Post-cardiac arrest syndrome: Epidemiology, pathophysiology, treatment, and prognostication: A scientific statement from the International Liaison Committee on Resuscitation; the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; the Council on Stroke (Part 1)

The impact of levosimendan on survival and weaning from ECMO after extracorporeal cardiopulmonary resuscitation

OBJECTIVES

Extracorporeal cardiopulmonary resuscitation (eCPR) is increasingly used due to its beneficial outcomes and results compared to conventional CPR. After cardiac arrest, the overall ejection fraction is severely impaired; thus, weaning from ECMO is often prolonged or impossible. We hypothesized that early application of levosimendan in these patients facilitates ECMO weaning and survival.

METHODS

From 2016 until 2020, patients who underwent eCPR after cardiac arrest at our institution were analyzed retrospectively and divided into two groups: patients who received levosimendan during ICU stay (n = 24) and those who did not receive levosimendan (n = 84) and analyzed for outcome parameters. Furthermore, we used propensity-score matching and multinomial regression analysis to show the effect of levosimendan on outcome parameters.

RESULTS

Overall, in-hospital mortality was significantly lower in the group which received levosimendan (28% vs. 88%, p ≤ 0.01), and ECMO weaning was more feasible in patients who received levosimendan (88% vs. 20%, p ≤ 0.01). CPR duration until ECMO cannulation was significantly shorter in the levosimendan group (44 + 26 vs. 65 + 28, p = 0.002); interestingly, the rate of mechanical chest compressions before ECMO cannulation was lower in the levosimendan group (50% vs. 69%, p = 0.005).

CONCLUSION

In patients after cardiac arrest treated with eCPR, levosimendan seems to contribute to higher success rates of ECMO weaning, potentially due to a short to mid-term increase in inotropy. Also, the survival after levosimendan application was higher than patients who did not receive levosimendan.

Status Myoclonus with Post-cardiac-arrest Syndrome: Implications for Prognostication

BACKGROUND

Status myoclonus (SM) after cardiac arrest (CA) may signify devastating brain injury. We hypothesized that SM correlates with severe neurologic and systemic post-cardiac-arrest syndrome (PCAS).

METHODS

Charts of patients admitted with CA to Mayo Clinic Saint Marys Hospital between 2005 and 2019 were retrospectively reviewed. Data included the neurologic examination, ancillary neurologic tests, and systemic markers of PCAS. Nonsustained myoclonus was clinically differentiated from SM. The cerebral performance category score at discharge was assessed; poor outcome was a cerebral performance category score > 2 prior to withdrawal of life-sustaining therapies or death.

RESULTS

Of 296 patients included, 276 (93.2%) had out-of-hospital arrest and 202 (68.5%) had a shockable rhythm; the mean time to return of spontaneous circulation was 32 ± 19 min. One hundred seventy-six (59.5%) patients had a poor outcome. One hundred one (34.1%) patients had myoclonus, and 74 (73.2%) had SM. Neurologic predictors of poor outcome were extensor or absent motor response to noxious stimulus (p = 0.02, odds ratio [OR] 3.8, confidence interval [CI] 1.2-12.4), SM (p = 0.01, OR 10.3, CI 1.5-205.4), and burst suppression on EEG (p = 0.01, OR 4.6, CI 1.4-17.4). Of 74 patients with SM, 73 (98.6%) had a poor outcome. A nonshockable rhythm (p < 0.001, OR 4.5, CI 2.6-7.9), respiratory arrest (p < 0.001, OR 3.5, CI 1.7-7.2), chronic kidney disease (p < 0.001, OR 3.1, CI 1.6-6.0), and a pressor requirement (p < 0.001, OR 4.4, CI 1.8-10.6) were associated with SM. No patients with SM, anoxic-ischemic magnetic resonance imaging findings, and absent electroencephalographic reactivity had a good outcome.

CONCLUSIONS

Sustained status myoclonus after CPR is observed in patients with other reliable indicators of severe acute brain injury and systemic PCAS. These clinical determinants should be incorporated as part of a comprehensive approach to prognostication after CA.

