Can the full range of paramedic skills improve survival from out of hospital cardiac arrests?

OBJECTIVE: To examine the effect of full implementation of advanced skills by ambulance personnel on the outcome from out of hospital cardiac arrest. SETTING: Patients with cardiac arrest treated at the accident and emergency department of the Royal Infirmary of Edinburgh. METHODS: All cardiorespiratory arrests occurring in the community were studied over a one year period. For patients arresting before the arrival of an ambulance crew, outcome of 92 patients treated by emergency medical technicians equipped with defibrillators was compared with that of 155 treated by paramedic crews. The proportions of patients whose arrest was witnessed by lay persons and those that had bystander cardiopulmonary resuscitation (CPR) were similar in both groups. RESULTS: There was no difference in the presenting rhythm between the two groups. Eight of the 92 patients (8.7%) treated by technicians survived to discharge compared with eight of 155 (5.2%) treated by paramedics (NS). Of those in ventricular fibrillation or pulseless ventricular tachycardia, eight of 43 (18.6%) in the technician group and seven of 80 (8.8%) in the paramedic group survived to hospital discharge (NS). For patients arresting in the presence of an ambulance crew, four of 13 patients treated by technicians compared with seven of 15 by paramedics survived to hospital discharge. Only two patients surviving to hospital discharge received drug treatment before the return of spontaneous circulation. CONCLUSIONS: No improvement in survival was demonstrated with more advanced prehospital care.     

Early defibrillation and the chain of survival in 'in-hospital' adult cardiac arrest; minutes count

OBJECTIVE: To report the outcomes from and the impact of the chain of survival in 'in-hospital' cardiac arrest where the presenting rhythm was VF/VT, the arrest was witnessed, defibrillation was conducted rapidly and no other resuscitation interventions were required. Outcome measures: Any return of spontaneous circulation and discharge from hospital. METHODS: A 2-year prospective resuscitation audit using the Utstein style was conducted within a major London NHS Hospital Group. RESULTS: There were 124 patients who had primary VF/VT arrest. Eight were excluded from the study and 14 had non-witnessed cardiac arrest. Twenty one patients had witnessed VF/VT arrest but with delayed defibrillation, 81 patients had witnessed VF/VT arrest with rapid defibrillation, 69 patients had witnessed VF/VT arrest with rapid defibrillation, CPR and other additional interventions. There were 15 patients that had witnessed cardiac arrest with a presenting rhythm of VF/VT, who received rapid defibrillation and had no ventilation or chest compression prior to or following defibrillation. All 15 patients achieved a return of spontaneous circulation, and 12 were discharged alive. CONCLUSIONS: Rapid defibrillation prior to any other resuscitation intervention is associated with increased survival from witnessed VF/VT arrest in in-hospital cardiac arrest victims, and that the time to first shock is critical in enhancing the prospects of long-term survival in these patients.     

Seven years' experience with early defibrillation by police and paramedics in an emergency medical services system

PRIMARY OBJECTIVE: To assess the outcome of patients with out-of-hospital cardiac arrest with ventricular fibrillation as the presenting rhythm in an emergency medical services system utilizing a combined police/paramedic response to provide early defibrillation. MATERIALS AND METHODS: Police and paramedics were dispatched from law enforcement and ambulance communications centers, respectively. First-arriving personnel delivered initial shocks, all using automated external defibrillators. Patients were classified according to response to initial shocks: restoration of pulses with shocks only or in need of advanced life support, including epinephrine. Discharge survival was defined as return to home without disabling neurologic injury. RESULTS: Over the 7-year period of study 131 patients presented with ventricular fibrillation: 58 were first treated by police and 73 by paramedics. Restoration of pulses with shocks only and discharge survival were not different in police and paramedic groups, with overall survival of 40% (53 of 131 patients). Among the survivors, 19% (18/95 patients) obtained a spontaneous circulation only after administration of epinephrine and other ALS interventions. CONCLUSION: Both restoration of a functional circulation, without need for advanced life support interventions, and discharge survival without neurologic disability are very dependent upon the rapidity with which defibrillation is accomplished, regardless of who delivers the shocks. In addition, a smaller but significant number of patients who require ALS interventions, including epinephrine, for restoration of a spontaneous circulation survive to discharge. Short time differences, on the order of 1 min, are significant determinants of both immediate response to shocks and discharge survival.     

