Assessment of outcomes and differences between in- and out-of-hospital cardiac arrest patients treated with cardiopulmonary resuscitation using extracorporeal life support

Aim

Cardiopulmonary resuscitation (CPR) using extracorporeal life support (ECLS) for in-hospital cardiac arrest (IHCA) patients has been assigned a low-grade recommendation in current resuscitation guidelines. This study compared the outcomes of IHCA and out-of-hospital cardiac arrest (OHCA) patients treated with ECLS.

Methods

A total of 77 patients were treated with ECLS. Baselines characteristics and outcomes were compared for 38 IHCA and 39 OCHA patients.

Results

The time interval between collapse and starting ECLS was significantly shorter after IHCA than after OHCA (25 (21-43) min versus 59 (45-65) min, p < 0.001). The weaning rate from ECLS (61% versus 36%, p = 0.03) and 30-day survival (34% versus 13%, p = 0.03) were higher for IHCA compared with OHCA patients. IHCA patients had a higher rate of favourable neurological outcome compared to OHCA patients, but the difference was not statistically significant (26% versus 10%, p = 0.07). Kaplan-Meier analysis showed improved 30-day and 1-year survival for IHCA patients treated with ECLS compared to OHCA patients who had ECLS. However, multivariate stepwise Cox regression model analysis indicated no difference in 30-day (odds ratio 0.94 (95% confidence interval 0.68-1.27), p = 0.67) and 1-year survival (0.99 (0.73-1.33), p = 0.95).

Conclusion

CPR with ECLS led to more favourable patient outcomes after IHCA compared with OHCA in our patient group. The difference in outcomes for ECLS after IHCA and OHCA disappeared after adjusting for patient factors and the time delay in starting ECLS.     

Improved outcome of extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest – A comparison with that for extracorporeal rescue for in-hospital cardiac arrest

Purpose

The aim was to investigate the effects of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) and compare the results with those of in-hospital cardiac arrest (IHCA).

Methods

We analyzed our extracorporeal membrane oxygenation (ECMO) results for patients who received ECPR for OHCA or IHCA in the last 5 years. Pre-arrest, resuscitation, and post-resuscitative data were evaluated.

Results

In the last 5 years, ECPR was used 230 times for OHCA (n = 31) and IHCA (n = 199). The basic demographic data showed significant differences in age, cardiomyopathy, and location of the initial CPR. Duration of ischemia was shorter in the IHCA group (44.4 ± 24.7 min vs. 67.5 ± 30.6 min, p < 0.05). About 50% of each group underwent a further intervention to treat the underlying etiology. ECMO was maintained for a shorter duration in the OHCA patients (61 ± 48 h vs. 94 ± 122 h, p < 0.05). Survival to discharge was similar in the two groups (38.7% for OHCA vs. 31.2% for IHCA, p > 0.05), as was the favorable outcome rate (25.5% for OHCA vs. 25.1% for IHCA, p > 0.05). Survival was acceptable (about 33%) in both groups when the duration of ischemia was no longer than 75 min.

Conclusions

In addition to having a beneficial effect in IHCA, ECPR can lead to survival and a positive neurological outcome in selected OHCA patients after prolonged resuscitation. Our results suggest that further investigation of the use of ECMO in OHCA is warranted.     

Extracorporeal life support associated with hypothermia and normoxemia in refractory cardiac arrest

Aim

We describe a 1-year experience with extracorporeal cardiopulmonary resuscitation (ECPR) for in-hospital (IHCA) and out-of-hospital cardiac arrest (OHCA) associated with intra-arrest hypothermia and normoxemia.

Methods

Since January 1st 2012, ECPR has been applied in our hospital to all patients less than 65 years of age and without major co-morbidities who develop refractory cardiac arrest (CA) with bystander CPR. Over a 1-year period of observation, we recorded 28-day survival with intact neurological outcome and the rate of organ donation.