Levosimendan increases brain tissue oxygen levels after cardiopulmonary resuscitation independent of cardiac function and cerebral perfusion

Prompt reperfusion is important to rescue ischemic tissue; however, the process itself presents a key pathomechanism that contributes to a poor outcome following cardiac arrest. Experimental data have suggested the use of levosimendan to limit ischemia–reperfusion injury by improving cerebral microcirculation. However, recent studies have questioned this effect. The present study aimed to investigate the influence on hemodynamic parameters, cerebral perfusion and oxygenation following cardiac arrest by ventricular fibrillation in juvenile male pigs. Following the return of spontaneous circulation (ROSC), animals were randomly assigned to levosimendan (12 µg/kg, followed by 0.3 µg/kg/min) or vehicle treatment for 6 h. Levosimendan-treated animals showed significantly higher brain PbtO₂ levels. This effect was not accompanied by changes in cardiac output, preload and afterload, arterial blood pressure, or cerebral microcirculation indicating a local effect. Cerebral oxygenation is key to minimizing damage, and thus, current concepts are aimed at improving impaired cardiac output or cerebral perfusion. In the present study, we showed that NIRS does not reliably detect low PbtO₂ levels and that levosimendan increases brain oxygen content. Thus, levosimendan may present a promising therapeutic approach to rescue brain tissue at risk following cardiac arrest or ischemic events such as stroke or traumatic brain injury.

Echocardiographic parameters during prolonged targeted temperature Management in out-of-hospital Cardiac Arrest Survivors to predict neurological outcome - a post-hoc analysis of the TTH48 trial

BACKGROUND

Transthoracic echocardiographic (TTE) indices of myocardial function among survivors of out-of-hospital cardiac arrest (OHCA) have been related to neurological outcome; however, results are inconsistent. We hypothesized that changes in average peak systolic mitral annular velocity (s') from 24 h (h) to 72 h following start of targeted temperature management (TTM) predict six-month neurological outcome in comatose OHCA survivors.

METHODS

We investigated the association between peak systolic velocity of the mitral plane (s') and six-month neurological outcome in a population of 99 patients from a randomised controlled trial comparing TTM at 33 ± 1 °C for 24 h (h) (n = 47) vs. 48 h (n = 52) following OHCA (TTH48-trial). TTE was conducted at 24 h, 48 h, and 72 h after reaching target temperature. The primary outcome was 180 days neurological outcome assessed by Cerebral Performance Category score (CPC180) and the primary TTE outcome measure was s'. Secondary outcome measures were left ventricular ejection fraction (LVEF), global longitudinal strain (GLS), e', E/e' and tricuspid annular plane systolic excursion (TAPSE).

RESULTS

Across all three scan time points s' was not associated with neurological outcome (ORs: 24 h: 1.0 (95%CI: 0.7-1.4, p = 0.98), 48 h: 1.13 (95%CI: 0.9-1.4, p = 0.34), 72 h: 1.04 (95%CI: 0.8-1.4, p = 0.76)). LVEF, GLS, E/e', and TAPSE recorded on serial TTEs following OHCA were neither associated with nor did they predict CPC180. Estimated median e' at 48 h following TTM was 5.74 cm/s (95%CI: 5.27-6.22) in patients with good outcome (CPC180 1-2) vs. 4.95 cm/s (95%CI: 4.37-5.54) in patients with poor outcome (CPC180 3-5) (p = 0.04).

CONCLUSIONS

s' assessed on serial TTEs in comatose survivors of OHCA treated with TTM was not associated with CPC180. Our findings suggest that serial TTEs in the early post-resuscitation phase during TTM do not aid the prognostication of neurological outcome following OHCA.

TRIAL REGISTRATION

NCT02066753 . Registered 14 February 2014 - Retrospectively registered.

