The Utstein style for uniform reporting of data from out-of-hospital cardiac arrest

Emergency care and health systems: consensus-based recommendations and future research priorities

The theme of the 14th annual Academic Emergency Medicine consensus conference was "Global Health and Emergency Care: A Research Agenda." The goal of the conference was to create a robust and measurable research agenda for evaluating emergency health care delivery systems. The concept of health systems includes the organizations, institutions, and resources whose primary purpose is to promote, restore, and/or maintain health. This article further conceptualizes the vertical and horizontal delivery of acute and emergency care in low-resource settings by defining specific terminology for emergency care platforms and discussing how they fit into broader health systems models. This was accomplished through discussion surrounding four principal questions touching upon the interplay between health systems and acute and emergency care. This research agenda is intended to assist countries that are in the early stages of integrating emergency services into their health systems and are looking for guidance to maximize their development and health systems planning efforts.

Association of ozone and particulate air pollution with out-of-hospital cardiac arrest in Helsinki, Finland: evidence for two different etiologies

Out-of-hospital cardiac arrest (OHCA) has been previously associated with exposure to particulate air pollution. However, there is uncertainty about the agents and mechanisms that are involved. We aimed to determine the association of gases and particulates with OHCA, and differences in pollutant effects on OHCAs due to acute myocardial infarction (AMI) vs those due to other causes. Helsinki Emergency Medical Services provided data on OHCAs of cardiac origin (OHCA_Cardiac). Hospital and autopsy reports determined whether OHCAs were due to AMI (OHCA_MI) or other cardiac causes (OHCA_Other). Pollutant data was obtained from central ambient monitors. A case-crossover analysis determined odds ratios (ORs) for hourly lagged exposures (Lag 0-3) and daily lagged exposures (Lag 0d-3d), expressed per interquartile range of pollutant level. For OHCA_Cardiac, elevated ORs were found for PM(2.5) (Lag 0, 1.07; 95% confidence interval (CI): 1.01-1.13) and ozone (O(3)) (Lag 2d, 1.18; CI: 1.03-1.35). For OHCA_MI, elevated ORs were found for PM(2.5) (Lag 0, 1.14; CI: 1.03-1.27; Lag 0d, 1.17; CI: 1.03-1.33), accumulation mode particulate (Acc) (Lag 0d, 1.19; CI: 1.04-1.35), NO (Lag 0d, 1.07; CI: 1.01-1.13), and ultrafine particulate (Lag 0d, 1.27; CI: 1.05-1.54). For OHCA_Other, elevated ORs were found only for O(3) (Lag 1d, 1.26; CI: 1.07-1.48; Lag 2d, 1.30; CI: 1.11-1.53). Results from two-pollutant models, with one of the pollutants either PM(2.5) or O(3), suggested that associations were primarily due to effects of PM(2.5) and O(3), rather than other pollutants. The results suggest that air pollution triggers OHCA via two distinct modes: one associated with particulates leading to AMI and one associated with O(3) involving etiologies other than AMI, for example, arrhythmias or respiratory insufficiency.

Femoro-iliacal artery versus pulmonary artery core temperature measurement during therapeutic hypothermia: an observational study

AIM OF THE STUDY

Therapeutic hypothermia after cardiac arrest improves neurologic outcome. The temperature measured in the pulmonary artery is considered to best reflect core temperature, yet is limited by invasiveness. Recently a femoro-arterial thermodilution catheter (PiCCO-Pulse Contour Cardiac Output) has been introduced in clinical practice as a safe and accurate haemodynamic monitoring system, which is also able to measure blood temperature. The aim of the study was to investigate, if the temperature measured with the PiCCO catheter reflects pulmonary artery temperature better than other sites during therapeutic hypothermia.

METHODS

In this observational study twenty patients after cardiac arrest and successful resuscitation were cooled with various cooling methods to 33 ± 1°C for 24h, followed by rewarming. Temperatures were recorded continuously in the pulmonary artery (Tpa), femoro-iliacal artery (Tpicco), ear canal (Tear), oesophagus (Toeso) and urinary bladder (Tbla). We assessed agreement of methods using the Bland Altman approach including bias and limits of agreement (LA).

RESULTS

All other sites differed significantly from Tpa with the bias varying from 0.4°C (Tbla) to -0.6°C (Tear). Standard deviations varied from 0.1°C (Tpicco, Toeso) to 0.5°C (Tear). For all sites bias was closer to zero with increasing average temperatures. Bias tended to be larger in the cooling phase compared to overall measurements.

CONCLUSIONS

Temperature measurement in the femoro-iliacal artery (Tpicco) reflects the gold standard of pulmonary artery temperature most accurately, especially during the cooling phase. Tpicco is easily accessible and might be used for monitoring core temperature without the need for additional temperature probes.

Pyrexia and neurologic outcomes after therapeutic hypothermia for cardiac arrest

OBJECTIVE

Therapeutic hypothermia, also known as targeted temperature management (TTM), improves clinical outcomes in patients resuscitated from cardiac arrest. Hyperthermia after discontinuation of active temperature management ("rebound pyrexia") has been observed, but its incidence and association with clinical outcomes is poorly described. We hypothesized that rebound pyrexia is common after rewarming in post-arrest patients and is associated with poor neurologic outcomes.

