Survival from prehospital cardiac arrest is critically dependent upon response time

STUDY OBJECTIVE: This study correlated the delay in initiation of bystander cardiopulmonary resuscitation (ByCPR), basic (BLS) or advanced cardiac (ACLS) life support, and transport time (TT) to survival from prehospital cardiac arrest. This was a secondary endpoint in a study primarily evaluating the effect of bicarbonate on survival. DESIGN: Prospective multicenter trial. SETTING: Patients treated by urban, suburban, and rural emergency medical services (EMS) services. PATIENTS: Eight hundred and seventy-four prehospital cardiac arrest patients. INTERVENTIONS: This group underwent conventional ACLS intervention followed by empiric early administration of sodium bicarbonate noting resuscitation times. Survival was measured as the presence of vital signs on emergency department (ED) arrival. Data analysis utilized Student's t-test and logistic regression (p<0.05). RESULTS: Survival was improved with decreased time to BLS (5.52 min versus 6.81 min, p=0.047) and ACLS (7.29 min versus 9.49 min, p=0.002) intervention, as well as difference in time to return of spontaneous circulation (ROSC). The upper limit time interval after which no patient survived was 30 min for ACLS time, and 90 min for transport time. There was no overall difference in survival except at longer arrest times when considering the primary study intervention bicarbonate administration. CONCLUSION: Delay to the initiation of BLS and ACLS intervention influenced outcome from prehospital cardiac arrest negatively. There were no survivors after prolonged delay in initiation of ACLS of 30 min or greater or total resuscitation and transport time of 90 min. This result was not influenced by giving bicarbonate, the primary study intervention, except at longer arrest times.     

Prehospital cardiac arrest outcome is adversely associated with antiarrythmic agent use, but not associated with presenting complaint or medical history

Methods: This prospective multicentre trial enrolled 874 prehospital cardiac arrest patients encountered by urban, suburban, and rural emergency medical services. This group underwent conventional ACLS intervention followed by empiric early administration of sodium bicarbonate (1mEq/l). Survival was measured as the presence of vital signs on emergency department arrival. Data analysis used Student's t test, Fisher's exact test, χ² with Pearson correlation, and logistic regression (p<0.05).

Secondary end points were analysed including an association with common historical variables such as medical history, presenting complaint, or drugs used.

Results: The overall survival rate was 13.9% (110 of 793) of prehospital arrest patients. There was no correlation between historical factors, such as chief complaint or history of present illness (p = 0.277), medical history (p = 0.425), presence of specific disease conditions (p = 0.1125–0.956), or overall drug use (p = 0.002–0.9848). However, there was an adverse association between specific antiarrhythmic use (p = 0.003) and outcome.

Conclusion: There is little relation of patient historical factors on the outcome from prehospital cardiac arrest raising issues of efficiency with history taking in prehospital care and transport.

     

Neurological outcomes in patients transported to hospital without a prehospital return of spontaneous circulation after cardiac arrest

Introduction

As emergency medical services (EMS) personnel in Japan are not allowed to perform termination of resuscitation in the field, most patients experiencing an out-of-hospital cardiac arrest (OHCA) are transported to hospitals without a prehospital return of spontaneous circulation (ROSC). As the crucial prehospital factors for outcomes are not clear in patients who had an OHCA without a prehospital ROSC, we aimed to determine the prehospital factors associated with 1-month favorable neurological outcomes (Cerebral Performance Category scale 1 or 2 (CPC 1–2)).

Methods

We analyzed the data of 398,121 adult OHCA patients without a prehospital ROSC from a prospectively recorded nationwide Utstein-style Japanese database from 2007 to 2010. The primary endpoint was 1-month CPC 1–2.