Results

During the observational period, 24 patients were treated with ECPR, with a median age of 48 years. Ten patients had IHCA. Acute coronary syndrome and/or major arrhythmias were the main cause of arrest. Intra-arrest cooling was used in 17 patients; temperature on ECMO initiation in these patients was 32.9 °C [32–34]. The time from collapse to ECPR was 58 min [45–70] and was shorter in survivors than in non-survivors (41 min [39–58] vs. 60 min [55–77], p = 0.059). Non-survivors were more likely to have coagulopathy and received more blood transfusions. Six patients (25%) survived with good neurological outcome at day 28. Four patients with irreversible brain damage had organ function suitable for donation.

Conclusion

ECPR provided satisfactory survival rates with good neurologic recovery in refractory CA for both IHCA and OHCA. ECMO may help rapidly stabilise systemic haemodynamic status and restore organ function.     

New treatment bundles improve survival in out-of-hospital cardiac arrest patients: A historical comparison

Introduction

Before the introduction of the new international cardiac arrest treatment guidelines in 2005, patients with out-of-hospital cardiac arrest (OHCA) of cardiac origin in Northern Italy had very poor prognosis. Since 2006, a new bundle of care comprising use of automated external defibrillators (AEDs) and therapeutic hypothermia (TH) was started, while extracorporeal CPR program (ECPR) for selected refractory CA and dispatcher-assisted cardio-pulmonary resuscitation (CPR) was started in January 2010.

Objectives

We hypothesized that a program of bundled care might improve outcome of OHCA patients.

Methods

We analyzed data collected in the OHCA registry of the MB area between September 2007 and August 2011 and compared this with data from 2000 to 2003.

Results

Between 2007 and 2011, 1128 OHCAs occurred in the MB area, 745 received CPR and 461 of these had a CA of presumed cardiac origin. Of these, 125 (27%) achieved sustained ROSC, 60 (13%) survived to 1 month, of whom 51 (11%) were discharged from hospital with a good neurological outcome (CPC ≤ 2), and 9 with a poor neurological outcome (CPC > 2).Compared with data from the 2000 to 2003 periods, survival increased from 5.6% to 13.01% (p < 0.0001). In the 2007–2011 group, low-flow time and bystander CPR were independent markers of survival.

Conclusions

OHCA survival has improved in our region. An increased bystander CPR rate associated with dispatcher-assisted CPR was the most significant cause of increased survival, but duration of CA remains critical for patient outcome.     

Aspects on the increase in bystander CPR in Sweden and its association with outcome

Aim

To describe changes in the proportion of bystanders performing cardiopulmonary resuscitation (CPR) in out of hospital cardiac arrest (OHCA) in Sweden and to study the impact of bystander CPR on ventricular fibrillation and on survival during various times.

Patients and methods

All patients who suffered from OHCA in Sweden in whom CPR was attempted and who were included in the Swedish cardiac arrest register (SCAR) between 1992 and 2005. Crew witnessed cases were excluded.

Results

In all 34,125 patients were included in the survey. Among witnessed OHCA the proportion of patients receiving bystander CPR increased from 40% in 1992 to 55% in 2005 (p < 0.0001). In non-witnessed OHCA the corresponding proportion increased from 22% to 44% (p < 0.0001). There was a significant increase in bystander CPR regardless of age, sex and place. The increase was only found when CPR was performed by lay persons (21% in 1992 to 40% in 2005; p < 0.0001). Bystander CPR was associated with an increased proportion of patients found in a shockable rhythm and a lower number of shocks to receive return of spontaneous circulation. Bystander CPR was associated with a similar increase in survival early and late in the evaluation.

Conclusion

There was a marked increase in bystander CPR in OHCA, when performed by lay persons, during the last 14 years in Sweden. Bystander CPR was associated with positive effects both on ventricular fibrillation and survival.     

Evaluation of pre-arrest morbidity score and prognosis after resuscitation score and other clinical variables associated with in-hospital cardiac arrest in southern Sweden

Objective

To evaluate pre-arrest morbidity score (PAM), prognosis after resuscitation score (PAR) and to identify additional clinical variables associated with survival after in-hospital cardiac arrest (IHCA) treated with cardiopulmonary resuscitation (CPR).