METHODS

Retrospective multicenter US clinical registry study of post-cardiac arrest patients treated with TTM at 11 hospitals between 5/2005 and 10/2011. We assessed the incidence of rebound pyrexia (defined as temperature >38°C) in post-arrest patients treated with TTM and subsequent clinical outcomes of survival to discharge and "good" neurologic outcome at discharge, defined as cerebral performance category (CPC) 1-2.

RESULTS

In this cohort of 236 post-arrest patients treated with TTM, mean age was 58.1 ± 15.7 y and 106/236 (45%) were female. Of patients who survived at least 24h after TTM discontinuation (n=167), post-rewarming pyrexia occurred in 69/167 (41%), with a median maximum temperature of 38.7 (IQR 38.3-38.9). There were no significant differences between patients experiencing any pyrexia and those without pyrexia regarding either survival to discharge (37/69 (54%) v 51/98 (52%), p=0.88) or good neurologic outcomes (26/37 (70%) v 42/51 (82%), p=0.21). We compared patients with marked pyrexia (greater than the median pyrexia of 38.7°C) versus those who experienced no pyrexia or milder pyrexia (below the median) and found that survival to discharge was not statistically significant (40% v 56% p=0.16). However, marked pyrexia was associated with a significantly lower proportion of CPC 1-2 survivors (58% v 80% p=0.04).

CONCLUSIONS

Rebound pyrexia occurred in 41% of TTM-treated post-arrest patients, and was not associated with lower survival to discharge or worsened neurologic outcomes. However, among patients with pyrexia, higher maximum temperature (>38.7°C) was associated with worse neurologic outcomes among survivors to hospital discharge.

Comparing emergency medical service systems--a project of the European Emergency Data (EED) Project

AIM

The aim of this prospective study was the comparison of four emergency medical service (EMS) systems-emergency physician (EP) and paramedic (PM) based-and the impact of advanced live support (ALS) on patients status in preclinical care.

METHODS

The EMS systems of Bonn (GER, EP), Cantabria (ESP, EP), Coventry (UK, PM) and Richmond (US, PM) were analysed in relation to quality of structure, process and performance when first diagnosis on scene was cardiac arrest (OHCA), chest pain or dyspnoea. Data were collected prospectively between 01.01.2001 and 31.12.2004 for at least 12 month.

RESULTS

Over all 6277 patients were included in this study. The rate of drug therapy was highest in the EP-based systems Bonn and Cantabria. Pain relief was more effective in Bonn in patients with severe chest pain. In the group of patients with chest pain and tachycardia ≥ 120 beats/min, the heart rate was reduced most effective by the EP-systems. In patients with dyspnoea and S(p)O(2) <90% the improvement of oxygen saturation was most effective in Bonn and Richmond. After OHCA significant more patients reached the hospital alive in EMS systems with EPs than in the paramedic staffed (Bonn = 35.6%, Cantabria = 30.1%; Coventry = 11.9%, Richmond = 9.2%). The introduction of a Load Distributing Band chest compression device in Richmond improved admittance rate after OHCA (21.7%) but did not reach the survival rate of the Bonn EMS system.

CONCLUSIONS

Higher qualification and greater training and experience of ALS unit personnel increased survival after OHCA and improved patient's status with cardiac chest pain and respiratory failure.

Prehospital care and new models of regionalization

This article summarizes the discussions of the emergency medical services (EMS) breakout session at the June 2010 Academic Emergency Medicine consensus conference "Beyond Regionalization: Integrated Networks of Emergency Care." The group focused on prehospital issues such as the identification of patients by EMS personnel, protocol-driven destination selection, bypassing closer nondesignated centers to transport patients directly to more distant designated specialty centers, and the modes of transport to be used as they relate to the regionalization of emergency care. It is our hope that the proposed research agenda will be advanced in a way that begins to rigorously approach the unanswered research questions and that these answers, in turn, will lead to an evidence-based, cohesive, comprehensive, and more uniform set of guidelines that govern the delivery and practice of prehospital emergency care.

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

AIM

Mild therapeutic hypothermia improves survival and neurologic recovery in primary comatose survivors of cardiac arrest. Cooling effectivity, safety and feasibility of nasopharyngeal cooling with the RhinoChill device (BeneChill Inc., San Diego, USA) were determined for induction of therapeutic hypothermia.

METHODS

Eleven emergency departments and intensive care units participated in this multi-centre, single-arm descriptive study. Eighty-four patients after successful resuscitation from cardiac arrest were cooled with nasopharyngeal delivery of an evaporative coolant for 1h. Subsequently, temperature was controlled with systemic cooling at 33 degrees C. Cooling rates, adverse events and neurologic outcome at hospital discharge using cerebral performance categories (CPC; CPC 1=normal to CPC 5=dead) were documented. Temperatures are presented as median and the range from the first to the third quartile.

RESULTS

Nasopharyngeal cooling for 1h reduced tympanic temperature by median 2.3 (1.6; 3.0) degrees C, core temperature by 1.1 (0.7; 1.5) degrees C. Nasal discoloration occurred during the procedure in 10 (12%) patients, resolved in 9, and was persistent in 1 (1%). Epistaxis was observed in 2 (2%) patients. Periorbital gas emphysema occurred in 1 (1%) patient and resolved spontaneously. Thirty-four of 84 patients (40%) patients survived, 26/34 with favorable neurological outcome (CPC of 1-2) at discharge.

