Analysis of factors associated with successful cardiopulmonary resuscitation in non-traumatic dead-on-arrival patients in emergency department

Out-of-hospital cardiopulmonary arrest has a dismal prognosis. Successful resuscitation of these patients depends on the "chain of survival". In Taiwan, the emergency medical services (EMS) system is under development and the links of "chain of survival" are weak and frequently broken. A 2-year retrospective study was conducted from January, 1999, to December, 2000 to evaluate the factors of successful cardiopulmonary resuscitation (CPR) in non-traumatic DOA patients in ED. Of 175 studied patients, 51 patients (29.1%) were successfully resuscitated with return of spontaneous circulation (ROSC), but only 7 patients (4%) survived to hospital discharge. Most successfully resuscitated patients (84.3%) regained their vital signs within 30 minutes. There were no significant differences in age, sex, vehicle of transportation, administration of prehospital CPR or not, EMS response interval, on-scene duration, and scene-to-hospital interval between patients with ROSC and without ROSC. Compared with asystole cardiac rhythm, patients with pulseless electrical activity (PEA) had a higher successful resuscitation rate (p = 0.001), but no significant differences existed between patients with ventricular fibrillation/ventricular tachycardia (VF/VT) and PEA or VF/VT and asystole. However, there were no significant differences in the survival discharge rate among patients with different initial cardiac rhythms in ED.     

CPR-only survivors of out-of-hospital cardiac arrest: implications for out-of-hospital care and cardiac arrest research methodology

STUDY OBJECTIVE: There is little evidence that cardiopulmonary resuscitation (CPR) alone may lead to the resuscitation of cardiac arrest victims with other than respiratory causes (eg, pediatric arrest, drowning, drug overdose). The objective of this study was to identify out-of-hospital cardiac arrest survivors resuscitated without defibrillation or advanced cardiac life support. METHODS: This observational cohort included all adult survivors of out-of-hospital cardiac arrest of a cardiac cause from phases I and II of the Ontario Prehospital Advanced Life Support Study. During the study period, the system provided a basic life support/defibrillation level of care but no advanced life support. CPR-only patients were patients determined to be without vital signs by EMS personnel who regained a palpable pulse in the field with precordial thump or CPR only and then were admitted alive to the hospital. Six members of a 7-member expert review panel had to rate the patient as either probably or definitely having an out-of-hospital cardiac arrest, and a rhythm strip consistent with a cardiac arrest rhythm had to be present to be considered a patient. Criteria considered were witness status, citizen or first responder CPR, CPR duration, arrest rhythm and rate, and performance of precordial thump. RESULTS: From January 1, 1991, to June 30, 1997, 9,667 patients with out-of-hospital cardiac arrest were treated. The overall survival rate to hospital discharge was 4.6%. There were 97 apparent CPR-only patients admitted to the hospital. Application of the inclusion criteria yielded 24 CPR-only patients who had true out-of-hospital cardiac arrest and 73 patients judged not to have cardiac arrest. Of the 24 true CPR-only patients admitted to the hospital, 15 patients were discharged alive, 10 patients were witnessed by bystanders, and 7 patients were witnessed by EMS personnel. The initial arrest rhythm was pulseless electrical activity in 9 patients, asystole in 12 patients, and ventricular tachycardia in 3 patients. One patient with ventricular tachycardia converted to sinus tachycardia with a single precordial thump. CONCLUSION: CPR-only survivors of true out-of-hospital cardiac arrest do exist; some victims of out-of-hospital cardiac arrest of primary cardiac cause can survive after provision of out-of-hospital basic life support care only. However, many patients found to be pulseless by means of out-of-hospital evaluation likely did not have a true cardiac arrest. This has implications for the survival rates of most, if not all, previous cardiac arrest reports. Survival rates from cardiac arrest may actually be lower if one excludes survivors who never had a true arrest. The absence of vital signs by out-of-hospital assessment alone is not adequate to include patients in research reports or quality evaluations for cardiac arrest.     