Methods

A retrospective observational study involving all cases of IHCA at Skåne University Hospital Malmö 2007–2010.

Results

Two-hundred-eighty-seven cases of IHCA were identified (61.3% male; mean age 70 years) of whom 20.2% survived until discharge. The odds ratio (95% confidence interval) for death prior to discharge was 6.49 (1.50–28.19) (p = 0.013) for PAM > 6 and 3.88 (1.95–7.73) (p < 0.001) for PAR > 4. At PAM- and PAR-scores >5, specificity exceeded 90%, while sensitivity was only 20–30%. The odds ratio for in-hospital mortality was 0.38 (0.20–0.72) (p = 0.003) for patients with cardiac monitoring, 9.86 (5.08–19.12) (p < 0.001) for non-shockable vs shockable rhythm, 0.32 (0.15–0.69) (p = 0.004) for presence of ST-elevation myocardial infarction (STEMI), 0.27 (0.09–0.78) (p = 0.016) for patients with independent Activities of Daily Life (ADL) and 13.86 (1.86–103.46) (p = 0.010) for patients with malignancies. Heart rate (HR) on admission (per bpm) [1.024 (1.009–1.040) (p = 0.002)] and sodium plasma concentration on admission (per mmol l⁻¹) [0.92 (0.85–0.99) (p = 0.023)] were significantly associated with in-hospital mortality.

Conclusion

PAM- and PAR-scores do not sufficiently discriminate between in-hospital death and survival after IHCA to be used as clinical tools guiding CPR decisions. We confirm that malignancy is associated with increased in-hospital mortality, and cardiac monitoring, shockable rhythm, STEMI and independent ADL, with decreased in-hospital mortality. Interestingly, our results suggest that HR and plasma sodium concentration upon admission may represent new tools for risk stratification.     

Pulse pressure as a prognostic marker in patients receiving extracorporeal life support

Background

It is not easy to predict the prognosis of patients receiving extracorporeal life support (ECLS) because of the highly variable situation around its implementation. We evaluated the role of pulse pressure (PP), which is available on real-time basis, as a hemodynamic prognostic marker during ECLS.

Methods

From January 2009 to August 2011, data from 69 patients who were treated with ECLS for at least 6 h in a single center for any cause was collected. We calculated the mean PP over the first 6 h after ECLS implantation and examined if there was any correlation between mean PP and the study endpoints, in-hospital death and ECLS weaning failure.

Results

The causes of ECLS were of cardiac origin in 36 patients (52%). 27 patients (39.1%) weaned off ELCS and 13 patients (18.8%) survived to discharge. In Cox regression analysis (with age, Killip class ≥3, ECLS implementation during cardiopulmonary resuscitation (CPR), CPR duration, out-of-hospital arrest, initial laboratory results including blood gas analysis, initial systolic blood pressure (SBP), mean SBP over the first 6 h after ECLS implantation, mean PP over the first 6 h after ECLS implantation as independent variables), mean PP over the first 6 h after ECLS implantation (hazard ratio [95% confidence interval] = 0.96[0.94–0.98], P < 0.001) and out-of-hospital arrest (HR[95%CI] = 2.04[1.14–3.62], P = 0.02) were independent predictors of in-hospital mortality and mean PP over the first 6 h after ECLS implantation (HR[95% CI] = 0.95[0.93–0.98], P < 0.001) was the sole independent predictor of weaning failure.

Conclusion

Higher mean PP over the initial 6 h after ECLS implementation independently predicted successful weaning and survival. Our findings may help better predict and analyze prognosis in patients receiving ECLS.     

Comparison of Medical Priority Dispatch (MPD) and Criteria Based Dispatch (CBD) relating to cardiac arrest calls

Background

Prompt emergency medical service (EMS) system activation with rapid delivery of pre-hospital treatment is essential for patients suffering out-of-hospital cardiac arrest (OHCA). The two most commonly used dispatch tools are Medical Priority Dispatch (MPD) and Criteria Based Dispatch (CBD). We compared cardiac arrest call processing using these two dispatch tools in two different dispatch centres.

