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.

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.

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.

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.

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.

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.

A prediction tool for initial out-of-hospital cardiac arrest survivors.

AIM: Improvement in predicting survival after out-of-hospital cardiac arrest is of major medical, scientific and socioeconomic interest. The current study aimed at developing an accurate outcome-prediction tool for patients following out-of-hospital cardiac arrests. METHODS: This retrospective cohort study was based on a cardiac arrest registry. From out-of-hospital cardiac arrest patients (n=1932), a set of variables established before restoration of spontaneous circulation was explored using multivariable logistic regression. To obtain reliable estimates of the classification performance the patients were allocated to training (oldest 80%) and validation (most recent 20%) sets. The main performance parameter was the area under the ROC curve (AUC), classifying patients into survivors/non-survivors after 30 days. Based on rankings of importance, a subset of variables was selected that would have the same predictive power as the entire set. This reduced-variable set was used to derive a comprehensive score to predict mortality. RESULTS: The average AUC was 0.827 (CI 0.793-0.861) for a logistic regression model using all 21 variables. This was significantly better than the AUC for any single considered variable. The total amount of adrenaline, number of minutes to sustained restoration of spontaneous circulation, patient age and first rhythm had the same predictive power as all 21 variables. Based on this finding, our score was built and had excellent predictive accuracy (the AUC was 0.810), discriminating patients into 10%, 30%, 50%, 70%, and 90% survival probabilities. CONCLUSION: The current results are promising to increase prognostication accuracy, and we are confident that our score will be helpful in the daily clinical routine.

Cardiac arrest due to accidental hypothermia--a 20 year review of a rare condition in an urban area.

BACKGROUND: Accidental hypothermic cardiac arrest is associated with unfortunate prognosis and large studies are rare. We therefore have performed an outcome analysis in patients that were admitted to Vienna University Hospital with the diagnosis of accidental hypothermic cardiac arrest. METHODS: This study employed a retrospective outcome analysis of prospectively collected data in a selected cohort of hypothermic cardiac arrest patients. We screened 3800 cardiac arrest patients, treated at our department between 1991 and 2010, for eligibility. Inclusion criteria were cardiac arrest with a body core temperature ≤28 °C and return of spontaneous circulation. RESULTS: A total of 18 patients who achieved return of spontaneous circulation were analysed. Nine patients (50%) achieved survival in good neurologic condition (defined as cerebral performance category CPC 1 or 2). Accidental hypothermia with consecutive cardiac arrest was caused by intoxication in most cases (67%). These patients had a better outcome than patients with other causes of accidental hypothermic cardiac arrest (OR=28; 95%KI 2-37.9; p<0.01). Hypothermia associated typical ECG changes after return of spontaneous circulation (Osborne waves) were more frequent in the surviving population (OR 16; 95%KI 1.3-19.5; p=0.05). CONCLUSIONS: Accidental hypothermic cardiac arrest in a central European urban area is rare. Prognosis was excellent in patients where hypothermic cardiac arrest was caused by intoxication.

Effects of repetitive or intensified instructions in telephone assisted, bystander cardiopulmonary resuscitation: an investigator-blinded, 4-armed, randomized, factorial simulation trial.

BACKGROUND: Compression depth is frequently suboptimal in cardiopulmonary resuscitation (CPR). We investigated effects of intensified wording and/or repetitive target depth instructions on compression depth in telephone-assisted, protocol driven, bystander CPR on a simulation manikin. METHODS: Thirty-two volunteers performed 10 min of compression only-CPR in a prospective, investigator-blinded, 4-armed, factorial setting. Participants were randomized either to standard wording ("push down firmly 5 cm"), intensified wording ("it is very important to push down 5 cm every time") or standard or intensified wording repeated every 20s. Three dispatchers were randomized to give these instructions. Primary outcome was relative compression depth (absolute compression depth minus leaning depth). Secondary outcomes were absolute distance, hands-off times as well as BORG-scale and nine-hole peg test (NHPT), pulse rate and blood pressure to reflect physical exertion. We applied a random effects linear regression model. RESULTS: Relative compression depth was 35 ± 10 mm (standard) versus 31 ± 11 mm (intensified wording) versus 25 ± 8 mm (repeated standard) and 31 ± 14 mm (repeated intensified wording). Adjusted for design, body mass index and female sex, intensified wording and repetition led to decreased compression depth of 13 (95%CI -25 to -1) mm (p=0.04) and 9 (95%CI -21 to 3) mm (p=0.13), respectively. Secondary outcomes regarding intensified wording showed significant differences for absolute distance (43 ± 2 versus 20 (95%CI 3-37) mm; p=0.01) and hands-off times (60 ± 40 versus 157 (95%CI 63-251) s; p=0.04). CONCLUSION: In protocol driven, telephone-assisted, bystander CPR, intensified wording and/or repetitive target depth instruction will not improve compression depth compared to the standard instruction.

