Community cardiopulmonary resuscitation

Effective CPR Procedure With Real Time Evaluation and Feedback Using Smartphones

Timely cardio pulmonary resuscitation (CPR) can mean the difference between life and death. A trained person may not be available at emergency sites to give CPR. Normally, a 9-1-1 operator gives verbal instructions over the phone to a person giving CPR. In this paper, we discuss the use of smartphones to assist in administering CPR more efficiently and accurately. The two important CPR parameters are the frequency and depth of compressions. In this paper, we used smartphones to calculate these factors and to give real-time guidance to improve CPR. In addition, we used an application to measure oxygen saturation in blood. If blood oxygen saturation falls below an acceptable threshold, the person giving CPR can be asked to do mouth-to-mouth breathing. The 9-1-1 operator receives this information real time and can further guide the person giving CPR. Our experiments show accuracy >90% for compression frequency, depth, and oxygen saturation.

Heart Disease Awareness and Intervention Training: An Alternative to Citizen CPR

Each year in the United States 700,000 people die from the sudden onset of heart attack symptoms. Of these deaths over 350,000 occur in the prehospital setting. Many of these deaths are felt to be avoidable if a greater number of the lay public were trained in Cardiopulmonary Resuscitation.

In the twenty-five years since Kouwenhoven, et al, suggested that closed chest cardiac compression and mouth-to-mouth artificial ventilation may artificially produce a satisfactory oxygenated systemic blood flow, there have been thousands of published research reports and articles focused upon a broad spectrum of subtopics ranging from the improvement of these techniques to the training of the lay rescuer. Knopp has suggested some parameters within which new CPR techniques must fall. First, any new skill should be applicable to the field setting. Second, the techniques should be simple to apply. And thirdly, any new techniques must be statistically linked with a significant increase in survival rates. Citizen Cardiopulmonary Resuscitation (CPR) has taken on almost religious connotations. A national strategy has been adopted by the American Heart Association and American Red Cross to train the lay public using a variety of training techniques of varying lengths.

Geographical distribution of cardiac arrest in Nottinghamshire

BACKGROUND

to analyse the incidence of out-of-hospital cardiac arrest in Nottinghamshire; to ascertain its geographical distribution; and to determine whether the geography of coronary heart disease mortality and out-of-hospital cardiac arrest are the same.

METHODS AND RESULTS

population based, retrospective study in the County of Nottinghamshire with a total population of 993,914 in an area of 2183 km2 divided into 191 electoral areas. In the 4 years from 1 January, 1991 to 31 December, 1994, 1634 patients sustained a cardiac arrest attributed to a cardiac cause (International Classification of Diseases codes 390-414 and 420-429) and were attended by the Nottinghamshire Ambulance Service. The overall crude mean incidence rate of community cardiac arrest per electoral area was 40.2 per 100,000 population (range 0-121.2). Thirteen electoral areas, relatively deprived according to the Townsend score, had a significantly greater than expected incidence rate of cardiac arrest (median of 75.6/100,000 per electoral area; interquartile range (IQR) 65.3, 83.8). Twelve relatively affluent electoral areas had a significantly lower than expected incidence rate (median of 18.5/100,000 per area (IQR 13.0, 28.7). After adjusting for deprivation index, there were no differences in coronary heart disease (CHD) mortality and community cardiac arrest in urban and rural electoral areas. Apart from response times by ambulance crews, the events that follow the cardiac arrest such as bystander resuscitation, ventricular fibrillation found as the presenting rhythm and survival were similar in all electoral areas.

CONCLUSIONS

increasing level of deprivation is associated with areas of increased incidence of out-of-hospital cardiac arrest in Nottinghamshire, and the effect is apparently different from that on CHD mortality. There is scope for reducing incidence rates of community cardiac arrest and to introduce strategies to improve survival in areas identified as having high rates of community cardiac arrest.

Prognostic implications of ventricular fibrillation in acute myocardial infarction: new strategies required for further mortality reduction

OBJECTIVE

To determine the changing risk of ventricular fibrillation, the prognostic implications, and the potential long term prognostic benefit of earlier hospital admission, after acute myocardial infarction.

DESIGN

Prospective observational study.

SETTING

A district general hospital in east London.

PATIENTS

1225 consecutive patients admitted to a coronary care unit with acute myocardial infarction.

MAIN OUTCOME MEASURES

Time of onset of pain and ventricular fibrillation, and long term survival of patients admitted with acute myocardial infarction.

RESULTS

The rate of ventricular fibrillation in these hospital inpatients was high in the first hour from onset of pain (118 events/1000 persons/h; 95% confidence interval (CI) 50.7 to 231) and fell rapidly to an almost constant low level by six hours; 27.4% of patients with early ventricular fibrillation died in hospital, compared with 11.6% of those without (p < 0.0001), but mortality in patients who survived to hospital discharge was not altered by early ventricular fibrillation (five year survival: 75.0% (95% CI 60.0% to 84.8%) with ventricular fibrillation v 73.3% (95% CI 69.6% to 76.6%) without ventricular fibrillation).

CONCLUSIONS

Patients successfully resuscitated from early ventricular fibrillation have the same prognosis as those without ventricular fibrillation after acute myocardial infarction. Faster access to facilities for resuscitation must be achieved if major improvements in the persistently high case fatality of patients after acute myocardial infarction are to be made.