Methods

Observational study of adult EMS confirmed (non-EMS witnessed) OHCA calls during one year in Richmond, USA (MPD) and Oslo, Norway (CBD). Patients receiving CPR prior to call, interrupted calls or calls where the caller did not have access to the patients were excluded from analysis. Dispatch logs, ambulance records and digitalized dispatcher and caller voice recordings were compared.

Results

The MPDS-site processed 182 cardiac arrest calls and the CBD-site 232, of which 100 and 140 calls met the inclusion criteria, respectively. The recognition of cardiac arrest was not different in the MPD and CBD systems; 82% vs. 77% (p = 0.42), and pre-EMS arrival CPR instructions were offered to 81% vs. 74% (p = 0.22) of callers, respectively. Time to ambulance dispatch was median (95% confidence interval) 15 (13, 17) vs. 33 (29, 36) seconds (p < 0.001) and time to chest compression delivery; 4.3 (3.7, 4.9) vs. 3.7 (3.0, 4.1) min for the MPD and CBD systems, respectively (p = 0.05).

Conclusion

Pre-arrival CPR instructions were offered faster and more frequently in the CBD system, but in both systems chest compressions were delayed 3–4 min. Earlier recognition of cardiac arrest and improved CPR instructions may facilitate earlier lay rescuer CPR.     

Myocardial infarction is a frequent cause of exercise-related resuscitated out-of-hospital cardiac arrest in a general non-athletic population

Background

Performing exercise is shown to prevent cardiovascular disease, but the risk of an out-of-hospital cardiac arrest (OHCA) is temporarily increased during strenuous activity. We examined the etiology and outcome after successfully resuscitated OHCA during exercise in a general non-athletic population.

Methods

Consecutive patients with OHCA were admitted with return of spontaneous circulation (ROSC) or on-going resuscitation at hospital arrival (2002–2011). Patient charts were reviewed for post-resuscitation data. Exercise was defined as moderate/vigorous physical activity.

Results

A total of 1393 OHCA-patients were included with 91(7%) arrests occurring during exercise. Exercise-related OHCA-patients were younger (60 ± 13 vs. 65 ± 15, p < 0.001) and predominantly male (96% vs. 69%, p < 0.001). The arrest was more frequently witnessed (94% vs. 86%, p = 0.02), bystander CPR was more often performed (88% vs. 54%, p < 0.001), time to ROSC was shorter (12 min (IQR: 5–19) vs. 15 (9–22), p = 0.007) and the primary rhythm was more frequently shock-able (91% vs. 49%, p < 0.001) compared to non-exercise patients. Cardiac etiology was the predominant cause of OHCA in both exercise and non-exercise patients (97% vs. 80%, p < 0.001) and acute coronary syndrome was more frequent among exercise patients (59% vs. 38%, p < 0.001). One-year mortality was 25% vs. 65% (p < 0.001), and exercise was even after adjustment associated with a significantly lower mortality (HR = 0.40 (95%CI: 0.23–0.72), p = 0.002).

Conclusions

OHCA occurring during exercise was associated with a significantly lower mortality in successfully resuscitated patients even after adjusting for confounding factors. Acute coronary syndrome was more common among exercise-related cardiac arrest patients.     

Dispatcher-assisted bystander cardiopulmonary resuscitation in a metropolitan city: A before–after population-based study

Background

The goal of this study was to determine the effects of dispatcher-assisted bystander cardiopulmonary resuscitation (DA-CPR) on outcomes of out-of-hospital cardiac arrest (OHCA).

Methods

All EMS in a metropolitan city with a population of 10 million are dispatched by a single, centralized, and physician-supervised center. Data on patients with adult OHCA with cardiac etiology were collected from the dispatch center registry and from EMS run sheets and hospital medical record review from 2009 to 2011. A standardized DA-CPR protocol (aligned with the 2010 AHA guidelines) we implemented as an intervention in January 2011. The end points were survival to discharge, good neurological outcome, and bystander CPR rate. Multivariate logistic analysis was used to compare between intervention group (2011) and historical control group (2009–2010).