Refibrillation,resuscitation and survival in out-of-hospital sudden cardiac arrest victims treated with biphasic automated external defibrillators

PRIMARY OBJECTIVE: Defibrillation is essential for victims of sudden cardiac arrest (SCA) with ventricular fibrillation (VF), yet it does not terminate the underlying causes of VF. Prior to more definitive interventions, these same causes may result in recurrence of VF following defibrillation (refibrillation). The incidence and course of refibrillation, and its relation to patient outcomes, has not been previously described in the context of treatment of out-of-hospital SCA with biphasic waveform automated external defibrillators (AEDs). MATERIALS AND METHODS: ECGs were recovered from all shocks delivered with biphasic AEDs by Basic Life Support (BLS) first responders, primarily police, in witnessed cardiac arrests occurring from December 1996 to December 2001 in the Rochester, MN public service area. Only events prior to administration of cardio-active medications were considered. Frequency and time to occurrence of refibrillation were compared in patients in relation to the progress of their resuscitation and survival. RESULTS AND CONCLUSIONS: One hundred and sixteen of 128 shocks delivered under BLS care to 49 patients with witnessed cardiac arrests presenting with VF terminated VF. Most patients (61%) refibrillated while under BLS care, many (35%) more than once. Occurrence of and time to refibrillation were unrelated to achievement of return of spontaneous circulation (ROSC) under BLS care (BLS ROSC), to survival to hospital discharge and to neurologically intact survival.     

Improving survival after in-hospital cardiac arrest: the Australian experience.

BACKGROUND: Survival rates after in-hospital cardiac arrest have not improved markedly despite improvements in technology and resuscitation training. OBJECTIVES: To investigate clinical variables that influence return of spontaneous circulation and survival to discharge after in-hospital cardiac arrest. METHODS: An Utstein-style resuscitation template was implemented in a 750-bed hospital. Data on 158 events were collected from January 2004 through November 2004. Significant variables were analyzed by using a multiple logistic regression model. RESULTS: Of the 158 events, 128 were confirmed cardiac arrests. Return of spontaneous circulation occurred in 69 cases (54%), and the patient survived to discharge in 41 (32%). An initial shockable rhythm was present in 42 cases (33%), with a return of spontaneous circulation in 32 (76%) and survival to discharge in 24 (57%). An initial nonshockable rhythm was present in the remaining 86 cases (67%), with a return of spontaneous circulation in 37 (43%) and survival to discharge in 17 (20%). Witnessed or monitored arrests (P=.006), time to arrival of the cardiac arrest team (P=.002), afternoon shift (P=.02), and initial shockable rhythm (P=.005) were independently associated with return of spontaneous circulation. Location of patient in a critical care area (P=.002), initial shockable rhythm (P<.001), and length of resuscitation (P=.02) were independently associated with survival to hospital discharge. CONCLUSIONS: The high rate of survival to discharge after cardiac arrest is attributed to extensive education and the incorporation of semiautomatic external defibrillators into basic life support management.     

A model of survival following pre-hospital cardiac arrest based on the Victorian Ambulance Cardiac Arrest Register

AIMS: This study describes the epidemiology of sudden cardiac arrest patients in Victoria, Australia, as captured via the Victorian Ambulance Cardiac Arrest Register (VACAR). We used the VACAR data to construct a new model of out-of-hospital cardiac arrest (OHCA), which was specified in accordance with observed trends. PATIENTS: All cases of cardiac arrest in Victoria that were attended by Victorian ambulance services during the period of 2002-2005. RESULTS: Overall survival to hospital discharge was 3.8% among 18,827 cases of OHCA. Survival was 15.7% among 1726 bystander witnessed, adult cardiac arrests of presumed cardiac aetiology, presenting in ventricular fibrillation or ventricular tachycardia (VF/VT), where resuscitation was attempted. In multivariate logistic regression analysis, bystander CPR, cardiac arrest (CA) location, response time, age and sex were predictors of VF/VT, which, in turn, was a strong predictor of survival. The same factors that affected VF/VT made an additional contribution to survival. However, for bystander CPR, CA location and response time this additional contribution was limited to VF/VT patients only. There was no detectable association between survival and age younger than 60 years or response time over 15min. CONCLUSION: The new model accounts for relationships among predictors of survival. These relationships indicate that interventions such as reduced response times and bystander CPR act in multiple ways to improve survival.     