Cardiac Arrest in Stockholm with Special Reference to the Ambulance Organization

ABSTRACT During a one-year period all patients with cardiac arrest (CA) taken care of by three ambulances were studied. An incidence of 110 cardiac arrests/100000 inhabitantslyear was found. The majority of CAs affected the elderly and occurred during the day in their homes. The majority of CAs were witnessed but cardiopulmonary resuscitation (CPR) had been initiated by bystanders in only a few cases. The ambulance arrived within a mean time of 7.7±4.0 min. Forty-eight per cent of the CA patients showed ventricular tachycardia or ventricular fibrillation (VT/VF) on ambulance arrival. Patients with a prolonged ambulance delay showed a lower incidence of VT/VF than patients with a short delay. Patients in whom CPR had been initiated by bystanders showed a significantly higher incidence of VT/VF (67%) than unattended patients (45%). Bystander CPR was furthermore associated with an increased incidence of VT/VF in patients with prolonged ambulance delay. VT/VF was present at the time when the ambulance arrived in 86% of the CA patients who had received CPR from a bystander and were reached within 8 min by the ambulance.     

Immediate countershock versus cardiopulmonary resuscitation before countershock in a 5-minute swine model of ventricular fibrillation arrest

STUDY OBJECTIVE: Prior laboratory and clinical studies demonstrate that cardiopulmonary resuscitation (CPR) preceding countershock of prolonged ventricular fibrillation (VF) increases the likelihood of successful cardiac resuscitation. The lower limit of VF duration at which time preshock CPR provides no benefit has not been specifically studied. The purpose of this study was to compare countershock and cardiac resuscitation outcome between immediate countershock of VF of 5-minute duration and CPR without drug therapy before countershock in a swine model. METHODS: VF was induced in anesthetized and instrumented swine. After 5 minutes of VF, animals received 1 of 2 treatments. Animals in group 1, a "historical" control group (n=20), received immediate countershock followed by CPR and repeated shocks if needed. Group 2 animals (n=11) received CPR for 90 seconds preceding countershock, then continued CPR and repeated countershock if necessary. Drugs were not administered to either group, and resuscitation efforts were discontinued if a perfusing rhythm was not restored within 10 minutes of the first countershock. First shock success rate (defined as termination of VF), the number of shocks required to terminate VF, and the cardiac resuscitation rate were compared between groups. RESULTS: The first shock terminated VF in 13 of 20 group 1 animals and 2 of 11 group 2 animals (P =.023). All but 1 animal in group 1 developed pulseless electrical activity after countershock. All but 1 animal in group 1 were eventually successfully resuscitated with CPR and repeated shocks if necessary. Four group 2 animals could not be resuscitated (P =.042). CONCLUSION: Although effective in improving outcome of prolonged VF, CPR preceding countershock of VF of 5-minute duration does not improve the response to the first shock, decrease the incidence of postshock pulseless electrical activity, or the rate of return of circulation. In this study, CPR preceding countershock resulted in a significantly lower cardiac resuscitation rate.     

Outcomes of cardiac catheterization and percutaneous coronary intervention for in‐hospital ventricular tachycardia or fibrillation cardiac arrest

Objective: This study examined outcomes of patients with sudden cardiac death attributable to primary ventricular tachycardia (VT) or ventricular fibrillation (VF) that underwent cardiac catheterization with or without percutaneous coronary intervention (PCI). Background: The decision to perform cardiac catheterization and PCI in resuscitated patients with sudden cardiac death remains controversial. Prior data suggest a potential benefit from percutaneous revascularization. Methods: All patients with an in‐hospital pulseless VT or VF cardiac arrest from August 2002 to February 2008 who underwent cardiac catheterization were included. Retrospective chart review was performed to obtain clinical, neurologic, and angiographic data. Primary endpoints were all‐cause mortality and neurologic outcome. Results: Two thousand and thirty‐four patients had in‐hospital cardiac arrest, of these 116 had pulseless VT or VF and were resuscitated and 93 (80%) underwent coronary angiography. The median time to follow‐up was 1.3 years (IQR: 0.5–2.9 years). Obstructive coronary artery disease (CAD) was observed in 74 (79%) individuals, of whom 37 underwent PCI. Thirty‐five patients with obstructive CAD (47%) died compared to 41% with nonobstructive CAD. In unadjusted and multivariable adjusted analysis PCI was not associated with lower mortality (adjusted hazard ratio: 1.54, 95% CI, 0.79–3.02, P = 0.20). No significant differences were noted in neurologic status at discharge (P = 0.49). Conclusion: In this study, an aggressive revascularization strategy with PCI did not confer a survival advantage nor was it associated with improved neurologic outcomes. There was no suggestion of harm with PCI and further studies are necessary to identify potential subgroups that may benefit from revascularization. © 2011 Wiley Periodicals, Inc.     