Results

Of 8.144 eligible patients, bystander CPR was performed for the patients in 5.7% (148/2600) of cases in 2009, 6.7% (190/2857) in 2010, and 12.4% (334/2686) in 2011 (p < 0.001). The survival to discharge rates was 7.1% (2009), 7.1% (2010), and 9.4% (2011) (p = 0.001). Good neurological outcomes occurred in 2.1% (2009), 2.0% (2010), and 3.6% (2011) of cases (p < 0.001). The adjusted ORs (95% CIs) for survival to discharge compared with 2009 were 1.33 (1.07–1.66) in 2011 and 1.12 (0.89–1.41) in 2010. The adjusted ORs (95% CIs) for good neurological outcomes were 1.67 (1.13–2.45) in 2011 and 1.13 (0.74–1.72) in 2010.

Conclusions

An EMS intervention using the DA-CPR protocol was associated with a significant increase in bystander CPR and an improved survival and neurologic outcome after OHCA.     

Diurnal variations in incidence and outcome of out-of-hospital cardiac arrest including prior comorbidity and pharmacotherapy: A nationwide study in Denmark

Aim

To investigate diurnal variations in incidence and outcomes following out-of-hospital cardiac arrest (OHCA).

Methods

OHCA of presumed cardiac etiology were identified through the nationwide Danish Cardiac Arrest Registry (2001–2010). Time of day was divided into three time periods: daytime 07.00–14.59; evening 15.00–22.59; and nighttime 23.00–06.59.

Results

We identified 18,929 OHCA patients, aged ≥18 years. The median age was 72 years (IQR 62–80) and the majority were male (67.5%). OHCA occurrence varied across time periods, with 43.9%, 35.7% and 20.6% occurring during daytime, evening and nighttime, respectively. Nighttime patients were more likely to have: severe comorbidity (i.e. COPD), arrest in private home (87.2% vs. 69.0% and 73.0% daytime and evening, respectively), non-witnessed arrest (51.2% vs. 48.4% and 43.7%), no bystander CPR (75.9% vs. 68.4% and 66.1%), longer time interval from recognition of OHCA to rhythm analysis (12 min vs. 11 min and 11 min), and non-shockable heart rhythm (80.1% vs. 70.3% and 69.4%), all p < 0.0001. Nighttime patients were less likely to achieve return of spontaneous circulation on arrival at the hospital (7.5% vs. 14.8% and 15.1%) and 1-year survival (2.8% vs. 7.2% and 7.1%), p < 0.0001. Overall, the lower 1-year survival rate persisted after adjusting for patient-related and cardiac-arrest related characteristics mentioned above (OR 0.47, 95%CI 0.37–0.59; OR 0.51, 95%CI 0.40–0.65, compared to daytime and evening, respectively).

Conclusions

We found nighttime patients to have a lower survival compared to daytime and evening that persisted when adjusting for patient-related and cardiac-arrest related characteristics including comorbidities.     

Chest compression-only cardiopulmonary resuscitation performed by lay rescuers for adult out-of-hospital cardiac arrest due to non-cardiac aetiologies

Objective

Bystander CPR improves survival in patients with out-of-hospital cardiac arrest (OHCA). For adult sudden collapse, bystander chest compression-only CPR (COCPR) is recommended in some circumstances by the American Heart Association and European Resuscitation Council. However, adults who arrest from non-cardiac causes may also receive COCPR. Because rescue breathing may be more important for individuals suffering OHCA secondary to non-cardiac causes, COCPR is not recommended for these cases. We evaluated the relationship of lay rescuer COCPR and survival after OHCA from non-cardiac causes.

Methods

Analysis of a statewide Utstein-style registry of adult OHCA, during a large scale campaign endorsing COCPR for OHCA from presumed cardiac cause. The relationship between lay rescuer CPR (both conventional CPR and COCPR) and survival to hospital discharge was evaluated.

