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.     

Prognostic value of electroencephalography (EEG) after out-of-hospital cardiac arrest in successfully resuscitated patients used in daily clinical practice

Background

Out-of-hospital cardiac arrest (OHCA) is associated with a poor prognosis and predicting outcome is complex with neurophysiological testing and repeated clinical neurological examinations as key components of the assessment. In this study we examine the association between different electroencephalography (EEG) patterns and mortality in a clinical cohort of OHCA-patients.

Methods

From 2002 to 2011 consecutive patients were admitted to an intensive-care-unit after resuscitation from OHCA. Utstein-criteria for pre-hospital data and review of individual patients’ charts for post-resuscitation care were used. EEG reports were analysed according to the 2012 American Clinical Neurophysiology Society's guidelines.

Results

A total of 1076 patients were included, and EEG was performed in 20% (n = 219) with a median of 3(IQR 2–4) days after OHCA. Rhythmic Delta Activity (RDA) was found in 71 patients (36%) and Periodic Discharges (PD) in 100 patients (45%). Background EEG frequency of Alpha+ or Theta was noted in 107 patients (49%), and change in cerebral EEG activity to stimulation (reactivity) was found in 38 patients (17%). Suppression (all activity <10 μV) was found in 26 (12%) and burst-suppression in 17 (8%) patients. A favourable EEG pattern (reactivity, favourable background frequency and RDA) was independently associated with reduced mortality with hazard ratio (HR) 0.43 (95%CI: 0.24–0.76), p = 0.004 (false positive rate: 31%) and a non-favourable EEG pattern (no reactivity, unfavourable background frequency, and PD, suppressed voltage or burst-suppression) was associated with higher mortality (HR = 1.62(1.09–2.41), p = 0.02) after adjustment for known prognostic factors (false positive rate: 9%).

Conclusion

EEG may be useful in work-up in prognostication of patients with OHCA. Findings such as Rhythmic Delta Activity (RDA) seem to be associated with a better prognosis, whereas suppressed voltage and burst-suppression patterns were associated with poor prognosis.     

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.     

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.     

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.     

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.     

The impact of therapeutic hypothermia on neurological function and quality of life after cardiac arrest

Aims

To assess the impact of therapeutic hypothermia on cognitive function and quality of life in comatose survivors of out of Hospital Cardiac arrest (OHCA).

Methods

We prospectively studied comatose survivors of OHCA consecutively admitted in a 4-year period. Therapeutic hypothermia was implemented in the last 2-year period, intervention period (n = 79), and this group was compared to patients admitted the 2 previous years, control period (n = 77). We assessed Cerebral Performance Category (CPC), survival, Mini Mental State Examination (MMSE) and self-rated quality of life (SF-36) 6 months after OHCA in the subgroup with VF/VT as initial rhythm.

Results

CPC in patients alive at hospital discharge was significantly better in the intervention period with a CPC of 1–2 in 97% vs. 71% in the control period, p = 0.003, corresponding to an adjusted odds ratio of a favourable cerebral outcome of 17, p = 0.01. No significant differences were found in long-term survival (57% vs. 56% alive at 30 months), MMSE, or SF-36. Therapeutic hypothermia (hazard ratio: 0.15, p = 0.007) and bystander CPR (hazard ratio 0.19, p = 0.002) were significantly related to survival in the intervention period.

Conclusion

CPC at discharge from hospital was significantly improved following implementation of therapeutic hypothermia in comatose patients resuscitated from OCHA with VF/VT. However, significant improvement in survival, cognitive status or quality of life could not be detected at long-term follow-up.     

Benefit of an early and systematic imaging procedure after cardiac arrest: Insights from the PROCAT (Parisian Region Out of Hospital Cardiac Arrest) registry

Aims

Identification of the cause of out-of-hospital cardiac arrest (OHCA) is of paramount importance. We investigated the ability of our imaging strategy to provide an early etiological diagnosis of OHCA and the influence of this strategy on ICU survival.

Methods

Retrospective review of a prospectively acquired ICU database (01/2000–12/2010) including all OHCA patients without obvious extracardiac cause, for which an early diagnosis research was conducted (coronary angiography and/or brain and chest CT scan) within 24 h after resuscitation. These procedures could be performed separately or be combined, according to a decision algorithm.

Results

Of the 1274 patients admitted after OHCA during this 10-year period, the imaging strategy was applied in 896 patients. Patients who benefited from coronary angiography and/or CT scan were admitted to our ICU after a median delay of 180 [130–220] min after resuscitation. Seven hundred and forty-five coronary angiographies were performed, of which 452 (61%) identified at least one significant coronary lesion deemed responsible for the OHCA. CT-scan was performed in 355 patients and provided a diagnosis in 72 patients (20%), mainly stroke (n = 38) and pulmonary embolism (n = 19). Overall, this strategy allowed early diagnosis in 524 patients (59%). ICU survival was significantly higher for patients with a diagnosis identified by coronary angiography as compared with CT-scan (43% vs 10%, p < 0.001).