Narrative review: cardiopulmonary resuscitation and emergency cardiovascular care: review of the current guidelines

Sudden cardiac death is a major clinical problem, causing 300,000 to 400,000 deaths annually and 63% of all cardiac deaths. Despite the overall decrease in cardiovascular mortality, the proportion of cardiovascular death from sudden cardiac death has remained constant. Survival rates among patients who have out-of-hospital cardiac arrest vary from 5% to 18%, depending on the presenting rhythm. The latest guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiovascular care published by the American Heart Association include substantial changes to the algorithms for basic life support and advanced cardiovascular life support. For unwitnessed cardiac arrest, immediate defibrillation of the patient is no longer recommended. Rather, 2 minutes of CPR before defibrillation is now recommended. People in cardiac arrest should no longer receive stacked shocks. The compression-ventilation ratio has been changed from 15:2 to 30:2. This article is a contemporary review of the management of CPR and emergency cardiovascular care. It examines current practice and data supporting use of CPR, along with changes in the management of sudden cardiac death.     

Efficacy of Nifekalant hydrochloride for life-threatening ventricular tachyarrhythmias in patients with resistance to lidocaine: a study of patients with out-of-hospital cardiac arrest

OBJECTIVES: Class I antiarrhythmic agents are not always effective in the treatment of life-threatening ventricular tachycardia/ventricular fibrillation (VT/VF) especially in patients with cardiopulmonary arrest. Nifekalant hydrochloride(NIF) is a novel class III antiarrhythmic agent for malignant VT/VF. This study prospectively evaluated NIF efficacy for life-threatening VT/VF observed after cardiopulmonary arrest. METHODS: Thirty-two of 145 patients who were transferred to the emergency room in Tokai University Hospital showed VT/VF after resuscitation from cardiopulmonary arrest from June 2000 to March 2001. These 32 patients were treated with 12 mg (mean) epinephrine and 1.0-2.0 mg/kg lidocaine following direct current application(200 to 360J), and then classified into two groups. Eleven patients received intravenous 0.15 to 0.3 mg/kg NIF followed by intravenous infusion of 0.3 to 0.4 mg/kg/hr NIF(NIF group). The other 21 patients received 1.0 to 2.0 mg/kg of lidocaine(non-NIF group). RESULTS: Sinus rhythm was restored in the nine patients(82%) in the NIF group but only four patients (19%) in the non-NIF group. QTc was not prolonged(0.45 +/- 0.04 sec, n = 9) and no torsades de pointes was observed in the NIF group. Two patients survived but the remaining nine patients died in the NIF group. Five patients died of cardiac standstill following sinus bradycardia and repeated sinus arrest within 2 to 27 hr after admission, two patients died of sudden cardiac arrest from sinus rhythm, and two patients died of persistent VT/VF. In contrast, all 21 patients in the non-NIF group died. Seventeen patients died of persistent VT/VF before hospitalization, one patient died of recurrent VT/VF, and three patients died of cardiac standstill following sinus bradycardia. CONCLUSIONS: NIF effectively suppresses VT/VF which is refractory to direct current shock in patients with cardiopulmonary arrest. However, NIF may rather worsen electrophysiological function in the sinus node after administration of high doses of epinephrine, and may induce sinus bradycardia and/or sinus arrest. Careful observation, such as monitoring of electrocardiography and blood pressure and temporary cardiac pacemaker use, is needed to prevent death in patients surviving after cardiopulmonary arrest if NIF is administered following high dose epinephrine infusion.     

Advanced cardiac life support: Update on recent guidelines and a look at the future