Radioprotective effects of induced astronaut torpor and advanced propulsion systems during deep space travel

BACKGROUND

Human metabolic suppression is not a new concept, with 1950s scientific literature and movies demonstrating its potential use for deep space travel (Hock, 1960). An artificially induced state of metabolic suppression in the form of torpor would improve the amount of supplies required and therefore lessen weight and fuel required for missions to Mars and beyond (Choukèr et al., 2019). Transfer habitats for human stasis to Mars have been conceived (Bradford et al., 2018). Evidence suggests that animals, when hibernating, demonstrate relative radioprotection compared to their awake state. Experiments have also demonstrated relative radioprotection in conditions of hypothermia as well as during sleep (Bellesi et al., 2016 and Andersen et al., 2009). Circadian rhythm disrupted cells also appear to be more susceptible to radiation damage compared to those that are under a rhythmic control (Dakup et al., 2018). An induced torpor state for astronauts on deep space missions may provide a biological radioprotective state due to a decreased metabolism and hypothermic conditions. A regular enforced circadian rhythm might further limit DNA damage from radiation. The As Low As Reasonably Achievable (A.L.A.R.A.) radiation protection concept defines time, distance and shielding as ways to decrease radiation exposure. Whilst distance cannot be altered in space and shielding either passively or actively may be beneficial, time of exposure may be drastically decreased with improved propulsion systems. Whilst chemical propulsion systems have superior thrust to other systems, they lack high changes in velocity and fuel efficiency which can be achieved with nuclear or electric based propulsion systems. Radiation toxicity could be limited by reduced transit times, combined with the radioprotective effects of enforced circadian rhythms during a state of torpor or hibernation.

OBJECTIVES

1. Investigate how the circadian clock and body temperature may contribute to radioprotection during human torpor on deep space missions. 2. Estimate radiation dose received by astronauts during a transit to Mars with varying propulsion systems.

METHODS

We simulated three types of conditions to investigate the potential radioprotective effect of the circadian clock and decreased temperature on cells being exposed to radiation such that may be the case during astronaut torpor. These conditions were: - Circadian clock strength: strong vs weak. - Light exposure: dark-dark vs light-dark cycle - Body temperature: 37C vs hypothermia vs torpor. We estimated transit times for a mission to Mars from Earth utilizing chemical, nuclear and electrical propulsion systems. Transit times were generated using the General Mission Analysis Tool (GMAT) and Matlab. These times were then input into the National Aeronautics and Space Administration (NASA) Online Tool for the Assessment of Radiation In Space (OLTARIS) computer simulator to estimate doses received by an astronaut for the three propulsion methods.

RESULTS

Our simulation demonstrated an increase in radioprotection with decreasing temperature. The greatest degree of radioprotection was shown in cells that maintained a strong circadian clock during torpor. This was in contrast to relatively lower radioprotection in cells with a weak clock during normothermia. We were also able to demonstrate that if torpor weakened the circadian clock, a protective effect could be partially restored by an external drive such as lighting schedules to aid entrainment i.e.: Blue light exposure for periods of awake and no light for rest times For the propulsion simulation, estimated transit times from Earth to Mars were 258 days for chemical propulsion with 165.9mSv received, 209 days for nuclear propulsion with 134.4mSv received and 80 days for electrical propulsion with 51.4mSv received.

CONCLUSION

A state of torpor for astronauts on deep space missions may not only improve weight, fuel and storage requirements but also provide a potential biological radiation protection strategy. Moreover, maintaining a controlled circadian rhythm during torpor conditions may aid radioprotection. In the not too distant future, propulsion techniques will be improved to limit transit time and hence decrease radiation dose to astronauts. Limiting exposure time and enhancing physiological radioprotection during transit could provide superior radioprotection benefits compared with active and passive radiation shielding strategies alone.

Serum neprilysin and the risk of death in patients with out-of-hospital cardiac arrest of non-traumatic origin

BACKGROUND

Early risk stratification remains an unmet clinical need in patients with in out-of-hospital cardiac arrest. We hypothesised that soluble neprilysin may represent a promising biomarker in patients with out-of-hospital cardiac arrest of non-traumatic origin and provide new pathobiological insight.

METHODS

This pilot study was a biomarker analysis from the Heidelberg Resuscitation Registry. Serum soluble neprilysin levels on admission were measured in 144 patients with successful return of spontaneous circulation after out-of-hospital cardiac arrest of non-traumatic origin. The primary endpoint was time to all-cause mortality. KM Event Rates are reported. Cox models were adjusted for age, bystander resuscitation, initial ECG rhythm, baseline estimated glomerular filtration rate, baseline lactate, left ventricular function at baseline, and targeted temperature management.