Results

The rate of 1-month CPC 1–2 was 0.49%. Multivariate logistic regression analysis indicated that the independent variables associated with CPC 1–2 were the following nine prehospital factors: (1) initial non-asystole rhythm (ventricular fibrillation (VF): adjusted odds ratio (aOR), 9.37; 95% confidence interval (CI), 7.71 to 11.4; pulseless ventricular tachycardia (VT): aOR, 8.50; 95% CI, 5.36 to 12.9; pulseless electrical activity (PEA): aOR, 2.75; 95% CI, 2.40 to 3.15), (2) age <65 years (aOR, 3.90; 95% CI, 3.28 to 4.67), (3) arrest witnessed by EMS personnel (aOR, 2.82; 95% CI, 2.48 to 3.19), (4) call-to-hospital arrival time <24 minutes (aOR, 2.58; 95% CI, 2.22 to 3.01), (5) arrest witnessed by any layperson, (6) physician-staffed ambulance, (7) call-to-response time <5 minutes, (8) prehospital shock delivery, and (9) presumed cardiac cause. When four crucial key factors (with an aOR >2.0 in the regression model: initial non-asystole rhythm, age <65 years, EMS-witnessed arrest, and call-to-hospital arrival time <24 minutes) were present, the rates of 1-month CPC 1–2 and 1-month survival were 16.1% and 23.2% in initial VF, 8.3% and 16.7% in pulseless VT, and 3.8% and 9.4% in PEA, respectively.

Conclusions

In OHCA patients transported to hospitals without a prehospital ROSC, nine prehospital factors were significantly associated with 1-month CPC 1–2. Of those, four are crucial key factors: initial non-asystole rhythm, age <65 years, EMS-witnessed arrest, and call-to-hospital arrival time <24 minutes.     

Amiodarone and rural emergency medical services cardiac arrest patients: A cost analysis

Objective: Recent American Heart Association guidelines suggest amiodarone as an antiarrhythmic in refractory ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). The authors sought to assess the impact of amiodarone use on outcomes and cost associated with this practice in a rural emergency medical services (EMS) state. Methods: Statewide EMS records were reviewed for the calendar year 1999. Data reviewed included prehospital diagnosis, medications given by prehospital providers to patients with cardiac arrest, and procedures performed, including cardiopulmonary resuscitation (CPR) and defibrillation. Cost-benefit analysis assumed the cost of amiodarone treatment to be $137.65 per patient encounter. Absolute risk reduction (ARR) and number needed to treat (NNT) analysis utilized resuscitation rates published in the ARREST and ALIVE trials. Results: During the study period, EMS providers diagnosed 2,189 patients as having cardiac arrest. Five hundred thirty-five (24.4%) cardiac arrest patients were defibrillated. One hundred sixty patients (7.3%), including 15 who did not receive defibrillation, were given lidocaine during resuscitation efforts. The annual cost increase from current practice for a statewide amiodarone VF/VT protocol was $21,822.40 (10,572.87%). The initial cost to stock EMS vehicles for this protocol would be $50,115.52. The cost-benefit analysis yielded a potential for one additional patient survival to hospital discharge in Maine per 3.125 years of system-wide practice at a cost of $68,840.00. Conclusion: Based on current data, instituting amiodarone treatment for refractory VF and pulseless VT in a rural EMS setting requires the investment of substantial resources, relative to current treatment strategies, for any potential survival benefit. PREHOSPITAL EMERGENCY CARE 2002;6:291-294     

Characteristics of prehospital cardiac arrest patients in Japan and determinant factors for survival

Two hundred forty-seven consecutive patients who had prehospital cardiac arrest and were transferred to a municipal hospital were studied to elucidate the characteristics of these patients and to investigate factors for improving the survival rate among prehospital cardiac arrest patients. Detailed information on 130 patients with cardiac etiology was analyzed: 110 were confirmed dead in the emergency department (group A); 14 survived less than 1 week (group B); 6 survived longer than 1 week (group C). Only one patient received cardiopulmonary resuscitation (CPR) from a bystander, and none received electrical defibrillation before arriving at hospital because, at the time, emergency personnel were not allowed to perform advanced life support (ALS) in Japan. The three characteristics for better prognosis after prehospital cardiac arrest were found to be as follows: being witnessed on collapse, receiving prompt ALS, and ventricular fibrillation on arrival at hospital. The survival rate would have been higher if more lay people could have performed CPR and if emergency unit personnel had been allowed to perform ALS.     