Outcome after cardiac arrest in adults in UK hospitals: effect of the 1997 guidelines

AIM: To assess the effectiveness of the ILCOR Advisory Statements on Advanced Life Support adopted by the Resuscitation Council (UK), as the standard for resuscitation following cardiac arrest. METHOD: Over the period May to November 1997, data on the process and outcome of cardiopulmonary resuscitation following in-hospital cardiac arrest were collected from 49 hospitals throughout the UK. RESULTS: Of 2074 audit forms submitted, 1368 were included in the final analysis. The initial rhythm monitored was ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) in 429 patients, of whom 181 (42.2%) were discharged alive, compared to 6. 2% when the initial rhythm was non-VF/VT. Overall, 240 (17.6%) patients were discharged alive. At 6 months after discharge 195 (82. 3%) of 237 patients were still alive. Successful initial resuscitation, defined as return of spontaneous circulation lasting longer than 20 min (ROSC>20 min), was significantly associated with VF/VT as the initial arrest rhythm, return of circulation in less than 3 min, age less than 70 years and the use of an advanced airway (P<0.01). There was a significant increased likelihood of survival to discharge when the circulation was restored in less than 3 min and age was less than 70 years (P<0.05). The administration of any adrenaline (epinephrine) was significantly associated with a reduced likelihood of ROSC>20 min or alive discharge (P<0.0001). CONCLUSION: Compared to the last major multiple hospital study published in 1992, the results of this study suggest that there appears to have been an improvement in survival of in-hospital patients in the UK who have a VF/VT cardiac arrest. How much of this is directly attributable to the adoption of the latest guidelines is uncertain.     

Effectiveness of ambulance paramedics versus ambulance technicians in managing out of hospital cardiac arrest.

OBJECTIVE: To determine the effectiveness of extended trained ambulance personnel (paramedics) for the management of out of hospital cardiac arrest. METHODS: A retrospective cohort study of patients who suffered a cardiac arrest between 1 January 1992 and 31 July 1994, and who were transported to their local accident and emergency (A&E) department. Data were collected on basic demography, operational time intervals, and ambulance crew status. Further clinical data were collected, and outcome measures included status on arrival at A&E, status on leaving A&E (hospital admission), and status on leaving hospital. The data were analysed using univariate and multivariate techniques. RESULTS: Univariate analysis showed the likelihood of arriving in A&E with a return of spontaneous circulation was more than doubled among patients attended by a paramedic crew compared with those attended by technicians (relative risk = 2.48, 95% confidence interval 1.34 to 4.60). The likelihood of successful hospital admission was also significantly increased (RR = 1.92, 95% CI 1.13 to 3.27); however, beyond this point, further survival benefits appeared to be much smaller. Similar findings were revealed using multivariate analysis. Second level modelling revealed further possible differences between paramedic and technician crews according to type of incident. Patients successfully admitted to hospital who died before discharge remained severely disabled between admission and death. CONCLUSIONS: There are marked short term survival advantages after cardiac arrest associated with paramedic care, but these probably diminish rapidly over time.     