Conclusion

The use of an early diagnosis protocol with immediate coronary angiography and/or CT scan provided the etiology of nearly two thirds of OHCA cases. In this large retrospective database, coronary angiography yielded a better diagnostic value than brain and/or chest CT-scan.     

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.     

Early antibiotics improve survival following out-of hospital cardiac arrest

Introduction

Therapeutic hypothermia (TH) has become standard management following out of hospital cardiac arrest (OHCA). Recent evidence suggests TH increases the incidence of pneumonia. We retrospectively assessed infective indicators after OHCA and evaluated the effect of antibiotics on survival.

Method

We identified all patients admitted to the ICU of a regional primary angioplasty hospital following OHCA from May 2007 to December 2010. We collected demographic and outcome data, evidence of infection and the use of antimicrobial therapy.

Results

138 patients were admitted to ICU following OHCA. The mortality rate was 68.1% with mean ICNARC predicted mortality of 77.5%. Of 138 patients, 135 (97.8%) had at least one positive marker of infection within 72 h.53 of 138 patients (38.4%) received antibiotics during the first 7 days of their ICU stay. The hospital mortality rate for these patients was significantly less than those not receiving antibiotics (56.6% vs. 75.3%; p = 0.025) with NNT of 5. Multivariate analysis demonstrated that antibiotic use was an independent predictor of survival.

Conclusion

The post-arrest management of OHCA is commonly complicated by infections, the accurate diagnosis of which is impaired by the associated increase in inflammatory markers, body temperature control, delay in the processing of samples and poor quality chest radiography.We have shown a significant reduction in mortality in patients who received antibiotics compared with patients who did not. This suggests that a formal clinical trial is warranted.     

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.     

A 5-year experience with cardiopulmonary resuscitation using extracorporeal life support in non-postcardiotomy patients with cardiac arrest

Background

Cardiopulmonary resuscitation (CPR) using extracorporeal life support (ECLS) system has been successfully used to support patients with in- and out-of-hospital cardiac arrest (IHCA, OHCA) when conventional measures have failed. The purpose of the current study is to report on our experience with extracorporeal CPR in non-postcardiotomy patients.

Methods

We retrospectively analysed a total of 85 consecutive adult patients, who have been treated with ECLS between January 2007 and January 2012.

Results

The mean CPR duration was 40 min (20–70 min). The mean ECLS support duration was 49 h (12–92 h). Twenty-eight patients (33%) had ECLS related complications. Forty patients (47%) were successfully weaned and 29 patients (34%) survived to hospital discharge. Among survivors, 93% were without severe neurologic deficit. Duration of CPR was shorter for survivors than for non-survivors [(25: 20–50 min) vs. (50: 25–86 min); p = 0.003]. Immediately after ECLS start, the mean blood lactate level was lower (p = 0.003), and the mean pH value was higher in the survivors’ group (p < 0.0001) compared to the non-survivors’ group. The CPR duration for the IHCA group (25: 20–50 min) was shorter compared to the OHCA group (70: 55–110 min; p < 0.0001). The survival rate in this group was higher compared to the OHCA group (42% vs. 15%; p < 0.02).

Conclusions

CPR using modern miniaturized ECLS systems should be established in the treatment of prolonged cardiac arrest and unsuccessful conventional CPR in selected patients. CPR with ECLS for OHCA has worse outcomes compared to IHCA. Duration of CPR was independent risk factor for mortality after extracorporeal CPR.     

Implementation of the ALERT algorithm,a new dispatcher-assisted telephone cardiopulmonary resuscitation protocol,in non-Advanced Medical Priority Dispatch System (AMPDS) Emergency Medical Services centres

Objectives

Early bystander cardiopulmonary resuscitation (CPR) is a key factor in improving survival from out-of-hospital cardiac arrest (OHCA). The ALERT (Algorithme Liégeois d’Encadrement à la Réanimation par Téléphone) algorithm has the potential to help bystanders initiate CPR. This study evaluates the effectiveness of the implementation of this protocol in a non-Advanced Medical Priority Dispatch System area.

Methods

We designed a before and after study based on a 3-month retrospective assessment of victims of OHCA in 2009, before the implementation of the ALERT protocol in Liege emergency medical communication centre (EMCC), and the prospective evaluation of the same 3 months in 2011, immediately after the implementation.