RESULTS

In total, 90 (62.5%) patients died over a follow-up of at least 30 days. Soluble neprilysin correlated weakly with high-sensitivity troponin T (r=0.18, P=0.032) but did not correlate significantly with estimated glomerular filtration rate (r=-0.12) or lactate (r=0.11). Patients with elevated soluble neprilysin levels on admission were at significantly higher risk of all-cause mortality (Q4 69.1% vs. Q1 48.4%). After multivariable adjustment, soluble neprilysin in the top quartile (Q4) was significantly associated with all-cause mortality (Q4 vs. Q1: adjusted hazard ratio 2.48 (1.20-5.12)). In an adjusted multimarker model including high-sensitivity troponin T and high-sensitivity C-reactive protein, soluble neprilysin and high-sensitivity troponin T remained independently associated with all-cause mortality (soluble neprilysin: adjusted hazard ratio 2.27 (1.08-4.78); high-sensitivity troponin T: adjusted hazard ratio 3.40 (1.63-7.09)).

CONCLUSION

Soluble neprilysin, measured as early as on hospital admission, was independently associated with all-cause mortality in patients with out-of-hospital cardiac arrest of non-traumatic origin and may prove to be useful in the estimation of risk in these patients.

Prognostication in Anoxic Brain Injury

Cardiac arrest is a common cause of coma with frequent poor outcomes. Palliative medicine teams are often called upon to discuss the scope of treatment and future care in cases of anoxic brain injury. Understanding prognostic tools in this setting would help medical teams communicate more effectively with patients’ families and caregivers and may promote improved quality of life overall. This article reviews multiple tools that are useful in determining outcomes in the setting of postarrest anoxic brain injury.

Does Early Coronary Angiography Improve Survival After out-of-Hospital Cardiac Arrest? A Systematic Review With Meta-Analysis

BACKGROUND

In patients with out-of-hospital cardiac arrest who achieve return of spontaneous circulation, coronary angiography (CAG) might improve outcomes. We conducted a systematic review and meta-analysis to elucidate the benefit and optimal timing of early CAG in comatose out-of-hospital cardiac arrest patients with return of spontaneous circulation.

METHODS

We searched MEDLINE, EMBASE, and Cochrane from 1990 to May 2017. Studies reporting survival and/or neurological survival in early (< 24-hour) vs late/no CAG were selected. We used the Clinical Advances Through Research and Information Translation (CLARITY) risk of bias in cohort studies tool and Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) criteria to assess risk of bias and quality of evidence, respectively. Results were pooled using random effects and presented as risk ratios (RRs) with 95% confidence intervals (CIs).

RESULTS

After screening 9185 titles/abstracts and 631 full-text articles, we included 23 nonrandomized studies. Short (to discharge or 30 days) and long-term (1-5 years) survival were significantly improved (52% and 56%, respectively) in the early < 24-hour CAG group compared with the late/no CAG group (RR, 1.52; 95% CI, 1.32-1.74; P < 0.00001; I2, 94% and RR, 1.56; 95% CI, 1.14-2.14; P = 0.006; I2, 86%). Survival with good neurological outcome was also improved by 69% in the < 24-hour CAG group at short- (RR, 1.69; 95% CI, 1.40-2.04; P < 0.00001; I2, 93%) and intermediate-term (3-11 months; RR, 1.49; 95% CI, 1.27-1.76; P < 0.00001; I2, 67%). We found consistent benefits in the < 2-hour and < 6-hour subgroups. Early CAG was associated with significantly better outcomes in studies of patients without ST-elevation, but the results did not reach statistical significance in studies of patients with ST-elevation.

CONCLUSIONS

On the basis of very low quality, but consistent evidence, early CAG (< 24 hours) was associated with significantly higher survival and better neurologic outcomes.