An outcome study of out-of-hospital cardiac arrest using the Utstein template--a Japanese experience

Publication of the Utstein style template has made it possible to evaluate and compare national, regional, and hospital based Emergency Medical Services. This research was a national investigation to present outcome data for out-of-hospital cardiac arrest (OHCA) patients in Japan. 3029 OHCA patients who were transported to 10 Emergency and Critical Care Medical Center from November 1997 to April 1999 were recorded according to the Utstein style and the outcome evaluated by logistic regression analysis. Among 3029 OHCA patients, 109 were found dead. The remaining 2920 patients who underwent cardiopulmonary resuscitation (CPR) by emergency medical technicians (EMT) were included in this study. Among these patients, 1294 were considered of primary cardiac origin patients by the EMT and 722 of these patients suffered a witnessed cardiac arrest. Bystander CPR were performed in 28.4% of these witnessed patients and the discharge rate was 3.5% overall and 11.4% in witnessed VF/VT. Outcome analysis showed that a discharge rate in witnessed primary cardiac arrest was 30% in prehospital resuscitation which was 7.5 times higher than in-hospital emergency room resuscitation groups (4.0%). The longer the interval between an emergency telephone call and defibrillation, the lower the 1 month survival rate, which reached almost 0% at 30 min. Follow up evaluation after discharge revealed that the survival rate rapidly decreased from 24 h to 3 months, then became a plateau in primary cardiac patients was rapidly decreased from 24 h to 1 month, then became a near plateau in non-cardiac origin group. To improve the resuscitation rate in the prehospital phase, a prehospital medical control system should be developed with expansion of on scene techniques by Japanese paramedics such as tracheal intubation, administration of emergency drugs and early defibrillation with standing orders. Education and motivation of first responders will be needed and every effort should be concentrated on improving bystander CPR rate.     

Resuscitation Predictor Scoring Scale for inhospital cardiac arrests

Objectives: The purpose of this study was to determine the key factors influencing survival from cardiopulmonary resuscitation attempts and to produce a survival predictor scale for use during a resuscitation attempt.

Method: Bivariate analysis of individual survival predictors and a prospective analysis of survival based on logistic regression models. Included in this seven year study (1993–2000) were 2567 inhospital resuscitation calls of which 1633 received full cardiopulmonary resuscitation. Immediate, 24 hour and discharge survival rates were the main outcome measures with additional analysis for the development of the Resuscitation Predictor Scoring Scale (RPS Scale).

Results: The immediate survival rate was 41%, 28% at 24 hours, and 19% by discharge. Multivariate analysis showed the main factors influencing 24 hour survival to be the duration of the arrest, primary arrhythmia (VT, VF, asystole, or PEA), age, and the primary mode of arrest (respiratory or cardiac). The RPS Scale was developed from these key predictors giving resuscitation teams an accurate prediction of survival 15 minutes into a resuscitation attempt.

Conclusion: Data collection and analysis of cardiopulmonary resuscitation attempts are essential for the formulation of survival indicators. In this case the data have enabled the formulation of a survival predictor scale that will quantify the decision making process regarding the termination of cardiopulmonary resuscitation attempts.

     

Numerators, denominators, and survival rates: reporting survival from out-of-hospital cardiac arrest

This study demonstrates the effect of different denominators on the survival rate from out-of-hospital cardiac arrest. We retrospectively analyzed data from a cardiac arrest surveillance system in King County, Washington during the years 1976 to 1988, and calculated survival rates using eight different definitions of denominators. The eight survival rates ranged from 16% to 49% discharge from hospital. The denominator for the lowest survival rate included all cases of cardiac arrest for whom emergency medical services personnel started cardiopulmonary resuscitation. The denominator for the highest survival rate included: all cases of presumed cardiac etiology; first recorded rhythm was ventricular fibrillation; collapse witnessed; cardiopulmonary resuscitation started by bystanders within 4 minutes; and definitive care provided within 8 minutes. The definition of cases included in the denominator can dramatically effect the resultant survival rate. There must be national and international agreement about definitions of denominators for valid cross community comparisons.     