Results

Presumed non-cardiac aetiologies of OHCA accounted for 15% of all cases, and lay rescuer CPR was provided in 29% of these cases. Survival to hospital discharge occurred in 3.8% after conventional CPR, 2.7% after COCPR, and 4.0% after no CPR (p = 0.85). The proportion of patients receiving COCPR was much lower in the cohort of OHCA from respiratory causes (8.3%) than for those with presumed cardiac OHCA (18.0%; p < 0.001).

Conclusions

In the setting of a campaign endorsing lay rescuer COCPR for cardiac OHCA, bystanders were less likely to perform COCPR on OHCA victims who might benefit from rescue breathing.     

Prodromal symptoms and health care consumption prior to out-of-hospital cardiac arrest in patients without previously known ischaemic heart disease

Aims

To describe prodromal symptoms and health care consumption prior to an out-of-hospital cardiac arrest (OHCA) in patients without previously known ischaemic heart disease (IHD).

Background

The most common lethal event of cardiovascular disease is sudden cardiac death, and the majority occur outside hospital. Little is known about prodromal symptoms and health care consumption associated with OHCAs.

Design

Case-crossover study.

Methods

Medical records of 403 OHCA cases without previously known IHD, age 25–74 years in the MONICA myocardial registry in Norrbotten County 2000–2008, were reviewed. Presenting symptoms and emergency visits at public primary care facilities and internal medicine clinics in Norrbotten County were analyzed from the week prior to the OHCA and from the same week one year previously, which served as a control week. Unlike most studies we included unwitnessed arrests and those where no cardiopulmonary resuscitation (CPR) was attempted.

Results

Emergency visits were more common during the week prior to the OHCA than during the control week, both for visits to primary care (29 vs. 6, p < 0.001) and to internal medicine clinics (16 vs. 0, p < 0.001). Symptoms were more prevalent during the week prior to the OHCA (36.7 vs. 6.7%, p < 0.001). The most prevalent symptoms were chest pain (14.6 vs. 0%, p < 0.001), gastrointestinal symptoms (7.7 vs. 1.2%, p < 0.001) and dyspnoea/peripheral oedema (6.9 vs. 0.2%, p < 0.001).

Conclusions

Patients who suffer an OHCA seek health care and present prodromal symptoms significantly more often the week prior to the event than the same week one year earlier.     

Validity of reported data in the Swedish Cardiac Arrest Register in selected parts in Sweden

Aim

To describe differences and similarities between reported and non-reported data in the Swedish Cardiac Arrest Register in selected parts in Sweden.

Methods

Prospective and retrospective data for treated OHCA patients in Sweden, 2008–2010, were compared in the Swedish Cardiac Arrest Register. Data were investigated in three Swedish counties, which represented one third of the population. The recording models varied. Prospective data are those reported by the emergency medical service (EMS) crews, while retrospective data are those missed by the EMS crews but discovered afterwards by cross-checking with the local ambulance register.

Result

In 2008–2010, the number of prospectively (n = 2398) and retrospectively (n = 800) reported OHCA cases was n = 3198, which indicates a 25% missing rate.When comparing the two groups, the mean age was higher in patients who were reported retrospectively (69 years vs. 67 years; p = 0.003). There was no difference between groups with regard to gender, time of day and year of OHCA, witnessed status or initial rhythm. Bystander cardiopulmonary resuscitation (CPR) was more frequent among patients who were reported prospectively (65% vs. 60%; p = 0.023), whereas survival to one month was higher among patients who were reported retrospectively (9.2% vs. 11.9%; p = 0.035).

Conclusion

Among 3198 cases of OHCA in three counties in Sweden, 800 (25%) were not reported prospectively by the EMS crews but were discovered retrospectively as missing cases. Patients who were reported retrospectively differed from prospectively reported cases by being older, having less frequently received bystander CPR but having a higher survival rate. Our data suggest that reports on OHCA from national quality registers which are based on prospectively recorded data may be influenced by selection bias.     

Cardiac arrest due to drowning—Changes over time and factors of importance for survival

Aim

To evaluate changes in characteristics and survival over time in out-of-hospital cardiac arrest (OHCA) due to drowning and describe factors of importance for survival.

Method

Retrospectively reported and treated drowning cases reported to the Swedish OHCA registry between 1990 and 2012, n = 529. The data were clustered into three seven-year intervals for comparisons of changes over time.

