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Abstract: Aim: Mild therapeutic hypothermia (32–34°C) improves neurological recovery and reduces the risk of death in comatose survivors of cardiac arrest when the initial rhythm is ventricular fibrillation or pulseless ventricular tachycardia. The aim of the presented study was to investigate the effect of mild therapeutic hypothermia (32–34°C for 24h) on neurological outcome and mortality in patients who had been successfully resuscitated from non-ventricular fibrillation cardiac arrest. Methods: In this retrospective cohort study we included cardiac arrest survivors of 18 years of age or older suffering a witnessed out-of-hospital cardiac arrest with asystole or pulseless electric activity as the first documented rhythm. Data were collected from 1992 to 2009. Main outcome measures were neurological outcome within six month and mortality after six months. Results: Three hundred and seventy-four patients were analysed. Hypothermia was induced in 135 patients. Patients who were treated with mild therapeutic hypothermia were more likely to have good neurological outcomes in comparison to patients who were not treated with hypothermia with an odds ratio of 1.84 (95% confidence interval: 1.08–3.13). In addition, the rate of mortality was significantly lower in the hypothermia group (odds ratio: 0.56; 95% confidence interval: 0.34–0.93). Conclusion: Treatment with mild therapeutic hypothermia at a temperature of 32–34°C for 24h is associated with improved neurological outcome and a reduced risk of death following out-of-hospital cardiac arrest with non-shockable rhythms. [Copyright &y& Elsevier]

Abstract: Aim of the study: A reproducible long-term intensive care and outcome cardiac arrest model for exploring new cerebral preservation strategies is needed. We tried to determine effects and limitations of current therapies after different ‘no-flow’ times. Methods: Thirty-five female Large White Breed pigs (26–37kg) were included in the study. Three pigs served as sham animals without cardiac arrest (CA). Ventricular fibrillation (VF) CA was induced in 32 animals for 0, 7, 10 and 13min (each group consisting of 8 animals), followed by 8min of chest compressions, mechanical ventilation and vasopressors. Thereafter, up to 3 defibrillations were delivered. After restoration of spontaneous circulation (ROSC), the animals underwent intensive care for 20h. Neurologic examination was performed at designated time points using a neurologic deficit (ND) and an overall performance category (OPC) score. Results: Restoration of spontaneous circulation was achieved in 8 of 8 animals in the 0min-group, 6 of 8 in the 7min-group, 7 of 8 in the 10min-group and 0 of 8 in the 13min-group. All animals of the sham-group and 0min-group were neurologically intact survivors; the 7 and 10min-groups showed a median ND of 55%(26;94) and 73%(58;78), respectively. There were no significant differences between the 7 and 10min-groups regarding OPC and NDS. Coronary perfusion pressure during CPR decreased concordantly with ‘no-flow’ times with a tendency towards significance. Conclusion: This study established a reproducible cardiac arrest and resuscitation model in pigs which will be used to test novel resuscitation strategies to improve neurologic outcome after cardiac arrest. [ABSTRACT FROM AUTHOR]

Abstract: Aim of the study: To identify the optimal level of hypothermia during cardiac arrest, just prior to resuscitation with an extracorporeal cooling system and without fluid overload, for neurological outcome at day 9 in pigs. Methods: In a prospective randomised laboratory investigation, 24 female Large White pigs (31–38kg) underwent ventricular-fibrillation cardiac arrest for 15min, followed by 1min, 3min or 5min (n =8 per group) of 4°C cooling with an extracorporeal cooling system via an aortic balloon catheter and resuscitation with cardiopulmonary bypass. Sixty minutes following induction of cardiac arrest, defibrillation attempts were started. Mild hypothermia (34.5°C) and intensive care were continued for 20h and final outcome was evaluated after 9 days. Results: Brain temperature decreased from 38.5°C to 30.4±1.6°C within 221±81s in the 1-min group; to 24.2±4.6°C within 375±127s in the 3-min group; and to 18.8±4.0°C within 450±121s in the 5-min group. Restoration of spontaneous circulation was achieved in seven (1-min group), six (3-min group) and six (5-min group) animals (p =0.78), whereas survival to 9 days was only achieved in six, three and three animals in each group (p =0.22), respectively. Conclusions: An extracorporeal cooling system rapidly induced brain hypothermia following prolonged normovolaemic cardiac arrest in pigs. Difference in outcome was not statistically significant amongst the three groups with various levels of hypothermia (30°C, 24°C and 18°C) during cardiac arrest prior to resuscitation; however, the animals with the least temperature reduction showed a trend to better survival at 9 days. Further studies are necessary to investigate optimised methods for induction, as well as level, of cerebral hypothermia. [Copyright &y& Elsevier]

Abstract: Aim of the study: The appropriate time point of evaluation of functional outcome in cardiac arrest survivors remains a matter of debate. In this cohort study we posed the hypothesis that there are no significant changes in Cerebral Performance Categories (CPC) between one month and six months after out-of hospital cardiac arrest. If changes were present we aimed to identify reasons for these changes. Methods: Based on a cardiac arrest registry, a potential change in CPC and mortality between one month and six months after cardiac arrest was analysed. Variables that were associated with these changes were identified. Results: Thirty percent of 681 patients showed a significant change in functional outcome and mortality between one month and six months after out-of hospital cardiac arrest, 12% improved in CPC, 1% deteriorated, 17% died. The only factor that was associated with an improvement in CPC in the multivariate analysis was time to restoration of spontaneous circulation (ROSC) (RRR 1.04, 95% CI 1.01–1.06, per minute). We could not find any significant factors associated with a deterioration of CPC. Factors that were associated with mortality were age (RRR 1.03, 95% CI 1.01–1.06) and ventricular fibrillation as initial cardiac rhythm (RRR 0.34, 95% CI 0.16–0.71). Conclusions: There is a relevant change of functional outcome even one month after out-of hospital cardiac arrest. Especially when studies compare patient groups with unequal arrest times, and an unequal distribution of initial cardiac rhythms a follow-up period longer than one month should be considered for the final outcome evaluation after cardiac arrest. [Copyright &y& Elsevier]