The challenges and possibilities of public access defibrillation.

Out-of-hospital cardiac arrest (OHCA) is a major health problem that affects approximately four hundred and thousand patients annually in the United States alone. It is a major challenge for the emergency medical system as decreased survival rates are directly proportional to the time delay from collapse to defibrillation. Historically, defibrillation has only been performed by physicians and in-hospital. With the development of automated external defibrillators (AEDs), rapid defibrillation by nonmedical professionals and subsequently by trained or untrained lay bystanders has become possible. Much hope has been put to the concept of Public Access Defibrillation with a massive dissemination of public available AEDs throughout most Western countries. Accordingly, current guidelines recommend that AEDs should be deployed in places with a high likelihood of OHCA. Despite these efforts, AED use is in most settings anecdotal with little effect on overall OHCA survival. The major reasons for low use of public AEDs are that most OHCAs take place outside high incidence sites of cardiac arrest and that most OHCAs take place in residential settings, currently defined as not suitable for Public Access Defibrillation. However, the use of new technology for identification and recruitment of lay bystanders and nearby AEDs to the scene of the cardiac arrest as well as new methods for strategic AED placement redefines and challenges the current concept and definitions of Public Access Defibrillation. Existing evidence of Public Access Defibrillation and knowledge gaps and future directions to improve outcomes for OHCA are discussed. In addition, a new definition of the different levels of Public Access Defibrillation is offered as well as new strategies for increasing AED use in the society.

Return of spontaneous circulation and long-term survival according to feedback provided by automated external defibrillators.

BACKGROUND: We aimed to investigate the effect of automated external defibrillator (AED) feedback mechanisms on survival in out-of-hospital cardiac arrest (OHCA) victims. In addition, we investigated converting rates in patients with shockable rhythms according to AED shock waveforms and energy levels. METHODS: We collected data on OHCA occurring between 2011 and 2014 in the Capital Region of Denmark where an AED was applied prior to ambulance arrival. Patient data were obtained from the Danish Cardiac Arrest Registry and medical records. AED data were retrieved from the Emergency Medical Dispatch Centre (EMDC) and information on feedback mechanisms, energy waveform and energy level was downloaded from the applied AEDs. RESULTS: A total of 196 OHCAs had an AED applied prior to ambulance arrival; 62 of these (32%) provided audio visual (AV) feedback while no feedback was provided in 134 (68%). We found no difference in return of spontaneous circulation (ROSC) at hospital arrival according to AV-feedback; 34 (55%, 95% confidence interval (CI) [13-67]) vs. 72 (54%, 95% CI [45-62]), P = 1 (odds ratio (OR) 1.1, 95% CI [0.6-1.9]) or 30-day survival; 24 (39%, 95% CI [28-51]) vs. 53 (40%, 95% CI [32-49]), P = 0.88 (OR 1.1 (95% CI [0.6-2.0])). Moreover, we found no difference in converting rates among patients with initial shockable rhythm receiving one or more shocks according to AED energy waveform and energy level. CONCLUSIONS: No difference in survival after OHCA according to AED feedback mechanisms, nor any difference in converting rates according to AED waveform or energy levels was detected.

Long-term outcomes after in-hospital cardiac arrest: 30-day survival and 1-year follow-up of mortality, anoxic brain damage, nursing home admission and in-home care.