The objectives of this article are to provide an update of the American Heart Association (AHA) 1992 National Conference guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiac care and to review the investigation and development of new methods of CPR which may be considered in future recommendations. Despite an organized approach to sudden cardiac arrest, survival in patients receiving CPR is in the range of 5–15%. The new AHA guidelines recommend standard manual CPR performed at a rate of 80–100 compressions/min and organized algorithms of advanced cardiac life support. These guidelines stress widespread community training and rapid response in the following sequence: (1) recognition of early warning signs, (2) activation of the emergency medical system (EMS), (3) basic CPR, (4) early defibrillation, (5) intubation, and (6) intravenous medication. Several new recommendations pertain specifically to in-hospital care and are, therefore, particularly relevant to physician management of cardiac arrest. The best predictor of survival in patients requiring circulatory support after cardiac arrest is attainable coronary and cerebral perfusion. Unfortunately, the minimal levels of end-organ perfusion required to sustain life are often difficult or impossible to achieve with standard manual cardiopulmonary resuscitation and several new techniques have therefore been introduced. The most promising of these techniques are (1) interposed abdominal compression, (2) pneumatic vest, and (3) active compression-decompression resuscitation. Each of these techniques offers unique advantages when compared with standard manual cardiopulmonary resuscitation. The 1992 National Conference recommendations provide a rational framework for the resuscitation of cardiac arrest victims. New methods of cardiopulmonary resuscitation are now available and investigation into these methods continues. In the future, these modalities may be incorporated in newer guidelines and be available on a widespread basis to supplement our current approach to cardiac arrest.     

Out-of-hospital cardiac arrests in Helsinki: Utstein style reporting.

OBJECTIVE: To determine the epidemiology of out-of-hospital cardiac arrests and survival after resuscitation and to apply the Utstein style of reporting to data collection. DESIGN: Prospective cohort study. SETTING: A middle-sized urban city (population 516,000) served by a single emergency medical services system. PATIENTS: Consecutive prehospital cardiac arrests occurring between 1 January and 31 December 1994. INTERVENTION: Advanced cardiac life support according to the recommendations of American Heart Association. MAIN OUTCOME MEASURES: Survival from cardiac arrest to hospital discharge, and factors associated with survival. RESULTS: Four hundred and twelve patients were considered for resuscitation. The overall incidence of out-of-hospital cardiac arrest was 79.8/100,000 inhabitants/year. Fifty seven patients (16.6%) survived to discharge when resuscitation was attempted. 32.5% survived when cardiac arrest was bystander witnessed and was of cardiac origin with ventricular fibrillation as the initial rhythm. When asystole or pulseless electrical activity was the first rhythm recorded, discharge rates were 6.2 and 2.7% respectively. The cause of cardiac arrest was cardiac in 66.5%, and ventricular fibrillation was the initial rhythm in 65.0% of bystander witnessed cardiac arrests of cardiac origin. 22.1% of patients received bystander initiated cardiopulmonary resuscitation. The mean time intervals from the receipt of the call to the arrival of a first response advanced life support unit and mobile intensive care unit at the patient's side and to the return of spontaneous circulation were 7.0 and 10.3 and 12.6 and 16.7 min respectively. In the logistic regression model bystander witnessed arrest, age, ventricular fibrillation as initial rhythm, and the call-to-arrival interval of the first response unit were independent factors relating to survival. Utstein style reporting with modification of time zero was found to be an appropriate form of data collection in this emergency medical services system. CONCLUSIONS: After implementation of major changes in the emergency medical services system during the 1980s survival from out-of-hospital cardiac arrest markedly increased. However, early access, which has turned out to be the weakest link in the chain of survival, should receive major attention in the near future. Utstein style reporting with a modified time zero was found to be appropriate, although laborious, protocol for data collection.     

Short- and long-term survival after cardiopulmonary resuscitation

BACKGROUND: The objective was to evaluate the effect of patient characteristics and other factors on cardiopulmonary resuscitation (CPR) survival, hospital discharge survival and function, and long-term survival. METHODS: All patients 18 years and older experiencing in-hospital CPR from December 1983 through November 1991 at Marshfield Medical Center (Marshfield Clinic and adjoining St Joseph's Hospital), Marshfield, Wis, were selected. We performed a retrospective medical record review and augmented these data with updated vital status information. MAIN OUTCOME MEASURES: Cardiopulmonary resuscitation survival, hospital discharge survival and function, and long-term survival. RESULTS: Of 948 admissions during which CPR was performed, 61.2% of patients survived the arrest and 32.2% survived to hospital discharge. Mechanism of arrest was the most important variable associated with hospital discharge. Patients with pulseless electrical activity had the worst chance of hospital discharge, followed by those with asystole and bradycardia. Follow-up information was available for 298 patients who survived to discharge. One year after hospital discharge, 24.5% of patients, regardless of age, had died. Survival was 18.5% at 7 years in those 70 years or older, compared with 45.4% in those aged 18 to 69 years. Heart rhythm at the time of arrest strongly influenced long-term survival. Bradyarrhythmias produced a nearly 2-fold increased mortality risk compared with normal sinus rhythm. CONCLUSIONS: Survival until hospital discharge after CPR at our institution during an 8-year period was higher than previously reported for other institutions. Long-term survival after discharge was equal to or higher than reported estimates from other institutions. Hospital admission practices and selection of patients receiving CPR may account for these findings.     