Results

There were no changes in age, gender, witnessed status, shockable rhythm or place of OHCA during the time periods. Bystander CPR increased over time, 59% in interval 1992–1998, versus 74% in interval 2006–2012 (p = 0.005). There was a decrease in delay between OHCA and calling for the Emergency Medical Service (EMS) over the years, while calling for the EMS to arrival increased in terms of time. Survival to hospital admission appears to have increased over the years (p = 0.009), whereas survival to one month did not change significantly over time. In a multivariate analysis, witnessed status, female gender, bystander CPR, place–home and EMS response time were associated with survival to hospital admission. For survival to one month, place, age, shockable rhythm and logarithmised delay from calling for an ambulance to arrival were of significance for survival.

Conclusion

In OHCA due to drowning, over a period of 20 years, bystanders have called for help at an earlier stage and administered CPR more frequently in the past few years. Survival to hospital admission has increased, while shockable rhythm and early arrival of the EMS appear to be the most important factors for survival to one month.     

Early coronary revascularization improves 24 h survival and neurological function after ischemic cardiac arrest. A randomized animal study

Background

Survival after out-of-hospital cardiac arrest (OHCA) remains poor. Acute coronary obstruction is a major cause of OHCA. We hypothesize that early coronary reperfusion will improve 24 h-survival and neurological outcomes.

Methods

Total occlusion of the mid LAD was induced by balloon inflation in 27 pigs. After 5 min, VF was induced and left untreated for 8 min. If return of spontaneous circulation (ROSC) was achieved within 15 min (21/27 animals) of cardiopulmonary resuscitation (CPR), animals were randomized to a total of either 45 min (group A) or 4 h (group B) of LAD occlusion. Animals without ROSC after 15 min of CPR were classified as refractory VF (group C). In those pigs, CPR was continued up to 45 min of total LAD occlusion at which point reperfusion was achieved. CPR was continued until ROSC or another 10 min of CPR had been performed. Primary endpoints for groups A and B were 24-h survival and cerebral performance category (CPC). Primary endpoint for group C was ROSC before or after reperfusion.

Results

Early compared to late reperfusion improved survival (10/11 versus 4/10, p = 0.02), mean CPC (1.4 ± 0.7 versus 2.5 ± 0.6, p = 0.017), LVEF (43 ± 13 versus 32 ± 9%, p = 0.01), troponin I (37 ± 28 versus 99 ± 12, p = 0.005) and CK-MB (11 ± 4 versus 20.1 ± 5, p = 0.031) at 24-h after ROSC. ROSC was achieved in 4/6 animals only after reperfusion in group C.

Conclusions

Early reperfusion after ischemic cardiac arrest improved 24 h survival rate and neurological function. In animals with refractory VF, reperfusion was necessary to achieve ROSC.     

Neurologic outcome in comatose patients resuscitated from out-of-hospital cardiac arrest with prolonged downtime and treated with therapeutic hypothermia

Background

Previous reports have shown that prolonged duration of resuscitation efforts in out-of-hospital cardiac arrest (OHCA) is associated with poor neurologic outcome. This concept has recently been questioned with advancements in post-cardiac arrest care including the use of therapeutic hypothermia (TH). The aim of this study was to determine the rate of good neurologic outcome based on the duration of resuscitation efforts in OHCA patients treated with TH.

Methods

This prospective, observational, study was conducted between January 2008 and September 2012. Inclusion criteria consisted of adult non-traumatic OHCA patients who were comatose after return of spontaneous circulation (ROSC) and received TH. The primary endpoint was good neurologic outcome defined as a cerebral performance category score of 1 or 2. Downtime was calculated as the length of time between the patient being recognized as pulseless and ROSC.

Results

105 patients were treated with TH and 19 were excluded due to unknown downtime, leaving 86 patients for analysis. The median downtime was 18.5 (10.0–32.3) min and 33 patients (38.0%) had a good neurologic outcome. When downtime was divided into four groups (≤10 min, 11–20 min, 21–30 min, >30 min), good neurologic outcomes were 62.5%, 37%, 25%, and 21.7%, respectively (p = 0.02). However, even with downtime >20 min, 22.9% had a good neurologic outcome, and this percentage increased to 37.5% in patients with an initial shockable rhythm.