In-hospital resuscitation among the elderly: Substantial survival to hospital discharge

The appropriateness of aggressive resuscitation in many clinical settings has been questioned. Survival rates from cardiac arrest in the elderly are generally reported as poor, and satisfactory results from resuscitation attempts prolonged beyond 15 minutes are said to be rare. It was the purpose of this study to examine success rates for resuscitation in a cohort of elderly inpatients suffering cardiac arrest. We retrospectively reviewed 213 consecutive cardiac arrests occurring during a 12-month period in a single large tertiary private hospital. Patient age, presenting rhythm, and survival to hospital discharge were recorded. Elderly was defined as age 70 years or older. Cardiac arrests in the elderly totaled 89. Average age in this cohort was 76.2 ± 4.5 years. Eighteen patients (20.2%) had return of spontaneous circulation and 8 patients survived to hospital discharge (44.4% of those with return of spontaneous circulation). No significant difference in age or presenting rhythm of survivors versus nonsurvivors could be demonstrated, although a trend to more frequent ventricular fibrillation or ventricular tachycardia was seen (P = .059, Fisher's exact). Time for resuscitation averaged 25.75 ± 9.2 minutes for survivors and 32.6 ± 22.1 minutes for nonsurvivors. Survival to hospital discharge occurs in 9% of in-hospital cardiac arrests in the elderly following average CPR times substantially in excess of 15 minutes.     

A 2-year prospective cohort study of cardiac resuscitation in a major Canadian hospital

OBJECTIVES: To determine the outcome of cardiopulmonary resuscitation (CPR) for in-hospital cardiac arrest and to identify risk factors associated with survival to the time of hospital discharge. DESIGN: A 2-year prospective cohort study. SETTING: Foothills Medical Centre, a 700-bed tertiary, academic and regional referral centre for Calgary and southern Alberta. PATIENTS: Adult inpatients, excluding those who had cardiac arrest in the Emergency Department or operating room. INTERVENTION: Cardiac resuscitation. MAIN OUTCOME MEASURES: Spontaneous return of the pulse with a minimum systolic blood pressure of 80 mm Hg and survival defined as survival to the time of hospital discharge. RESULTS: In 334 patients there were 390 cardiac arrests, of which 200 were primary cardiac arrests and 39 cardiac arrests that occurred while the resuscitation team was in attendance. Of 239 resuscitated patients, 51 (21.3%) survived. Fifteen variables were identified as being associated with survival. This association could be explained, through multivariate analysis, by the effect of the following 3 variables (odds ratio [OR], 95% confidence interval [CI]): initial observed rhythm other than pulseless electrical activity or asystole (OR 17.34, 95% CI 8.2 to 36.8); a patient who was ambulatory and able to provide self-care (OR 3.8, 95% CI 1.9 to 7.5); and a spontaneous return of circulation with resuscitation in less than 20 minutes (OR 12.9, 95% CI 4.8 to 20.7). CONCLUSIONS: Survival to hospital discharge after cardiac arrest remains static. Initial cardiac rhythm and duration of resuscitation before spontaneous return of circulation were the most important risk factors for survival. These factors and the patient's functional status are relevant when discussing cardiac resuscitation with patients or when considering whether to discontinue resuscitation efforts.     

In-hospital cardiac resuscitation outside the ICU by nursing staff equipped with automated external defibrillators--the first 500 cases

BACKGROUND: Since nursing staff in the hospital are frequently the first to witness a cardiac arrest, they may play a central role in the effective management of in-hospital cardiac arrest. In this retrospective study the first 500 in-hospital cardiac arrests in non-monitored areas, which were treated initially by nursing staff equipped with automated external defibrillators (AEDs) are reported. METHODS AND RESULTS: Between April 2001 and December 2004, 500 in-hospital cardiac arrest calls were made: there were false arrests in 61 patients, so a total of 439 patients (88%) were evaluated using the Utstein style of data collection. ROSC occurred in 256 patients (58%), 125 (28%) were discharged from hospital and 95 (22%) were still alive 6 months after discharge. Among the 73 patients with VF/VT 63 (86%) had ROSC, 34 (47%) were discharged from hospital and 28 (38%) were alive after 6 months. The chance of survival was not influenced by the time between the call of the arrest team and the 1st defibrillation but was slightly higher with physicians as in-hospital first responders (p=0.078). In contrast, 366 patients with non-VF/VT, 193 (53%) had ROSC, but only 91 (25%) were discharged from hospital and 67 (18%) were alive after 6 months. The risk of dying was significantly higher in patients with non-VF/VT (p<0.001), and there was a trend to a higher risk ratio in patients older than 65 years and in patients with non-witnessed cardiac arrest (p=0.056 and 0.079, respectively). CONCLUSION: This observational study supports the concept of hospital-wide first responder resuscitation performed by nursing staff before the arrival of the CPR-team. Among these patients survival rate was higher in those with VF/VT defibrillated at an early stage. Consequently, it may be assumed that patients may die unnecessarily due to sudden cardiac arrest if proper in-hospital resuscitation programmes are not available.     

