Esophageal temperature after out-of-hospital cardiac arrest: An observational study

Introduction

Out-of-hospital cardiac arrest (OHCA) is a significant cause of death and severe neurological disability. The only post-return of spontaneous circulation (ROSC) therapy shown to increase survival is mild therapeutic hypothermia (MTH). The relationship between esophageal temperature post OHCA and outcome is still poorly defined.

Methods

Prospective observational study of all OHCA patients admitted to a single centre for a 14-month period (1/08/2008 to 31/09/2009). Esophageal temperature was measured in the Emergency Department and Intensive Care Unit (ICU). Selected patients had pre-hospital temperature monitoring. Time taken to reach target temperature after ROSC was recorded, together with time to admission to the Emergency Department and ICU.

Results

164 OHCA patients were included in the study. 105 (64.0%) were pronounced dead in the Emergency Department. 59 (36.0%) were admitted to ICU for cooling; 40 (24.4%) died in ICU and 19 (11.6%) survived to hospital discharge. Patients who achieved ROSC and had esophageal temperature measured pre-hospital (n = 29) had a mean pre-hospital temperature of 33.9 °C (95% CI 33.2-34.5). All patients arriving in the ED post OHCA had a relatively low esophageal temperature (34.3 °C, 95% CI 34.1-34.6). Patients surviving to hospital discharge were warmer on admission to ICU than patients who died in hospital (35.7 °C vs 34.3 °C, p < 0.05). Patients surviving to hospital discharge also took longer to reach T_targ than non-survivors (2 h 48 min vs 1 h 32 min, p < 0.05).

Conclusions

Following OHCA all patients have esophageal temperatures below normal in the pre-hospital phase and on arrival in the Emergency Department. Patients who achieve ROSC following OHCA and survive to hospital discharge are warmer on arrival in ICU and take longer to reach target MTH temperatures compared to patients who die in hospital. The mechanisms of action underlying esophageal temperature and survival from OHCA remain unclear and further research is warranted to clarify this relationship.     

Prognostic indicators and outcome prediction model for patients with return of spontaneous circulation from cardiopulmonary arrest: the Utstein Osaka Project

Objective

To determine the most important indicators of prognosis in patients with return of spontaneous circulation (ROSC) following out-of-hospital cardiopulmonary arrest (OHCA) and to develop a best outcome prediction model.

Design and patients

All patients were prospectively recorded based on the Utstein Style in Osaka over a period of 3 years (2005-2007). Criteria for inclusion were a witnessed cardiac arrest, age greater than 17 years, presumed cardiac origin of the arrest, and successful ROSC. Multivariate logistic regression (MLR) analysis was used to develop the best prediction model. The dependent variables were favourable outcome (cerebral-performance category [CPC]: 1-2) and poor outcome (CPC: 3-5) at 1 month after the event. Eight explanatory pre-hospital variables were used concerning patient characteristics and resuscitation. External validation was performed on an independent set of Utstein data in 2007.

Results

Subjects comprised 285 patients in VF and 577 patients with pulseless electrical activity (PEA)/asystole. The percentage of favourable outcomes was 31.9% (91/285) in VF and 5.7% (33/577) in PEA/asystole. The most important prognostic indicators of favourable outcome found by MLR were age (p = 0.10), time from collapse to ROSC (TROSC) (p < 0.01), and presence of pre-hospital ROSC (PROSC) (p = 0.15) for VF and age (p = 0.03), TROSC (p < 0.01), PROSC (p < 0.01), and conversion to VF (p = 0.01) for PEA/asystole. For external validation data, areas under the receiver-operating characteristic curve were 0.867 for VF and 0.873 for PEA/asystole.

Conclusions

A model based on four selected indicators showed a high predictive value for favourable outcome in OHCA patients with ROSC.     

