Analysis of the outcomes of cardiopulmonary resuscitation in an emergency department

OBJECTIVE: The aim of this study is to analyse the factors affecting emergency department (ED) cardiopulmonary resuscitation (CPR) outcome. METHODS: A standard CPR protocol was performed in all patients and certain pre and postresuscitation parameters including age, sex, initial arrest rhythm, primary underlying disease, initiation time of advanced cardiac life support, duration of return of spontaneous circulation were recorded. Patients were followed up to determine rates of successful CPR, survival and one-year survival. RESULTS: From December 1999 to May 2001, 80 consecutive adult patients in whom a standard CPR was performed in the ED were prospectively included in the study. The overall rate for successful CPR, survival and one-year survival were found to be 58.8% (47/80), 15% (12/80) and 10% (8/80), respectively. Survival and one-year survival rates were better in patients with an initial arrest rhythm of ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT) than both pulseless electrical activity (pEA) and asystole; survival and one-year survival rates were better in patients with a primary underlying disease of cardiac origin than non-cardiac origin. Acute myocardial infarction had the best prognosis among conditions causing arrest. Presence of sudden death was found to have a better survival and one-year survival rate. CONCLUSION: Initial cardiac rhythm of VF/pVT, cardiac origin as the primary disease causing cardiopulmonary arrest and presence of sudden death were found to be good prognostic factors in CPR.     

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.     

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.     

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.     

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.     

Study of pre-hospital care of out of hospital cardiac arrest victims and their outcome in a tertiary care hospital in India

BackgroundIndia does not have a formal cardiac arrest registry or a centralized emergency medical system. In this study, we aimed to assess the prehospital care received by the patients with OHCA and predict the factors that could influence their outcome.MethodsOut-of-hospital cardiac arrest patients presenting to the emergency department in a tertiary care centre were included in the study. Prehospital care was assessed in terms of bystander cardiopulmonary resuscitation (CPR), mode of transport, resuscitation in ambulance. OHCA outcomes like Return of spontaneous circulation (ROSC), survival to hospital discharge and favourable neurological outcome at discharge were assessed.ResultsAmong 205 patients, the majority were male (71.2%) and were above 60 years of age (49.3%); Predominantly non-traumatic (82.4%). 30.7% of the patients had sustained cardiac arrest in transit to the hospital. 41.5% of patients reached hospital by means other than ambulance. Only 9.8% patients had received bystander CPR. Only 12.5% ambulances had BLS trained personnel. AED was used only in 1% of patients. The initial rhythm at presentation to the hospital was non-shockable (96.5%). Return of spontaneous circulation (ROSC) was achieved in 17 (8.3%) patients, of which only 3 (1.4%) patients survived till discharge. The initial shockable rhythm was a significant predictor of ROSC (OR 18.97 95%CI 3.83–93.89; p < 0.001) and survival to discharge (OR 42.67; 95%CI 7.69–234.32; p < 0.001).ConclusionThe outcome of OHCA in India is dismal. The pre-hospital care received by the OHCA victim needs attention. Low by-stander CPR rate, under-utilised and under-equipped EMS system are the challenges.     

Can nifekalant hydrochloride be used as a first-line drug for cardiopulmonary arrest (CPA)? : comparative study of out-of-hospital CPA with acidosis and in-hospital CPA without acidosis.

BACKGROUND: Early defibrillation of ventricular tachycardia and fibrillation (VT/VF) is an urgent and most important method of resuscitation for survival in cardiopulmonary arrest (CPA). We have previously reported that nifekalant (NIF), a specific I(Kr) blocker developed in Japan, is effective for lidocaine (LID) resistant VT/VF in out-of-hospital CPA (OHCPA). However, little is known about the differences in the effect of NIF on OHCPA with acidosis and in-hospital CPA (IHCPA) without acidosis. METHODS AND RESULTS: The present study enrolled 91 cases of DC shock resistant VT/VF among 892 cases of CPA that occurred between June 2000 and May 2003. NIF was used (0.15-0.3 mg/kg) after LID according to the cardiopulmonary resuscitation (CPR) algorithm of Tokai University. The defibrillation rate was higher in the NIF group for both OHCPA and IHCPA than for LID alone, and the VT/VF rate reduction effect could be maintained even with acidosis. However, sinus bradycardia in OHCPA, and torsades de pointes in IHCPA were occasionally observed. These differences in adverse effects might be related to the amount of epinephrine, serum potassium levels, serum pH, and interaction with LID. CONCLUSIONS: NIF had a favorable defibrillating effect in both CPA groups, and it shows promise of becoming a first-line drug for CPR.     