CONCLUSIONS

Nasopharyngeal evaporative cooling used for 1h in primary cardiac arrest survivors is feasible and safe at flow rates of 40-50L/min in a hospital setting.

Statistical analysis of joint short-term and long-term survival in resuscitation research

OBJECTIVE

To develop statistical tools that use combined initial survival data and post-resuscitation survival data to test the null hypothesis that true, population-wide outcomes following experimental CPR interventions are not different from control.

METHOD

A new test statistic, d(2), for evaluating Type 1 error is derived from a bivariate, two-dimensional analysis of categorical initial resuscitation and post-resuscitation survival data, which are statistically independent because they are obtained during non-overlapping periods of time. The d(2) test statistic, which is distributed as a chi-squared distribution, is derived from first principles and validated using Monte Carlo methods of computer simulation for thousands of clinical trials.

RESULTS

Under the null hypothesis, the normalized difference in the proportions of patients surviving the initial resuscitation period and the normalized difference in the proportions of such short-term survivors that also survive the post-resuscitation period are jointly distributed in a two-dimensional space as a bivariate standard normal distribution, against which observed intervention and control outcomes can be compared in a test of statistical significance. Typically this two-dimensional approach has greater statistical power to detect true differences, compared to conventional one-dimensional tests. Smaller group sizes (Ns) are usually required to reach statistical significance when both initial survival and post-resuscitation survival are considered together. Such two-dimensional analysis is easily extended to meta-analysis of multiple trials.

CONCLUSIONS

A straightforward, easy-to-use bivariate test for Type I errors in statistical inference can be done for resuscitation studies reporting both short-term and long-term survival data. Acceptance of such two-dimensional tests of the null hypothesis, as proposed by Hallstrom, can save time, money, effort, and disappointment in the difficult and sometimes frustrating field of resuscitation research.

Cardiac Arrests in Skilled Nursing Facilities: Continuing Room for Improvement?

OBJECTIVES

To characterize the care received by skilled nursing facility (SNF/NF) patients suffering cardiac arrest and to evaluate the outcome of SNF/NF patients experiencing cardiac arrest.

DESIGN

A retrospective analysis of an existing cardiac arrest registry to characterize SNF/NF cardiac arrest patients and to compare them to community-dwelling cardiac arrest patients was performed.

SETTING

The study took place in Rochester, NY, an urban city in upstate New York with approximately 220,000 residents.

PARTICIPANTS

All patients for whom emergency medical services (EMS) assistance was requested via the 911 system and who were treated for cardiac arrest between January 1998 and December 2001 were included.

MEASUREMENTS

Demographic characteristics such as age, gender, race; clinical characteristics and interventions such as cardiopulmonary resuscitation (CPR), defibrillation, initial cardiac rhythm, and call response interval; outcomes measures such as return of spontaneous circulation and 1-year survival were obtained.

RESULTS

Forty-two (8%) of cardiac arrest patients resided in an SNF/NF. Sixteen (38%) of the events were witnessed arrests. Only 28 (67%) patients received CPR and none were defibrillated prior to EMS arrival. One (2%) patient was alive 1 year after the event, a survival rate similar to the community-dwelling population (5%).

CONCLUSION

SNF/NF patients suffering cardiac arrest often did not receive CPR or defibrillation while awaiting EMS arrival. SNF/NF patients suffering cardiac arrest have a very low survival rate, similar to the community-dwelling population. The impact of not providing CPR and defibrillation on the survival rate is unclear, but needs to be evaluated prior to any decisions regarding the medical futility of resuscitating SNF/NF patients.

Epidemiology and outcomes of out-of-hospital cardiac arrest in Rochester, New York

OBJECTIVE

To characterize out-of-hospital cardiac arrest (OHCA) and factors that affect survival in a medium sized city that uses system status management for dispatch.

METHODS

A retrospective cohort study of all adult OHCA patients treated by EMS between 1998 and 2001 was conducted using Utstein definitions. The primary endpoint was 1-year survival.

RESULTS

Of the 1177 patients who experienced OHCA during the study period, 539 (46%) met inclusion criteria. Age ranged from 18 to 98 years (median 67). The median call-response interval was 5 min (range 0-21), and 93% were 9 min or less. There was no significant difference in the median call-response intervals between call location zip (Post) codes (p=0.07). Twenty percent of experienced ROSC (95% CI 17-23), 7% survived more than 30 days (95% CI 5-9%), and 5% survived to 1 year (95% CI 3-7%). In bivariate analysis, first rhythm and bystander CPR affected survival to 1 year. There was no significant difference in survival between male (4%) and female (7%), black (4%) and white (6%), or witnessed (7%) and unwitnessed arrest (4%). Logistic regression identified younger age, CPR initiated by bystander (19%) or first responder (41%), and presenting rhythm of VF/VT (32%) as factors associated with survival to 1 year.

CONCLUSIONS

This study finds a 5% survival to 1 year among OHCA patients in Rochester, NY. A presenting rhythm of VF/VT and bystander CPR were associated with increased survival.

Prospective performance evaluation of emergency medical services for cardiac arrest in Lombardia: is something moving forward?

BACKGROUND

Limited data are available in our region on out-of-hospital treatment of cardiac arrest. The aim of this study is to evaluate whether the changes implemented in the emergency system (i.e. an increased number of basic life support and advance life support crews that were dispatched) produced the expected outcome improvements.