Improving outcome after out-of-hospital cardiac arrest by strengthening weak links of the local Chain of Survival; quality of advanced life support and post-resuscitation care

Background

Survival after out-of-hospital cardiac arrest (OHCA) depends on a well functioning Chain of Survival. We wanted to assess if targeted attempts to strengthen the weak links of our local chain; quality of advanced life support (ALS) and post-resuscitation care, would improve outcome.

Materials and methods

Utstein data from all OHCAs in Oslo during three distinct 2-year time periods 1996-1998, 2001-2003 and 2004-2005 were collected. Before the second period the local ALS guidelines changed with increased focus on good quality chest compressions with minimal pauses, while standardized post-resuscitation care including goal directed therapy with therapeutic hypothermia and percutaneous coronary intervention was added in the third period. Additional a priori sub-group analyses of arrests with cardiac aetiology as well as bystander witnessed ventricular fibrillation/tachycardia (VF/VT) arrests with cardiac aetiology were performed.

Results

ALS was attempted in 454, 449, and 417 patients with OHCA in the first, second and last time period, respectively. From the first to the third period VF/VT arrests declined (40% vs. 33%, p = 0.039) and fewer arrests were witnessed (80% vs. 72%, p = 0.022) and response intervals increased (7 ± 4 to 9 ± 4 min, p < 0.001). Overall survival increased from 7% (first period) to 13% (last period), p = 0.002, and survival in the sub-group of bystander witnessed VF/VT arrests with cardiac aetiology increased from 15% (first period) to 35% (last period), p = 0.001.

Conclusions

Survival after OHCA was increased after improving weak links of our local Chain of Survival, quality of ALS and post-resuscitation care.     

Post-resuscitative clinical features in the first hour after achieving sustained ROSC predict the duration of survival in children with non-traumatic out-of-hospital cardiac arrest

Aim of the study

Although sustained return of spontaneous circulation (ROSC) can be initially established after resuscitation from non-traumatic out-of-hospital cardiac arrest (OHCA) in some children, many of the children lose spontaneous circulation during hospital stay and do not survive to discharge. The aim of this study was to determine the clinical features during the first hour after ROSC that may predict survival to hospital discharge.

Methods

We retrospectively evaluated the medical records of 228 children who presented to the emergency department without spontaneous circulation following non-traumatic OHCA during the period January 1996 to December 2008. Among these children, 80 achieved sustained ROSC for at least 20 min. The post-resuscitative clinical features during the first hour after achieving sustained ROSC that correlated with survival, median duration of survival, and death were analyzed.

Results

Among the 80 children who achieved sustained ROSC for at least 20 min, 28 survived to hospital discharge and 6 had good neurologic outcomes (PCPC scale = 1 or 2). Post-resuscitative clinical features associated with survival included sinus cardiac rhythm (p = 0.012), normal heart rate (p = 0.008), normal blood pressure (p < 0.001), urine output > 1 ml/kg/h (p = 0.002), normal skin color (p = 0.016), lack of cardiopulmonary resuscitation (CPR)-induced rib fracture (p = 0.044), initial Glasgow Coma Scale score > 7 (p < 0.001), and duration of in-hospital CPR ≤ 10 min (p < 0.001). Furthermore, these variables were also significantly associated with the duration of survival (all p < 0.05).

Conclusions

The most important predictors of survival to hospital discharge in children with OHCA who achieve sustained ROSC are a normal heart rate, normal blood pressure, and an initial urine output > 1 ml/kg/h.     

Effects of sustained abdominal aorta compression on coronary perfusion pressures and restoration of spontaneous circulation during cardiopulmonary resuscitation in swine

Objectives

The present study was undertaken to explore whether sustained abdominal aorta compression-cardiopulmonary resuscitation (SAAC-CPR), as a means, can raise coronary perfusion pressure (CPP) as well as restoration of spontaneous circulation (ROSC) during CPR. In the present study, we hypothesised that SAAC-CPR elevates CPP during CPR and improves ROSC, without causing liver laceration.

