Survival in out-of-hospital cardiac arrests with initial asystole or pulseless electrical activity and subsequent shockable rhythms

Background

Non-shockable arrest rhythms (pulseless electrical activity and asystole) represent an increasing proportion of reported cases of out-of-hospital cardiac arrest (OHCA). The prognostic significance of conversion from non-shockable to shockable rhythms during the course of resuscitation remains unclear.

Objective

To evaluate whether out-of-hospital cardiac arrest survival with initially non-shockable arrest rhythms is improved with subsequent conversion to shockable rhythms.

Methods

Secondary analysis of data in Epistry – Cardiac Arrest, an epidemiologic registry maintained by the Resuscitation Outcomes Consortium (ROC). This analysis includes OHCA events from December 1, 2005 through May 31, 2007 contributed by six US and two Canadian sites. For all EMS-treated adult (18 and older) cardiac arrest patients who presented with non-shockable cardiac arrest, we compared survival to hospital discharge between patients who did develop a shockable rhythm and those who did not based on receipt of subsequent defibrillation. Missing data were handled using multiple imputation. Multivariable logistic regression was used to adjust for potentially confounding variables.

Results

A total of 6556 EMS treated adult cardiac arrest cases presented in non-shockable rhythms. Survival to discharge in patients who converted to a shockable rhythm was 2.77% while survival in those who did not was 2.72% (p = 0.92). After adjusting for confounders, conversion to a shockable rhythm was not associated with improved survival (OR 0.88, 95% CI: 0.60–1.30).

Conclusion

For OHCA patients presenting in PEA/asystole, survival to hospital discharge was not associated with conversion to a shockable rhythm during EMS resuscitation efforts.     

Out-of-hospital cardiac arrest outcomes stratified by rhythm analysis

Background

Survival data for out-of-hospital cardiac arrest (OHCA) victims initially in PEA or asystole who convert to a shockable rhythm during attempted resuscitation, relative to an initial shockable rhythm, have never been previously reported. This study was done to assess OHCA outcomes among a large cohort of adults in the CARES dataset stratified by three rhythm categories: initial shockable (IS), converted shockable (CS), and never shockable (NS).

Methods

The study was IRB approved. All adult index events at participating sites (2005–2010) were study eligible. All patient data elements were provided. Odds ratios of CS and NS status for survival to hospital discharge were calculated via multivariate logistic regression that adjusted for demographics, site, resuscitation initiators, AED use, and other covariates.

Results

There were 40,274 OHCA records submitted to the CARES registry during the study period. After exclusions, our final sample size was 30,939 (7404 IS [23.9%], 3225 CS [10.4%], 20,310 NS [65.7%]). Raw survival rates of CS and NS patients were similar (4.7% vs. 4.1%, respectively; p = 0.08) but significantly lower than IS patients (26.9%; p < 0.001). The adjusted OR of survival to hospital discharge for CS was 0.17 (95%CI: 0.14, 0.20) and for NS it was 0.17 (95%CI: 0.15, 0.18) with IS as the referent.

Conclusion

After OHCA, the survival rate for CS victims is significantly lower than for IS patients. These findings suggest that CS and IS are different entities and that alternatives to existing resuscitation algorithm tailored to patients with CS should be investigated.     

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.     

Systematic downloading and analysis of data from automated external defibrillators used in out-of-hospital cardiac arrest

Background

Valuable information can be retrieved from automated external defibrillators (AEDs) used in victims of out-of-hospital cardiac arrest (OHCA). We describe our experience with systematic downloading of data from deployed AEDs. The primary aim was to compare the proportion of shockable rhythm from AEDs used by laypersons with the corresponding proportion recorded by the Emergency Medical Services (EMS) on arrival.

Methods

In a 20-month study, we collected data on OHCAs in the Capital Region of Denmark where an AED was deployed prior to arrival of EMS. The AEDs were brought to the emergency medical dispatch centre for data downloading and rhythm analysis. Patient data were retrieved from the medical records from the admitting hospital, whereas data on EMS rhythm analyses were obtained from the Danish Cardiac Arrest Register between 2001 and 2010.