METHODS

(a)

EXPERIMENTAL DESIGN

data were prospectively collected on patients with sudden out-of-hospital cardiac arrest in three emergency dispatch centers for 3 months during two study periods, year 2000 and year 2003, differentiated only by the increase of qualified crews. Outcomes and survival were evaluated at 24 h and 1 month after the event. (b)

SETTING

out-of-hospital treatment. (c)

PATIENTS

352 (174 in the second study period) patients suffering cardiac arrest. (d)

INTERVENTIONS

the study was observational.

RESULTS

We could document, between the two study periods, stable 24 h (12.6 vs 9.1%) and 1 month survival (3.4 vs 5.8%, NS). Nevertheless, arrival time on site was significantly higher in the second period (from 8.3+/-3.3 to 10.1+/-5.4 min, P<0.05).

CONCLUSIONS

The strengthening of only one link of the chain-of-survival did not improve 1 month survival.

Cardiac Arrests in Skilled Nursing Facilities: Continuing Room for Improvement?

OBJECTIVES

To characterize the care received by skilled nursing facility (SNF/NF) patients suffering cardiac arrest and to evaluate the outcome of SNF/NF patients experiencing cardiac arrest.

DESIGN

A retrospective analysis of an existing cardiac arrest registry to characterize SNF/NF cardiac arrest patients and to compare them to community-dwelling cardiac arrest patients was performed.

SETTING

The study took place in Rochester, NY, an urban city in upstate New York with approximately 220,000 residents.

PARTICIPANTS

All patients for whom emergency medical services (EMS) assistance was requested via the 911 system and who were treated for cardiac arrest between January 1998 and December 2001 were included.

MEASUREMENTS

Demographic characteristics such as age, gender, race; clinical characteristics and interventions such as cardiopulmonary resuscitation (CPR), defibrillation, initial cardiac rhythm, and call response interval; outcomes measures such as return of spontaneous circulation and 1-year survival were obtained.

RESULTS

Forty-two (8%) of cardiac arrest patients resided in an SNF/NF. Sixteen (38%) of the events were witnessed arrests. Only 28 (67%) patients received CPR and none were defibrillated prior to EMS arrival. One (2%) patient was alive 1 year after the event, a survival rate similar to the community-dwelling population (5%).

CONCLUSION

SNF/NF patients suffering cardiac arrest often did not receive CPR or defibrillation while awaiting EMS arrival. SNF/NF patients suffering cardiac arrest have a very low survival rate, similar to the community-dwelling population. The impact of not providing CPR and defibrillation on the survival rate is unclear, but needs to be evaluated prior to any decisions regarding the medical futility of resuscitating SNF/NF patients.

Aminophylline in bradyasystolic cardiac arrest: a randomised placebo-controlled trial

BACKGROUND

Endogenous adenosine might cause or perpetuate bradyasystole. Our aim was to determine whether aminophylline, an adenosine antagonist, increases the rate of return of spontaneous circulation (ROSC) after out-of-hospital cardiac arrest.

METHODS

In a double-blind trial, we randomly assigned 971 patients older than 16 years with asystole or pulseless electrical activity at fewer than 60 beats per minute, and who were unresponsive to initial treatment with epinephrine and atropine, to receive intravenous aminophylline (250 mg, and an additional 250 mg if necessary) (n=486) or placebo (n=485). The patients were enrolled between January, 2001 and September, 2003, from 1886 people who had had cardiac arrests. Standard resuscitation measures were used for at least 10 mins after the study drug was administered. Analysis was by intention-to-treat. This trial is registered with the ClinicalTrials.gov registry with the number NCT00312273.

FINDINGS

Baseline characteristics and survival predictors were similar in both groups. The median time from the arrival of the advanced life-support paramedic team to study drug administration was 13 min. The proportion of patients who had an ROSC was 24.5% in the aminophylline group and 23.7% in the placebo group (difference 0.8%; 95% CI -4.6% to 6.2%; p=0.778). The proportion of patients with non-sinus tachyarrhythmias after study drug administration was 34.6% in the aminophylline group and 26.2% in the placebo group (p=0.004). Survival to hospital admission and survival to hospital discharge were not significantly different between the groups. A multivariate logistic regression analysis showed no evidence of a significant subgroup or interactive effect from aminophylline.

INTERPRETATION

Although aminophylline increases non-sinus tachyarrhythmias, we noted no evidence that it significantly increases the proportion of patients who achieve ROSC after bradyasystolic cardiac arrest.

Recommended guidelines for reviewing, reporting, and conducting research on post-resuscitation care: The Utstein style

The aim of this report is to establish recommendations for reviewing, reporting, and conducting research during the post-resuscitation period in hospital. It defines data that are needed for research and more specialised registries and therefore supplements the recently updated Utstein template for resuscitation registries. The updated Utstein template and the out-of-hospital "Chain of Survival" describe factors of importance for successful resuscitation up until return of spontaneous circulation (ROSC). Several factors in the in-hospital phase after ROSC are also likely to affect the ultimate outcome of the patient. Large differences in survival to hospital discharge for patients admitted alive are reported between hospitals. Therapeutic hypothermia has been demonstrated to improve the outcome, and other factors such as blood glucose, haemodynamics, ventilatory support, etc., might also influence the result. No generally accepted, scientifically based protocol exists for the post-resuscitation period in hospital, other than general brain-oriented intensive care. There is little published information on this in-hospital phase. This statement is the result of a scientific consensus development process started as a symposium by a task force at the Utstein Abbey, Norway, in September 2003. Suggested data are defined as core and supplementary and include the following categories: pre-arrest co-morbidity and functional status, cause of death, patients' quality of life, in-hospital system factors, investigations and treatment, and physiological data at various time points during the first three days after admission. It is hoped that the publication of these recommendations will encourage research into the in-hospital post-resuscitation phase, which we propose should be included in the chain-of-survival as a fifth ring. Following these recommendations should enable better understanding of the impact of different in-hospital treatment strategies on outcome.

