T ERMINATION OF R ESUSCITATION IN THE P REHOSPITAL S ETTING FOR A DULT P ATIENTS S UFFERING N ONTRAUMATIC C ARDIAC A RREST

The National Association of EMS Physicians (NAEMSP) supports out-of-hospital termination of resuscitation for adult, nontraumatic cardiac arrest patients who have not responded to full resuscitative efforts. The following factors should be considered in establishing termination of resuscitation protocols: 1) Termination of resuscitation may be considered for any adult patient who suffers sudden cardiac death that is likely to be medical. 2) Unwitnessed cardiac arrest with delayed initiation of cardiopulmonary resuscitation (CPR) beyond 6 minutes and delayed defibrillation beyond 8 minutes has a poor prognosis. 3) In the absence of “do not resuscitate” or advanced directives, a full resuscitative effort including CPR, definitive airway management, medication administration, defibrillation if necessary, and at least 20 minutes of treatment following Advanced Cardiac Life Support (ACLS) guidelines should be performed prior to declaring the patient dead. 4) A patient whose rhythm changes to, or remains in, ventricular fibrillation or ventricular tachycardia should have continued resuscitative efforts. Patients in asystole or pulseless electrical activity should be strongly considered for out-of-hospital termination of resuscitation. 5) Logistic factors should be considered, such as collapse in a public place, family wishes, and safety of the crew and public. 6) Online medical direction should be established prior to termination of resuscitation. The decision to terminate efforts should be a consensus between the on-scene paramedic and the online physician. 7) The on-scene providers and family should have access to resources, such as clergy, crisis workers, and social workers. 8) Quality review is necessary to ensure appropriate application of the termination protocol, law enforcement notification, medical examiner or coroner involvement, and family counseling.     

Spontaneous defibrillation after cessation of resuscitation in out-of-hospital cardiac arrest: a case of Lazarus phenomenon

This report describes a case of out-of-hospital cardiac arrest with spontaneous defibrillation and subsequent return of circulation after cessation of resuscitative efforts. A 47-year-old man was found in cardiac arrest and resuscitation was initiated. As no response was achieved, the efforts were withdrawn and final registered cardiac rhythm was ventricular fibrillation. Fifteen minutes later the patient was found to be normotensive and breathing spontaneously. The patient made a poor neurological recovery and died 3 months after the arrest. The authors are unable to give an explanation to the event, but suspect the effect of adrenaline combined with mild hypothermia to have contributed to the self-defibrillation of the myocardium.     

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.     

Partial pressure of end-tidal carbon dioxide successful predicts cardiopulmonary resuscitation in the field: a prospective observational study

Introduction

Prognosis in patients suffering out-of-hospital cardiac arrest is poor. Higher survival rates have been observed only in patients with ventricular fibrillation who were fortunate enough to have basic and advanced life support initiated soon after cardiac arrest. An ability to predict cardiac arrest outcomes would be useful for resuscitation. Changes in expired end-tidal carbon dioxide levels during cardiopulmonary resuscitation (CPR) may be a useful, noninvasive predictor of successful resuscitation and survival from cardiac arrest, and could help in determining when to cease CPR efforts.

Methods

This is a prospective, observational study of 737 cases of out-of-hospital cardiac arrest. The patients were intubated and measurements of end-tidal carbon dioxide taken. Data according to the Utstein criteria, demographic information, medical data, and partial pressure of end-tidal carbon dioxide (Pet CO ₂) values were collected for each patient in cardiac arrest by the emergency physician. We hypothesized that an end-tidal carbon dioxide level of 1.9 kPa (14.3 mmHg) or more after 20 minutes of standard advanced cardiac life support would predict restoration of spontaneous circulation (ROSC).

Results

Pet CO ₂ after 20 minutes of advanced life support averaged 0.92 ± 0.29 kPa (6.9 ± 2.2 mmHg) in patients who did not have ROSC and 4.36 ± 1.11 kPa (32.8 ± 9.1 mmHg) in those who did (P < 0.001). End-tidal carbon dioxide values of 1.9 kPa (14.3 mmHg) or less discriminated between the 402 patients with ROSC and 335 patients without. When a 20-minute end-tidal carbon dioxide value of 1.9 kPa (14.3 mmHg) or less was used as a screening test to predict ROSC, the sensitivity, specificity, positive predictive value, and negative predictive value were all 100%.