What can you teach about cardiopulmonary resuscitation (CPR) in 30 seconds? Evaluation of a television campaign

This study evaluated an 8-month media campaign, implemented in western Washington, to educate people on the basic steps of cardiopulmonary resuscitation (CPR) for cardiac arrest. A telephone survey was conducted with a total of 384 adults randomly selected from two towns, one that had been exposed to the campaign (intervention town) and one that had not been exposed to the campaign (comparison town). Results showed that respondents in the intervention town were more likely than respondents in the comparison town to report (a) having heard messages on CPR in the past month, (b) having seen the CPR media campaign, and (c) knowing the three basic steps of CPR. Respondents who had seen the campaign evaluated it very favorably. There were no differences between respondent groups in self-reported CPR training or intentions to perform CPR, suggesting that the campaign had a greater impact on knowledge and awareness than on intentions and behavior.

Determinants of reluctance to perform CPR among residents and applicants: the impact of experience on helping behavior

BACKGROUND

Though mouth-to-mouth resuscitation (MMR) is widely endorsed as a useful lifesaving technique, studies have shown that health care professionals are reluctant to perform it. To characterize the circumstances which facilitate this reluctance among physicians, we have surveyed current and future residency trainees regarding attitudes toward providing ventilation by this method to strangers experiencing arrest in the community.

METHODS

A total of 280 categorical emergency medicine (EM) and internal medicine (IM) house officers and respective program applicants at a 655 bed Brooklyn, New York teaching hospital were anonymously surveyed regarding their willingness to attempt resuscitation in five hypothetical scenarios of cardiopulmonary arrest.

RESULTS

A direct relationship was observed between residency training level and reluctance to perform MMR in each scenario. Applicants expressed greater overall willingness to perform MMR than all residents (56 versus 34%, P < 0.00001). Willingness among experienced residents was lower than for junior-level residents (29 versus 40%, P = 0.01). EM and IM physicians were statistically indifferent in their responses. There were no differences in willingness to perform MMR by age in MD applicant or resident groups.

CONCLUSIONS

Many physicians and future doctors are reluctant to perform MMR on arrest victims in the community, a trend that increases in prevalence among those with more residency training. These data support the hypothesis that diminished helping behavior occurs gradually over the training period and may occur as a direct consequence of the training experience. A model for characterizing the elements that make up a rescuer's decision process is proposed.

Poor correlation of mouth-to-mouth ventilation skills after basic life support training and 6 months later

The purpose of the present study was to evaluate the cardiopulmonary resuscitation (CPR) skills of medical students after a 2-h basic life support class (n = 129) and 6 months later (n = 113). Mean +/- SD written test score decreased from 6.4 +/- 0.7 to 6.2 +/- 0.8 (P = 0.03). Mean +/- SD breaths delivered before CPR decreased from 2.9 +/- 0.6 to 2.2 +/- 1.2 (P = 0.0001), ventilation rate increased from 12.2 +/- 1.9 to 14.3 +/- 5.0 breaths/min (P = 0.0001), tidal volume increased from 0.75 +/- 0.2 to 0.8 +/- 0.31 (P = 0.11), minute ventilation from 9.1 +/- 2.6 to 10.8 +/- 3.61 (P = 0.0001), and stomach inflation from 13 +/- 22 to 18 +/- 27% of CPR breaths (P = 0.11). Mean +/- SD chest compression/min decreased from 56 +/- 9 to 54 +/- 12 (P = 0.34), depth of chest compression increased from 41 +/- 6 to 46 +/- 7 mm (P = 0.0001), hands held incorrectly on the thorax increased from 22 +/- 27 to 23 +/- 32% (P = 0.59), and leaning on the chest from 4 +/- 12 to 18 +/- 28% of compressions (P < 0.0001). In summary, ventilation skills were unpredictable; there was only a 5% chance that a given student would achieve the same mouth-to-mouth ventilation performance in both the BLS class and 6 months later. Despite the respiratory mechanics of the CPR manikin which prevented stomach inflation much better than an unconscious patient with an unprotected airway, stomach inflation occurred repeatedly. Teachers of basic life support classes need to consider the respiratory mechanics of the CPR manikin being used to assure clinically realistic and appropriate mouth-to-mouth ventilation skills.

Reluctance of paramedics and emergency medical technicians to perform mouth-to-mouth resuscitation

Recently, a reluctance of lay and medical personnel to perform mouth-to-mouth resuscitation (MMR) in hospital and community settings has been documented, with 45% of respondents declining to perform MMR on a stranger. In the present study, we examined whether the perceived risk and fear of contracting infectious diseases diminishes the willingness of paramedics and emergency medical technicians (EMTs) to perform MMR. Seventy-seven EMTs and 27 paramedics responded to a questionnaire, administered by one of two physicians, containing mock cardiac arrest scenarios that were designed to assess willingness to perform MMR as a citizen responder. Faced with a situation in which an adult stranger required MMR, 57% of the participating EMTs and all of the paramedics stated that they would refuse to perform MMR. None of the paramedics and only 32.5% of the EMTs stated that they would perform MMR on a man in a gay neighborhood. In addition, 23% of the EMTs and 37% of the paramedics indicated that they would refuse to perform MMR on a child. White respondents were more willing than nonwhite respondents to perform MMR. Twenty-nine percent of the prehospital-care providers had been in situations requiring MMR in the community, and 40% either had walked away or did only external compression. Of those participating paramedics and EMTs who had performed MMR in emergency situations, only 45% indicated that they would do so again. The respondents indicated that they would not be willing to administer MMR because of the fear of contracting infectious agents, especially the human immunodeficiency virus. Despite the proven effectiveness of MMR in saving lives, paramedics and EMTs are highly reluctant to perform MMR as citizen responders. Their perceived risks of contracting infectious agents during MMR are high, despite the low actual risks. We recommend that instruction in cardiopulmonary resuscitation for providers of pre-hospital care, the medical community, and the general public should emphasize the benefits of providing MMR, the actual low risks of contracting infectious diseases during administration of MMR, and the use of widely available and effective barrier masks to minimize any risks due to administration of MMR.