Temporal patterns in long-term survival after resuscitation from out-of-hospital cardiac arrest

BACKGROUND

During the past quarter century, advances in treatment of cardiovascular disease have occurred that might potentially benefit survivors of sudden cardiac arrest (SCA). Little is known, however, about the temporal patterns in long-term survival among persons resuscitated from SCA. We hypothesized that long-term survival would improve over time and that this temporal pattern would be most evident for cardiac causes of death.

METHODS AND RESULTS

The investigation was a retrospective cohort study of survival among persons who were discharged alive from the hospital after resuscitation from out-of-hospital SCA due to heart disease in King County, Wash, between May 1, 1976, and December 31, 2001 (n=2035). Calendar time was divided into four 5-year intervals: 1976 to 1980, 1981 to 1985, 1986 to 1990, and 1991 to 1995, and one 6-year interval, 1996 to 2001. Age-adjusted survival curves were constructed, and Cox proportional-hazards regression was used to compute hazard ratios (HRs) for the association between mortality and time period. During 11 201 person-years of follow-up, 1334 persons died. Compared with the initial time period, the HR for total mortality was 0.86 (95% confidence interval, 0.73 to 1.01) for 1981 to 1985, 0.82 (0.69 to 0.96) for 1986 to 1990, 0.66 (0.55 to 0.79) for 1991 to 1995, and 0.58 (0.47 to 0.71) for 1996 to 2001 (HR for trend=0.87 [0.84 to 0.91] for each successive time period). In analyses that assessed cardiac mortality, an even stronger temporal association was evident (HR for trend=0.79 [0.75 to 0.84]).

CONCLUSIONS

Long-term survival after resuscitation from SCA improved steadily over time in this cohort. To continue this trend, future studies should identify circumstances in which proven treatments are underutilized as well as investigate new therapies that might benefit survivors of SCA.

Resuscitation of residents with do not resuscitate orders in long-term care facilities

BACKGROUND

A considerable number of emergency medical services (EMS) responses for cardiac arrest occur in long-term care facilities. In some instances, these responses are for residents who have expressed wishes not to be resuscitated by signing a do not resuscitate (DNR) order.

OBJECTIVES

To assess the magnitude of EMS use for cardiac arrest in long-term care facilities for residents with DNR orders and to determine reasons why EMS is called.

METHODS

A retrospective study was conducted using data collected from medical incident reports between July 1999 and December 2000 for all persons experiencing cardiac arrest in long-term care facilities defined as nursing homes, adult family homes, and assisted-living centers in King County, Washington, excluding Seattle. The authors also surveyed facilities to determine their policies for calling 9-1-1 in the event of cardiac arrest. Results. Of the 392 cardiac arrests in long-term care facilities to which EMS responded, 139 (35%) of the residents had DNR orders. Of these 139, 29 (21%) received attempted resuscitation by EMS. The problem appeared to be greater among nursing homes and adult family homes than in assisted-living centers. Among nursing homes, the primary reason for an EMS call was concern for validity of the DNR order, whereas among adult family homes, the primary concern was appropriate medical authority to declare death.

CONCLUSION

Efforts to clarify existing regulations, streamline the DNR transfer process, and improve communication between EMS and long-term care facilities may result in better fulfillment of residents' end-of-life wishes and a saving of EMS resources.

Tissue plasminogen activator in cardiac arrest with pulseless electrical activity

BACKGROUND

Coronary thrombosis and pulmonary thromboembolism are common causes of cardiac arrest. We assessed whether the administration of tissue plasminogen activator (t-PA) during cardiopulmonary resuscitation would benefit patients with cardiac arrest and pulseless electrical activity of unknown or presumed cardiovascular cause.

METHODS

Patients who were older than 16 years of age and who had more than one minute of pulseless electrical activity that was unresponsive to initial therapy outside the hospital or in the emergency department were eligible. Patients were randomly assigned to receive 100 mg of t-PA or placebo intravenously over a 15-minute period in a double-blind fashion. Standard resuscitation was then continued for at least 15 minutes. The primary outcome was survival to hospital discharge.

RESULTS

During the study period, 1583 patients with cardiac arrest were treated and 233 patients were enrolled (117 in the t-PA group and 116 in the placebo group). The characteristics of the patients in the two groups were similar. One patient in the t-PA group survived to hospital discharge, as compared with none in the placebo group (absolute difference between groups, 0.9; 95 percent confidence interval, -2.6 to 4.8; P=0.99). The proportion of patients with return of spontaneous circulation was 21.4 percent in the t-PA group and 23.3 percent in the placebo group (absolute difference between groups, -1.9; 95 percent confidence interval, -12.6 to 8.8; P=0.85).