The presence of an Emergency Airway Response Team and its effects on in-hospital Code Blue

The survival rate from in-hospital cardiac arrest due to pulseless electrical activity (PEA)/asystole in our institution was higher than expected (70%). It was the impression of the Emergency Department-led Code Blue Team (CBT) that many of these patients were actually suffering respiratory arrests before their cardiac events. To address this, the facility developed an early intervention team focused on early airway intervention-the Emergency Airway Response Team (EART). The objective of this study was to assess the effect of early intervention in patients during the "pre-Code Blue" period, specifically with regard to airway stabilization. Our hypothesis was that there would be fewer CBT calls (cardiac arrests) due to PEA and asystole and that the survival from these events would decrease. This was a retrospective review of all cardiac arrests responded to by the CBT and EART for a period of 2 years. Charts were reviewed for the initial presenting rhythm (as defined by the Utstein Format) and event survival for the 12-month period immediately before and immediately after the establishment of the EART (Time Periods 1 and 2, respectively). The total number of CBT calls decreased by 15%, return of spontaneous circulation from any rhythm decreased by 9%, and survival to discharge decreased by 8% (p = non-significant). The number of CBT calls specifically for asystole/PEA decreased by 8%. Deaths in hospital were significantly associated with Period 2 (odds ratio 1.84; 95% confidence interval 1.03-3.28) after adjusting for age, gender, and presenting rhythms. The total number of CBT calls decreased slightly with the creation of the Emergency Airway Response Team. Return of spontaneous circulation and survival to hospital discharge after cardiac arrest due to asystole/PEA were significantly decreased, suggesting early intervention may have benefit.     

Magnesium in cardiac arrest (the magic trial)

The prognosis of out of hospital cardiac arrest (OHCA) is dismal. Recent reports indicate that high dose magnesium may improve survival. A prospective randomized double blind placebo controlled trial was conducted at the emergency department (ED) of Royal Perth Hospital, a University teaching hospital. Patients with OHCA of cardiac origin received either 5 g MgSO4 or placebo as first line drug therapy. The remainder of their management was standard advanced cardiac life support (ACLS). Study endpoints were: (1) ECG rhythm 2 min after the trial drug; (2) return of spontaneous circulation; (3) survival to leave the ED; (4) survival to leave intensive care; and (5) survival to hospital discharge. Of 67 patients enrolled, 31 received magnesium and 36 placebo. There were no significant differences between groups for all criteria, except that there were significantly more arrests witnessed after arrival of EMS personnel in the magnesium group (11 or 35% vs 4 or 11%). Return of spontaneous circulation occurred in seven (23%) patients receiving magnesium and eight (22%) placebo. Four patients in each group survived to leave the ED and one from the magnesium group survived to hospital discharge. There were no survivors in the placebo group. In this study, the use of high dose magnesium as first line drug therapy for OHCA was not associated with a significantly improved survival. Early defibrillation remains the single most important treatment for ventricular fibrillation (VF). Further studies are required to evaluate the role of magnesium in cardiac and cerebral resuscitation.     

Patient outcomes following defibrillation with a low energy biphasic truncated exponential waveform in out-of-hospital cardiac arrest