Effectiveness of the BBC's 999 training roadshows on cardiopulmonary resuscitation: video performance of cohort of unforewarned participants at home six months afterwards

OBJECTIVE

To examine the competence of a cohort trained in cardiopulmonary resuscitation by the BBC's 999 training roadshows.

DESIGN

Descriptive cohort study applying an innovative testing procedure to a nationwide systematic sample. The test sample received an unsolicited home visit and without warning were required to perform cardiopulmonary resuscitation on a manikin while being videoed. The videos were then analysed for effectiveness and safety using the new test.

SETTING

Nine cities and surrounding areas in the United Kingdom.

SUBJECTS

280 people aged between 11 and 72.

RESULTS

Thirty three (12%) trainees were able to perform effective cardiopulmonary resuscitation, but of these 14 (5%) performed one or more elements in a way that was deemed to be potentially injurious. Thus only 19 (7%) trainees were able at six months to provide safe cardiopulmonary resuscitation. In addition, large numbers of subjects failed to shout for help, effectively assess the status of the patient, or alert an ambulance. Significantly better performances were recorded by those under 45 years old (31 (14%) v 2 (4%) gave effective performances respectively, P < 0.05), those who had attended a subsequent cardiopulmonary resuscitation course (8 (40%) v 25 (10%) gave effective performances respectively, P < 0.0001), and those confident in their initial ability (26 (20%) v 7 (6%) gave effective performances respectively, P < 0.005). Females were significantly less likely than males to perform procedures in a harmful way (117 (62%) v 10 (12%) performed safely respectively, P < 0.005).

CONCLUSION

Television is an effective means of generating large training cohorts. Volunteers will cooperate with unsolicited testing in their home, such testing being a realistic simulation of the stress and lack of forewarning that would surround a real event. Under such conditions the performance of cardiopulmonary resuscitation was disappointing. However, retraining greatly improves performance.

A reliable and valid method for evaluating cardiopulmonary resuscitation training outcomes

In order to compare the quality of CPR performance after various training methods, training outcome assessment must provide meaningful data and do it in a way that is reliable. Few studies have provided details of their assessment procedures, and even fewer report on whether the measures to evaluate performance are reliable (yielding information consistently over multiple trials), or valid (measuring the outcome intended). Few studies have attempted to replicate assessment methods used by other authors. Conventional skill sheets have not been shown to assess compressions and ventilations reliably and validly. When using an instrumented manikin, skill checklists can be simplified by eliminating qualitative assessment of compressions and ventilations. Using a sample of 171 CPR trainees rated by trained evaluators, we provide details of agreement between two evaluators and use an established statistic (Cronbach's alpha) to assess the reliability of a 14-item simplified CPR checklist. The level of agreement between two raters was high (Pearson product-moment correlation = 0.87) as was the reliability estimate obtained by Cronbach's alpha (0.89). As criterion-related evidence of the validity of the CPR checklist to assess CPR performance, a correlation with a five-point subjective overall rating of CPR was estimated (Spearman correlation = 0.92). We urge standardized reporting of CPR training outcomes in order to achieve comparability across studies.

Ethnicity and proficiency in English as factors affecting community cardiopulmonary resuscitation (CPR) class attendance

Communities with a high prevalence of cardiopulmonary resuscitation (CPR) knowledge have a greater out of hospital cardiac arrest survival rate. Within metropolitan Adelaide, 12.4% of the community is from a non-English speaking country and 20.3% of these have a poor proficiency in English. The purpose of this study was to examine the effect of ethnicity (specifically, Southern European born (SEB) and South East Asian born (SEAB)) and a poor proficiency in English (PENG) on CPR skill acquisition. Population Census postcode data were compared to postcode student CPR classes attendance. Results showed a negative correlation between SEB (-0.44), SEAB (-0.36), PENG (-0.42) with CPR class attendance. Postcodes with a less than community average of SEB, SEAB and PENG had an average proportion of CPR class attendees of 2.64% (C.I. 2.43, 2.85), 2.54% (C.I. 2.35, 2.73) and 2.65% (C.I. 2.35, 2.73), respectively, whilst those postcodes with a greater than community average had 2.03% (C.I. 1.90, 2.16), 2.07% (C.I. 1.90, 2.24) and 2.04% (C.I. 1.90, 2.18) proportion of CPR class attendees. The difference for each category was significant to a P < 0.001. This study points to SEB, SEAB, and PENG as factors associated with fewer CPR class attendances. Future CPR classes should specifically target and cater for ethnic groups from non-English speaking countries with poor English skills if CPR skills are to be widely disseminated throughout the entire community.