Safety and feasibility of nasopharyngeal evaporative cooling in the emergency department setting in survivors of cardiac arrest.

AIM: Mild therapeutic hypothermia improves survival and neurologic recovery in primary comatose survivors of cardiac arrest. Cooling effectivity, safety and feasibility of nasopharyngeal cooling with the RhinoChill device (BeneChill Inc., San Diego, USA) were determined for induction of therapeutic hypothermia. METHODS: Eleven emergency departments and intensive care units participated in this multi-centre, single-arm descriptive study. Eighty-four patients after successful resuscitation from cardiac arrest were cooled with nasopharyngeal delivery of an evaporative coolant for 1h. Subsequently, temperature was controlled with systemic cooling at 33 degrees C. Cooling rates, adverse events and neurologic outcome at hospital discharge using cerebral performance categories (CPC; CPC 1=normal to CPC 5=dead) were documented. Temperatures are presented as median and the range from the first to the third quartile. RESULTS: Nasopharyngeal cooling for 1h reduced tympanic temperature by median 2.3 (1.6; 3.0) degrees C, core temperature by 1.1 (0.7; 1.5) degrees C. Nasal discoloration occurred during the procedure in 10 (12%) patients, resolved in 9, and was persistent in 1 (1%). Epistaxis was observed in 2 (2%) patients. Periorbital gas emphysema occurred in 1 (1%) patient and resolved spontaneously. Thirty-four of 84 patients (40%) patients survived, 26/34 with favorable neurological outcome (CPC of 1-2) at discharge. CONCLUSIONS: Nasopharyngeal evaporative cooling used for 1h in primary cardiac arrest survivors is feasible and safe at flow rates of 40-50L/min in a hospital setting.

Massive pulmonary embolism leading to cardiac arrest is associated with consumptive coagulopathy presenting as disseminated intravascular coagulation.

SUMMARY BACKGROUND: A consumptive coagulopathy resembling disseminated intravascular coagulation (DIC) has been seen in patients with massive pulmonary embolism (PE). We hypothesized that a DIC-like condition is relevant in patients whose pulmonary embolism leads to cardiopulmonary arrest and cardiopulmonary resuscitation (CPR). METHODS: This hypothesis was tested by the use of a database consisting of all cases of PE diagnosed at the Department of Emergency Medicine from June 1993 to October 2007. Out of 1018 cases with PE, 113 patients underwent CPR. In this cohort study, the resuscitated patients were compared with those with PE but without CPR. RESULTS: Patients with PE and CPR had 3-fold higher D-dimer, prolonged prothrombin time (PT), reduced platelet counts and lower fibrinogen and antithrombin (AT) levels compared with PE patients without cardiac arrest (P < 0.001 for all). Among patients with PE and CPR, D-dimer was abnormal in 100%, PT in 44%, AT in 53%, fibrinogen in 19% and platelets in 25%. In comparison, PE without CPR was associated with abnormal D-dimer in 99%, abnormal PT in 15%, low AT in 6%, low fibrinogen in 1% and low platelets in 2%. Nine per cent of the resuscitated patients had a DIC score >or= 5, indicating overt DIC. The DIC score highly correlated with 1-year and in-hospital mortality. CONCLUSIONS: Massive PE leading to CPR is associated with consumptive coagulopathy and overt DIC. In resuscitated patients, DIC markers may indicate pulmonary embolism as the underlying cause of arrest.

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.

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.

[Therapeutic hypothermia after cardiac arrest]. / Therapeutische milde Hypothermie nach Herz-Kreislauf-Stillstand.