Methods

Animals were randomised into one of two groups (Standard CPR and SAAC-CPR). Ten domestic swine (22-25 kg) were anaesthetised, intubated and mechanically ventilated. Ventricular fibrillation was induced, and after 3 min of untreated ventricular fibrillation, the animals were treated with standard CPR (with simplex chest compression (SCC) and epinephrine) or SAAC-CPR (SCC with sustained abdominal aorta compression, without epinephrine). CPP and ROSC were compared.

Results

SCC with sustained abdominal aorta compression (SCC + SAAC) significantly increased CPP in comparison with SCC during CPR (p < 0.05). The increase in CPP with SCC + SAAC is equivalent to that achieved with epinephrine (p > 0.05). All animals in the standard CPR and SAAC-CPR groups restored spontaneous circulation. No liver damage was found in post-mortem examinations of the swine subjects.

Conclusions

During CPR, non-invasive SAAC can rapidly and reversibly raise the CPP as much as can epinephrine and is especially suitable for out-of-hospital CPR.     

Are trained individuals more likely to perform bystander CPR? An observational study

Background

This study aimed to evaluate the association of cardiopulmonary resuscitation (CPR) training with bystander resuscitation performance and patient outcomes after out-of-hospital cardiac arrest (OHCA).

Methods

This was a prospective, population-based cohort study of all persons aged 18 years or older with OHCA of presumed intrinsic origin and their rescuers from January through December 2008 in Takatsuki, Osaka prefecture, Japan. Data on resuscitation of OHCA patients were obtained by emergency medical service (EMS) personnel in charge based on the Utstein style. Rescuers’ characteristics including experience of CPR training were obtained by EMS personnel interview on the scene. The primary outcome was the attempt of bystander CPR.

Results

Data were collected for 120 cases out of 170 OHCAs of intrinsic origin. Among the available cases, 60 (50.0%) had previous CPR training (trained rescuer group). The proportion of bystander CPR was significantly higher in the trained rescuer group than in the untrained rescuer group (75.0% and 43.3%; p = 0.001). Bystanders who had previous experience of CPR training were 3.40 times (95% confidence interval 1.31-8.85) more likely to perform CPR compared with those without previous CPR training. The number of patients with neurologically favorable one-month survival was too small to evaluate statistical difference between the groups (2 [3.3%] in the trained rescuer group versus 1 [1.7%] in the untrained rescuer group; p = 0.500).

Conclusions

People who had experienced CPR training had a greater tendency to perform bystander CPR than people without experience of CPR training. Further studies are needed to prove the effectiveness of CPR training on survival.     

Comparing the survival between extracorporeal rescue and conventional resuscitation in adult in-hospital cardiac arrests: Propensity analysis of three-year data

Aim

Extracorporeal cardiopulmonary resuscitation (ECPR) has been shown to have survival benefit over conventional CPR (CCPR) in patients with in-hospital cardiac arrest of cardiac origin. We compared the survival of patients who had return of spontaneous beating (ROSB) after ECPR with the survival of those who had return of spontaneous circulation (ROSC) after conventional CPR.

Methods

Propensity score-matched cohort of adults with in-hospital prolonged CPR (>10 min) of cardiac origin in a university-affiliated tertiary extracorporeal resuscitation center were included in this study. Fifty-nine patients with ROSB after ECPR and 63 patients with sustained ROSC by CCPR were analyzed. Main outcome measures were survival at hospital discharge, 30 days, 6 months, and one year, and neurological outcome.

Results

There was no statistical difference in survival to discharge (29.1% of ECPR responders vs. 22.2% of CCPR responders, p = 0.394) and neurological outcome at discharge and one year later. In the propensity score-matched groups, 9 out of 27 ECPR patients survived to one month (33.3%) and 7 out of 27 CCPR patients survived (25.9%). Survival analysis showed no survival difference (HR: 0.856, p = 0.634, 95% CI: 0.453-1.620) between the groups, either at 30 days or at the end of one year (HR: 0.602, p = 0.093, 95% CI: 0.333-1.088).