Cost-effectiveness analysis of potential improvements to emergency medical services for victims of out-of-hospital cardiac arrest

STUDY OBJECTIVE

To measure the incremental cost-effectiveness of various improvements to emergency medical services (EMS) systems aimed at increasing survival after out-of-hospital cardiac arrest.

METHODS

We performed cost-effectiveness analysis based on (1) metaanalysis of effectiveness of the various EMS systems, (2) costing of each component of EMS systems, (3) modeling of the relationship between the proportion of cardiac arrest victims who receive CPR and the proportion of individuals trained, (4) modeling of the relationship between response time interval and the characteristics of the EMS system, (5) measurement of quality of life, and (6) decision analysis to combine the results of the first five components.

RESULTS

The incremental cost-effectiveness ratio for a 48-second improvement in mean response time in a one-tier EMS system yielded by the addition of more EMS providers was $368,000 per quality-adjusted life year (QALY). For improved response time in a two-tier EMS system by the addition of more basic life support (BLS)/BLS-defibrillator (BLS-D) providers to the first tier, the ratio was $53,000 per QALY with pump vehicles or $159,000 per QALY with ambulances. Change from a one-tier EMS to a two-tier EMS system by the addition of initial BLS/BLS-D providers in pump vehicles as the first tier was associated with a cost per QALY of $40,000. Change from one-tier EMS to two-tier EMS by the addition of initial BLS/BLS-D providers in ambulances as the first tier was associated with a cost per QALY of $94,000.

CONCLUSION

The most attractive options in terms of incremental cost-effectiveness were improved response time in a two-tier EMS system or change from a one-tier to a two-tier EMS system. Future research should be directed toward identification of the costs of instituting the first tier of a two-tier EMS system and identification of cost-effective methods of improving response time.

Response to cardiac arrests in a hospital setting: delays in ventilation

The outcome following a cardiac arrest is affected by the length of time that elapses before cardiopulmonary resuscitation is initiated. Only 10-15% of patients experiencing cardiac arrest in hospital settings survive to discharge. Therefore, the time between cardiac arrest and administration of cardiopulmonary resuscitation in a metropolitan hospital was examined. All cardiac and respiratory arrests that occurred in the adult non-intensive care areas of a medical center over a period of 16 months were evaluated within 12 h to determine how much time had elapsed before resuscitation was initiated, the devices utilized for initial airway management, and the outcome. To initiate ventilation, bag-valve-masks (BVMs) were used in the majority (76%) of the efforts to resuscitate while mouth-to-mask resuscitation was performed in another 18%; however, in only 37% of the codes was ventilation initiated within 1 min and in 18% ventilation was started after 3 min. Mouth-to-mask resuscitation resulted in more rapid time to onset of ventilation than BVM. In only 18% of the arrests studied was a 'lay-on' mask available in the room and utilized. In 11%, a bag-valve-mask was at the patient's bedside, and in 53% a BVM was taken from the crash cart outside the room. In 63% of the cases where using a lay-on mask was appropriate, it was either not looked for or not present in the patient's room. Also in 37% of the cases where a BVM was needed, one was not readily present because of difficulty in locating the crash cart immediately. Although initiation of cardiopulmonary resuscitation within a minute of a cardiac or respiratory arrest is the standard of care, in the non-intensive care in-patient cases surveyed, typically more than a minute elapsed, and frequently 3 or more minutes, before resuscitation was started. If the time elapsing before an arresting in-patient is ventilated can be shortened, which is easily and effectively achieved by mouth-to-mouth or mouth-to-mask resuscitation, an increase in both the survival rate and the number of good neurological outcomes should be expected.

Pre-hospital cardiac arrest: room for improvement

OBJECTIVE

To audit the outcome from pre-hospital cardiac arrest managed by ambulance personnel, and to assess their proficiency by analysing the time to initiate basic and advanced cardiac life support, the compliance with national guidelines, and the overall success of resuscitation.

DESIGN

A retrospective analysis of ambulance service report forms of pre-hospital cardiac arrests, where active resuscitation was attempted by ambulance personnel between October 1992 and May 1993.

SETTING

The City of Salford.

SUBJECTS

100 consecutive patients who suffered cardiac arrest out-of-hospital and who were brought to the accident and emergency department of Hope Hospital alive, or with resuscitation still in progress.

RESULTS

Only 4 of 100 patients were successfully resuscitated out of hospital, of whom 2 survived to leave hospital. Detailed analysis of pre-hospital performance was performed on 89 patients only, as 11 report forms were missing (no successful pre-hospital resuscitations in this 11). Ventricular fibrillation was the first recorded rhythm in 51.7%, but 85.7% were in asystole or electromechanical dissociation on arrival at hospital. No patient who was still in cardiac arrest on arrival at hospital was successfully resuscitated. 11 patients received 'bystander CPR'. The median time to basic life support was 6 min; the median call-to-response interval was 8 min; the median call-to-advanced cardiac life support interval was 21 min; the median on-scene time was 31 min (paramedics), or 15 min (technicians). The dose of drugs given by the intravenous route did not comply with the contemporary recommendations in 43.2%, and those doses given by the endotracheal route were inadequate in 37.9% of the cases. Endotracheal intubation was attempted in all paramedic resuscitations (91.4% success); intravenous access was attempted in 60.3% (91.7% success).