The International Liaison Committee on Resuscitation-Review of the last 25 years and vision for the future

2017 marks the 25th anniversary of the International Liaison Committee on Resuscitation (ILCOR). ILCOR was formed in 1992 to create a forum for collaboration among principal resuscitation councils worldwide. Since then, ILCOR has established and distinguished itself for its pioneering vision and leadership in resuscitation science. By systematically assessing the evidence for resuscitation standards and guidelines and by identifying national and regional differences, ILCOR reached consensus on international resuscitation guidelines in 2000, and on international science and treatment recommendations in 2005, 2010 and 2015. However, local variation and contextualization of guidelines are evident by subtle differences in regional and national resuscitation guidelines. ILCOR's efforts to date have enhanced international cooperation, and progressively more transparent and systematic collection and analysis of pertinent scientific evidence. Going forward, this sets the stage for ILCOR to pursue its vision to save more lives globally through resuscitation.

The use of therapeutic magnesium for neuroprotection during global cerebral ischemia associated with cardiac arrest and cardiac surgery in adults: a systematic review

BACKGROUND

Global cerebral ischemia occurs due to reduced blood supply to the brain. This is commonly caused by a cessation of myocardial activity associated with cardiac arrest and cardiac surgery. Survival is not the only important outcome because neurological dysfunction impacts on quality of life, reducing independent living. Magnesium has been identified as a potential neuroprotective agent; however, its role in this context is not yet clear.

OBJECTIVES

The objective of this review was to present the best currently available evidence related to the neuroprotective effects of magnesium during a period of global cerebral ischemia in adults with cardiac arrest or cardiac surgery.

INCLUSION CRITERIA TYPES OF PARTICIPANTS

The current review considered adults aged over 18 years who were at risk of global cerebral ischemia associated with cardiac arrest or cardiac surgery. Studies of patients with existing neurological deficits or under the age of 18 years were excluded from the review.

TYPES OF INTERVENTION(S)/PHENOMENA OF INTEREST

The intervention of interest was magnesium administered in doses of at least of 2 g compared to placebo to adult patients within 24 hours of cardiac arrest or cardiac surgery.

TYPES OF STUDIES

The current review considered experimental designs including randomized controlled trials, non-randomized controlled trials and quasi-experimental designs.

OUTCOMES

The outcome of interest were neurological recovery post-cardiac arrest or cardiac surgery, as measured by objective scales, such as but not limited to, cerebral performance category, brain stem reflexes, Glasgow Coma Score and independent living or dependent living status. To enable assessment of the available data, neuroprotection was examined by breaking down neurological outcomes into three domains - functional neurological outcomes, neurophysiological outcomes and neuropsychological outcomes.

SEARCH STRATEGY

The search strategy aimed to find both published and unpublished studies between January 1980 and August 2014, utilizing the Joanna Briggs Institute (JBI) three-step search strategy. Databases searched included PubMed, Embase, CINAHL, Cochrane Central Register of Controlled Trials, Australian Clinical Trials Register, Australian and New Zealand Clinical Trials Register, Clinical Trials, European Clinical Trials Register and ISRCTN Registry.

METHODOLOGICAL QUALITY

The studies included in this review were of moderate-to-good-quality randomized controlled trials. Studies included measured neurological outcome using functional neurological assessment, neuropsychiatric assessment or neurophysiological assessment.

DATA EXTRACTION

Data were extracted using standardized templates provided by the JBI Meta-analysis of Statistics Assessment and Review Instrument software.

DATA SYNTHESIS

Quantitative data were, where possible, pooled in statistical meta-analysis using Review Manager 5.3 (The Nordic Cochrane Centre, Cochrane; Copenhagen, Denmark). Where statistical pooling was not possible, the findings were presented in narrative form, including tables and figures, to aid in data presentation, where appropriate.

RESULTS

Seven studies with a total of 1164 participants were included in this review. Neurological outcome was categorized into three domains: functional neurological, neurophysiological and neuropsychological outcomes. Meta-analysis of three studies assessing the neuroprotective properties of magnesium administration post cardiac arrest found improved functional neurological outcome (odds ratio 0.44; 95% confidence interval 0.24-0.81).