Results

A total of 121 AEDs were deployed, of which 91 cases were OHCAs with presumed cardiac origin. The prevalence of initial shockable rhythm was 55.0% (95% CI [44.7–64.8%]). This was significantly greater than the proportion recorded by the EMS (27.6%, 95% CI [27.0–28.3%], p < 0.0001). Shockable arrests were significantly more likely to be witnessed (92% vs. 34%, p < 0.0001) and the bystander CPR rate was higher (98% vs. 85%, p = 0.04). More patients with initial shockable rhythm achieved return of spontaneous circulation upon hospital arrival (88% vs. 7%, p < 0.0001) and had higher 30-day survival rate (72% vs. 5%, p < 0.0001).

Conclusion

AEDs used by laypersons revealed a higher proportion of shockable rhythms compared to the EMS rhythm analyses.     

Compressions during defibrillator charging shortens shock pause duration and improves chest compression fraction during shockable out of hospital cardiac arrest

Background

Previous studies have demonstrated significant relationships between shock pause duration and survival to hospital discharge from shockable out-of hospital (OHCA) cardiac arrest. Compressions during defibrillator charging (CDC) has been proposed as a technique to shorten shock pause duration.

Objective

We sought to determine the impact of CDC on shock pause duration and CPR quality measures in shockable OHCA.

Methods

We performed a retrospective review of all treated adult OHCA occurring over a 1 year period beginning August 1, 2011 after training EMS agencies in CDC. We included OHCA patients with an initial shockable rhythm, available CPR process data and shock pause data for up to the first three shocks of the resuscitation. CDC by EMS personnel was confirmed by review of impedance channel measures. We evaluated the relationship between CDC and shock pause duration as the primary outcome measure. Secondary outcome measures investigated the association between CDC and CPR quality measures.

Results

Among 747 treated OHCA 149 (23.4%) presented in a shockable rhythm of which 129 (81.6%) met study inclusion criteria. Seventy (54.2%) received CDC. There was no significant difference between the CDC and no CDC group with respect to Utstein variables. Median pre-shock pause (15.0 vs. 3.5 s; Δ 11.5; 95% CI: 6.81, 16.19), post-shock pause (4.0 vs. 3.0 s; Δ 1.0; 95% CI: −2.57, 4.57), and peri-shock pause (21.0 vs. 9.0 s; Δ 12.0; 95% CI: 5.03, 18.97) were all lower for those who received CDC. Mean chest compression fraction was significantly greater (0.77 vs. 0.70, Δ 0.07; 95% CI: 0.03, 0.11) with CDC. No significant difference was noted in compression rate or depth with CDC. Clinical outcomes did not differ between the two approaches (return of spontaneous circulation 62.7% vs. 62.9% p = 0.98, survival 25.4% vs. 27.1% p = 0.82), although the study was not powered to detect clinical outcome differences.

Conclusions

Compressions during defibrillator charging may shorten shock pause duration and improves chest compression fraction in shockable OHCA. Given the impact on shock pause duration, further study with a larger sample size is required to determine the impact of this technique on clinical outcomes from shockable OHCA.     

Females of childbearing age have a survival benefit after out-of-hospital cardiac arrest

Background

There is controversy regarding the association between age and being female and survival to hospital discharge after out-of-hospital cardiac arrest (OHCA). We hypothesized that younger females (aged 12–49 years) would be independently associated with increased survival after OHCA when compared to other age and sex groups.

Methods

We conducted a secondary analysis of prospectively collected data from 29 United States cities that participate in the Cardiac Arrest Registry to Enhance Survival (CARES). Patients were included if they were ≥12 years of age and had a documented resuscitation attempt from October 1, 2005 through December 31, 2009. Hierarchical multivariable logistic regression analyses were used to estimate the associations between age and sex groups and survival to hospital discharge.

Results

Females were less likely to have a cardiac arrest in public, was witnessed, or was treatable with defibrillation. Females in the 12–49 year old age group had a similar proportion of survival to hospital discharge when compared to age-matched males (females 11.6% vs. males 11.2%), while males ≥50 years old were more likely to survive when compared to age matched females (females 6.9% vs. males 9.6%). Age stratified regression models demonstrated that 12–49 year old females had the largest association with survival to hospital discharge (OR 1.55, 95% CI 1.20–2.00), while females in the ≥50 year old age group had a smaller increased odds of survival to hospital discharge (OR 1.18, 95% CI 1.03–1.35), which only lasted until the age of 55 years (OR 1.12, 95% CI 0.97–1.29).