CONCLUSIONS

The survival from pre-hospital cardiac arrest in this community is worse than the national average. There is no single explanation for this. Better community CPR training, greater efficiency at the scene through additional personnel, and stricter compliance with national ACLS guidelines, facilitated by extended refresher training, are all required if outcome is to be improved.

Factors affecting outcome following cardiopulmonary resuscitation

Many patients who receive cardiopulmonary resuscitation (CPR) for cardiac arrest do not survive to leave hospital. Factors associated with adverse outcomes include unwitnessed cardiac arrest in general wards, particularly at night, prolonged resuscitation, asystole, associated disorders (e.g. sepsis, malignancy, renal failure, and left ventricular dysfunction), absent pupillary responses, hypoxaemia, low PetCO2 during resuscitation, and severe acid base imbalance. Outside hospitals, cardiac arrests result in more favourable outcomes if they occur at work, and bystander CPR and early defibrillation are initiated. On admission to ICU, likely predictors of death or severe neurological disability include prolonged coma, impaired brainstem reflexes, and persistent convulsions. Experience with cerebrospinal fluid enzymes and electrophysiological measurements is limited. Multivariate scoring systems are not sufficiently reliable. The importance of hyperglycaemia, the required level of CPR training, and the appropriateness of responding to some cases, remain debatable.

The reluctance of house staff to perform mouth-to-mouth resuscitation in the inpatient setting: what are the considerations?

OBJECTIVE

Medical house staff are required to perform cardiopulmonary resuscitation (CPR) as part of their job responsibilities. Previously it has been shown that house staff are reluctant to perform mouth-to-mouth resuscitation (MMR) in an out of hospital setting. Therefore, whether reluctance to perform MMR extends to the inpatient setting, and, if so, the reasons for this reluctance were investigated.

DESIGN

All 74 internal medicine house officers of a large metropolitan hospital responded to presentations of hypothetical inpatient cardiac arrest scenarios to assess their willingness to perform MMR.

SETTING

A 1200 bed university-affiliated teaching hospital in Los Angeles, California.

SUBJECTS

All categorical internal medicine house officers at this hospital.

INTERVENTIONS

This study is a survey which concerns whether the house officer would perform mouth-to-mouth resuscitation in different hypothetical cardiac arrest scenarios.

RESULTS

Forty-five percent would perform MMR on an unknown patient and 39% would perform MMR in the elderly patient scenario. Only 16% would do MMR on a patient with a small amount of blood on his lips and only 7% would perform MMR on a patient with presumed acquired immunodeficiency syndrome. Medical housestaff were much more reluctant to perform MMR on elderly, trauma, or presumed immunodeficient patients in an inpatient setting than in an outpatient setting. All house staff that indicated their unwillingness to perform MMR cited fear of human immunodeficiency virus infection as their reason.

CONCLUSION

Medical housestaff are quite reluctant to perform MMR in an inpatient setting. Thus, educating the medical house staff about the percent of patients that survive inpatient cardiac arrest and the actual risks of contracting infectious diseases, especially HIV infections, from MMR and preventative measures, such as effective barrier masks, should result in an increased willingness of physicians to perform MMR or mouth-to-mask ventilation on inpatients.

Resuscitation skills of lay public after recent training

STUDY OBJECTIVE

To investigate the ability of laypeople to apply basic CPR techniques after recent training.

DESIGN

Cross-sectional assessment of practical CPR skills.

TYPE OF PARTICIPANTS

151 laypeople who were trained twice in the preceding 20 to 24 months.

MEASUREMENTS AND MAIN RESULTS

Practical skills were tested using six primary recorded variables that describe the quality of CPR techniques in a training situation. A total score on the skills of each participant was computed on the basis of a predefined scoring system. Thirty-three percent of the participants were able to perform adequate CPR. The compression:relaxation ratio, the breathing volume, and the breathing interval were points of concern.

CONCLUSION

Practical skills in basic CPR after a 12-month training interval, though better in this study than in many previous studies, are insufficient in the majority of laypeople. The results of this study could be used to design a better tailored (re)instruction program, with an emphasis on regular, frequent refresher courses.

Racial differences in the incidence of cardiac arrest and subsequent survival. The CPR Chicago Project

BACKGROUND

Differences between blacks and whites have been reported in the incidence of several forms of cardiovascular disease, including hypertension and stroke. We examined racial differences in the incidence of cardiac arrest in a large urban population and in subsequent survival.

METHODS

We collected data on all nontraumatic, out-of-hospital cardiac arrests in Chicago from January 1, 1987, through December 31, 1988, and compared the incidence and survival rates for blacks and whites. We examined the association between survival and race and seven other known risk factors by logistic-regression analysis. We computed incidence rates by coupling our data with U.S. Census population data.

RESULTS

Our study population comprised 6451 patients: 3207 whites, 2910 blacks, and 334 persons of other races. The incidence of cardiac arrest was significantly higher for blacks than for whites in every age group. The survival rate after cardiac arrest was 2.6 percent in whites, as compared with 0.8 percent in blacks (P < 0.001). Blacks were significantly less likely to have a witnessed cardiac arrest, bystander-initiated cardiopulmonary resuscitation, or a "favorable" initial rhythm or to be admitted to the hospital. When they were admitted, blacks were half as likely to survive. The association between race and survival persisted even when other recognized risk factors were taken into account. We did not find important differences between blacks and whites in the response times of the emergency medical services.