Results

At the moment of the call, dispatchers were able to identify 233 OHCA in the first period and 235 in the second. Victims were predominantly male (59%, both periods), with mean ages of 64.1 and 63.9 years, respectively. In 2009, only 9.9% victims benefited from bystander CPR, this increased to 22.5% in 2011 (p < 0.0002). The main reasons for protocol under-utilisation were: assistance not offered by the dispatcher (42.3%), caller physically remote from the victim (20.6%). Median time from call to first compression, defined here as no flow time, was 253 s in 2009 and 168 s in 2011 (NS). Ten victims were admitted to hospital after ROSC in 2009 and 13 in 2011 (p = 0.09).

Conclusion

From the beginning and despite its under-utilisation, the ALERT protocol significantly improved the number of patients in whom bystander CPR was attempted.     

Predictive value of electrocardiogram in diagnosing acute coronary artery lesions among patients with out-of-hospital-cardiac-arrest

Aims

Acute coronary lesions are known to be the most common trigger of out of hospital cardiac arrest (OHCA). Aim of the present study was to assess the predictive value of ST-segment changes in diagnosing the presence of acute coronary lesions among OHCA patients

Methods

Findings of coronary angiography (CA) performed in patients resuscitated from OCHA were retrospectively reviewed and related to ST-segment changes on post-ROSC electrocardiogram (ECG)

Results

Ninety-one patients underwent CA after OHCA; 44% of patients had ST-segment elevation and 56% of patients had other ECG patterns on post-ROSC ECG. Significant coronary artery disease (CAD) was found in 86% of patients; CAD was observed in 98% of patients with ST-segment elevation and in 77% of patients with other ECG patterns on post-ROSC ECG (p = 0.004). Acute or presumed recent coronary artery lesions were diagnosed in 56% of patients, respectively in 85% of patients with ST-segment elevation and in 33% of patients with other ECG patterns (p < 0.001). ST-segment analysis on post-ROSC ECG has a good positive predictive value but a low negative predictive value in diagnosing the presence of acute or presumed recent coronary artery lesions (85% and 67%, respectively)

Conclusions

Electrocardiographic findings after OHCA should not be considered as strict selection criteria for performing emergent CA in patients resuscitated from OHCA without obvious extra-cardiac cause; even in the absence of ST-segment elevation on post-ROSC ECG, acute culprit coronary lesions may be present and considered the trigger of cardiac arrest     

Haemodynamic variables and functional outcome in hypothermic patients following out-of-hospital cardiac arrest

Aim of the study

To evaluate the association between haemodynamic variables during the first 24 h after intensive care unit (ICU) admission and neurological outcome in out-of-hospital cardiac arrest (OHCA) victims undergoing therapeutic hypothermia.

Methods

In a multi-disciplinary ICU, records were reviewed for comatose OHCA patients undergoing therapeutic hypothermia. The hourly variable time integral of haemodynamic variables during the first 24 h after admission was calculated. Neurologic outcome was assessed at day 28 and graded as favourable or adverse based on the Cerebral Performance Category of 1–2 and 3–5. Bi- and multivariate regression models adjusted for confounding variables were used to evaluate the association between haemodynamic variables and functional outcome.

Results

67/134 patients (50%) were classified as having favourable outcome. Patients with adverse outcome had a higher mean heart rate (73 [62–86] vs. 66 [60–78] bpm; p = 0.04) and received noradrenaline more frequently (n = 17 [25.4%] vs. n = 9 [6%]; p = 0.02) and at a higher dosage (128 [56–1004] vs. 13 [2–162] μg h⁻¹; p = 0.03) than patients with favourable outcome. The mean perfusion pressure (mean arterial blood pressure minus central venous blood pressure) (OR = 1.001, 95% CI  = 1–1.003; p = 0.04) and cardiac index time integral (OR = 1.055, 95% CI = 1.003–1.109; p = 0.04) were independently associated with adverse outcome at day 28.

Conclusion

Mean perfusion pressure and cardiac index during the first 24 h after ICU admission were weakly associated with neurological outcome in an OHCA population undergoing therapeutic hypothermia. Further studies need to elucidate whether norepinephrine-induced increases in perfusion pressure and cardiac index may contribute to adverse neurologic outcome following OHCA.     

Can experienced paramedics perform tracheal intubation at cardiac arrests? Five years experience of a regional air ambulance service in the UK

Aims

Paramedic tracheal intubation has been reported to carry a high failure rate and morbidity. A comparison between doctor and paramedic-led intubation at out-of-hospital cardiac arrests (OHCA) was conducted to assess whether this finding was observed in our clinical practice.

Methods

Retrospective review of all medical OHCA attended by the Warwickshire and Northamptonshire Air Ambulance (WNAA) over a 64-month period. Cases were identified and divided into doctor-led or paramedic-led groups. Self-reported intubation failure rate, morbidity and clinical outcome were observed and compared. Paramedic exposure to tracheal intubation was assessed.