Conclusions

This study failed to demonstrate a survival difference between patients who had ROSB after institution of ECMO and those who had ROSC after conventional CPR. Further studies evaluating the role of ECMO in conventional CPR rescued patients are warranted.     

Association between deprivation status at community level and outcomes from out-of-hospital cardiac arrest: a nationwide observational study

Study objectives

We sought to examine the association between area deprivation and outcomes of out-of-hospital cardiac arrest in Korea.

Methods

Data were obtained from the emergency medical service (EMS) system. A nationwide OHCA cohort database from January2006 to December 2007 was constructed via hospital chart review and ambulance run sheet data. We enrolled all EMS-assessed OHCA victims and excluded cases without available hospital outcome data or residential address. The Carstairs index was used to categorize districts according to level of deprivation into five quintiles, from (Q1, the least deprived) to (Q5, the most deprived). Main outcomes were survival to hospital discharge, survival to admission, and return of spontaneous circulation (ROSC).

Results

34,227 patients were included. Initial rhythm, witnessed status, attempted bystander cardiopulmonary resuscitation (CPR), CPR by EMS, CPR in the emergency department (ED), and elapsed time interval significantly varied according to area deprivation level (p < 0.001). OHCA outcomes were consistently worse in the most deprived areas. The adjusted OR (95% CI) for survival to hospital discharge was 0.58 (0.45-0.77) in the most deprived areas compared to the least deprived areas.

Conclusion

Community deprivation was strongly associated with survival among out-of-hospital cardiac arrest patients in Korea.     

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.     

Resuscitation of out-of-hospital cardiac arrests in residential aged care facilities in Melbourne, Australia

Introduction

CPR in patients in residential aged care facilities (RACF) deserves careful consideration. We examined the characteristics, management and outcomes of out-of-hospital cardiac arrest (OHCA) in RACF patients in Melbourne, Australia.

Methods

The Victorian Ambulance Cardiac Arrest Registry (VACAR) was searched for all OHCAs occurring in RACFs in Melbourne. The characteristics and outcomes were compared to non-RACF patients in the VACAR.

Results

Between 2000 and 2009 there were 30,006 OHCAs, 2350 (7.8%) occurring in a RACF.A shockable rhythm was present in 179 (7.6%) patients on arrival of paramedics of whom bystander CPR had been performed in 118 (66%); 173 (97%) received an EMS attempted resuscitation. ROSC was achieved in 71 (41%) patients and 15 (8.7%) patients survived to leave hospital. Non shockable rhythm was present in 2171 patients (92%) of whom 804 (37%) had an attempted resuscitation by paramedics. ROSC was achieved in 176 patients (22%) and 10 patients (1.2%) were discharged alive. Survival from OHCA occurring in a RACF was less than survival in those aged >70 years of age who suffered OHCA in their own homes (1.8% vs. 4.7%, p = 0.001). On multivariable analysis, witnessed OHCA (OR 3.0, 95% CI 2.4-3.7) and the presence of bystander CPR (OR 4.6, 95% CI 3.7-5.8) was associated with the paramedic decision to resuscitate.

Conclusion

Resuscitation of patients in RACF is not futile. However, informed decisions concerning resuscitation status should be made by patients and their families on entry to a RACF. Where it is appropriate to perform resuscitation, outcomes may be improved by the provision of BLS training and possibly AED equipment to RACF staff.     

Can early serum levels of S100B protein predict the prognosis of patients with out-of-hospital cardiac arrest?

Objective

This study aims to know if the level of S100B protein at the initiation of cardiopulmonary resuscitation (CPR) and immediately after return of spontaneous circulation (ROSC) can predict clinical outcome.

Materials and methods

A prospective observational study from December 2004 to October 2006 was conducted in an urban tertiary hospital emergency department. Clinical demographics for out-of-hospital cardiac arrest patients were collected based on the Utstein style. Outcomes collected included ROSC for 20 min, survival to admission, survival and Glasgow Outcome Scale (GOS) at 1 month. S100B protein was measured twice before starting CPR (first S100B) and immediately after ROSC (second S100B). We investigated the association between S100B protein levels and clinical outcomes using a multivariate logistic regression model.