CONCLUSION

Magnesium may improve functional neurological outcome in patients who suffer global cerebral ischemia associated with cardiac surgery and cardiac arrest. Magnesium does not decrease neuropsychological decline.Further testing of neurological outcomes in the domains of functional outcomes, neurophysiological markers and neuropsychological tests are required to further understanding of the neuroprotective effects of magnesium. Suitable dosing regimens should be investigated prior to introduction into clinical practice. Further research is required to investigate the optimal magnesium dose.

Therapeutic hypothermia post-cardiac arrest: a clinical nurse specialist initiative in Pakistan

PURPOSE

The purpose of this project was to assess the feasibility of an evidence-based therapeutic hypothermia protocol in adult post-cardiac arrest (CA) patients in a university hospital in Pakistan.

BACKGROUND

Cardiac arrest has a deleterious effect on neurological function, and survival is associated with significant morbidity. The International Liaison Committee of Cardiopulmonary Resuscitation and the American Heart Association recommend the use of mild hypothermia in post-CA victims to mitigate brain injury caused by anoxia. In Pakistan, the survival rate in CA victims is poor. At present, there are no hospitals in the country that use the evidence-based hypothermia intervention in adult post-CA victims.

DESCRIPTION

This pilot project of therapeutic hypothermia in adult post-CA patients was implemented in a university hospital in Pakistan by a clinical nurse specialist in collaboration with the cardiopulmonary resuscitation committee and the nursing leadership of the hospital. Various clinical nurse specialist competencies and roles were used to address the 3 spheres of influence: patient, nurses, and system, while executing an evidence-based hypothermia protocol. Process and outcome indicators were monitored to evaluate the effectiveness and feasibility of hypothermia intervention in this setting.

OUTCOME

The hypothermia protocol was successfully implemented in 3 adult post-CA patients using cost-effective measures. All 3 patients were extubated within 72 hours after CA, and 2 patients were discharged home with good neurological outcome.

CONCLUSION

Adoption of an evidence-based hypothermia protocol for adult CA patients is feasible in the intensive care setting of a university hospital in Pakistan.

IMPLICATIONS

The process used in the project can serve as a road map to other hospitals in resource-limited countries such as Pakistan that are motivated to improve post-CA outcomes. This experience reveals that advanced practice nurses can be instrumental in translation of evidence into practice in a healthcare system in Pakistan.

Patterns of multiorgan dysfunction after pediatric drowning

AIMS

To evaluate patterns of multiorgan dysfunction and neurologic outcome in children with respiratory and cardiac arrest after drowning.

METHODS

Single center retrospective chart review of children aged 0-21 years admitted between January 2001 and January 2012 to the pediatric intensive care unit at Children's Hospital of Pittsburgh with a diagnosis of drowning/submersion/immersion. Organ dysfunction scores were calculated for first 24h of admission as defined by the Pediatric Logistic Organ Dysfunction Score-1 (PELOD-1) and Pediatric Multiple Organ Dysfunction Score (P-MODS). Neurologic outcome at hospital discharge was assigned Pediatric Cerebral and Overall Performance Category Scale scores.

RESULTS

We identified 60 cases of pediatric drowning in which 21 children experienced cardiorespiratory arrest (CA) and 39 had respiratory arrest (RA). All children with CA had multiorgan failure and 81% had a poor neurologic outcome at hospital discharge while 49% of children with RA had multiorgan failure and none had an unfavorable neurological outcome (p<0.001). The most common organ failures in both CA and RA groups within the first 24h of admission were respiratory, followed by neurologic, cardiovascular, gastrointestinal, hematological, and least commonly, renal.

CONCLUSION

Patterns of organ failure differ in children with CA and RA due to drowning. The contribution of multiorgan failure to poor outcome and evaluation of the impact of augmenting cerebral resuscitation with MOF-targeting therapies after drowning deserves to be explored.

Access to care for patients with time-sensitive conditions in Pennsylvania

STUDY OBJECTIVE

Collective knowledge and coordination of vital interventions for time-sensitive conditions (ST-segment elevation myocardial infarction [STEMI], stroke, cardiac arrest, and septic shock) could contribute to a comprehensive statewide emergency care system, but little is known about population access to the resources required. We seek to describe existing clinical management strategies for time-sensitive conditions in Pennsylvania hospitals.