Aetiology of unsuccessful prehospital witnessed cardiac arrest of unclear origin.

OBJECTIVES: To determine, by means of autopsy, the cause of death following unsuccessful cardiopulmonary resuscitation of patients with a witnessed prehospital cardiac arrest of unclear origin. METHOD: Observational study of all prehospital-witnessed cardiac arrest of unclear origin over a period of 19 months in the emergency medical service region of a tertiary care hospital. RESULTS: During the study period, 211 prehospital cardiopulmonary resuscitation attempts were recorded. In 144 study participants, cardiopulmonary resuscitation was not successful: there was no return of spontaneous circulation. Cardiac arrest of traumatic or other clear origin was not considered, nor were paediatric cases. Thirty out of the 114 remaining patients underwent an autopsy (26.3%). The main aetiology of cardiac arrest in this selected population was ischaemic heart disease in 16 out of 30 patients (53.3%) followed by pulmonary embolism in four patients (13.3%) and vascular disease other than coronary disease in two patients (6.7%). Other causes consisted of hypertrophic obstructive cardiomyopathy (one patient) (3.3%) and poisoning (one patient) (3.3%). The cause of death could not be identified in six cardiac arrest victims (20%). CONCLUSIONS: Ischaemic heart disease and pulmonary embolism account for 66.6% of all witnessed cardiac arrest with no return of spontaneous circulation.     

Time to intubation and survival in prehospital cardiac arrest

Objective

To examine the correlation between time to paramedic intubation and survival after prehospital cardiac arrest.

Methods

This was a retrospective cohort study of 693 patients who had paramedic endotracheal intubation for prehospital cardiac arrest in King County, Washington (excluding Seattle), between January 1991 and May 2003. Based on the time from patient collapse until intubation, cases were divided into quartiles. Survival in the slower three quartiles (defined as “slow intubation”) was compared with survival in the fastest quartile (defined as “quick intubation”).

Results

In the quick intubation group (intubation time ≤12 minutes), 46% of the patients survived; in the slow intubation group (intubation time ≥13 minutes), 23% of the patients survived. Logistic regression was used to adjust for possible confounders that affect survival: age, gender, location, bystander cardiopulmonary resuscitation, cardiac rhythm, emergency medical technician response time, and paramedic response time. The fully adjusted odds ratio of survival for the slow intubation group compared with the quick intubation group was 0.42 (95% confidence interval 0.26, 0.69).

Conclusions

This study is the first of its kind to compare survival with the time interval until an aspect of advanced life support is performed. These findings suggest that faster intubation times may increase odds of survival in prehospital cardiac arrest. Future prospective studies are merited to further understand this association.     

Sodium bicarbonate improves outcome in prolonged prehospital cardiac arrest

OBJECTIVE: This study evaluates the effect of early administration of an empirical (1 mEq/kg) sodium bicarbonate dose on survival from prehospital cardiac arrest within brief (<5 minutes), moderate (5-15 minutes), and prolonged (>15 minutes) down time. METHODS: Prospective randomized, double-blinded clinical intervention trial that enrolled 874 prehospital cardiopulmonary arrest patients managed by prehospital, suburban, and rural regional emergency medical services. Over a 4-year period, the randomized experimental group received an empirical dose of bicarbonate (1 mEq/kg) after standard advanced cardiac life support interventions. Outcome was measured as survival to emergency department, as this was a prehospital study. RESULTS: The overall survival rate was 13.9% (110/792) for prehospital arrest patients. There was no difference in the amount of sodium bicarbonate administered to nonsurvivors (0.859 +/- 0.284 mEq/kg) and survivors (0.8683 +/- 0.284 mEq/kg) (P = .199). Overall, there was no difference in survival in those who received bicarbonate (7.4% [58/420]), compared with those who received placebo (6.7% [52/372]) (P = .88; risk ratio, 1.0236; 0.142-0.1387). There was, however, a trend toward improved outcome with bicarbonate in prolonged (>15 minute) arrest with a 2-fold increase in survival (32.8% vs 15.4%; P = .007). CONCLUSION: The empirical early administration of sodium bicarbonate (1 mEq/kg) has no effect on the overall outcome in prehospital cardiac arrest. However, a trend toward improvement in prolonged (>15 minutes) arrest outcome was noted.     