CONCLUSIONS

We found no evidence of a beneficial effect of fibrinolysis in patients with cardiac arrest and pulseless electrical activity of unknown or presumed cardiovascular cause. Our study had limited statistical power, and it remains unknown whether there is a small treatment effect or whether selected subgroups may benefit.

Influence of early defibrillation on the survival rate and quality of life after CPR in prehospital emergency medical service in a German metropolitan area

Early defibrillation by emergency medical personnel has been shown to improve survival in patients suffering from out-of-hospital cardiac arrest with ventricular fibrillation. Due to organisational differences it is difficult to compare results in various studies. Comparison of studies has been simplified by introduction of the Utstein template. After introduction of an early defibrillation program in Hamburg, we compared the patients being treated with early defibrillation by emergency medical technicians (EMTs) with patients being defibrillated by physicians in an out-of-hospital emergency service in a prospective study. All patients suffered from non EMT-witnessed ventricular fibrillation of cardiac origin. During 1 year, 103 patients were analyzed with respect to survival rate and quality of life. Of the 53 patients in the early defibrillation group (G1) 11 regained a palpable pulse at physicians' arrival, whereas all patients of the control group (G2) showed ventricular fibrillation. More patients treated with early defibrillation regained sinus rhythm without antiarrhythmics in the prehospital phase (G1: n=43 (86%); G2: n=32 (60%); P<0.05) and had a shorter in-hospital stay (G1: median, 23 days; range 5-51 days; G2: median 39, range 15-88 days; P<0.05). Twelve patients in G1 and 16 in G2 were discharged from hospital. The survival rate was similar in both groups (after 6 months G1: n=12; G2: n=14, after 12 months G1: n=10; G2: n=13 and after 24 months G1: n=9; G2: n=10), and the quality of life according to Glasgow-Pittsburgh Cerebral Performance Category (CPC) and Overall Performance Category (OPC) scores also was comparable between groups. We conclude that early defibrillation provides a higher incidence of return of a spontaneous circulation, a reduced need for antiarrhythmics and shorter in-hospital treatment times in patients with out-of-hospital ventricular fibrillation.

Emergency medical services information systems and a future EMS national database

Since the early 1970s, various publications and legislation have contributed to the development of emergency medical services (EMS) information systems and databases. Yet, even today, EMS systems vary in their ability to collect patient and systems data and to put these data to use. In addition, no means currently exists to easily link disparate EMS databases to allow analysis at local, state, and national levels. For this reason, the National Association of State EMS Directors is working with its federal partners at the National Highway Traffic Safety Administration (NHTSA) and the Trauma and EMS program of the Health Resources and Services Administration's (HRSA's) Maternal and Child Health Bureau to develop a national EMS database. Such a database would be useful in developing nationwide EMS training curricula, evaluating patient and EMS system outcomes, facilitating research efforts, determining national fee schedules and reimbursement rates, and providing valuable information on other issues related to EMS care.

Drowning. Rescue, resuscitation, and reanimation

Several myths about drowning have developed over the years. This article has attempted to dispel some of these myths, as follows: 1. Drowning victims are unable to call or wave for help. 2. "Dry drownings" probably do not exist; if there is no water in the lungs at autopsy, the victim probably was not alive when he or she entered the water. 3. Do not use furosemide to treat the pulmonary edema of drowning; victims may need volume. 4. Seawater drowning does not cause hypovolemia, and freshwater drowning does not cause hypervolemia, hemolysis, or hyperkalemia. 5. Drowning victims swallow much more water than they inhale, resulting in a high risk for vomiting spontaneously or on resuscitation. No discussion of drowning would be complete without mentioning the importance of prevention. Proper pool fencing and water safety training at a young age are instrumental in reducing the risk for drowning. Not leaving an infant or young child unattended in or near water can prevent many of these deaths, especially bathtub drownings. Also crucial is the use of personal flotation devices whenever boating. Proper training in water safety is crucial for participation in water recreation and sporting activities, including SCUBA diving. The incidence of pediatric drowning deaths in the United States has decreased steadily over the past decade, perhaps as a result of increased awareness and attention to drowning-prevention measures (Box 1).

Now that we have the Utstein style, are we using it?

OBJECTIVES

To examine the extent to which the Utstein style has been used for out-of-hospital cardiac arrest (OOHCA) research since its publication in 1991. The style was developed in an effort to standardize OOHCA research and reporting.

METHODS

To locate all OOHCA research papers published between 1992 and 1997, all issues of six emergency medicine/emergency medical services (EM/ EMS) journals were examined manually, and papers from other journals were located using computerized searches. All located articles were examined by the first author to determine whether use of the Utstein style was indicated and if so, whether it had actually been used. When either of these was uncertain, all three authors reviewed the paper, and a consensus was reached. The Pearson chi-square test was used to compare rates of use from U.S. and non-U.S. institutions, and from the EM/EMS and non-EM/EMS literature, with significance set at p < 0.05.

RESULTS

All 143 OOHCA research articles identified by the search were examined. The Utstein style was found to be not applicable to 41 (29%), and these were eliminated. The Utstein style was indicated for the remaining 102 studies. Of these, 41 (40%) used the Utstein style, and 61 (60%) did not. There was no difference in rates between papers from sites in the United States (18/48, 38%) and elsewhere (23/54, 43%), or between papers from the EM/EMS literature (17/44, 39%) and non-EM/EMS literature (25/59, 42%). Despite an upward trend in the use of the Utstein style seen from 1992 to 1994, use leveled off from 1994 to 1997, and has not exceeded 60% in any given calendar year studied.