The incidence of pulmonary embolism in unexplained sudden cardiac arrest with pulseless electrical activity

PURPOSE: The cause of many cases of sudden cardiac arrest from pulseless electrical activity is unknown. We hypothesized that pulmonary embolism was responsible for a substantial proportion of these cases and used transesophageal echocardiography to identify pulmonary embolism among patients with sudden cardiac arrest. SUBJECTS AND METHODS: We performed a prospective study at a tertiary care, university-operated county hospital, with a level 1 trauma center. Consecutive patients (n = 36) who were admitted with (n = 20) or unexpectedly developed (n = 16) sudden cardiac arrest of unknown cause were studied with transesophageal echocardiography during cardiopulmonary resuscitation. We determined the presence of central pulmonary embolism, right ventricular enlargement, and other causes of sudden cardiac arrest (such as myocardial infarction and aortic dissection) using prospectively defined criteria. RESULTS: Of the 25 patients with pulseless electrical activity as the initial event, 9 (36%) had pulmonary emboli (8 seen with transesophageal echocardiography and 1 diagnosed at autopsy) compared with none of the 11 patients with other rhythms, such as asystole or ventricular tachycardia or fibrillation (P = 0.02). Of the 8 patients who had pulmonary embolism diagnosed by transesophageal echocardiography, 2 survived to hospital discharge. CONCLUSIONS: Mortality from massive pulmonary embolism is high, particularly if patients present with sudden cardiac arrest. Earlier diagnosis of pulmonary embolus may permit wider use of thrombolytic agents or other interventions and may potentially increase survival.     

Circumstances and causes of out-of-hospital cardiac arrest in sudden death survivors

Objective—To study the circumstances and medical profile of out-of-hospital sudden cardiac arrest (SCA) patients in whom resuscitation was attempted by the ambulance service, and to identify causes of SCA in survivors and factors that influence resuscitation success rate.
Methods—During a five year period (1991-95) all cases of out-of-hospital SCA between the ages of 20 and 75 years and living in the Maastricht area in the Netherlands were studied. Information was gathered about the circumstances of SCA, as well as medical history for all patients in whom resuscitation was attempted by the ambulance personnel. Causes of SCA in survivors were studied and logistic regression analysis was performed to identify factors associated with survival.
Results—Of 288 SCA patients in whom cardiopulmonary resuscitation (CPR) and advanced life support were applied, 47 (16%) were discharged alive from the hospital. Their mean (SD) age was 58 (11) years, 37 (79%) were men, and 24 (51%) had a history of cardiac disease. Acute myocardial infarction was diagnosed in 24 (51%) of the survivors; seven with and 17 without a history of cardiac disease. Ventricular fibrillation (VF) or ventricular tachycardia (VT) as the first documented rhythm was significantly positively associated with survival (odds ratio (OR) 5.7, 95% confidence interval (CI) 2.1 to 15.9). A time interval of less than four minutes between the moment of collapse and the start of resuscitation, and an ambulance delay time of less than eight minutes were significantly positively associated with survival (OR 3.3, 95% CI 1.3 to 8.6, and OR, 3.6, 95% CI 1.3 to 10.5, respectively). A history of cardiac disease was negatively associated with survival (OR 0.46, 95% CI 0.21 to 0.98).
Conclusions—Acute myocardial infarction was the underlying mechanism of SCA in most of the survivors, especially in those without a history of cardiac disease. CPR within four minutes, an ambulance delay time less than eight minutes, and VT or VF diagnosed by the paramedics were positively associated with success.