Conclusions

Younger aged females were associated with increased odds of survival despite being found with poorer prognostic arrest characteristics.     

Use and benefits of public access defibrillation in a nation-wide network

Background

Automated External Defibrillators (AEDs) are known to increase survival after out-of-hospital cardiac arrest (OHCA). The aim of this study was to examine the use and benefit of public-access defibrillation (PAD) in a nation-wide network. We primarily sought to assess survival at 1 month but information about the circumstances of each OHCA is provided as well.

Methods

In this 28-month study, we assessed the use of 807 AEDs in Denmark. When an AED was deployed information about the circumstances of OHCA, the bystander, the AED and the victim's condition was obtained.

Results

An AED was connected to an OHCA victim prior to the arrival of Emergency Medical Services (EMS) in 48 instances. Ten percent of bystanders were off-duty healthcare professionals. Shockable arrests (N = 31, 70%) were significantly more likely to be witnessed (94% vs. 54%) to occur at sports facilities (74% vs. 31%), in relation to exercise (42% vs. 0%), and with improved 30-day survival (69% vs. 15%, p = 0.001). Among those presenting with a shockable rhythm, 20 (65%) had Return of Spontaneous Circulation upon arrival of EMS and 8 (26%) were conscious, which emphasizes the diagnostic value of ECG downloads from AEDs. Survival could be determined in 42 of 44 patients with OHCA of cardiac origin, and was 52% (n = 22, 95% CI [38–67]) and the Cerebral Performance Category was 1 (Good Cerebral Performance) in all survivors.

Conclusion

With a 30-day neurologically intact survival of 69% for patients with shockable rhythms, this study provides further evidence of the lifesaving potential of PAD.     

Drowning related out-of-hospital cardiac arrests: Characteristics and outcomes

Aim

There are few studies on drowning-related out-of-hospital cardiac arrest (OHCA) in which patients are followed from the scene through to hospital discharge. This study aims to describe this population and their outcomes in the state of Victoria (Australia).

Methods

The Victorian Ambulance Cardiac Arrest Registry was searched for all cases of OHCA with a precipitating event of drowning attended by emergency medical services (EMS) between October 1999 and December 2011.

Results

EMS attended 336 drowning-related OHCA during the study period. Cases frequently occurred in summer (45%) and the majority of patients were male (70%) and adult (77%). EMS resuscitation was attempted on 154 (46%) patients. Of these patients, 41 (27%) survived to hospital arrival and 12 (8%) survived to hospital discharge (5 adults [6%] and 7 [12%] children). Few patients were found in a shockable rhythm (6%), with the majority presenting in asystole (79%) or pulse-less electrical activity (13%). An initial shockable rhythm was found to positively predict survival (AOR 48.70, 95% CI: 3.80–624.86) while increased EMS response time (AOR 0.73, 95% CI: 0.54–0.98) and salt water drowning (AOR 0.69, 95% CI: 0.01–0.84) were found to negatively predict survival.

Conclusions

Rates of survival in OHCA caused by drowning are comparable to other OHCA causes. Patients were more likely to survive if they did not drown in salt water, had a quick EMS response and they were found in a shockable rhythm. Prevention efforts and reducing EMS response time are likely to improve survival of drowning patients.     

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.     

Good outcome in every fourth resuscitation attempt is achievable--an Utstein template report from the Stavanger region

Aim of the study

Out-of-hospital cardiac arrest (OHCA) is a major cause of death in the western world. We wanted to study changes in survival over time and factors linked to this in a region which have already reported high survival rates.

Methods

We used a prospectively collected Utstein template database to identify all resuscitation attempts in adult patients with OHCA of presumed cardiac origin. We included 846 resuscitation attempts and compared survival to discharge with good outcome in two time periods (2001-2005 vs. 2006-2008).

Results

We found no significant differences between the two time periods for mean age (71 and 70 years (p = 0.309)), sex distribution (males 70% and 71% (p = 0.708)), location of the OHCA (home 64% and 63% (p = 0.732)), proportion of shockable rhythms (44% and 47% (p = 0.261)) and rate of return of spontaneous circulation (38% and 43% (p = 0.136)), respectively. Bystander cardiopulmonary resuscitation (CPR), however, increased significantly from 60% to 73% (p < 0.0001), as did the overall rate of survival to discharge from 18% to 25% (p = 0.018). In patients with a shockable first rhythm, rate of survival to discharge increased significantly from 37% to 48% (p = 0.036). In witnessed arrest with shockable rhythm survival to discharge increased from 37% to 52% (p = 0.0105).