CONCLUSIONS

The black community in our study was at higher risk for cardiac arrest and subsequent death than the white community, even after we controlled for other variables.

A scoring system for basic cardiac life support skills in training situations

A valid and reproducible system for determining basic cardiac life support (BCLS) skills can help to evaluate the effect of instruction courses and to estimate the results of educational activities. The aim of this study was to develop and test such a system in accordance with the Standards and Guidelines of the American Heart Association (AHA). Five criteria were defined in advance towards such a system (1) Inadequate techniques must be reflected by a fail score. (2) Skilled persons should achieve a pass score. (3) The effect of training must be reflected by an improvement of the score. (4) Inter- and intra-observer variability must be negligible. (5) The system should be simple to apply. The system was developed, and in order to test the system, the BCLS skills of 40 ambulance nurses were tested once and those of 148 lay people twice. All cardiopulmonary resuscitation (CPR) attempts were performed on a mannequin. The relevant parameters of the attempt were continuously recorded and printed. Penalty points were assigned in a predefined way for aberrations of the techniques advised in the Standards and Guidelines. The system satisfied the five criteria mentioned above. It therefore offers a reliable and reproducible evaluation of BCLS skills.

Cardiopulmonary resuscitation skills retention in family members of cardiac patients

The purpose of this study was to determine if the use of a retention strategy would maintain cardiopulmonary resuscitation (CPR) skills in family members of cardiac patients. Thirty-one subjects trained in CPR received retention packets 3 and 6 months after CPR training. Sixteen subjects were tested for CPR retention at 7 months after initial training, and 15 at 12 months. Likelihood chi 2 was used to compare the 7- and 12-month groups. There were no differences between the 7- and 12-month groups, because CPR retention overall was poor. Only 19.4% of subjects reported using the retention packet; therefore, subjects were regrouped into practice and no practice groups for purposes of further statistical analysis. There were significant differences in retention in subjects who practiced compared with subjects who did not. These findings underscore the importance of promoting practice/review after initial CPR training for family members of cardiac patients.

Prehospital cardiac arrest: the impact of witnessed collapse and bystander CPR in a metropolitan EMS system with short response times

OBJECTIVE

Numerous studies have shown initiation of bystander CPR to significantly improve survival from prehospital cardiac arrest. However, in emergency medical services (EMS) systems with very short response times, bystander CPR has not been shown to impact outcome. The purpose of this study was to determine the effect of bystander CPR on survival from out-of-hospital cardiac arrest in such a system.

DESIGN

Prehospital, hospital, and death certificate data from a medium-sized metropolitan area were retrospectively analyzed for adult, nontraumatic cardiac arrest during a 16-month period.

RESULTS

A total of 298 patients met study criteria. One hundred ninety-five arrests (65.4%) were witnessed, and 103 (34.6%) were unwitnessed. Twenty-five witnessed victims (12.8%) were discharged alive, whereas no unwitnessed victims survived (P less than .001). Patients suffering a witnessed episode of ventricular fibrillation/tachycardia (VF/VT) were more likely to survive (21.9%) than were other patients (2.0%, P less than .0001). Among witnessed patients, initiation of bystander CPR was associated with a significant improvement in survival (20.0%) compared with the no-bystander CPR group (9.2%, P less than .05). Bystander CPR was also associated with improved outcome when witnessed patients with successful prehospital resuscitation were evaluated as a group; 18 had bystander CPR, of whom 13 (72.2%) survived compared with only 12 of 38 patients with no bystander CPR (31.6%, P less than .01).

CONCLUSION

Our data revealed improved survival rates when bystander CPR was initiated on victims of witnessed cardiac arrest in an EMS system with short response times.

Sudden arrhythmic cardiac death--mechanisms, resuscitation and classification: the Seattle perspective

Ventricular fibrillation (VF) is the first recorded arrhythmia in 75% of patients who have a sudden cardiovascular collapse. Rarely (1%) does sustained ventricular tachycardia (VT) alone cause collapse and unconsciousness. Whether all VF begins as VT is unknown. Early application of cardiopulmonary resuscitation and rapid defibrillation are essential to ensure survival and satisfactory neurologic recovery. During the last 2 years in Seattle, the initial resuscitation rate for VF was 269 of 447 patients (60%), with 114 of 447 patients (26%) surviving long-term. Survivors of VF have a high overall risk of recurrent VF, with many univariate risk factors identified: evidence of poor left ventricular function (history of congestive heart failure, prior myocardial infarction [MI] or low ejection fraction), extensive coronary artery disease, absence of a new MI (either Q wave or non-Q wave) with VF, male gender, advanced age, complex or high-frequency ventricular ectopy on Holter recording, inducibility at electrophysiologic study, exercise-induced angina or hypotension, and smoking. Classification of cardiac deaths as arrhythmic or nonarrhythmic is important in interpreting the therapeutic response. However, because many patients have chronic symptoms, timing of the onset of a new event is difficult. Furthermore, accurate timing of an event does not guarantee correct classification. Sudden death is not necessarily arrhythmic, nor is all arrhythmic death sudden. Total cardiac mortality may be a simpler and more relevant end point to measure the overall effect of antiarrhythmic therapy.