Keywords: cardiac arrest;  sudden death;  cardiopulmonary resuscitation;  paramedics     

Monophasic versus biphasic transthoracic countershock after prolonged ventricular fibrillation in a swine model

OBJECTIVE: We sought to compare the defibrillation efficacy of a low-energy biphasic truncated exponential (BTE) waveform and a conventional higher-energy monophasic truncated exponential (MTE) waveform after prolonged ventricular fibrillation (VF). BACKGROUND: Low energy biphasic countershocks have been shown to be effective after brief episodes of VF (15 to 30 s) and to produce few postshock electrocardiogram abnormalities. METHODS: Swine were randomized to MTE (n = 18) or BTE (n = 20) after 5 min of VF. The first MTE shock dose was 200 J, and first BTE dose 150 J. If required, up to two additional shocks were administered (300, 360 J MTE; 150, 150 J BTE). If VF persisted manual cardiopulmonary resuscitation (CPR) was begun, and shocks were administered until VF was terminated. Successful defibrillation was defined as termination of VF regardless of postshock rhythm. If countershock terminated VF but was followed by a nonperfusing rhythm, CPR was performed until a perfusing rhythm developed. Arterial pressure, left ventricular (LV) pressure, first derivative of LV pressure and cardiac output were measured at intervals for 60 min postresuscitation. RESULTS: The odds ratio of first-shock success with BTE versus MTE was 0.67 (p = 0.55). The rate of termination of VF with the second or third shocks was similar between groups, as was the incidence of postshock pulseless electrical activity (15/18 MTE, 18/20 BTE) and CPR time for those animals that were resuscitated. Hemodynamic variables were not significantly different between groups at 15, 30 and 60 min after resuscitation. CONCLUSIONS: Monophasic and biphasic waveforms were equally effective in terminating prolonged VF with the first shock, and there was no apparent clinical disadvantage of subsequent low-energy biphasic shocks compared with progressive energy monophasic shocks. Lower-energy shocks were not associated with less postresuscitation myocardial dysfunction.     

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.     

Postcountershock pulseless rhythms: response to CPR, artificial cardiac pacing, and adrenergic agonists

Clinically, countershock of ventricular fibrillation (VF) may result in asystole or a pulseless rhythm in more than 50% of attempts. We conducted a study to assess the effects of immediate artificial pacing, CPR, and adrenergic drug therapy in the management of postcountershock pulseless rhythms. Thirty-four episodes of VF followed by countershock were studied in eight anesthetized dogs. Transducer-tipped catheters were positioned in the ascending aorta (Ao) and right atrium (RA). A bipolar pacing catheter was advanced to the apex of the right ventricle and a catheter for measurement of coronary sinus blood flow (CSQ) (continuous thermodilution technique) was positioned in the coronary sinus. VF was induced electrically and a countershock at 400 J was given two minutes later; CPR was not performed during VF episodes. Countershock was followed by asystole or a pulseless rhythm in all animals. Immediate endocardial pacing (0.1 to 5 mA) of bradyarrhythmias produced electrical capture but did not result in arterial pressure pulses in any animal. After pacing, CPR was performed for two minutes or until restoration of spontaneous circulation (ROSC). During CPR, the diastolic coronary perfusion gradient (Ao-RA) was 20 +/- 7 mm Hg (mean +/- SD) and CSQ was 14 +/- 7 mL/min/100 g (53% +/- 43% of control). ROSC followed CPR of less than two minutes duration in 24% of VF study episodes. If ROSC did not follow two minutes of CPR, 1 mg epinephrine, or 50 micrograms or 100 micrograms isoproterenol was given IV.(ABSTRACT TRUNCATED AT 250 WORDS)     

CPR for patients labeled DNR: the role of the limited aggressive therapy order

Patients who sustain a cardiac arrest have a less than 20% chance of surviving to hospital discharge. Patients may request do-not-resuscitate (DNR) orders if they believe that their chances for a meaningful recovery after cardiopulmonary arrest are low. However, in some identifiable circumstances, cardiopulmonary resuscitation (CPR) has a higher chance of success and lower likelihood of neurologic impairment. The probability of survival from a cardiac arrest influences patients' wishes regarding resuscitation; thus, when CPR has a higher likelihood of success, patients' expressed preferences for treatment as contained within a DNR order may not accurately reflect their intended goals. Patients should be offered the option of consenting to CPR for "higher-success" situations, including a witnessed cardiopulmonary arrest in which the initial cardiac rhythm is ventricular tachycardia or fibrillation, cardiac arrest in the operating room, and cardiac arrest resulting from a readily identifiable iatrogenic cause. This new level of resuscitation could be called a "limited aggressive therapy" order.     