Hyperkalemia and ionized hypocalcemia during cardiac arrest and resuscitation: possible culprits for postcountershock arrhythmias?

STUDY OBJECTIVE: Early countershock of ventricular fibrillation (VF) has been shown to improve immediate and long-term outcome of out-of-hospital cardiac arrest. However, studies indicate that countershock of prolonged VF most commonly results in asystole or a nonperfusing bradyarrhythmia (pulseless electrical activity [PEA]), which rarely respond to current therapy. The cause of these postcountershock rhythm disturbances is not well understood but may be related to electrical injury of the globally ischemic myocardium or to local metabolic abnormalities that impair impulse formation and cardiac contraction. The purpose of this study was to evaluate changes in serum potassium and free calcium homeostasis during cardiac arrest and advanced cardiac life support (ACLS) interventions. METHODS: After sedation, intubation, anesthesia, and instrumentation, VF was induced in 13 dogs. After 7.5 minutes of VF, animals were immediately countershocked, standard closed-chest CPR was initiated, and epinephrine was administered (1 mg in repeated doses if necessary). RESULTS: Ten animals could not be resuscitated despite 20 minutes of ACLS interventions. In these animals, a progressive increase in serum potassium was observed from the onset of ACLS to the termination of resuscitation efforts (4.3+/-.6 to 6.0+/-.8 mEq/L, P<.01). A significant increase was observed within 10 minutes of beginning ACLS measures. This was accompanied by a decrease in ionized calcium concentration over the same period (4.95+/-.40 to 3.44 mg/dL, P<.01). The decrease in ionized calcium was significant within 5 minutes of ACLS interventions. Nine of these 10 animals had either postcountershock asystole or PEA at the termination of resuscitative efforts. The increase in potassium was not related to acidemia. Successfully resuscitated animals did not demonstrate these electrolyte changes. CONCLUSION: Ionized hypocalcemia and hyperkalemia occur during prolonged resuscitative efforts and may be related to dysfunctional transcellular ionic transport mechanisms. These cations play important roles in cardiac electrical and contractile activity and may play a role in refractory postcountershock rhythm disturbances.     

Resuscitation time in ventricular fibrillation — a prognostic indicator

Length of resuscitation in prehospital ventricular fibrillation patients was studied to define its relationship to survival. Five hundred sixty-five patients presenting with the initial rhythm of ventricular fibrillation to the Milwaukee County Paramedic System between January 1978 and April 1982 were resuscitated successfully. Pediatric patients and patients with trauma, poisoning, and drowning were excluded. Of the 565 resuscitated patients, 262 (46%) were discharged alive and 303 (54%) died during hospitalization. For all 565 patients the resuscitation time and times from arrival of paramedics until the first sustained pulse were plotted against survival to define a curve. The curve demonstrated rapidly declining survival rates for resuscitation time up to 20 minutes; thereafter, survival declined more gradually with respect to resuscitation time. The mean resuscitation time for those eventually discharged alive was 12.6 minutes, which was statistically shorter (P less than .0001) than the mean resuscitation time of 23.9 minutes for those who eventually died. The overall survival curve of witnessed arrest patients was not statistically different from that of unwitnessed patients. The survival curve of those patients receiving bystander cardiopulmonary resuscitation (CPR) was similar to the curve of those who received no CPR. We conclude that resuscitation time is a heretofore undefined significant predictor of survival of resuscitated prehospital ventricular fibrillation patients.     