Conclusion

Overall, good outcome is now achievable in every fourth resuscitation attempt and in every second resuscitation attempt when patients have a shockable rhythm. The reason for the better outcomes is most likely multi-factorial and linked to improvements in the local chain of survival.     

Resuscitation of patients suffering from sudden cardiac arrests in nursing homes is not futile

Background

Survival after out-of-hospital cardiac arrest (OHCA) has increased in recent years, and new data are therefore needed to avoid unsubstantiated statements when debating futility of resuscitation attempts following OHCA in nursing home (NH)-residents. We aimed to investigate the outcome and prognosis after OHCA in NH.

Methods

Consecutive Emergency Medical Service (EMS) attended OHCA-patients in Copenhagen during 2007–2011 were included. Utstein-criteria for pre-hospital data and review of individual patient charts for in-hospital post-resuscitation care were collected.

Results

A total of 2541 consecutive OHCA-patients were recorded, 245 (10%) of who were current NH-residents. NH-patients were older, more frequently female, had more witnessed arrests, fewer shockable primary rhythm and assumed cardiac aetiology, but shorter time to the return of spontaneous circulation (ROSC) compared to OHCA in non-nursing homes (non-NH). Overall 30-day survival rate was 9% in NH and 18% in non-NH, p < 0.001. Of the 245 NH-arrests 79 (32%) patients were admitted to hospital compared to 937 (41%) from non-NH (p < 0.001). Thirty-day survival rate in patients admitted to hospital were 27% for NH- and 42% for non-NH-patients, p < 0.001. OHCA in NH was, however, not associated with a significantly worse prognosis (HR = 0.88 (0.64–1.21), p = 0.4) after adjustment for known prognostic factors including co-morbidity.

Conclusions

Nursing home residents resuscitated from OHCA and admitted to hospital have similar survival rates as non-NH-patients when adjusting for known prognostic factors and pre-existing co-morbidity. A policy of not attempting resuscitation in nursing homes at all may therefore not be justified.     

Adult Out-of-Hospital Cardiac Arrest Based on Chain of Survival in Taoyuan County,Northern Taiwan

Background

Most out-of-hospital cardiac arrest (OHCA) studies have been conducted in developed countries or metropolitan areas, and few in developing countries or rural areas.

Objectives

The aims of this study were to determine the weak links in the chain of survival and to estimate the outcomes of OHCA patients in Taoyuan, a nonmetropolitan area in Taiwan.

Methods

A retrospective review and analysis of OHCA data was conducted. The three outcomes were whether a return of spontaneous circulation (ROSC) was achieved, whether the patient survived to admission, or whether the patient survived to hospital discharge.

Results

From April to December 2008, 1048 OHCA patients were resuscitated, and 712 (67.9%) adult cardiac patients were used in this study. Among these 712 patients, 17.8% achieved ROSC (95% confidence interval [CI] 15.2–20.8%), 16.3% survived to admission (95% CI 13.6–19.0%), and 1.4% survived to discharge (95% CI 0.5–2.3%). Factors significantly associated with the three outcomes were witness status, response time to emergency medical services, and whether the patient had a shockable rhythm. Bystander cardiopulmonary resuscitation (CPR) did not add a notable benefit to the outcomes of OHCA.

Conclusions

The survival rate of OHCA patients in nonmetropolitan Taiwan was very low (1.4%). Lower witnessed rate, lower bystander CPR rate, and longer response interval in remote areas are the main causes of inferior survival rate.     

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.     

Neurological prognostication by gender in out-of-hospital cardiac arrest patients receiving hypothermia treatment

Objectives

This study examined whether the extent to which out-of-hospital cardiac arrest (OHCA) patients recover neurological function after therapeutic hypothermia (TH) is augmented in specific gender, age, and primary ECG group.

Methods

A cross-sectional analysis was conducted using a nationwide database of OHCAs in Korea which was constructed from emergency medical services (EMS) run sheet and hospital medical record review between 2008 and 2012. Patients survived to admission were enrolled. Study endpoint was survival with neurological recovery (cerebral performance category 1 and 2). Main exposure was hypothermia. Gender, age group (<45, 45–65, and >65 years old) and primary ECG rhythm were considered as potential effect modifiers. Potential factors were accounted for adjustment using multivariable logistic regression.