Results

A total of 151 patients were included (age: 60.2 ± 16.8 years, male: 64.2%). Of these, 60 (39.7%) had ROSC and 46 (30.5%) survived to admission. After 1 month, 12 (8.0%) survived and only three patients showed good GOS (≥4 points). The S100B levels were not different for ROSC, survival to admission and 1-month survival between survivors and non-survivors (p > 0.05, first and second S100 B level). For the witnessed out-of-hospital cardiac arrest (OHCA) group (N = 87), only the first S100B (1.22 ± 0.85 μg l⁻¹ vs. 3.91 ± 4.25 μg l⁻¹, p < 0.001) showed significant difference for 1-month survival between survivors and non-survivors. The first S100B showed significant association with survival to emergency department (ED) but not 1-month survival (adjusted odds ratio (OR) = 0.905, 95% confidence interval = 0.821-0.998).

Conclusion

Higher levels of S100B at start of CPR were significantly associated with lower survival to admission, and not for 1-month survival.     

The addition of voice prompts to audiovisual feedback and debriefing does not modify CPR quality or outcomes in out of hospital cardiac arrest--a prospective, randomized trial

Aims

Chest compression quality is a determinant of survival from out-of-hospital cardiac arrest (OHCA). ERC 2005 guidelines recommend the use of technical devices to support rescuers giving compressions. This prospective randomized study reviewed influence of different feedback configurations on survival and compression quality.

Materials and methods

312 patients suffering an OHCA were randomly allocated to two different feedback configurations. In the limited feedback group a metronome and visual feedback was used. In the extended feedback group voice prompts were added. A training program was completed prior to implementation, performance debriefing was conducted throughout the study.

Results

Survival did not differ between the extended and limited feedback groups (47.8% vs 43.9%, p = 0.49). Average compression depth (mean ± SD: 4.74 ± 0.86 cm vs 4.84 ± 0.93 cm, p = 0.31) was similar in both groups. There were no differences in compression rate (103 ± 7 vs 102 ± 5 min(−1), p = 0.74) or hands-off fraction (16.16% ± 0.07 to 17.04% ± 0.07, p = 0.38). Bystander CPR, public arrest location, presenting rhythm and chest compression depth were predictors of short term survival (ROSC to ED).

Conclusions

Even limited CPR-feedback combined with training and ongoing debriefing leads to high chest compression quality. Bystander CPR, location, rhythm and chest compression depth are determinants of survival from out of hospital cardiac arrest. Addition of voice prompts does neither modify CPR quality nor outcome in OHCA. CC depth significantly influences survival and therefore more focus should be put on correct delivery. Further studies are needed to examine the best configuration of feedback to improve CPR quality and survival.

Registration

ClinicalTrials.gov (NCT00449969), http://www.clinicalTrials.gov.     

Feasibility and safety of combined percutaneous coronary intervention and therapeutic hypothermia following cardiac arrest

Review

Mild therapeautic hypothermia (MTH) has been associated with cardiac dysrhythmias, coagulopathy and infection. After restoration of spontaneous circulation (ROSC), many cardiac arrest patients undergo percutaneous coronary intervention (PCI). The safety and feasibility of combined MTH and PCI remains unclear. This is the first study to evaluate whether PCI increases cardiac risk or compromises functional outcomes in comatose cardiac arrest patients who undergo MTH.

Methods

Ninety patients within a 6-h window following cardiac arrest and ROSC were included. Twenty subjects (23%) who underwent PCI following MTH induction were compared to 70 control patients who underwent MTH without PCI. The primary endpoint was the rate of dysrhythmias; secondary endpoints were time-to-MTH induction, rates of adverse events (dysrhythmia, coagulopathy, hypotension and infection) and mortality.