CONCLUSIONS

Six years after the release of the Utstein style for OOHCA research, fewer than 60% of OOHCA research articles actually use the style.

Cardiac arrest in Saudi Arabia: a 7-year experience in Riyadh

All out-of-hospital and Emergency Department (ED) cardiac arrests treated at a tertiary care hospital in Riyadh, Saudi Arabia, from 1989 through 1995 were studied. Of patients arresting out-of-hospital, 3.0% received bystander cardiopulmonary resuscitation (CPR), 9.1% had some prehospital CPR, 12.1% were transported via ambulance, and 13.6% had ventricular fibrillation (VF) on ED arrival. In the witnessed arrests (80%), the estimated interval from arrest to initiation of CPR was 21.1 +/- 14.7 min. None of these variables was shown to influence outcome. Survival to hospital discharge from out-of-hospital arrest was 5.1% for adults and 7.4% for children; all had poor neurologic outcome. For patients arresting in the ED, an initial rhythm of ventricular tachycardia (VT) or VF was strongly correlated with survival. Survival from ED arrest was 30.4% in adults, 42.9% in children; all but one had normal neurologic outcome. These results are similar to those reported from large cities and EDs elsewhere. The unique set of variables influencing out-of-hospital care and transportation in Riyadh are discussed, and potential areas for improvement are noted.

The impact of paramedics on out-of-hospital cardiac arrests in a rural community

OBJECTIVE

To determine whether paramedics influence the outcome of cardiac arrest patients in a rural area.

METHODS

Retrospective analysis of cardiorespiratory arrest patients in rural southeast Alaska from 1987 to 1996.

RESULTS

Paramedics treated 37 patients and advanced life support emergency medical technicians (EMT-IIIs) treated 34 patients. Demographics/CPR variables of the two groups were similar. Return of spontaneous circulation (ROSC) was 46% (17/37) for the paramedic-treated patients and 18% (6/34) for the EMT-III-treated patients (p = 0.01). Intensive care unit (ICU) admission was 38% (14/37) for the paramedic-treated patients and 15% (5/34) for the EMT-III-treated patients (p < 0.03). Discharge from the hospital neurologically intact was 20% (7/35) for the paramedic-treated patients and 9% (3/34) for the EMT-III-treated patients (p = NS). Two patients in the paramedic-treated group had ROSC and survived in the local hospital ICU for several days before being transferred to a tertiary care hospital in another state and were lost to follow-up for the discharge-from-hospital-neurologically-intact category but were included in the ROSC and ICU admission analysis.

CONCLUSION

In this rural setting, a paramedic on the scene significantly improved the ROSC (paramedics = 46% vs 18% for EMT-III, p = 0.01) and survival to ICU admission (38% vs 15%, p = 0.03). The presence of a paramedic on the scene increased survival to hospital discharge neurologically intact (20% vs 9%), although this was not statistically significant.

Randomised comparison of epinephrine and vasopressin in patients with out-of-hospital ventricular fibrillation

BACKGROUND

Studies in animals have suggested that intravenous vasopressin is associated with better vital-organ perfusion and resuscitation rates than is epinephrine in the treatment of cardiac arrest. We did a randomised comparison of vasopressin with epinephrine in patients with ventricular fibrillation in out-of-hospital cardiac arrest.

METHODS

40 patients in ventricular fibrillation resistant to electrical defibrillation were prospectively and randomly assigned epinephrine (1 mg intravenously; n = 20) or vasopressin (40 U intravenously; n = 20) as primary drug therapy for cardiac arrest. The endpoints of this double blind study were successful resuscitation (hospital admission), survival for 24 h, survival to hospital discharge and neurological outcome (Glasgow coma scale). Analyses were by intention to treat.

FINDINGS

Seven (35%) patients in the epinephrine group and 14 (70%) in the vasopressin group survived to hospital admission (p = 0.06). At 24 h, four (20%) epinephrine-treated patients and 12 (60%) vasopressin-treated patients were alive (p = 0.02). Three (15%) patients in the epinephrine group and eight (40%) in the vasopressin group survived to hospital discharge (p = 0.16). Neurological outcomes were similar (mean Glasgow coma score at hospital discharge 10.7 [SE 3.8] vs 11.7 [1.6], p = 0.78).

INTERPRETATION

In this preliminary study, a significantly larger proportion of patients created with vasopressin than of those treated with epinephrine were resuscitated successfully from out-of-hospital ventricular fibrillation and survived for 24 h. Based upon these findings, larger multicentre studies of vasopressin in the treatment of cardiac arrest are needed.