PRIMARY OBJECTIVE: To determine the outcome of patients with out-of-hospital cardiac arrest and ventricular fibrillation as the presenting rhythm while using automated external defibrillators (AEDs) that delivered non-escalating, impedance-compensated low-energy (150 J) shocks. MATERIALS and METHODS: AEDs delivering low-energy biphasic truncated exponential (BTE) shocks were employed in an emergency medical services (EMS) system in which first-arriving personnel - police, firefighters or paramedics - delivered the initial shocks. Patients were classified according to their response to shocks: restoration of sustained spontaneous circulation (ROSC) without need for epinephrine and other advanced life support (ALS) interventions; and ALS, those requiring epinephrine in all instances. The primary end-point was neurologically-intact discharge survival. Secondary end-points were ROSC with shocks only and the call-to-shock time interval. RESULTS: Of 42 patients with VF arrest treated with BTE shocks, 35 were bystander-witnessed. Of these 35, 14 (38%) regained a sustained ROSC on-scene with shocks only, needing no epinephrine for ROSC. All 14 survived to discharge home. Of the remaining 21 patients needing ALS intervention, only two (9.5%) survived to discharge. Overall, 16/35 patients (46%) survived to discharge home, an outcome comparable to our experience with patients treated with escalating high-energy monophasic waveform shocks. CONCLUSIONS: Low-energy (150 J) non-escalating biphasic truncated exponential waveform shocks terminate VF in out-of-hospital cardiac arrest with high efficacy; patient outcome is comparable with that observed with escalating high-energy monophasic shocks. Low-energy shocks, in addition to high efficacy, may confer the advantage of less shock-induced myocardial dysfunction, though this will be difficult to define in the clinical circumstance of long-duration VF provoked by a pre-existing diseased myocardial substrate.     

Population Density, Automated External Defibrillator Use, and Survival in Rural Cardiac Arrest

Objective: To determine whether population density is an independent predictor of survival from out-of-hospital cardiac arrest managed by basic life support (BLS) services using automated external defibrillators (AEDs).
Methods: A retrospective, observational study in Kentucky of 34 BLS services covering 22 counties during the years 1992 to 1994 who used AEDs to treat patients who had out-of-hospital cardiac arrests.
Results: Of 311 patients who had out-of-hospital cardiac arrests, 110 (35%) were defibrillated, 46 (15%) were resuscitated to hospital admission, and 19 (6%) survived to hospital discharge. Univariate predictors for survival to hospital discharge were emergency medical services response interval (from call receipt to ambulance arrival) <8 minutes, defibrillation by the AED, initial rhythm of ventricular fibrillation or ventricular tachycardia (VF/VT), and population density >100/square mile (sq mi) for the BLS service area (p < 0.001). A forced logistic regression model of survival to hospital discharge, using these 4 factors plus the presence of a witnessed arrest or bystander CPR, demonstrated that population density >100/sq mi was highly significant (OR 9.4, 95% CI: 1.7 to 51.4, p < 0.01). Stepwise logistic regression models with combinations of these 6 factors found that survival to hospital discharge was best predicted by an initial rhythm of VF/VT (p = 0.004) and population density >100/sq mi (p = 0.011).
Conclusions: Population density is strongly associated with survival from out-of-hospital cardiac arrest. BLS services within areas with population densities ≤100/sq mi sustained little benefit from the addition of AEDs to their treatment of patients who had out-of-hospital cardiac arrests.     

A Utstein-style analysis of prognostic factors related to survival in out-of-hospital cardiac arrests in Akita-City, Japan

To analyze the epidemiology of out-of-hospital cardiac arrests and to elucidate modifiable factors affecting survival, we conducted a prospective cohort study in a middle-sized urban city served by a single emergency medical service (EMS) system in which emergency medical technicians use an automated external defibrillator. Data were collected from out-of-hospital cardiac arrests occurring between 1 January, 1994 and 31 December, 1998 by applying the Utstein style. The main outcome measure was survival at 1 year after hospital discharge. The overall incidence of out-of-hospital cardiac arrest was 71.7/100 000 inhabitants/year. Resuscitations were attempted in 762 of 1118 patients with confirmed cardiac arrest. Of the 762 patients, 37 (4.86%) survived. The cause of cardiac arrest was presumed to be cardiac in 340 (44.6%). Of the 340 cardiac arrests, 180 (52.9%) were witnessed by bystanders. Ventricular fibrillation (VF) was recorded as an initial rhythm in 56 (31.1%) of the 180 patients, and cardiopulmonary resuscitation (CPR) was performed by bystanders in 89 (49.4%). The survival rate was 39.2% (22/56) when cardiac arrest was bystander-witnessed and of cardiac origin with VF as an initial rhythm. VF as an initial rhythm, age of the patients and intervals of call-to-first CPR attempt and collapse-to-arrival at patient's side were major factors relating to survival in the witnessed cardiac arrests of cardiac origin. The age, and gender of the patients, place of collapse and intervals of collapse-to-first CPR and collapse-to-arrival at patient's side were representative factors affecting the incidence of VF as an initial rhythm. The survival rate in Akita-City from bystander-witnessed cardiac arrests of cardiac origin with VF as an initial rhythm was comparable to those in other regions with advanced EMS systems. However, the incidence of VF as an initial rhythm is extremely low. Reduction of intervals of call (collapse)-to-first CPR attempt and collapse-to-arrival at patient's side or authorization of use of automated external defibrillator in basic life support may increase the incidence of VF as an initial rhythm and improve the survival from witnessed cardiac arrests with cardiac origin.     