METHODS

All Pennsylvania emergency departments (EDs) open in 2009 were surveyed about resource availability and practice patterns for time-sensitive conditions. The frequency with which EDs provided essential clinical bundles for each condition was assessed. Penalized maximum likelihood regressions were used to evaluate associations between ED characteristics and the presence of the 4 clinical bundles of care. We used geographic information science to calculate 60-minute ambulance access to the nearest facility with these clinical bundles.

RESULTS

The percentage of EDs providing each of the 4 clinical bundles in 2009 ranged from 20% to 57% (stroke 20%, STEMI 32%, cardiac arrest 34%, sepsis 57%). For STEMI and stroke, presence of a board-certified/board-eligible emergency physician was significantly associated with presence of a clinical bundle. Only 8% of hospitals provided all 4 care bundles. However, 53% of the population was able to reach this minority of hospitals within 60 minutes.

CONCLUSION

Reliably matching patient needs to ED resources in time-dependent illness is a critical component of a coordinated emergency care system. Population access to critical interventions for the time-dependent diseases discussed here is limited. A population-based planning approach and improved coordination of care could improve access to interventions for patients with time-sensitive conditions.

Hyperoxia, hypocapnia and hypercapnia as outcome factors after cardiac arrest in children

PURPOSE

Arterial hyperoxia after resuscitation has been associated with increased mortality in adults. The aim of this study was to test the hypothesis that post-resuscitation hyperoxia and hypocapnia are associated with increased mortality after resuscitation in pediatric patients.

METHODS

We performed a prospective observational multicenter hospital-based study including 223 children aged between 1 month and 18 years who achieved return of spontaneous circulation after in-hospital cardiac arrest and for whom arterial blood gas analysis data were available.

RESULTS

After return of spontaneous circulation, 8.5% of patients had hyperoxia (defined as PaO(2)>300 mm Hg) and 26.5% hypoxia (defined as PaO(2)<60 mm Hg). No statistical differences in mortality were observed when patients with hyperoxia (52.6%), hypoxia (42.4%), or normoxia (40.7%) (p=0.61). Hypocapnia (defined as PaCO(2)<30 mm Hg) was observed in 13.5% of patients and hypercapnia (defined as PaCO(2)>50 mm Hg) in 27.6%. Patients with hypercapnia or hypocapnia had significantly higher mortality (59.0% and 50.0%, respectively) than patients with normocapnia (33.1%) (p=0.002). At 24h after return of spontaneous circulation, neither PaO(2) nor PaCO(2) values were associated with mortality. Multiple logistic regression analysis showed that hypercapnia (OR, 3.27; 95% CI, 1.62-6.61; p=0.001) and hypocapnia (OR, 2.71; 95% CI, 1.04-7.05; p=0.04) after return of spontaneous circulation were significant mortality factors.

CONCLUSIONS

In children resuscitated from cardiac arrest, hyperoxemia after return of spontaneous circulation or 24h later was not associated with mortality. On the other hand, hypercapnia and hypocapnia were associated with higher mortality than normocapnia.

The impact of response time reliability on CPR incidence and resuscitation success: a benchmark study from the German Resuscitation Registry

Introduction

Sudden cardiac arrest is one of the most frequent causes of death in the world. In highly qualified emergency medical service (EMS) systems, including well-trained emergency physicians, spontaneous circulation may be restored in up to 53% of patients at least until admission to hospital. Compared with these highly qualified EMS systems, markedly lower success rates are observed in other systems. These data clearly show that there are considerable differences between EMS systems concerning treatment success following cardiac arrest and resuscitation, although in all systems international guidelines for resuscitation are used. In this study, we investigated the impact of response time reliability (RTR) on cardiopulmonary resuscitation (CPR) incidence and resuscitation success by using the return of spontaneous circulation (ROSC) after cardiac arrest (RACA) scores and data from seven German EMS systems participating in the German Resuscitation Registry.