Results

286 cases of medical OHCA were identified, 199 (69.6%) were doctor-led and 87 (30.4%) paramedic-led. Paramedic and doctor-led crews intubated an equivalent proportion of cases (Para-led 60.7% [37] vs. Dr-led 62.8% [98]; p = 0.89) and no significant difference in failure rate was observed (Para-led 2.7% [1 case, 95% CI 0.0–7.9%] vs. Dr-led 3.1% [3 cases, 95% CI 0.0–6.5%]; p = 1). No morbidity from failure-to-intubate was recorded, and equal rates of return of spontaneous circulation (ROSC) were observed (Para-led 20.7% [18] vs. Dr-led 20.6% [41]; p = 0.89). Paramedics operating with the WNAA were found to have a higher exposure to tracheal intubation (WNAA 0.03 TT/shift vs. unselected paramedics 0.004 TT/shift).

Conclusions

Experienced paramedics regularly operating with physicians have a low tracheal intubation failure rate at OHCA, whether practicing independently or as part of a doctor-led team. This is likely due to increased and regular clinical exposure.     

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.     

The impact of therapeutic hypothermia as adjunctive therapy in a regional primary PCI program

Background

Therapeutic hypothermia (TH) is associated with improved neurologic outcomes in comatose survivors of out-of-hospital cardiac arrest (OHCA). There are currently limited data on the outcomes of patients presenting with resuscitated OHCA in the setting of ST-segment elevation myocardial infarction (STEMI). We conducted a retrospective study to determine the outcomes of patients treated with TH for OHCA in a large regionalized STEMI program.

Methods

Patients referred for primary PCI and TH between July 2004 and April 2011 were identified from the University of Ottawa Heart Institute STEMI database. The primary endpoint was survival to hospital discharge with sufficient neurologic recovery to enable discharge home.

Results

Among 2467 consecutive patients referred for primary PCI, we identified 50 patients treated with TH following OHCA. Forty-nine underwent PCI, of which 47 (96%) received a stent. Median door-to-balloon time was 113 min (IQR 91–151). Patients with good neurologic recovery were younger, mean 51 ± 9 years versus 64 ± 12, p < 0.001, and had higher baseline creatinine clearance, 70 ± 19 mL/min/1.73 m² versus 53 ± 23 mL/min/1.73 m², p = 0.007. The primary endpoint of survival with sufficient neurologic recovery to enable discharge home was reached in 30 patients (60%). Four survivors required levels of assistance that precluded discharge home.

Conclusions

Therapeutic hypothermia in conjunction with primary PCI is associated with a favorable neurologic outcome in the majority of STEMI patients surviving OHCA. Our results suggest that TH is an important adjunctive therapy for STEMI patients suffering OHCA.     

Hemodynamics and vasopressor support in therapeutic hypothermia after cardiac arrest: Prognostic implications

Aim

Inducing therapeutic hypothermia (TH) in Out-of-Hospital Cardiac Arrest (OHCA) can be challenging due to its impact on central hemodynamics and vasopressors are frequently used to maintain adequate organ perfusion. The aim of this study was to assess the association between level of vasopressor support and mortality.

Methods

In a 6-year period, 310 comatose OHCA patients treated with TH were included. Temperature, hemodynamic parameters and level of vasopressors were registered from admission to 24 h after rewarming. Level of vasopressor support was assessed by the cardiovascular sub-score of Sequential Organ Failure Assessment (SOFA). The population was stratified by use of dopamine as first line intervention (D-group) or use of dopamine + norepinephrine/epinephrine (DA-group). Primary endpoint was 30-day mortality and secondary endpoint was in-hospital cause of death.

Results

Patients in the DA-group carried a 49% all-cause 30-day mortality rate compared to 23% in the D-group, p_log-rank < 0.0001, corresponding to an adjusted hazard ratio (HR) of 2.0 (95% CI: 1.3–3.0), p = 0.001). The DA-group had an increased 30-day mortality due to neurological injury (HR = 1.7 (95% CI: 1.1–2.7), p = 0.02). Cause of death was anoxic brain injury in 78%, cardiovascular failure in 18% and multi-organ failure in 4%. The hemodynamic changes of TH reversed at normothermia, although the requirement for vasopressor support (cardiovascular SOFA ≥ 3) persisted in 80% of patients.

Conclusions

In survivors after OHCA treated with TH the induced hemodynamic changes reversed after normothermia, while the need for vasopressor support persisted. Patients requiring addition of norepinephrine/epinephrine on top of dopamine had an increased 30-day all-cause mortality, as well as death from neurological injury.