AIMS: Long-term functional outcomes after in-hospital cardiac arrest (IHCA) are scarcely studied. However, survivors are at risk of neurological impairment from anoxic brain damage which could affect quality of life and lead to need of care at home or in a nursing home. METHODS: We linked data on ICHAs in Denmark with nationwide registries to report 30-day survival as well as factors associated with survival. Furthermore, among 30-day survivors we reported the one-year cumulative risk of anoxic brain damage or nursing home admission with mortality as the competing risk. RESULTS: In total, 517 patients (27.3%) survived to day 30 out of 1892 eligible patients; 338 (65.9%) were men and median age was 68 (interquartile range 58-76). Lower age, witnessed arrest by health care personnel, monitored arrest and presumed cardiac cause of arrest were associated with 30-day survival. Among 454 30-day survivors without prior anoxic brain damage or nursing home admission, the risk of anoxic brain damage or nursing home admission within the first-year post-arrest was 4.6% (n = 21; 95% CI 2.7-6.6%) with a competing risk of death of 15.6% (n = 71; 95% CI 12.3-19.0%), leaving 79.7% (n = 362) alive without anoxic brain damage or nursing home admission. When adding the risk of need of in-home care among 343 30-day survivors without prior home care needs, 68.8% (n = 236) were alive without any of the composite events one-year post-arrest. CONCLUSION: The majority of 30-day survivors of IHCA are alive at one-year follow-up without anoxic brain damage, nursing home admission or need of in-home care.

Cerebral oxygenation and metabolism during exercise following three months of endurance training in healthy overweight males.

Endurance training improves muscular and cardiovascular fitness, but the effect on cerebral oxygenation and metabolism remains unknown. We hypothesized that 3 mo of endurance training would reduce cerebral carbohydrate uptake with maintained cerebral oxygenation during submaximal exercise. Healthy overweight males were included in a randomized, controlled study (training: n = 10; control: n = 7). Arterial and internal jugular venous catheterization was used to determine concentration differences for oxygen, glucose, and lactate across the brain and the oxygen-carbohydrate index [molar uptake of oxygen/(glucose + (1/2) lactate); OCI], changes in mitochondrial oxygen tension (DeltaP(Mito)O(2)) and the cerebral metabolic rate of oxygen (CMRO(2)) were calculated. For all subjects, resting OCI was higher at the 3-mo follow-up (6.3 +/- 1.3 compared with 4.7 +/- 0.9 at baseline, mean +/- SD; P < 0.05) and coincided with a lower plasma epinephrine concentration (P < 0.05). Cerebral adaptations to endurance training manifested when exercising at 70% of maximal oxygen uptake (approximately 211 W). Before training, both OCI (3.9 +/- 0.9) and DeltaP(Mito)O(2) (-22 mmHg) decreased (P < 0.05), whereas CMRO(2) increased by 79 +/- 53 micromol x 100 x g(-1) min(-1) (P < 0.05). At the 3-mo follow-up, OCI (4.9 +/- 1.0) and DeltaP(Mito)O(2) (-7 +/- 13 mmHg) did not decrease significantly from rest and when compared with values before training (P < 0.05), CMRO(2) did not increase. This study demonstrates that endurance training attenuates the cerebral metabolic response to submaximal exercise, as reflected in a lower carbohydrate uptake and maintained cerebral oxygenation.

Antipsychotics and associated risk of out-of-hospital cardiac arrest.

Antipsychotic drugs have been associated with sudden cardiac death, but differences in the risk of out-of-hospital cardiac arrest (OHCA) associated with different antipsychotic drug classes are not clear. We identified all OHCAs in Denmark (2001-2010). The risk of OHCA associated with antipsychotic drug use was evaluated by conditional logistic regression analysis in case-time-control models. In total, 2,205 (7.6%) of 28,947 OHCA patients received treatment with an antipsychotic drug at the time of the event. Overall, treatment with any antipsychotic drug was associated with OHCA (odds ratio (OR) = 1.53, 95% confidence interval (CI): 1.23-1.89), as was use with typical antipsychotics (OR = 1.66, CI: 1.27-2.17). By contrast, overall, atypical antipsychotic drug use was not (OR = 1.29, CI: 0.90-1.85). Two individual typical antipsychotic drugs, haloperidol (OR = 2.43, CI: 1.20-4.93) and levomepromazine (OR = 2.05, CI: 1.18-3.56), were associated with OHCA, as was one atypical antipsychotic drug, quetiapine (OR = 3.64, CI: 1.59-8.30).