Predicting defibrillation success in sudden cardiac arrest patients

Although the importance of quality cardiopulmonary resuscitation (CPR) and its link to survival is still emphasized, there has been recent debate about the balance between CPR and defibrillation, particularly for long response times. Defibrillation shocks for ventricular fibrillation (VF) of recently perfused hearts have high success for the return of spontaneous circulation (ROSC), but hearts with depleted adenosine triphosphate (ATP) stores have low recovery rates. Since quality CPR has been shown to both slow the degradation process and restore cardiac viability, a measurement of patient condition to optimize the timing of defibrillation shocks may improve outcomes compared to time-based protocols. Researchers have proposed numerous predictive features of VF and shockable ventricular tachycardia (VT) which can be computed from the electrocardiogram (ECG) signal to distinguish between the rhythms which convert to spontaneous circulation and those which do not. We looked at the shock-success prediction performance of thirteen of these features on a single evaluation database including the recordings from 116 out-of-hospital cardiac arrest patients which were collected for a separate study using defibrillators in ambulances and medical centers in 4 European regions and the US between March 2002 and September 2004. A total of 469 shocks preceded by VF or shockable VT rhythm episodes were identified in the recordings. Based on the experts' annotation for the post-shock rhythm, the shocks were categorized to result in either pulsatile (ROSC) or non-pulsatile (no-ROSC) rhythm. The features were calculated on a 4-second ECG segment prior to the shock delivery. These features examined were: Mean Amplitude, Average Peak-Peak Amplitude, Amplitude Range, Amplitude Spectrum Analysis (AMSA), Peak Frequency, Centroid Frequency, Spectral Flatness Measure (SFM), Energy, Max Power, Centroid Power, Power Spectrum Analysis (PSA), Mean Slope, and Median Slope. Statistical hypothesis tests (two-tailed t-test and Wilcoxon with 5% significance level) were applied to determine if the means and medians of these features were significantly different between the ROSC and no-ROSC groups. The ROC curve was computed for each feature, and Area Under the Curve (AUC) was calculated. Specificity (Sp) with Sensitivity (Se) held at 90% as well as Se with Sp held at 90% was also computed. All features showed statistically different mean and median values between the ROSC and no-ROSC groups with all p-values less than 0.0001. The AUC was >76% for all features. For Sp = 90%, the Se range was 33–45%; for Se = 90%, the Sp range was 49–63%. The features showed good shock-success prediction performance. We believe that a defibrillator employing a clinical decision tool based on these features has the potential to improve overall survival from cardiac arrest.     

The effect of bystander CPR on survival of out-of-hospital cardiac arrest victims

The effect of bystander cardiopulmonary resuscitation (CPR) was studied in 2142 emergency medical service (EMS) cardiac arrest runs. When bystander CPR was administered to cardiac arrest victims, 22.9% of the victims survived until they were admitted to the hospital and 11.9% were discharged alive. In comparison, the statistics for cardiac arrest victims who did not receive bystander CPR were 14.6% and 4.7%, respectively (p less than 0.001). A critical factor in patient survival was the amount of time that elapsed before the EMS personnel arrived and administered CPR. Patients who received bystander CPR were more likely to have ventricular fibrillation when the EMS arrived. Other factors relating to patient survival were the location of the victim at the time of the cardiac arrest and the age of the victim. Understanding these factors is important in developing community strategies to treat patients with cardiac arrest out of hospital.     

Lactic acidosis during closed-chest CPR in dogs

Survival after out-of-hospital cardiac arrest is intimately related to the time from cardiovascular collapse to the initiation of CPR, or downtime. Furthermore, the reperfusion technique that optimizes coronary and cerebral blood flow after cardiac arrest may also be dependent on downtime. Peak blood lactate levels have been shown to be unchanged throughout resuscitation and predictive of downtime in dogs subjected to cardiopulmonary arrest and open cardiac massage. The purpose of this study was to determine the course of arterial lactate levels in dogs subjected to a fibrillatory cardiopulmonary arrest and conventional closed-chest CPR (CCPR). Fourteen dogs were subjected to five minutes of cardiopulmonary arrest and 30 minutes of CCPR. Resuscitation was performed according to a standardized protocol. Arterial lactic acid samples were collected at timed intervals throughout the experiment. Mean arterial lactic acid levels increased significantly with each sampling interval during 30 minutes of CCPR (overall P less than .05). In nine dogs successfully resuscitated, there were no significant differences in mean arterial lactic acid levels after the return of spontaneous circulation (ROSC). Open-chest resuscitation after five minutes of ventricular fibrillation in dogs results in peak lactic acid levels that do not change significantly once internal cardiac massage is initiated. In contrast, CCPR in similarly arrested dogs does not appear to provide adequate tissue oxygenation and/or perfusion to prevent continuous lactic acid accumulation.     