Truncated exponential versus damped sinusoidal waveform shocks for transthoracic defibrillation

Currently available transthoracic defibrillators use either a damped sinusoidal or truncated exponential (TE) waveform. Truncated exponential waveforms deliver a long pulse if the transthoracic impedance is high; it has been suggested that such a long pulse may be less effective for defibrillation. Our objective was to compare the ability of damped sinusoidal (DS) waveform shocks versus TE waveform shocks to terminate ventricular fibrillation (VF) and achieve survival from witnessed cardiac arrest. We retrospectively reviewed field-recorded electrocardiograms from 86 patients with witnessed VF, treated by prehospital personnel equipped with DS or TE waveform defibrillators. Forty-four patients received 130 shocks from TE defibrillators; 42 patients received 108 shocks from DS defibrillators. There were no significant differences in time from arrest to first shock (8.0 vs 8.1 minutes), nor were there any differences in the size of the communities involved. The shocks resulted in the following rhythms: organized rhythm: TE: 15 of 130 (12%), DS: 24 of 108 (22%), p = 0.10 (NS); persistent VF: TE: 85 of 130 (65%), DS: 45 of 108 (42%), p <0.01; asystole: TE: 30 of 130 (23%), DS: 39 of 108 (36%), p = NS; and survival to hospital discharge: TE: 5 of 44 (11%), DS: 8 of 42 (19%), p = NS. We conclude that DS waveforms terminated VF more frequently than TE, but there was no significant difference in resumption of an organized rhythm or survival. A prospective comparison of these 2 waveforms is needed.

Prediction of survival after out-of-hospital cardiac arrest: results of a community-based study in Vienna

The objective of this study was the assessment of out-of-hospital cardiac arrest and the definition of possible predictive factors for final hospital discharge. Out of a database of 89,557 consecutive missions of the Vienna emergency medical system (EMS) during 1990, there were 623 missions due to a collapse of non-traumatic origin: in 374 cases (60.0%) the patients were declared dead without further attempts at resuscitation. The remaining 249 patients were analysed for predictive factors at site. Survival to hospital admission: 109 patients survived to hospital admission (43.7%); bystander support had a small impact (P < 0.05) on survival to hospital arrival whereas age and gender had no predictive power. Most patients with ventricular tachycardia/fibrillation (VT/VF) survived primarily (69 of 117, i.e. 59.0%). Survival to hospital discharge: 27 patients were discharged from hospital care (10.8%). ECG findings on arrival of the EMS physician at the site proved to be the only powerful predictor for survival: 24 of 117 patients with VT/VF survived compared with only one of 81 with primary asystole, two of 39 with severe bradycardia, and no patient with electromechanical dissociation.

Cardiac arrest research in humans--insights into failure

Cardiac arrest research in humans has failed to fulfil expectations generated by laboratory studies. This reflects a number of factors. It is difficult to perform clinical research in the setting of emergency cardiac resuscitation. Both the epidemiology and pathophysiology of sudden death present special problems to the clinical researcher. Laboratory studies and clinical trials have failed to faithfully mimic each other. Estimation of sample size and application of inclusion/exclusion criteria present special problems in methodology. Our focus on improving long term survival by changing one component of therapy may have been premature and obscured the utility of extant data. Many of these problems can be addressed through refinements in: laboratory models, our understanding of the underlying pathophysiology, estimation of sample size, the application of inclusion/exclusion criteria, the identification of the primary dependent variables and subgroups of interest, the overall quality of therapy. Clinical studies will not generate useful data until these issues, among others, have been addressed.

Uniform prehospital data elements and definitions: a report from the uniform prehospital emergency medical services data conference

One of the district and universal aspects of emergency medical service (EMS) is the belief that before its implementation many people were dying or being killed by ill-equipped, poorly trained "hearse drivers" and that this tragic state of affairs has been rectified by the advances in the prehospital phase of care. Except for cases of nontraumatic, out-of-hospital cardiac arrest there is almost no convincing scientific evidence to prove that prehospital care has had an impact on morbidity or mortality. At the very foundation of this problem is the lack of a set of broad-based, well-conceived, accurate, reliable, uniform EMS data. Many attempts have been made to develop a uniform EMS data set, but without a national consensus these have not achieved wide distribution. In 1992, with the assistance of the National Highway Traffic Safety Administration, the national consensus process began with a series of meetings involving many EMS agencies and organizations. This culminated in August 1994 with the development of an 81-item uniform EMS data set. We detail the prior attempts at data set development and outline the process leading to the this uniform, national EMS data set.

Methodology-dependent variation in documentation of outcome predictors in out-of-hospital cardiac arrest

OBJECTIVE

To identify variation in outcome predictor documentation in out-of-hospital cardiac arrest associated with two different methods of data collection: concurrent questioning of personnel following a resuscitation attempt and archival report review.

METHODS

All patients > or = 18 years old who had out-of-hospital cardiac arrests, verified using the New York City 911 telephone system, between October 1, 1990, and April 1, 1991, were eligible for inclusion. The authors reviewed the first 200 cases of presumed primary cardiac arrest involving a resuscitation attempt among 3,243 consecutive ambulance call reports for cardiac arrest occurring during the study period. This archival data set was compared with data for the same 200 cases gathered through direct interview of field personnel by trained paramedics. The two data sets had been compiled independently by different individuals, using the same data collection instrument, which conformed to the Utstein template.

RESULTS

Comparison of the data obtained from ambulance records with the data obtained from interviews of prehospital personnel revealed several areas of variance. Of note was a significantly lower proportion of bystander-witnessed ventricular fibrillation (VF) in the data set gathered from written reports (7% vs 18%; 95% CI for the difference 4-18%; p = 0.001).

CONCLUSION

differences in methods of collection of out-of-hospital cardiac arrest data are associated with a more than twofold variation in the reported incidences of witnessed cardiac arrests manifesting as VF. Methodology-dependent variation in this important "denominator" may produce substantially different estimates of survival within the same cohort of patients.