Predicting survival from out-of-hospital cardiac arrest.

OBJECTIVE: To determine the effect of a return of spontaneous circulation (RO SC) on survival to hospital discharge as compared to other established predictors of survival. METHODS: A retrospective case review of all out-of-hospital primary cardiac arrests from 01 January, 1992 to 31 December 1994 was conducted. The relative values of age, race, gender, presenting cardiac rhythm, witnessed event, initiation of CPR by bystanders, response time intervals, and return of spontaneous circulation (ROSC) in an Utstein-template database were tested as predictors of survival of patients who had suffered a cardiac arrest in the out-of-hospital setting. The ROSC was defined as return of spontaneous circulation prior to and present upon arrival at the emergency department. Predictors were evaluated for statistical significance using a logistic regression analysis (p < 0.05). Odds ratios (OR) and 95% confidence intervals (CI) with positive and negative predictive values (PPV, NPV) were calculated. RESULTS: Of 832 patients with primary cardiac arrest, 153 (18.4%) had ROSC and 67 (8.1%) survived to hospital discharge. Comparing survivors to nonsurvivors, the mean values for age were 64 to 67 years, with 59.7% to 36.1% being witnessed, 35.8% to 23.9% having bystander CPR initiated, 88.1% to 48.4% having ventricular fibrillation (V-fib) and 82.1% to 64.0% having ROSC. An initial electrocardiographic rhythm of V-fib (p = 0.009; OR = 2.2; CI = 1.2-3.9), and ROSC (p < 0.0001; OR = 5.2; CI = 3.6-7.5) are statistically significant predictors of survival to hospital discharge. The PPV was 13.8% for V-fib and 35.9% for ROSC, and the NPV was 98.0% for V-fib and 98.2% for ROSC. CONCLUSION: Presenting V-fib and out-of-hospital ROSC are significant predictors of survival from cardiac arrest. Failure to obtain ROSC in the out-of-hospital setting strongly suggests consideration for terminating resuscitation efforts.     

Comparison of two methods of transporting paramedics to cardiac arrests outside hospital.

OBJECTIVE: To compare the deployment of paramedics in a separate rapid response unit with their deployment in a standard emergency ambulance. DESIGN: A one year period of each deployment. SETTING: Throughout the community in some parts of West Yorkshire. PARTICIPANTS: All patients receiving resuscitation for cardiac arrest by paramedics. INTERVENTIONS: Using the same group of paramedics and central control, 12 months with the paramedics deployed in separate cars in addition to the standard ambulances (period 1) were followed by another 12 months when they were deployed as one crew member of a standard emergency ambulance (period 2). MAIN OUTCOME MEASURES: Number of arrests attended, number of patients in ventricular fibrillation at paramedic arrival, response times, survival to leave hospital. RESULTS: In period 1, 580 arrests were attended with 31 survivors. In period 2, 462 arrests resulted in 25 survivors. The mean response time was shorter in period 1 (6.24 versus 6.60 min, Cl--0.01-0.73 min). In period 1, 217 patients were found in ventricular fibrillation (23 survivors): In period 2, 141 patients were found in ventricular fibrillation (11 survivors). CONCLUSION: Separating paramedics from the standard emergency ambulances increases the number of survivors of cardiac arrest but the difference may not be sufficiently large to justify the additional expenditure.     