Outcomes of cardiopulmonary resuscitation in the elderly

STUDY OBJECTIVE: To determine the success rate of cardiopulmonary resuscitation in the elderly and to define characteristics of elderly patients for whom cardiopulmonary resuscitation is effective. DESIGN: Retrospective chart review. SETTING: Five Boston health-care institutions: two acute-care hospitals; two chronic-care hospitals; and one long-term-care institution. PATIENTS: Five hundred and three consecutive patients aged 70 and over who received cardiopulmonary resuscitation. MEASUREMENTS AND MAIN RESULTS: Of 503 patients, 112 (22%) survived initially but only 19 (3.8%) survived to hospital discharge. The poorest outcomes were for patients with unwitnessed arrests (1 of 116 survived), terminal arrhythmias such as asystole and electromechanical dissociation (1 of 237 survived), and patients with cardiopulmonary resuscitation lasting more than 15 minutes (1 of 360 survived). Only 2 (0.8%; CI, 0.0% to 2.0%) of 244 patients with out-of-hospital cardiopulmonary arrests left the hospital alive. Of 259 patients with in-hospital arrests, 17 (6.5%; CI, 3.4% to 9.6%) survived to discharge. Most survivors had ventricular arrhythmias and were resuscitated within minutes. Initial survivors with either impaired consciousness or functional impairment after the arrest had significantly worse chances of survival than patients without these impairments. CONCLUSION: Cardiopulmonary resuscitation is rarely effective for elderly patients with cardiopulmonary arrests that are either out-of-hospital, unwitnessed, or associated with asystole or electromechanical dissociation.     

Bystander CPR in prehospital coarse ventricular fibrillation

Prehospital bystander cardiopulmonary resuscitation (CPR) was studied to determine if it affected the outcome of defibrillation. Four hundred twenty-one consecutive witnessed cardiopulmonary arrests presenting with the initial rhythm of coarse ventricular fibrillation treated by the Milwaukee County Paramedic System from January 1980 to June 1982 were analyzed. Pediatric, trauma, and poisoning patients and those receiving intravenous or endotracheal medications before defibrillation (58) were excluded. Immediate professional bystander CPR (physician, nurse, EMT) and citizen bystander CPR were compared to a control group receiving no bystander CPR until arrival of EMS personnel. A successful defibrillation occurred if defibrillation prior to administration of medication produced an effective cardiac rhythm with pulses. Eighty-eight of the 363 remaining patients (24%) converted with initial defibrillations. While the group receiving professional bystander CPR had a higher successful defibrillation rate than did the no-CPR group (35% vs 22%, P less than .04), citizen bystander CPR and no-CPR groups had similar successful defibrillation rates (24% vs 22%, no significant difference). One hundred eighty-six of the 363 patients (51%) were transported to a hospital with a rhythm and a pulse (a successful resuscitation). Ninety-seven of the 363 patients (27%) were discharged alive from the hospital (a save). Patients who were converted successfully using initial "quick-look" defibrillations were far more likely to be successfully resuscitated (79/88 [90%] vs 107/275 [39%], P greater than .0001) and to be discharged alive from the hospital (54/88 [61%] vs 43/275 [16%], P greater than .0001) than were those who required further advanced cardiac life support techniques.(ABSTRACT TRUNCATED AT 250 WORDS)     