The use of therapeutic hypothermia following different hypoxic-ischaemic insults has played an important role in various concepts of non-specific protection of cells for a long time. Although the use of deep therapeutic hypothermia after cardiac arrest in the last century did not lead to an improved outcome, recent data have demonstrated very positive effects of mild therapeutic hypothermia. The data from the European multicenter trial as well as those from Australia have clearly demonstrated a decrease in mortality and a better neurological outcome for patients being cooled to 32-34 degrees C for 12 or 24 h. In 2003, this led to the implementation of mild therapeutic hypothermia (32-34 degrees C) into the International Liaison Committee on Resuscitation (ILCOR) recommendations and guidelines for the treatment of unconscious patients after prehospital cardiac arrest. This article gives an overview on existing concepts and future perspectives of therapeutic mild hypothermia.

Electrophysiological assessment of the afferent sensory pathway in cardiac arrest survivors.

BACKGROUND: Hypoxic-ischaemic brain damage in cardiac arrest survivors is global, but postmortem histology could identify parts of the brain that are selectively vulnerable to ischaemia, comprising the thalamus and cortex. We hypothesized that hypoxic-ischaemic brain damage increases along the afferent sensory pathway with a stepwise decrease of detectable somatosensory evoked potential peaks. METHODS: Somatosensory evoked potentials were recorded within 72 h after cardiac arrest in 305 comatose patients after cardiopulmonary resuscitation. We measured the short latency SEP peaks N9, P15, N20, P25 (reflecting the peripheral-thalamo-cortical pathway) and the long latency SEP peaks N35 and N70 (reflecting complex cortico-cortical interactions). Patients with a Cerebral Performance Category score > 2 at 1 year were defined as patients with hypoxic-ischaemic brain damage. RESULTS: Patients with hypoxic-ischaemic brain damage (n = 232) showed a statistically significant decrease of detectable peaks (P < 0.05) along the thalamo-cortical afferent pathway: N13, P15, N20, P25 and N70 peaks were detectable in 99%, 63%, 59%, 55% and 44% patients, respectively. In patients without hypoxic-ischaemic brain damage (n = 73) the N13, P15, N20, P25 peaks were detectable in all, and the N35 and N70 peaks in 98%. Furthermore, in patients with hypoxic-ischaemic brain damage and detectable SEP peaks, P15, N20, P25, N35 and N70, peak latencies were prolonged (P < 0.05) and N20 and N70 amplitudes were decreased (P < 0.05) compared with patients without hypoxic-ischaemic brain damage. CONCLUSION: Extent of hypoxic-ischaemic brain damage in cardiac arrest survivors increases along the afferent sensory pathway, with pronounced vulnerability of thalamic and cortical brain regions.

Major bleeding complications after cardiopulmonary resuscitation: impact of thrombolytic treatment.

OBJECTIVE: The risk of bleeding complications caused by thrombolysis in patients with cardiac arrest and prolonged cardiopulmonary resuscitation is unclear. We evaluate the complication rate of systemic thrombolysis in patients with out-of-hospital cardiac arrest caused by acute myocardial infarction, especially in relation to duration of cardiopulmonary resuscitation. DESIGN: The study was designed as retrospective cohort study, the risk factor being systemic thrombolysis and the end-point major haemorrhage, defined as life-threatening and/or need for transfusion. Over 10.5 years, emergency cardiac care data, therapy, major haemorrhage and outcome of 265 patients with acute myocardial infarction admitted to an emergency department after successful cardiopulmonary resuscitation were registered. RESULTS: We observed major haemorrhage in 13 of 132 patients who received thrombolysis (10%, 95% confidence interval 5-15%), five of these survived to discharge, none died because of this complication. Major haemorrhage occurred in seven of 133 patients in whom no thrombolytic treatment had been given (5%, 95% confidence interval 1-9%), two of these survived to discharge. Taking into account baseline imbalances between the groups, the risk of bleeding was slightly increased if thrombolytics were used (odds ratio 2.5, 95% confidence interval 0.9-7.4) but this was not significant (P = 0.09). There was no clear association between duration of resuscitation and bleeding complications (z for trend = 1.52, P = 0.12). Survival was not significantly better in patients receiving thrombolysis (odds ratio 1.6, 0.9-3.0, P = 0.12). CONCLUSIONS: Bleeding complications after cardiopulmonary resuscitation are frequent, particularly in patients with thrombolytic treatment, but do not appear to be related to the duration of resuscitation. In the light of possible benefits on outcome, thrombolytic treatment should not be withheld in carefully selected patients.