Methods

Anonymised patient data after out-of-hospital cardiac arrest gathered from seven EMS systems in Germany from 2006 to 2009 were analysed with regard to socioeconomic factors (population, area and EMS unit-hours), process quality (RTR, CPR incidence, special CPR measures and prehospital cooling), patient factors (age, gender, cause of cardiac arrest and bystander CPR). End points were defined as ROSC, admission to hospital, 24-hour survival and hospital discharge rate. χ² tests, odds ratios and the Bonferroni correction were used for statistical analyses.

Results

Our present study comprised 2,330 prehospital CPR patients at seven centres. The incidence of sudden cardiac arrest ranged from 36.0 to 65.1/100,000 inhabitants/year. We identified two EMS systems (RTR < 70%) that reached patients within 8 minutes of the call to the dispatch centre 62.0% and 65.6% of the time, respectively. The other five EMS systems (RTR > 70%) reached patients within 8 minutes of the call to the dispatch centre 70.4% up to 95.5% of the time. EMS systems arriving relatively later at the patients side (RTR < 70%) initiate CPR less frequently and admit fewer patients alive to hospital (calculated per 100,000 inhabitants/year) (CPR incidence (1/100,000 inhabitants/year) RTR > 70% = 57.2 vs RTR < 70% = 36.1, OR = 1.586 (99% CI = 1.383 to 1.819); P < 0.01) (admitted to hospital with ROSC (1/100,000 inhabitants/year) RTR > 70% = 24.4 vs RTR < 70% = 15.6, OR = 1.57 (99% CI = 1.274 to 1.935); P < 0.01). Using ROSC rate and the multivariate RACA score to predict outcomes, we found that the two groups did not differ, but ROSC rates were higher than predicted in both groups (ROSC RTR > 70% = 46.6% vs RTR < 70% = 47.3%, OR = 0.971 (95% CI = 0.787 to 1.196); P = n.s.) (ROSC RACA RTR > 70% = 42.4% vs RTR < 70% = 39.5%, OR = 1.127 (95% CI = 0.911 to 1.395); P = n.s.)

Conclusion

This study demonstrates that, on the level of EMS systems, faster ones more often initiate CPR and increase the number of patients admitted to hospital alive. Furthermore, we show that, with very different approaches, all centres that adhere to and are intensely trained according to the 2005 European Resuscitation Council guidelines are superior and, on the basis of international comparisons, achieve excellent success rates following CPR.

Cerebral effects of hyperglycemia in experimental cardiac arrest

OBJECTIVE

To investigate the effects of cardiac arrest on cerebral perfusion and oxidative stress during hyperglycemia and normoglycemia.

DESIGN

Experimental animal model.

SETTING

University laboratory.

SUBJECTS

Triple-breed pigs (weight, 22-27 kg).

INTERVENTIONS

Thirty-three pigs were randomized and clamped at blood glucose levels of 8.5-10 mM (high) or 4-5.5 mM (normal) and thereafter subjected to alternating current-induced 12-min cardiac arrest followed by 8 mins of cardiopulmonary resuscitation and direct-current shock to restore spontaneous circulation.

MEASUREMENTS AND MAIN RESULTS

Hemodynamics, regional near-infrared light spectroscopy, regional venous Hbo2, and biochemical markers (Protein S100beta, troponin I, F2-isoprostanes reflecting oxidative stress and inflammation) were monitored and/or sampled throughout an observation period of 4 hrs. No significant differences were seen in hemodynamics or biochemical profile. The cerebral oxygenation by means of regional near-infrared light spectroscopy was higher in the hyperglycemic (H) than in the normal (N) group after restoration of spontaneous circulation (p < .05). However, tendencies toward increased protein S100beta and 15-keto-dihydro-prostaglandin F2alpha were observed in the H group but were not statistically significant.

CONCLUSIONS

The responses to 12-min cardiac arrest and cardiopulmonary resuscitation share large similarities during hyperglycemia and normoglycemia. The higher cerebral tissue oxygenation observed in the hyperglycemia needs to be confirmed and the phenomenon needs to be addressed in future studies.