Factors impeding dispatcher-assisted telephone cardiopulmonary resuscitation

STUDY OBJECTIVE: Dispatcher-assisted telephone cardiopulmonary resuscitation (CPR) instruction can increase the proportion of sudden cardiac arrest victims who receive bystander CPR and has been associated with improved survival. Most sudden cardiac arrest victims, however, do not receive bystander CPR. The study objective was to examine factors that may impede implementation of telephone CPR. METHODS: We reviewed dispatcher audio recordings and emergency medical services reports for 404 cases of sudden cardiac arrest that occurred from July 1, 2000, to June 30, 2002, in the study county to assess the phase (1, instructions not offered; 2, instructions offered but declined; or 3, instructions offered and accepted but CPR not implemented) and specific factors within each phase that potentially impede telephone CPR. RESULTS: Twenty-five percent (99/404) of victims received bystander CPR without dispatch assistance, 34% (139/404) received telephone CPR, and 41% (166/404) did not receive bystander CPR. Each phase of telephone CPR process impeded the implementation of CPR: (1) instructions not offered in 48% (80/166); (2) instructions offered but declined in 31% (52/166); and (3) instructions offered and accepted but CPR not implemented in 21% (34/166). During the first phase, telephone CPR was potentially impeded most frequently because the victim was reported to have signs of life (51/80, 64%); during the second and third phases, telephone CPR was most often impeded because of bystander physical limitation (32/86, 37%). Emotional distress, disease transmission, disagreeable victim characteristics, or medicolegal concerns uncommonly impeded telephone CPR (10/86, 12%). CONCLUSION: Factors potentially impeding telephone CPR can be identified. Although many are logistically challenging, some may be addressable and hence provide opportunities to strengthen the chain of survival.     

Efficacy of pneumatic trousers in refractory prehospital cardiopulmonary arrest

Persons refractory to early application of advanced cardiac life support have a dismal prognosis. New modalities are needed to treat this almost universally lethal condition. We have evaluated pneumatic trousers in the treatment of refractory cardiopulmonary arrest. To date 136 patients have been entered into this controlled, prospective, randomized study. All patients were more than 20 years old and in cardiac arrest of apparent cardiac etiology. Patients were excluded if they had arrested secondary to trauma or overdose, or if an IV could not be started. In addition, patients had to be refractory to therapies included in our paramedic standing orders. If at the end of these standing orders the patient remained in arrest, he was entered into the study and pneumatic trousers were applied or not according to a randomized list. The attempted resuscitation was then continued with no other preset variables. The resuscitation and discharge rates for the control group were 21% and 4%, respectively. With pneumatic trousers, resuscitation increased to 33%, and discharge to 9%. The control group in ventricular fibrillation (VF) had a 27% resuscitation rate and a 5% discharge rate. The pneumatic trousers group with VF had a 35% resuscitation rate and a 12% discharge rate. In pulseless idioventricular rhythm (PIVR), the control group had a 0% resuscitation rate and a 0% discharge rate. In marked contrast, for PIVR the pneumatic trousers group had a 35% resuscitation rate and a 9% discharge rate. The control group in asystole (AS) had a 25% resuscitation rate and a 0% discharge rate. The pneumatic trousers group in AS had a 27% resuscitation rate and a 0% discharge rate. The improvement in resuscitation rate with pneumatic trousers was statistically significant only for the initial rhythm of PIVR (P less than .05). The pneumatic trousers improved resuscitation and discharge rates for refractory VF, but not to a statistically significant degree. These somewhat enhanced resuscitation and discharge rates with the pneumatic trousers make it an adjunct to be considered in refractory arrest.     

Differences in case definitions as a cause of variation in reported in-hospital CPR survival

To determine the effect of different case definitions on reported survival following in-hospital cardiopulmonary arrest, the authors reviewed the charts of 411 patients for whom a nurse completed a cardiac arrest form at a university hospital during a two-year period. Survival to discharge was 16.0% for patients who required basic cardiopulmonary resuscitation (chest compression and pulmonary ventilation), 18.6% for patients who were pulseless and apneic, 23.0% for patients who were pulseless or apneic, and 28.2% for all 411 patients for whom a cardiac arrest form was completed. These results demonstrate that reported survival to discharge following in-hospital cardiac arrest varies widely depending on the case definition that is used. Received from the Division of General Medicine, Department of Medicine, University of Virginia Health Sciences Center, Charlottesville, Virginia. Presented at the annual meeting of the Society of General Internal Medicine, April 30, 1993, Arlington, Virginia.