Thrombolytic therapy after cardiac arrest and its effect on neurological outcome.

OBJECTIVE: the aim of the study is to investigate the effect of thrombolytic therapy on neurological outcome in patients after cardiac arrest due to acute myocardial infarction. Laboratory investigations have demonstrated that thrombolytic therapy after cardiopulmonary resuscitation improves neurological function. METHODS: from July 1991 to June 1996, patients with witnessed ventricular fibrillation cardiac arrest due to acute MI and successful restoration of spontaneous circulation admitted to the emergency department were analyzed retrospectively. A logistic regression model was used to assess the association between thrombolytic therapy and neurological outcome [best cerebral performance category (CPC) within 6 months after cardiac arrest]. RESULTS: all 157 patients [median age 57 years (IQR 50-69)] were analyzed. Thrombolytic therapy was applied in 42 patients (27%). With thrombolytic therapy good functional neurological recovery (CPC 1 or 2) was achieved more frequently (69 vs. 50%, P=0.03). After controlling for age, prehospital dosage of epinephrine, and the duration of cardiac arrest we found a non significant trend towards good neurological recovery when thrombolytic therapy was given (OR 1.9, 95% CI 0.8-4.6). CONCLUSION: thrombolytic therapy after cardiac arrest due to acute myocardial infarction is associated with improved neurological outcome.

Spontaneous subarachnoid haemorrhage as a cause of out-of-hospital cardiac arrest.

OBJECTIVE: Spontaneous subarachnoid haemorrhage as a cause of out-of-hospital cardiac arrest is poorly evaluated. We analyse disease-specific and emergency care data in order to improve the recognition of subarachnoid haemorrhage as a cause of cardiac arrest. DESIGN: We searched a registry of cardiac arrest patients admitted after primarily successful resuscitation to an emergency department retrospectively and analysed the records of subarachnoid haemorrhage patients for predictive features. RESULTS: Over 8.5 years, spontaneous subarachnoidal haemorrhage was identified as the immediate cause in 27 (4%) of 765 out-of-hospital cardiac arrests. Of these 27 patients, 24 (89%) presented with at least three or more of the following common features: female gender (63%), age under 40 years (44%), lack of co-morbidity (70%), headache prior to cardiac arrest (39%), asystole or pulseless electric activity as the initial cardiac rhythm (93%), and no recovery of brain stem reflexes (89%). In six patients (22%), an intraventricular drain was placed, one of them (4%) survived to hospital discharge with a favourable outcome. CONCLUSIONS: Subarachnoid haemorrhage complicated by cardiac arrest is almost always fatal even when a spontaneous circulation can be restored initially. This is due to the severity of brain damage. Subarachnoid haemorrhage may present in young patients without any previous medical history with cardiac arrest masking the diagnosis initially.

Cardiac arrest patients in an alpine area during a six year period.

OBJECTIVE: The components of the 'chain of survival' remain the strongest pathway to save more people from out-of-hospital cardiac arrest. The 'Utstein Style' terminology has been applied to this study to evaluate survival in patients cared for by Emergency Medical Technicians--Defibrillation (EMT-D) and physicians in a rural alpine area. METHODS: Over a 6-year period in a descriptive observational study with prospective data collection special efforts were made to identify weaknesses in the 'links' of our emergency cardiac care system considering the special geographical and legal aspects. Data from all emergency calls dispatched by the ambulance centre for patients with cardiac arrest were collected and are presented as a median and interquartile range. RESULTS: We recorded 368 cardiac arrests and in 338 patients resuscitation was attempted. Ventricular fibrillation (VF) was observed in 118 patients (35%), of whom 13 (4%) were defibrillated by EMT-Ds and 105 (31%) by physicians. Response times were 1 (0,2) min to call, 8 (6-11) min to arrival of first tier and 16 (10-26) min to defibrillation. Restoration of spontaneous circulation was achieved in 54 (46%) VF-patients. In EMT-D vs. physician treated VF-patients 1 year survival was 1 (8%) versus 20 (19%). CONCLUSION: With the exception of publications on avalanche victims and mountaineers, there are no reports of patients with out-of-hospital cardiac arrest in alpine areas. Response intervals and survival rate are not as poor as might be expected and are similar to metropolitan areas.