years (interquartile range, 53-69 years); the estimated median no-flow duration was 5 minutes (interquartile range, 0-10 minutes), and the estimated median low-flow duration was 14.5 minutes (interquartile range, 3-25 minutes). Forty-two patients (28%) underwent bystander-administered basic life support. Within 6 months, 74 patients (49%) had a favorable functional neurologic recovery, and a total of 86 patients (57%) survived until 6 months after the event. The temperature on admission showed no statistically significant difference (P =.39). Patients with a favorable neurologic recovery showed a higher lowest temperature within 4 hours (35.8 degrees C [35.0 degrees C-36.1 degrees C] vs 35.2 degrees C [34.5 degrees C-35.7 degrees C]; P =.002) and a lower highest temperature during the first 48 hours after restoration of spontaneous circulation (37.7 degrees C [36.9 degrees C-38.6 degrees C] vs 38.3 degrees C [37.8 degrees C-38.9 degrees C]; P<.001) (data are given as the median [interquartile range]). For each degree Celsius higher than 37 degrees C, the risk of an unfavorable neurologic recovery increases, with an odds ratio of 2.26 (95% confidence interval, 1.24-4.12). CONCLUSION: Hyperthermia is a potential factor for an unfavorable functional neurologic recovery after successful cardiopulmonary resuscitation.

Clinical evaluation of different doses of intravenous enalaprilat in patients with hypertensive crises.

BACKGROUND: The appropriate dose of intravenous enalaprilat to be used in the treatment of hypertensive crisis is controversial. There has been no comparative study of the efficacy and safety of different dosages of enalaprilat in hypertensive patients. METHODS: Sixty-five consecutive patients with hypertensive urgencies (systolic blood pressure > 210 mm Hg and/or diastolic blood pressure > 110 mm Hg) or emergencies (diastolic blood pressure > 100 mm Hg and evidence of end-organ damage, ie, angina pectoris, hypertensive encephalopathy, or congestive heart failure) admitted to an emergency department from January 1, 1994, to September 30, 1994, were identified. The patients were randomized to receive different doses of enalaprilat (0.625, 1.25, 2.5, and 5 mg). Response to treatment was defined as a stable reduction of systolic blood pressure to below 180 mm Hg and diastolic blood pressure to below 95 mm Hg within 45 minutes after the start of treatment and relief of symptoms in patients with hypertensive emergencies. RESULTS: In 41 (63%) of 65 patients, the treatment goal was reached. Twenty-four patients (37%) failed to achieve the goal of treatment within 45 minutes after administration of enalaprilat. The response rates in the 0.625-mg, 1.25-mg, 2.5-mg, and 5-mg groups were 67%, 65%, 59%, and 62%, respectively. The proportion of patients initially randomized who responded to treatment was not different between any of the four groups of enalaprilat doses. There were no significant differences according to enalaprilat dose with respect to changes in systolic, diastolic, and mean arterial blood pressure. No severe side effects were observed. CONCLUSION: Enalaprilat is a safe antihypertensive drug with moderate efficacy in the treatment of hypertensive crisis. As doses above 0.625 mg alter neither response rates nor the magnitude of blood pressure reduction, we recommend 0.625 mg as the initial dose in the treatment of hypertensive crisis.

Apolipoprotein E polymorphism: survival and neurological outcome after cardiopulmonary resuscitation.

BACKGROUND AND PURPOSE: The apolipoprotein E 3/3 (apoE 3/3) genotype is associated with a reduced risk of developing Alzheimer's disease and with a favorable neurological outcome after traumatic head injury. In vitro studies suggest that the most common genotype, apoE 3/3, may be involved in neuroprotective and neuroregenerative mechanisms. The aim of this study was to determine whether the apoE 3/3 genotype has an impact on survival and neurological outcome after cardiopulmonary resuscitation. METHODS: Eighty patients with cardiac arrest were investigated prospectively for their apoE genotype. Epidemiological data were assessed according to recommended guidelines. Patients were divided into 2 groups, ie, with the apoE 3/3 genotype present or absent, and tested for differences in survival and neurological outcome. Further statistical analysis with respect to survival and neurological outcome was performed by using a stepwise logistic regression analysis. RESULTS: Patients with the apoE 3/3 genotype had a significantly higher survival rate (64% versus 33%, P:=0.007) and more often a favorable neurological outcome (55% versus 27%, P:=0. 013) compared with patients with other apoE genotypes. The apoE 3/3 genotype was shown to be a substantial predictive factor for a favorable neurological outcome (odds ratio 3.2) and was, apart from other essential factors, predictive for survival (odds ratio 4.4) after cardiopulmonary resuscitation. CONCLUSIONS: These data give evidence that patients with the apoE 3/3 genotype have a better chance of recovery after cardiopulmonary resuscitation than do patients with apoE genotypes other than 3/3.

Mild cerebral hypothermia during and after cardiac arrest improves neurologic outcome in dogs.