Prehospital resuscitation in Helsinki, Finland

Helsinki, a city of 500,000 inhabitants, is served by a two-tiered emergency medical system with basic emergency medical technicians in ordinary ambulances and one physician-staffed prehospital emergency care unit. All 266 patients with prehospital cardiopulmonary resuscitation during 1987 were studied. Two hundred twelve patients with presumed heart disease and a witnessed arrest were analyzed further. Their response times for basic life support and advanced life support were 5.5 and 10.7 minutes, respectively. The initial cardiac rhythm in 144 patients (68%) was ventricular fibrillation. In 79 of these patients, cardiopulmonary resuscitation was successful, and 39 patients (27%) were discharged from hospital. The patients who survived had shorter response times for basic life support and their arrest locations was more often outside home, compared with the nonsurvivors. The results seem comparable with emergency medical systems in the United States, but a need to reduce response times is identified.     

Out-of-hospital cardiac arrest in an oriental metropolitan city

To investigate the epidemiology of out-of-hospital cardiac arrest in Taipei City, Taiwan, a prospective chart review and follow-up study was conducted by collecting the prehospital cardiac arrest record from 10 designated responsible emergency departments (EDs) from August 1, 1992 through May 31, 1993. Cases with the restoration of spontaneous circulation (ROSC) were followed up until discharged from hospital. The information gathered included age, sex, bystander cardiopulmonary resuscitation, response time (time elapsed from receiving the call to arrival on the scene), advanced cardiac life support (ACLS) time (time elapsed from receiving the call to arrival at the ED), initial cardiac rhythm in the ED, ROSC, survival to discharge from the hospital, underlying disease, past history, personal history, and neurological outcome at discharge. Of 638 out-of-hospital cardiac arrests, 554 (86.7%) were nontraumatic. Response time, ACLS time, ROSC rates, and survival rates were 7.4 minutes, 21.6 minutes, 15.8%, and 1.4%, respectively. In comparing the trauma and nontrauma group, there were significant differences in age, sex, response time, and ACLS time. Between cases of patients who had ROSC and those who died, the data were statistically significant, P = .0143, showing that ACLS time was shorter in the ROSC group (19.5 v 21.9 minutes). In analysis of underlying disease, definite and probable cardiac-origin sudden deaths were found in only 120 patients, which may extend the annual sudden cardiac death rates to be 0.0053%. In conclusion, the low resuscitation and survival rates in this country were because of delayed initiation of both basic life support and ACLS. Out-of-hospital arrests of noncardiac origin had an extremely low survival rate     

Rethinking bystander CPR for out-of-hospital cardiac arrest

Citation

SOS-KANTO study group: Cardiopulmonary resuscitation by bystanders with chest compression only (SOS-KANTO): an observational study. Lancet 2007, 369:920–926 [1].

Background

Mouth-to-mouth ventilation is a barrier to bystanders doing cardiopulmonary resuscitation (CPR), but few clinical studies have investigated the efficacy of bystander resuscitation by chest compressions without mouth-to-mouth ventilation (cardiac-only resuscitation).

Methods

Objective

To compare the effect of bystander-provided cardiac-only resuscitation to conventional CPR in adults who had out-of-hospital cardiac arrest.

Design

Prospective multicenter observational study.

Setting

58 emergency hospitals and emergency medical service units in the Kanto region of Japan.

Subjects

Patients with witnessed out-of-hospital cardiac arrest who were subsequently transported by paramedics to participating emergency hospitals. Exclusion criteria were age <18 years, further cardiac arrest after the arrival of paramedics, documented terminal illness, presence of a do-not-resuscitate order, and bystander resuscitation without documented chest compressions.

Intervention

None. On arrival at the scene, paramedics assessed the technique of bystander resuscitation, recording it as conventional CPR (chest compressions with mouth-to-mouth ventilation), cardiac-only resuscitation (chest compressions alone), or no bystander CPR. Patients were followed and revaluated 30 days after the arrest to determine neurologic status.