Utstein模式下心源性心脏骤停心肺复苏的危险因素研究

目的:探讨影响Utstein模式下急诊心源性心脏骤停(CA)患者心肺复苏(CPR)预后的危险因素。方法:选取按Utstein模式要求登记的228例CA患者,记录患者CPR预后情况,对影响CA患者CPR预后的相关因素进行单因素及Logistic多因素分析。结果:228例CPR患者中,自主恢复循环(ROSC)125例(54.82%)、24 h存活55例(24.12%)、出院存活28例(12.28%)、神经功能恢复良好出院20例(8.77%)。经Logistic多因素分析显示,CPR持续时间、创伤性、首次监测心律、肾上腺素应用剂量是ROSC的独立预测因子;CPR持续时间、创伤性、首次监测心律是影响患者24 h存活的独立危险因素;首次监测心律、CA前状态、CPR持续时间是影响患者神经功能恢复良好及出院后存活的独立预测因子。结论:创伤性是影响CA患者ROSC及24 h存活的独立危险因素,肾上腺应用剂量≤5 mg、可除颤心律、CPR持续时间≤15 min均是影响患者ROCS及24 h存活的保护因素。可除颤心律、CPR持续时间≤15 min是影响患者神经功能恢复及出院后存活的有利因素,而CA前多器官功能衰竭(MOF)/疾病终末期则是危险因素。     

Neurologic benefits from the use of early cardiopulmonary resuscitation

The efficacy of bystander CPR in resuscitation from cardiac arrest when defibrillation is available within five to six minutes has been questioned. Epidemiologic studies from different cities have shown conflicting results. We conducted a study to determine the effect of early CPR versus no CPR on resuscitability, 24-hour survival, and neurologic deficit in an animal model of cardiac arrest. Twenty-two mongrel dogs were subjected to five minutes of electrically induced ventricular fibrillation. In 11 dogs, closed-chest massage and ventilation with room air was begun immediately and was continued for five minutes. The other 11 dogs received no CPR. At five minutes defibrillation was attempted and advanced cardiac life support (ACLS) protocols were followed until the animal was resuscitated or died. No statistical difference in resuscitability or 24-hour survival between the two groups was demonstrated. Eight of 11 "early CPR" animals were resuscitated and survived 24 hours; six of 11 "no CPR" dogs were resuscitated, and five lived for 24 hours. A significant difference was demonstrated by the Student t test in neurologic deficit and ease of resuscitation. "Early CPR" dogs had no neurologic deficit, while "no CPR" dogs had a 41% deficit (P less than .01). "Early CPR" dogs were resuscitated in significantly less time once ACLS was started (29 versus 317 seconds), and required less electrical energy (100 versus 560 J), fewer countershocks (1.3 versus 4.0), and less epinephrine (0.1 versus 1.7 mg) than did "no CPR" animals. In this animal model of cardiac arrest, early CPR was shown to be beneficial to neurologic function and ease of resuscitation, even when ACLS was provided within five minutes.     

Prehospital external cardiac pacing: a prospective, controlled clinical trial

This prehospital prospective, controlled study was conducted to determine if prehospital cardiac pacing affects survival. The study involved 239 patients, 226 pulseless, nonbreathing patients (rhythms of asystole and electromechanical dissociation with heart rates less than 70) and 13 patients with hemodynamically significant bradycardia (heart rate less than 60; blood pressure less than 90 mm Hg; not responding to atropine). Patients were assigned to treatment or control groups on an every-other-day basis. One hundred three patients were treated with an external cardiac pacing device; 22 (21.4%) were resuscitated (arrival at admitting hospital with pulse and blood pressure) and seven (6.8%) were saved (survival to hospital discharge). One hundred thirty-six patients were not paced and served as controls; 28 (20.6%) were resuscitated (P = .90) and six (4.4%) were saved (P = .71). Analysis of pacing times showed increased resuscitation in patients paced early. All surviving paced patients were paced in 17 minutes or less. Analysis of rhythm subgroups showed no significant difference in the resuscitation or survival rates of paced and control groups for primary asystole, primary electromechanical dissociation, and secondary asystole and electromechanical dissociation occurring after countershock treatment of ventricular fibrillation when compared respectively. However, among patients with hypotensive bradycardia, six of six paced patients were resuscitated and five were saved, while only two of seven controls were resuscitated (P = .01) and one was saved (P = .01). Interpretation of the bradycardic patient data is limited by inequalities noted between control and treatment groups with regard to the administration of isoproterenol.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