We previously found mild hypothermia (34-36 degrees C), induced before cardiac arrest, to improve neurologic outcome. In this study we used a reproducible dog model to evaluate mild hypothermia by head cooling during arrest, continued with systemic cooling (34 degrees C) during recirculation and for 1 h after arrest. In four groups of dogs, ventricular fibrillation (no flow) of 12.5 min at 37.5 degrees C was reversed with cardiopulmonary bypass and defibrillation in less than or equal to 5 min, and followed by controlled ventilation to 20 h and intensive care to 96 h. In Study A we resuscitated with normotension and normal hematocrit; Control Group A-I (n = 12) was maintained normothermic, while Treatment Group A-II (n = 10) was treated with hypothermia. In Study B we resuscitated with hypertension and hemodilution. Control Group B-I (n = 12) was maintained normothermic (6 of 12 were not hemodiluted), while Treatment Group B-II (n = 10) was treated with hypothermia. Best overall performance categories (OPCs) achieved between 24 and 96 h postarrest were in Group A-I: OPC 1 (normal) in 0 of 12 dogs, OPC 2 (moderate disability) in 2, OPC 3 (severe disability) in 7, and OPC 4 (coma) in 3 dogs. In Group A-II, OPC 1 was achieved in 5 of 10 dogs (p less than 0.01), OPC 2 in 4 (p less than 0.001), OPC 3 in 1, and OPC 4 in 0 dogs. In Group B-I, OPC 1 was achieved in 0 of 12 dogs, OPC 2 in 6, OPC 3 in 5, and OPC 4 in 1 dog. In Group B-II, OPC 1 was achieved in 6 of 10 dogs (p less than 0.01), OPC 2 in 4 (p less than 0.05), and OPC 3 or 4 in 0 dogs. Mean neurologic deficit and brain histopathologic damage scores showed similar significant group differences. Morphologic myocardial damage scores were the same in all four groups. We conclude that mild brain cooling during and after insult improves neurologic outcome after cardiac arrest.

Blood glucose concentration after cardiopulmonary resuscitation influences functional neurological recovery in human cardiac arrest survivors.

Experimental data suggest that postischemic blood glucose concentration plays an important role in modulating both ischemic cerebral infarction and selective neuronal necrosis. This study investigated the association between functional neurological recovery and blood glucose concentrations in human cardiac arrest survivors. A group of 145 nondiabetic patients were evaluated after witnessed ventricular fibrillation cardiac arrest. Data regarding cardiac arrest were collected according to an internationally accepted protocol immediately after arrival. Blood glucose was measured on admission and 6, 12, and 24 h thereafter. To control for duration of cardiac arrest and cardiogenic shock, both known to influence outcome as well as blood glucose, levels, Spearman rank partial correlation was used. In this multivariate analysis, a high admission blood glucose level tended to be associated with poor neurological outcome (rs = -0.16, n = 142, p = 0.06). The association between high median blood glucose levels over 24 h and poor neurological outcome was strong and statistically significant (rs = -0.2, n = 145, p = 0.015). High blood glucose concentrations occurring over the first 24 h after cardiac arrest have deleterious effects on functional neurological recovery. Whether cardiac arrest survivors might benefit from reduction of blood glucose levels needs further investigation.

The influence of chronic prearrest health conditions on mortality and functional neurological recovery in cardiac arrest survivors.

PURPOSE: To study the impact of chronic prearrest health conditions on mortality and neurological recovery in patients after witnessed cardiac arrest and primary successful resuscitation. PATIENTS AND METHODS: The study was set in the community of Vienna, Austria. Data concerning cardiopulmonary resuscitation of adult patients who survived a witnessed cardiac arrest were collected according to an internationally recommended protocol (Utstein-Style). Chronic prearrest health conditions and New York Heart Association (NYHA) functional classes were evaluated. All patients were followed up for 6 months after the event or death. Adverse outcome was defined as death or severe neurological impairment. A forward stepwise logistic regression model was applied to assess the impact of pre-arrest morbidity on unfavorable outcome, expressed as odds ratio (OR) with 95% confidence intervals (CI). RESULTS: Of 411 patients, 269 (66%) had one or more of the following pre-arrest diseases: coronary heart disease (45%), hypertension (26%), congestive heart failure (20%), diabetes mellitus (14%), chronic pulmonary disease (6%), and cerebrovascular disease (5%). In 22% a NYHA class of III or IV was present before cardiac arrest. At 6-month follow-up, 161 (40%) of the patients were alive with favorable neurological recovery; overall mortality was 57% (n = 233). Increasing NYHA classes (OR 1.4 per NYHA class increase; CI 1.1 to 1.7) and increasing age were independent predictors of adverse outcome (OR 1.03 per 10-year increase; CI 1.01 to 1.05), as were durations of cardiac arrest (OR 1.10 per 5-minute increase; CI 1.07 to 1.12) and the presence of ventricular fibrillation or tachycardia (OR 0.3; CI 0.2 to 0.5). The remaining health conditions, as listed above, were not independently associated with outcome. CONCLUSIONS: A large proportion of patients with cardiac arrest had chronic diseases before the event. The presence of impaired functional performance in patients with structural heart disease increased unfavorable outcome within 6 months in primary cardiac arrest survivors. However, the impact of chronic prearrest conditions on outcome seems to be very small, and should not influence decisions whether to withhold or withdraw therapy.