Outcome

The primary endpoint was favorable neurological outcome 30 days after cardiac arrest using the Glasgow-Pittsburgh cerebral-performance scale, with favorable neurological outcome defined as a category 1 (good performance) or 2 (moderate disability) on a 5-point scale.

Results

4068 adult patients who had out-of-hospital cardiac arrest witnessed by bystanders were included; 439 (11%) received cardiac-only resuscitation from bystanders, 712 (18%) conventional CPR, and 2917 (72%) received no bystander CPR. Any resuscitation attempt was associated with a higher proportion having favorable neurological outcomes than no resuscitation (5.0%vs 2.2%, p < 0.0001). Cardiac-only resuscitation resulted in a higher proportion of patients with favorable neurological outcomes than conventional CPR in patients with apnea (6.2%vs 3.1%; p = 0.0195), with shockable rhythm (19.4%vs 11.2%, p = 0.041), and with resuscitation that started within 4 min of arrest (10.1%vs 5.1%, p = 0.0221). However, there was no evidence for any benefit from the addition of mouth-to-mouth ventilation in any subgroup. The adjusted odds ratio for a favorable neurological outcome after cardiac-only resuscitation was 2.2 (95% CI 1.2–4.2) in patients who received any resuscitation from bystanders.

Conclusion

Cardiac-only resuscitation by bystanders is the preferable approach to resuscitation for adult patients with witnessed out-of-hospital cardiac arrest, especially those with apnea, shockable rhythm, or short periods of untreated arrest.     

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.     

Survival of out-of-hospital cardiac arrest with early initiation of cardiopulmonary resuscitation

Records on 1,297 people with witnessed out-of-hospital cardiac arrest, caused by heart disease and treated by both emergency medical technicians (EMTs) and paramedics, were examined to determine whether or not early cardiopulmonary resuscitation (CPR) initiated by bystanders independently improved survival. Bystanders initiated CPR for 579 patients (bystander CPR); for the remaining 718 patients, CPR was delayed until the arrival of EMTs (delayed CPR). Survival was significantly better (P less than 0.05) in the bystander-CPR group (32%) than in the delayed-CPR group (22%). Multivariate analysis revealed that the superior survival in the bystander-CPR group was due almost entirely to the much earlier initiation of CPR (1.9 minutes for the Bystander-CPR group and 5.7 minutes for the delayed-CPR group; P less than 0.001). There were significantly more people with ventricular fibrillation (VF) in the bystander-CPR group (80%) than in the delayed-CPR group (68%); and, for people in VF, the survival rate was significantly better if they had received bystander-CPR (37% versus 29%). The authors conclude that early initiation of CPR by bystanders significantly improves survival from out-of-hospital cardiac arrest, and they suggest that it may do so by prolonging the duration of VF after collapse and by increasing cardiac susceptibility to defibrillation. The benefit of this early CPR, however, appears to exist within a rather narrow window of effectiveness. It must be started within 4-6 minutes from the time of collapse and must be followed within 10-12 minutes of the collapse by advanced life support in order to be effective.     

Prehospital cardiac arrest in Leicestershire: targeting areas for improvement.