Rapid on-site defibrillation versus community program

INTRODUCTION: For patients who suffer out-of-hospital cardiac arrest, the time from collapse to initial defibrillation is the single most important factor that affects survival to hospital discharge. The purpose of this study was to compare the survival rates of cardiac arrest victims within an institution that has a rapid defibrillation program with those of its own urban community, tiered EMS system. METHODS: A logistic regression analysis of a retrospective data series (n = 23) and comparative analysis to a second retrospective data series (n = 724) were gathered for the study period September 1994 to September 1999. The first data series included all persons at Casino Windsor who suffered a cardiac arrest. Data collected included: age, gender, death/survival (neurologically intact discharge), presenting rhythm (ventricular fibrillation (VF), ventricular tachycardia (VT), or other), time of collapse, time to arrival of security personnel, time to initiation of cardiopulmonary resuscitation (CPR) prior to defibrillation (when applicable), time to arrival of staff nurse, time to initial defibrillation, and time to return of spontaneous circulation (if any). Significantly, all arrests within this series were witnessed by the surveillance camera systems, allowing time of collapse to be accurately determined rather than estimated. These data were compared to those of similar events, times, and intervals for all patients in the greater Windsor area who suffered cardiac arrest. This second series was based upon the Ontario Prehospital Advanced Life Support (OPALS) Study database, as coordinated by the Clinical Epidemiology Unit of the Ottawa Hospital, University of Ottawa. RESULTS: The Casino Windsor had 23 cases of cardiac arrests. Of the cases, 13 (56.5%) were male and 10 (43.5%) were female. All cases (100%) were witnessed. The average of the ages was 61.1 years, of the time to initial defibrillation was 7.7 minutes, and of the time for EMS to reach the patient was 13.3 minutes. The presenting rhythm was VF/VT in 91% of the case. Fifteen patients were discharged alive from hospital for a 65% survival rate. The Greater Windsor Study area included 668 cases of out-of-hospital cardiac arrest: Of these, 410 (61.4%) were male and 258 (38.6%) were female, 365 (54.6%) were witnessed, and 303 (45.4%) were not witnessed. The initial rhythm was VF/VT was in 34.3%. Thirty-seven (5.5%) were discharged alive from the hospital. CONCLUSION: This study provides further evidence that PAD Programs may enhance cardiac arrest survival rates and should be considered for any venue with large numbers of adults as well as areas with difficult medical access.     

CPR before defibrillation in out-of-hospital cardiac arrest: a randomized trial

Objective: Current resuscitation guidelines recommend that defibrillation be undertaken as soon as possible in patients suffering a cardiac arrest where the cardiac rhythm is either ventricular fibrillation (VF) or ventricular tachycardia (VT). Evidence from animal and clinical studies suggests that outcomes may be improved if a period of cardiopulmonary resuscitation (CPR) is given prior to defibrillation. The objective of this study was to determine if 90 seconds of CPR before defibrillation improved survival. Methods: Patients suffering non‐paramedic witnessed VF/VT cardiac arrest were randomized to receive either 90 seconds of CPR before defibrillation (treatment) or immediate defibrillation (control). The study was carried out in Perth, Western Australia between June 2000 and June 2002. The primary endpoint was survival to hospital discharge with secondary endpoints of return of spontaneous circulation (ROSC) and survival at 1 year. Results: A total of 256 patients underwent randomization. Baseline characteristics including response intervals were similar in both groups. Survival to hospital discharge in the CPR first group was 4.2% (5/119) compared with 5.1% (7/137) for the immediate defibrillation group (OR 0.81; 95%CI. 0.25–2.64). No difference in those achieving ROSC was observed between the groups (OR 1.16; 95% CI 0.49–2.80). Conclusion: Ninety seconds of CPR before defibrillation does not improve overall survival in patients suffering VF/VT cardiac arrests. Further studies to evaluate various aspects of this treatment strategy are required as published outcomes to date are inconclusive.