Creatine kinase and creatine kinase-MB release after nontraumatic cardiac arrest.

The aim of the study was to describe the course of serum creatine kinase (CK) and its MB fraction (CK-MB) in patients surviving cardiac arrest, and to identify factors influencing CK and CK-MB release. The study was set in the community of Vienna, Austria. Data concerning cardiopulmonary resuscitation, collected within a period of 33 months, were evaluated retrospectively and compared with laboratory blood investigations collected prospectively (on admission and after 6, 12, and 24 hours) in 107 adult patients surviving a witnessed cardiac arrest for 24 hours. CK and CK-MB were elevated in >75% of the patients within 24 hours. Release of CK and CK-MB was mainly associated with electrocardiographic evidence of acute myocardial infarction (AMI) cumulative energy administered during defibrillation, and duration of chest trauma by compression. The CK-MB/CK ratio was elevated in 32% of the patients. Of patients with electrocardiographic evidence of AMI, only 49% had an elevated CK-MB/CK ratio. In conclusion, the elevation in serum CK and CK-MB fraction in patients after nontraumatic cardiac arrest is a frequent finding, and is associated with ischemic myocardial injury, as well as physical trauma to the chest. This should be considered when interpreting the course of CK and CK-MB fraction for the diagnosis of AMI.

Acute renal failure after successful cardiopulmonary resuscitation.

OBJECTIVE: To assess the frequency and independent predictors of severe acute renal failure in patients resuscitated from out-of-hospital ventricular fibrillation cardiac arrest. DESIGN: A cohort study with a minimum follow-up of 6 months. SETTING: Emergency department of a tertiary care 2200-bed university hospital. PATIENTS AND PARTICIPANTS: Consecutive adult (> 18 years) patients admitted from 1 July 1991 to 31 October 1997 after witnessed ventricular fibrillation out-of-hospital cardiac arrest and successful resuscitation. MEASUREMENTS AND RESULTS: Acute renal failure was defined as a 25% decrease of creatinine clearance within 24 h after admission. Out of 187 eligible patients (median age 57 years, 146 male), acute renal failure occurred in 22 patients (12%); in 4 patients (18%) renal replacement therapy was performed. Congestive heart failure (OR 6.0, 95% CI 1.6-21.7; p = 0.007), history of hypertension (OR 4.4, 95% CI 1.3-14.7; p = 0.02) and total dose of epinephrine administered (OR 1.1, 95% CI 1.0-1.2; p = 0.009) were independent predictors of acute renal failure. Duration of cardiac arrest, pre-existing impaired renal function and blood pressure at admission were not independently associated with renal outcome. CONCLUSIONS: Severe progressive acute renal failure after cardiopulmonary resuscitation (CPR) is rare. Pre-existing haemodynamics seem to be more important for the occurrence of acute renal failure than actual hypoperfusion during resuscitation.

The association between blood lactate concentration on admission, duration of cardiac arrest, and functional neurological recovery in patients resuscitated from ventricular fibrillation.

OBJECTIVE: To assess the association between arterial lactate concentration on admission and the duration of human ventricular fibrillation cardiac arrest, and to what degree the arterial lactate concentration on admission is an early predictor of functional neurological recovery in human cardiac arrest survivors. DESIGN: Cohort study. Arterial lactate concentrations and out-of-hospital data concerning cardiac arrest and cardiopulmonary resuscitation were collected retrospectively according to a standardized protocol. Functional neurological recovery was assessed prospectively at regular intervals for 6 months. SETTING: Emergency department of an urban tertiary care hospital. PATIENTS: A total of 167 primary survivors of witnessed out-of-hospital ventricular fibrillation cardiac arrest. MEASUREMENTS: The association between arterial lactate concentration on admission, the duration of cardiac arrest, and functional neurological recovery was assessed. Further, we assessed whether admission concentrations of arterial lactate and duration of cardiac arrest can predict unfavorable functional neurological recovery. Functional neurological recovery was measured in cerebral performance categories (CPC). No or minimal functional impairment (CPC 1 and 2) was defined as favorable outcome; the remaining categories (CPC 3, 4 and 5) were defined as unfavorable functional neurological recovery. RESULTS: In 167 patients, a weak association between total duration of cardiac arrest and admission levels of lactate (r = 0.49, P < 0.001) could be shown. With increasing admission concentrations of arterial lactate functional neurological recovery was more likely to be unfavorable (OR 1.15 per mmol/l increase, 95% CI 1.04-1.27). Nevertheless, only at very high levels of lactate (16.3 mmol/l) could unfavorable neurological recovery be detected with 100% specificity, yielding a very low sensitivity of 16%. CONCLUSIONS: The arterial admission lactate concentration after out-of-hospital ventricular fibrillation cardiac arrest is a weak measure of the duration of ischemia. High admission lactate levels are associated with severe neurological impairment. However, this parameter has poor prognostic value for individual estimation of the severity of subsequent functional neurological impairment.