Training lay persons to use automatic external defibrillators: success of initial training and one-year retention of skills

This study was conducted to determine the feasibility of recruitment of lay persons to use automatic external defibrillators (AEDs), the effectiveness of their initial training, and the need for and frequency of retraining over time. Volunteers (n = 146), recruited from a variety of settings, included security personnel and administrative staff from large corporate centers, supervisors from senior care and exercise facilities, and employees in high-rise office buildings. Seven sites for 14 AEDs were recruited. In a single, two-hour class, participants learned to identify and respond to cardiac arrest, to notify emergency personnel, to retrieve and attach the semiautomatic (shock advisory) AED, and to respond to instructions presented on the display screen of the device. A skills check list was used to grade each student on performance of cardiopulmonary resuscitation, operation of the device, and time required to deliver an electric countershock. Retesting was performed one or more times after initial training to assess skill retention. The study lasted 1 year. All age groups, both sexes, and each responder type easily learned to operate the AED, with a trend for lower performance scores in people aged greater than 60 years. Performance time and skills declined significantly after initial training, but returned to satisfactory levels after one retraining session and were even higher after two retraining sessions. With retesting, errors that would have prevented delivery of countershocks to patients in ventricular fibrillation were rare (six of 146 tests, 4%). During the year of this study only three cardiac arrests occurred in the study sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Targeted recruitment of senior citizens and cardiac patients to a mass CPR training course

CPR courses attract a predominance of young, healthy adults. Targeted recruitment of senior citizens and family members of cardiac patients has been suggested but inadequately studied. We used a targeted recruitment strategy for our annual mass CPR training course to determine if such an approach would be effective in attracting the target group. Targeting significantly increased the percentage of senior citizen participants and participants who took the course because they or a close friend or relative had cardiac disease (P less than .00001). These data have important implications regarding potential future CPR training course recruitment methods compared with nontargeted recruitment approaches.

Improved survival from cardiac arrest in the community

We now know that the elements required to achieve the highest survival rates from out-of-hospital cardiac arrest include: witnessed arrest, rapid telephone notification of the emergency medical service, early initiation of cardiopulmonary resuscitation, rapid arrival within minutes of emergency personnel equipped with a defibrillator, and early advanced airway management and intravenous pharmacology. In the United States, and in several other countries innovative approaches have been tried to bring all these elements together in one system. These approaches include community-wide CPR training programs, telephone-assisted CPR instruction delivered at the time of a cardiac arrest, early defibrillation performed by family members of high risk patients, early defibrillation performed by minimally trained community responders, and early defibrillation performed by minimally trained ambulance personnel. Controlled, prospective studies have demonstrated the effectiveness and practicality of all of these approaches. New studies are in progress with the prehospital use of early transcutaneous cardiac pacing and these show promise. This article reviews the evidence that supports these multi-layered and innovative approaches to the treatment of out-of-hospital cardiac arrest.

Advanced training for ambulance crews: implications from 403 consecutive patients with cardiac arrest managed by crews with simple training

Sixty seven ambulance staff in Nottinghamshire completed a simple extended training programme in managing cardiac arrest and using a defibrillator. This enabled around one third of the ambulance emergency shifts to be manned by such a crew, with a defibrillator as part of their standard equipment. Forty four of 403 consecutive patients who suffered cardiac arrest in the community were managed by these crews and survived to leave hospital. The training programme does not include endotracheal intubation, intravenous infusion, or drug administration. The new official advanced training course for ambulance crews, which includes these skills, is inappropriate in its methods and may delay widespread introduction of emergency ambulances equipped with defibrillators.

A survey of participants in a mass CPR training course

To determine demographic data and reasons for CPR course taking among 891 participants of a mass CPR training event, a questionnaire was distributed at the time of the course. Of the 728 persons completing this initial survey, 379 (52.6%) were less than 20 years of age. Only 41 (5.6%) took the course because of a family member or close relative with cardiac disease. Of this subgroup, seven (17.1%) had taken a previous CPR course, compared with 25.7% for the entire population. Thirty-eight percent of the 60-and-over age group mentioned cardiac disease as their reason for taking the course, compared to only 2.1% for the under-20 age group. To assess recall and actual performance of CPR, a follow-up survey was mailed to all participants six months after the course. Seventy-two percent were still confident in their ability to perform CPR, although no one had performed the technique on a real victim; 61.9% thought there should have been more manikin practice time; 92.2% still had their CPR refresher card. Only 32.3% would perform CPR on a known AIDS patient. This survey provides demographic and personal data that should be considered when planning future large-scale CPR training programs.

CPR training for patients' families: do physicians recommend it?

All Seattle-area cardiologists and 25 per cent of selected other physicians were queried by mail to determine whether they recommended CPR (cardiopulmonary resuscitation) training for families of their patients. Two-thirds reported that they advocated training for some patients' families, but only 52 per cent of cardiologists and 37 per cent of the others did so for families of at least half of the patients considered at risk. Physicians who had performed out-of-hospital CPR or had received advanced or recent training were more likely to recommend instruction.