Results

Survival with good neurological recovery was 14.6% (9.3% in men and 17.2% in women). TH was performed in 15.5% (n = 1140). Strata-specific crude analysis showed enhanced neurological recovery for women of childbearing ages compared to men counterparts (OR = 4.38 (1.39, 13.74) vs. OR = 1.73 (0.97, 3.10)). After adjusted for effect modifiers and covariates, the strongest effect of TH on neurological recovery was observed in men younger than 45 years of age with shockable rhythm (OR = 2.00 (1.26, 3.19)), whereby no statistically significant associations were found in all women. In both genders, the magnitude of association decreased with age and having non-shockable cardiac rhythm.

Conclusion

TH was the strongest indicator for good neurological recovery in <45-year old men with shockable cardiac rhythm. Across all age groups, women were less likely to benefit from TH than men.     

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.     

The effect of time to defibrillation and targeted temperature management on functional survival after out-of-hospital cardiac arrest

Background

Cardiac arrest physiology has been proposed to occur in three distinct phases: electrical, circulatory and metabolic. There is limited research evaluating the relationship of the 3-phase model of cardiac arrest to functional survival at hospital discharge. Furthermore, the effect of post-cardiac arrest targeted temperature management (TTM) on functional survival during each phase is unknown.

Objective

To determine the effect of TTM on the relationship between the time of initial defibrillation during each phase of cardiac arrest and functional survival at hospital discharge.

Methods

This was a retrospective observational study of consecutive adult (≥18 years) out-of-hospital cardiac arrest (OHCA) patients with initial shockable rhythms. Included patients obtained a return of spontaneous circulation (ROSC) and were eligible for TTM. Multivariable logistic regression was used to determine predictors of functional survival at hospital discharge.

Results

There were 20,165 OHCA treated by EMS and 871 patients were eligible for TTM. Of these patients, 622 (71.4%) survived to hospital discharge and 487 (55.9%) had good functional survival. Good functional survival was associated with younger age (OR 0.94; 95% CI 0.93–0.95), shorter times from collapse to initial defibrillation (OR 0.73; 95% CI 0.65–0.82), and use of post-cardiac arrest TTM (OR 1.49; 95% CI 1.07–2.30). Functional survival decreased during each phase of the model (65.3% vs. 61.7% vs. 50.2%, P < 0.001).

Conclusion

Functional survival at hospital discharge was associated with shorter times to initial defibrillation and was decreased during each successive phase of the 3-phase model. Post-cardiac arrest TTM was associated with improved functional survival.     

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.     

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.     

Survival rates in out-of-hospital cardiac arrest patients transported without prehospital return of spontaneous circulation: An observational cohort study

Background

Some Emergency Medical Services currently use just one component of the Universal Termination of Resuscitation (TOR) Guideline, the absence of prehospital return of spontaneous circulation (ROSC), as the single criteria to terminate resuscitation, which may deny transport to potential survivors.

Objective

This study aimed to report the survival to hospital discharge rate in non-traumatic, adult out-of-hospital cardiac arrest (OHCA) patients transported to hospital without a prehospital ROSC.

Methods

An observational study of OHCA patients without a prehospital ROSC who met the Universal TOR Guideline for transport to hospital with ongoing resuscitation. Multivariable logistic regression was used to determine the association of each variable with survival to hospital discharge.

Results

Of 20,207 OHCA treated by EMS, 3374 (16.4%) did not have a prehospital ROSC but met the Universal TOR guideline for transport to hospital with ongoing resuscitation. Of these patients, 122 (3.6%) survived to hospital discharge. Survival to discharge was associated with initial shockable VF/VT rhythms (OR 5.07; 95% CI 2.77–9.30), EMS-witnessed arrests (OR 3.51; 95% CI 1.73–7.15), bystander-witnessed arrests (OR 2.11; 95% CI 1.18–3.77), and public locations (OR 1.57; 95% CI 1.02–2.40).

Conclusion

In OHCA patients without a prehospital ROSC who met the Universal TOR Guideline for transport with ongoing resuscitation survival rates were above the 1% futility rate. Employing only the lack of ROSC as criteria for termination of resuscitation may miss survivors after OHCA.