Conclusions

Although longer downtime is associated with worse outcome in OHCA patients, we found that comatose patients who have been successfully resuscitated and treated with TH have neurologically intact survival rates of 23% even with downtime >20 min.     

The impact of partial resuscitation attempts on the reported outcomes of out-of-hospital cardiac arrest in Victoria,Australia: Implications for Utstein-style outcome reports

Background

Success rates from cardiopulmonary resuscitation (CPR) are often quantified by Utstein-style outcome reports in populations who receive an attempted resuscitation. In some cases, evidence of futility is ascertained after a partial resuscitation attempt has been administered, and these cases reduce the overall effectiveness of CPR. We examine the impact of partial resuscitation attempts on the reported outcomes of out-of-hospital cardiac arrest (OHCA) in Victoria, Australia.

Methods

Between 2002 and 2012, 34,849 adult OHCA cases of presumed cardiac aetiology were included from the Victorian Ambulance Cardiac Arrest Registry. Resuscitation attempts lasting ≤10 min in cases which died on scene were defined as a partial resuscitation. We used logistic regression to identify factors associated with a partial resuscitation attempt in the emergency medical service (EMS) treated population. Survival outcomes with and without partial resuscitations were compared across included years.

Results

The proportion of partial resuscitations in the overall EMS treated population increased significantly from 8.6% in 2002 to 18.8% in 2012 (p for trend < 0.001), and were largely supported by documented evidence of irreversible death. Partial resuscitations were independently associated with older age, female gender, initial non-shockable rhythm, prolonged downtime, and lower skill level of EMS personnel. Selectively excluding partial resuscitations increased event survival by 7.6% (95% CI 4.1–11.2%), and survival to hospital discharge increased by 3.1% (95% CI 0.5–5.7%) in 2012 (p < 0.001 for both).

Conclusion

In our EMS system, evidence of futility was often identified after the commencement of a partial resuscitation attempt. Excluding these events from OHCA outcome reports may better reflect the overall effectiveness of CPR.     

Reduced in-hospital survival rates of out-of-hospital cardiac arrest victims with obstructive pulmonary disease

Aim

Out-of-hospital cardiac arrest (OHCA) due to sustained ventricular tachycardia/fibrillation (VT/VF) is common and often lethal. Patient's co-morbidities may determine survival after OHCA, and be instrumental in post-resuscitation care, but are poorly studied. We aimed to study whether patients with obstructive pulmonary disease (OPD) have a lower survival rate after OHCA than non-OPD patients.

Methods

We performed a community-based cohort study of 1172 patients with non-traumatic OHCA with ECG-documented VT/VF between 2005 and 2008. We compared survival to Emergency Room (ER), to hospital admission, to hospital discharge, and at 30 days after OHCA, of OPD-patients and non-OPD patients, using logistic regression analysis. We also compared 30-day survival of patients who were admitted to hospital, using multivariate logistic regression analysis.

Results

OPD patients (n = 178) and non-OPD patients (n = 994) had comparable survival to ER (75% vs. 78%, OR 0.9 [95% CI: 0.6–1.3]) and to hospital admission (56% vs. 57%, OR 1.0 [0.7–1.4]). However, survival to hospital discharge was significantly lower among OPD patients (21% vs. 33%, OR 0.6 [0.4–0.9]). Multivariate regression analysis among patients who were admitted to hospital (OPD: n = 100, no OPD: n = 561) revealed that OPD was an independent determinant of reduced 30-day survival rate (39% vs. 59%, adjusted OR 0.6 [0.4–1.0, p = 0.035]).

Conclusion

OPD-patients had lower survival rates after OHCA than non-OPD patients. Survival to ER and to hospital admission was not different between both groups. However, among OHCA victims who survived to hospital admission, OPD was an independent determinant of reduced 30-day survival rate.