Survival to leave hospital from ventricular fibrillation

In 125 consecutive patients with 173 arrests due to ventricular fibrillation, 53 survived to leave hospital. At the initial arrest and using univariate analysis, those who had primary ventricular fibrillation, had ventricular fibrillation less than 24 hours from the onset of symptoms, received the first DC shock less than 1 minute after the onset of ventricular fibrillation, who required less than 4 shocks to terminate the ventricular fibrillation, whose first established rhythm within the first minute of correction of ventricular fibrillation was atrial fibrillation, sinus rhythm or paced rhythm, or who were not receiving prior antiarrhythmic agents had a significantly improved survival to leave hospital (p less than 0.05). To predict survival to leave hospital using discriminant function analysis, the most significant factors ranking in order of importance at the time of the initial arrest were: less than or equal to 5 shocks to correct ventricular fibrillation, no prior antiarrhythmic therapy, primary ventricular fibrillation, and time from onset of ventricular fibrillation to first shock less than 1 minute. For the last arrest, the most significant factors were: no prior cardiac arrest, less than or equal to 5 shocks to correct ventricular fibrillation, no prior antiarrhythmic therapy, and primary ventricular fibrillation. The most significant factors measured at the time of the last arrest provided a better prediction of survival to leave hospital (sensitivity 77%, specificity 75%) than did similarly defined factors for the initial arrest (sensitivity 59%, specificity 89%).

Chest compression-induced vertebral fractures

Two cases with chest compression-induced thoracolumbar transvertebral fractures are discussed. This is a previously unreported complication of cardiopulmonary resuscitation. Dorsal kyphosis and osteopenia were present in both of these cases. There was no spinal cord injury documented, though the potential for injury and paraplegia exists. Care should be taken to avoid this complication, especially in the elderly with kyphosis; however, adequate compressions to insure support of circulation should be maintained.

CPR training in the community

To provide a profile of potential rescuers of cardiac arrest victims, 1,271 randomly selected subjects were interviewed by telephone. Thirty-nine percent had formal instruction in cardiopulmonary resuscitation (CPR), 90% knew the emergency telephone number (911), and 5% had performed CPR. Subjects with training were significantly younger than those without (36 vs 48 years old) (P less than .001), and they had a lower incidence of known heart disease in family members (7% vs 15%) (P less than .001). More men than women were trained in CPR (44% vs 37%) (P less than .015). We recommend that efforts be undertaken to reach target groups of middle-age and older women for CPR training, and that physicians assume an active role in encouraging families of cardiac patients to learn this procedure.

Physicians' attitudes and practices toward CPR training in family members of patients with coronary heart disease

A survey of 482 physicians practicing in central and western Massachusetts was carried out to examine attitudes and reported practices toward cardiopulmonary resuscitation (CPR) training for family members of patients with coronary heart disease (CHD). Seventy-nine per cent of physicians felt that CPR training was important for the family members of patients with CHD yet only 6 per cent actually provided information about CPR to families. Further studies are indicated to determine why physician behavior is at odds with their stated beliefs and to guide appropriate remedial action.

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.

Drug product selection: the Florida experience revisited

The comparison of drug product selection rates determined approximately one year and four years after passage of Florida's Drug Product Selection (DPS) Law indicates very little change in the product selection and brand interchange behaviors of Florida pharmacists. Lack of adequate guidelines from the state and the liability concerns of pharmacists appeared to limit an expected increase in the state DPS rate.

Emergency CPR instruction via telephone

We initiated a program of telephone CPR (cardiopulmonary resuscitation) instruction provided by emergency dispatchers to increase the percentage of bystander-initiated CPR for out-of-hospital cardiac arrest. Cardiac arrests in King County, Washington were studied for 20 months before and after the telephone CPR program began. Bystander-initiated CPR increased from 86 of 191 (45 per cent) cardiac arrests before the program to 143 of 255 (56 per cent) cardiac arrests after the program. During the after period, 58 patients received CPR as a result of telephone instruction, 12 of whom were discharged. We estimate that four lives may have been saved by the program. A review of hospital records revealed no excess morbidity in the group of patients receiving dispatcher-assisted CPR.

Cardiopulmonary Resuscitation — The Need for National Surveys

At the Second World Congress on Emergency and Disaster Medicine in Pittsburgh in 1981, Professor Negovsky talked about the Science of Resuscitation. Science is defined as systematic and formulated knowledge. Therefore, to be a science, resuscitation must be presented in accurate and concise terms. The introduction of Standards in the methodology of Resuscitation has achieved this. In 1977, the American Heart Association published Standards for Cardiopulmonary Resuscitation and Emergency Cardiac Care (1) and revised them in 1980 as Standards and Guidelines (2). Organizations in other countries have also introduced such standards: the Canadian Heart Foundation, the Heart Foundation of New Zealand, the Australian Resuscitation Council, and the Resuscitation Advisory Council in the United Kingdom; they all have systematic and formulated methodologies. The value of these standards and guidelines in Resuscitation methods can only be gauged by the results of various individual surveys. The definition of Resuscitation as a science runs into problems when one begins to examine these results. This paper will illustrate the difficulties of evaluating Resuscitation results.

Figure 1 shows a comparison of survival rates in5 centers (3-7) when Cardiopulmonary Resuscitation (CPR) was initiated by a rescue team or a bystander. It would appear that Seattle had the best overall survival rate, followed by Oslo. But Thompson and colleagues (5) from Seattle studied survival from cardiac arrest only when ventricular fibrillation was present when the paramedical personnel arrived. Lund and Skulberg (7) from Oslo did not state their type of victim, whereas Cobb and his colleagues (4) in suburban Seattle, with the lowest survival rates, looked at all forms of cardiac arrests.