OBJECTIVE: To identify the impact of advanced life support skills on outcome for prehospital cardiac arrest in a defined population and to assess the value of certain physiological variables in predicting the outcome in those successfully resuscitated in the accident and emergency (A&E) department; to identify areas for improvement in the outcome of such patients. DESIGN: Prospective 12 month study. SETTING: Leicestershire, United Kingdom. MAIN OUTCOME MEASURE: Survival to hospital discharge and status at 6 months. RESULTS: 266 patients were identified as having suffered a prehospital cardiac arrest; of these, 86 had their resuscitation attempt terminated in the community by a general practitioner and 180 were transferred to the A&E department of the Leicester Royal Infirmary. Of the latter, 159 were felt to be of cardiac aetiology, and 19 were eventually discharged from hospital. All survivors had experienced a witnessed cardiac arrest, ventricular fibrillation (VF) being identified as the initial rhythm. After adjusting for age and sex using logistic regression, the Glasgow coma score (GCS) was found to be associated with subsequent mortality (chi 2 = 18.22 on 2 df, P < 0.0001). Compared to a baseline GCS of 9-15, the relative odds of death for a GCS of 3 were 25.3 (95% confidence interval 4.3 to 149-9), while a GCS of 4-8 gave a relative odds of death of 12-18 (95% CI 1.8 to 80.2). No significant association was found between postarrest arterial pH and mortality. CONCLUSIONS: The immediate GCS on admission is a predictor of outcome and it is important to monitor its trend in the first 24 h. Multidisciplinary audit and joint guidelines with other specialties are important in optimising the care of these patients.     

The influence of urban, suburban, or rural locale on survival from refractory prehospital cardiac arrest

There are many variables that can have an effect on survival in cardiopulmonary arrest. This study examined the effect of urban, suburban, or rural location on the outcome of prehospital cardiac arrest as a secondary end point in a study evaluating the effect of bicarbonate on survival. The proportion of survivors within a type of EMS provider system as well as response times were compared. This prospective, randomized, double-blind clinical intervention trial enrolled 874 prehospital cardiopulmonary arrest patients encountered by prehospital urban, suburban, and rural regional EMS area. Population density (patients per square mile) calculation allowed classification into urban (>2000/mi2), suburban (>400/mi2), and rural (0-399/mi2) systems. This group underwent standard advanced cardiac life support (ACLS) intervention with or without early empiric administration of bicarbonate in a 1-mEq/kg dose. A group of demographic, diagnostic, and therapeutic variables were analyzed for their effect on survival. Times were measured from collapse until onset of medical intervention and survival measured as the presence of ED vital signs on arrival. Data analysis used chi-squared with Pearson correlation for survivorship and Student t test comparisons for response times. The overall survival rate was approximately 13.9% (110 of 793), ranging from 9% rural, 14% for suburban, and 23% for urban sites for 372 patients (P=.007). Survival differences were associated with classification of arrest locale in this sample-best for urban, suburban, followed by rural sites. There was no difference in time to bystander cardiopulmonary resuscitation, but medical response time (basic life support) was decreased for suburban or urban sites, and intervention (ACLS) and transport times were decreased for suburban sites alone. Although response times were differentiated by location, they were not necessarily predictive of survival. Factors other than response time such as patient population or resuscitation skill could influence survival from cardiac arrest occurring in diverse prehospital service areas.     

An analysis of time factors in out-of-hospital cardiac arrest in Osaka Prefecture

OBJECTIVE: To ascertain important factors in the improvement of out-of-hospital cardiac arrest survival rates through analysis of data for Osaka Prefecture with the focus on time factors. DESIGN: Prospective cohort study according to the Utstein style. SETTING: Osaka Prefecture (population 8,830,000) served by a single emergency medical services system. PATIENTS: Consecutive prehospital cardiac arrests occurring between May 1998 and April 1999. MAIN OUTCOME MEASURES: One-year survival from cardiac arrest, and time factors. RESULT: Of the 5047 cases of confirmed cardiac arrests, resuscitation was attempted in 4871 subjects. Of the 982 cases of cardiac origin and witnessed by bystanders, 31 (3.2%) were still alive, and of the 576 cases of non-cardiac origin and witnessed by bystanders, ten (1.7%) were still alive at the 1 year follow-up. The median time from receipt of the emergency call until ambulance arrival was 5 min and that from receipt of the call until the start of cardiopulmonary resuscitation (CPR) was 7 min. For the 214 patients for whom defibrillation was attempted, the median time from receipt of the call until the first shock was 15 min. The median time from receipt of the call until departure of the ambulance from the scene was 16 min and that until arrival of the ambulance at a hospital was 22 min. CONCLUSIONS: This study using the standardized format according to the Utstein style clearly elucidates the specific delay of the start of defibrillation by paramedics and also indicates the inappropriate rule for this procedure in Japan.