Results

Patients who underwent PCI plus MTH suffered no statistical increase in adverse events (P = .054). No significant difference was found in the rates of dysrhythmias (P = .27), infection (P = .90), coagulopathy (P = .90) or hypotension (P = .08). The PCI plus MTH group achieved similar neurological outcomes (modified Rankin Scale (mRS) ≤3 (P = .42) and survival rates (P = .40). PCI did not affect the speed of MTH induction; the target temperature was reached in both groups without a significant time difference (P = .29).

Conclusion

Percutaneous coronary intervention seems to be feasible when combined with MTH, and is not associated with increased cardiac or neurological risk.     

Examining the contextual effects of neighborhood on out-of-hospital cardiac arrest and the provision of bystander cardiopulmonary resuscitation

Objective

To understand the association between neighborhood and individual characteristics in determining whether or not bystanders perform cardiopulmonary resuscitation (CPR) in cases of out-of-hospital cardiac arrest (OHCA).

Methods

Between October 1, 2005 to November 30, 2008, 1108 OHCA cases from Fulton County (Atlanta), GA, were eligible for bystander CPR. We conducted multi-level non-linear regression analysis and derived Empirical Bayes estimates for bystander CPR by census tract.

Results

279 (25%) cardiac arrest victims received bystander CPR. Provision of bystander CPR was significantly more common in witnessed events (odds ratio [OR] 1.64; 95% confidence interval [CI] 1.21-2.22, p < 0.001) and those that occurred in public locations (OR 1.67; 95% CI 1.16-2.40, p < 0.001). Other individual-level characteristics were not significantly associated with bystander CPR. Cardiac arrests in the census tracts that rank in the highest income quintile, as compared to the lowest income quintile were much more likely (OR 4.98; 95% CI 1.65-15.04) to receive bystander CPR.

Conclusion

Cardiac arrest victims in the highest income census tracts were much more likely to receive bystander CPR than in the lowest income census tracts, even after controlling for individual and arrest characteristics. Low-income neighborhoods may be particularly appropriate targets for community-based CPR training and awareness efforts.     

Passive leg raising during cardiopulmonary resuscitation in out-of-hospital cardiac arrest—Does it improve circulation and outcome?

Background

Passive leg raising (PLR), to augment the artificial circulation, was deleted from cardiopulmonary resuscitation (CPR) guidelines in 1992. Increases in end-tidal carbon dioxide (P_ETCO₂) during CPR have been associated with increased pulmonary blood flow reflecting cardiac output. Measurements of P_ETCO₂ after PLR might therefore increase our understanding of its potential value in CPR. We also observed the alteration in P_ETCO₂ in relation to the return of spontaneous circulation (ROSC) and no ROSC.

Methods and results

The P_ETCO₂ was measured, subsequent to intubation, in 126 patients suffering an out-of-hospital cardiac arrest (OHCA), during 15 min or until ROSC. Forty-four patients were selected by the study protocol to PLR 35 cm; 21 patients received manual chest compressions and 23 mechanical compressions. The PLR was initiated during uninterrupted CPR, 5 min from the start of P_ETCO₂ measurements. During PLR, an increase in P_ETCO₂ was found in all 44 patients within 15 s (p = 0.003), 45 s (p = 0.002) and 75 s (p = 0.0001). Survival to hospital discharge was 7% among patients with PLR and 1% among those without PLR (p = 0.12). Among patients experiencing ROSC (60 of 126), we found a marked increase in P_ETCO₂ 1 min before the detection of a palpable pulse.

Conclusion

Since PLR during CPR appears to increase P_ETCO₂ after OHCA, larger studies are needed to evaluate its potential effects on survival. Further, the measurement of P_ETCO₂ could help to minimise the hands-off periods and pulse checks.     