A program encouraging early defibrillation results in improved in-hospital resuscitation efficacy

OBJECTIVES: The purpose of this study was to determine whether survival to discharge after in-hospital cardiopulmonary arrest could be improved by a program encouraging early defibrillation that included switching from monophasic to biphasic devices. BACKGROUND: In-hospital resuscitation continues to have a low success rate. Biphasic waveform devices have demonstrated characteristics that might improve survival, and outside the hospital, automated external defibrillators (AEDs) have shown promise in improving survival of patients suffering cardiopulmonary arrest. METHODS: A program including education and replacement of all manual monophasic defibrillators with a combination of manual biphasic defibrillators used in AED mode and AEDs in all outpatient clinics and chronic care units was implemented. RESULTS: With program implementation, the percentage survival of all patients with resuscitation events improved 2.6-fold, from 4.9% to 12.8%. Factors independently predicting survival included event location outside an intensive care unit, younger age, an initial rhythm of pulseless ventricular tachycardia (VT) or ventricular fibrillation (VF), pre-arrest beta-blocker, and program initiation. The outcome was independent of gender, race, work shift, number of previous resuscitation attempts, body mass index, comorbidity index, presence of diabetes, presence of hypertension, or use of angiotensin-converting enzyme inhibitors. The improvement in mortality was attributable solely to an effect on patients presenting with VT/VF. Patients with these initial rhythms were 14-fold (odds ratio = 0.07 of death, confidence interval = 0.02 to 0.3) more likely to survive to discharge after program initiation. Automated external defibrillators performed similarly to biphasic manual defibrillators in AED mode. CONCLUSIONS: A program including education and use of biphasic manual defibrillators in AED mode and selective use of AEDs improved survival to discharge in hospitalized patients suffering from cardiopulmonary arrest.     

Survival after cardiac arrest or sustained ventricular tachycardia in patients with hypertrophic cardiomyopathy.

OBJECTIVES: The aim of this study was to evaluate the survival of patients with hypertrophic cardiomyopathy (HCM) after resuscitated ventricular fibrillation or syncopal sustained ventricular tachycardia (VT/VF) when treated with low dose amiodarone or implantable cardioverter defibrillators (ICDs). BACKGROUND: Prospective data on clinical outcome in patients with HCM who survive a cardiac arrest are limited, but studies conducted before the widespread use of amiodarone and/or ICD therapy suggest that over a third die within seven years from sudden cardiac death or progressive heart failure. METHODS: Sixteen HCM patients with a history of VT/VF (nine male, age at VT/VF 19 +/- 8 years [range 10 to 36]) were studied. Syncopal sustained ventricular tachycardia/ventricular fibrillation occurred during or immediately after exertion in eight patients and was the initial presentation in eight. One patient had disabling neurologic deficit after VT/VF. Before VT/VF, two patients had angina, four had syncope and six had a family history of premature sudden cardiac death. After VT/VF all patients were in New York Heart Association class I or II, three had nonsustained VT during ambulatory electrocardiography and 11 had an abnormal exercise blood pressure response. After VT/VF eight patients were treated with low dose amiodarone and six received an ICD. Prophylactic therapy was declined by two patients. RESULTS: Mean follow-up was 6.1 +/- 4.0 years (range 0.5 to 14.5). Cumulative survival (death or ICD discharge) for the entire cohort was 59% at five years (95% confidence interval: 33% to 84%). Thirteen (81%) patients were alive at last follow-up. Two patients died suddenly while taking low dose amiodarone, and one died due to neurologic complications of his initial cardiac arrest. Three patients had one or more appropriate ICD discharges during follow-up; the times to first shock after ICD implantation were 23, 197 and 1,124 days. CONCLUSIONS: This study shows that patients with HCM who survive an episode of VT/VF remain at risk for a recurrent event. Implantable cardioverter defibrillator therapy appears to offer the best potential benefit regarding outcome.