Changing EMS dispatcher CPR instructions to 400 compressions before mouth-to-mouth improved bystander CPR rates

Background

To examine the impact of changing dispatcher CPR instructions (400 compressions: 2 breaths, followed by 100:2 ratio) on rates of bystander CPR and survival in adults with presumed cardiac out-of-hospital arrest (OHCA) in Melbourne, Australia.

Methods

The Victorian Ambulance Cardiac Arrest Registry (VACAR) was searched for OHCA where Emergency Medical Services (EMS) attempted CPR between August 2006 and August 2009. OHCA included were: (1) patients aged ≥18 years old; (2) presumed cardiac etiology; and (3) not witnessed by EMS.

Results

For the pre- and post-study periods, 1021 and 2101 OHCAs met inclusion criteria, respectively. Rates of bystander CPR increased overall (45-55%, p < 0.001) and by initial rhythm (shockable 55-70%, p < 0.001 and non-shockable 40-46%, p = 0.01). In VF/VT OHCA, there were improvements in the number of patients arriving at hospital with a return of spontaneous circulation (ROSC) (48-56%, p = 0.02) and in survival to hospital discharge (21-29%, p = 0.002), with improved outcomes restricted to patients receiving bystander CPR. After adjusting for factors associated with survival, the period of time following the change in CPR instructions was a significant predictor of survival to hospital discharge in VF/VT patients (OR 1.57, 95% CI: 1.15-2.20, p = 0.005).

Conclusion

Following changes to dispatcher CPR instructions, significant increases were seen in rates of bystander CPR and improvements were seen in survival in VF/VT patients who received bystander CPR, after adjusting for factors associated with survival.     

Cardiac arrest due to food asphyxiation in adults: Resuscitation profiles and outcomes

Aim

Food asphyxiation is uncommon but unignorable cause of sudden death in the elderly. Several autopsy studies, which identified those at particular risk, have been conducted on the subject. Resuscitation profiles and outcomes of food asphyxiation victims presenting with out-of-hospital cardiac arrest (OHCA) to the emergency department, however, have rarely been reported.

Methods

Data on adults (≥20 years) presenting with OHCA after witnessed food asphyxiation were retrieved from an institutional database. Clinical variables were evaluated to identify their demographic characteristics. Their outcomes, represented by return of spontaneous circulation (ROSC) and survival rate, were also investigated.

Results

Sixty-nine food asphyxiation victims presenting with OHCA were identified during the 4-year period. Food asphyxiation occurred most frequently in the age group of 71-80 years, followed by that of 81-90 years. The majority of victims had medical conditions that adversely affected mastication/swallowing, such as dementia. Bystander cardiopulmonary resuscitation (CPR) was performed only in 26%, although bystanders often attempted to clear the airway without performing CPR. Despite the high ROSC rate of 78%, only 7% survived to discharge. Asphyxiation-ROSC interval might play a crucial role in determining the outcomes: the interval was ≤10 min in all survivors, while it was longer than 10 min in all non-survivors.

Conclusion

Because of their advanced age and debilitating general condition, it may be difficult to substantially improve the outcomes of food asphyxiation victims. Effort should be directed to prevent food asphyxiation, and public education to perform standard CPR for food asphyxiation victims including the Heimlich manoeuvre is warranted.     

Cervical erector spinae and upper trapezius muscle activity in children using different information technologies

Objectives

Researchers investigating the effects of computer use and the development of musculoskeletal disorders have mainly focused on the effects of prolonged muscle loading associated with postures assumed during computer use in the adult population. The objective of this study was to investigate the effects of different forms of old and new information technology (IT) on muscle activity levels in a paediatric population.

Design

A 3 × 3 × 2 mixed model design was used for this study.

Participants

Thirty-two schoolchildren aged 4-17 years participated in this study.

Outcome measures

Surface electromyography (EMG) data were collected from the left and right cervical erector spinae and upper trapezius muscles. Participants performed a 5-minutes reading task using the three IT types (book, laptop and desktop computer).

Results

Cervical erector spinae and upper trapezius muscle activity levels were significantly higher when children used the laptop set-up (P < 0.001). The lowest muscle activity levels were found when children used the desktop set-up. Cervical erector spinae and upper trapezius muscle activities were found to be higher on the left side in the book set-up compared with higher right muscle activity levels in the computer set-ups (P = 0.047 and <0.001, respectively).

Conclusions

The three IT types had different effects on cervical erector spinae and upper trapezius muscle activity, suggesting varying risks associated with different IT types. Activity levels were often above 5% maximum EMG (MEMG). As adult studies have linked activity levels greater than 5%MEMG with the development of musculoskeletal disorders, it seems that children are potentially at risk of replicating these adverse health reactions associated with adult IT use.     

Vasopressin for cardiac arrest: meta-analysis of randomized controlled trials

Background

Prior meta-analyses-reported results of randomised controlled trials (RCTs) published between 1997 and 2004 failed to show any vasopressin-related benefit in cardiac arrest. Based on new RCT-data and a hypothesis of a potentially increased vasoconstricting efficacy of vasopressin, we sought to determine whether the cumulative, current evidence supports or refutes an overall and/or selective benefit for vasopressin regarding sustained restoration of spontaneous circulation (ROSC), long-term survival, and neurological outcome.

Methods

Two reviewers independently searched PubMed, EMBASE, and Cochrane Database for RCTs assigning adults with cardiac arrest to treatment with a vasopressin-containing regimen (vasopressin-group) vs adrenaline (epinephrine) alone (control-group) and reporting on long-term outcomes. Data from 4475 patients in 6 high-methodological quality RCTs were analyzed. Subgroup analyses were conducted according to initial cardiac rhythm and time from collapse to drug administration (T_DRUG) < 20 min.

Results

Vasopressin vs. control did not improve overall rates of sustained ROSC, long-term survival, or favourable neurological outcome. However, in asystole, vasopressin vs. control was associated with higher long-term survival {odds ratio (OR) = 1.80, 95% confidence interval (CI) = 1.04-3.12, P = 0.04}. In asystolic patients of RCTs with average T_DRUG < 20 min, vasopressin vs. control increased the rates of sustained ROSC (data available from 2 RCTs; OR = 1.70, 95% CI = 1.17-2.47, P = 0.005) and long-term survival (data available from 3 RCTs; OR = 2.84, 95% CI = 1.19-6.79, P = 0.02).

Conclusions

Vasopressin use in the resuscitation of cardiac arrest patients is not associated with any overall benefit or harm. However, vasopressin may improve the long-term survival of asystolic patients, especially when average T_DRUG is <20 min.     

Effectiveness of the new 'Mobile AED Map' to find and retrieve an AED: A randomised controlled trial

Background

Although early shock with an automated external defibrillator (AED) is one of the several key elements to save out-of-hospital cardiac arrest (OHCA) victims, it is not always easy to find and retrieve a nearby AED in emergency settings. We developed a cell phone web system, the Mobile AED Map, displaying nearby AEDs located anywhere. The simulation trial in the present study aims to compare the time and travel distance required to access an AED and retrieve it with and without the Mobile AED Map.

Methods

Design: Randomised controlled trial. Setting: Two fields where it was estimated to take 2 min (120-170 m) to access the nearest AED. Participants were randomly assigned to either the Mobile AED Map group or the control group. We provided each participant in both groups with an OHCA scenario, and measured the time and travel distance to find and retrieve a nearby AED.

Results

Forty-three volunteers were enrolled and completed the protocol. The time to access and retrieve an AED was not significantly different between the Mobile AED Map group (400 ± 238 s) and the control group (407 ± 256 s, p = 0.92). The travel distance was significantly shorter in the Mobile AED Map group (606 m vs. 891 m, p = 0.019). Trial field conditions affected the results differently.

Conclusions

Although the new Mobile AED Map reduced the travel distance to access and retrieve the AED, it failed to shorten the time. Further technological improvements of the system are needed to increase its usefulness in emergency settings (UMIN000002043).