Conclusions

End-tidal carbon dioxide levels of more than 1.9 kPa (14.3 mmHg) after 20 minutes may be used to predict ROSC with accuracy. End-tidal carbon dioxide levels should be monitored during CPR and considered a useful prognostic value for determining the outcome of resuscitative efforts and when to cease CPR in the field.     

CPR Induced Consciousness During Out-of-Hospital Cardiac Arrest: A Case Report on an Emerging Phenomenon

Background: High quality cardiopulmonary resuscitation (CPR) has produced a relatively new phenomenon of consciousness in patients with vital signs absent. Further research is necessary to produce a viable treatment strategy during and post resuscitation. Objective: To provide a case study done by paramedics in the field illustrating the need for sedation in a patient whose presentation was consistent with CPR induced consciousness. Resuscitative challenges are provided as well as potential future treatment options to minimize harm to both patients and prehospital providers. Case Report: A 52-year-old male presented as a witnessed out-of-hospital cardiac arrest (OHCA). During CPR the patient began to exhibit signs of life including severe agitation and thrashing of his limbs while CPR was ongoing for ventricular fibrillation prior to defibrillation. Resuscitation became considerably more complicated due to the violent and counterintuitive motions done by the patient during their own resuscitation. Despite the atypical presentation of cardiac arrest the patient was successfully resuscitated employing high quality CPR, standard advanced life support (ALS) care as well as two double sequential external defibrillation shocks. The patient underwent emergency percutaneous coronary intervention (PCI) for a 100% occlusion of his left anterior descending artery (LAD). The patient returned home 3 days later fully recovered with a Cerebral Performance Score of 1. Conclusion: CPR induced consciousness is emerging as a new phenomenon challenging providers of high quality CPR during cardiac arrest resuscitation. Our case report describes the manifestations of CPR induced consciousness as well as the resuscitative challenges which occur during resuscitation. Further research is required to determine the true frequency of this condition as well as treatment algorithms that would allow for appropriate and safe management for both the patient and EMS providers.     

Termination of Nontraumatic Cardiac Arrest Resuscitative Efforts in the Field: A National Survey

Objectives : 1) To describe elements of adult nontraumatic cardiac arrest protocols in those U.S. cities in which resuscitative efforts are being terminated in the out-of-hospital setting. 2) To determine the prevalence and methods of on-scene family grief counseling delivered in this setting.
Methods : Emergency medical services (EMS) systems in each of the 200 largest cities in the United States were surveyed by telephone regarding the content of their adult cardiac arrest protocols. Type of arrest (medical vs trauma), final dysrhythmia, termination policies, and presence or absence of a grief counseling protocol were recorded.
Results : All of the target population responded to the telephone survey. Most (135; 68%) EMS systems currently have written protocols that allow in-field termination of resuscitative efforts for adult nontraumatic cardiac arrest patients who remain asystolic. Only 47 (24%) EMS systems allow cessation of efforts for patients without return of spontaneous circulation regardless of the dysrhythmia. Base station contact is required for authorization to end resuscitative efforts in 120/135 (89%) EMS systems. Only 26/135 (19%) EMS systems that cease efforts in the field have written policies concerning on-scene family grief counseling. This counseling is most likely to be conducted by the out-of-hospital providers themselves.
Conclusion : Many U.S. urban EMS systems are terminating efforts for selected adult nontraumatic cardiac arrest patients, although few have written policies to address grief intervention for family members at the scene.     

Place des familles pendant la réanimation cardiopulmonaire en préhospitalier

Health care providers’ attitude towards family members during cardiopulmonary resuscitation (CPR) remains highly debated. Recent results from the “PRESENCE” clinical trial show a beneficial effect of offering the family the opportunity to observe CPR in terms of posttraumatic stress disorder and symptoms of anxiety and depression. In addition, family presence does not interfere with medical efforts, increase stress in the health care team, or result in medicolegal conflicts. This study increases the level of evidence of international guidelines for cardiac arrest management that, since 2005, advocated allowing the presence of relatives during CPR. This strategy should be guided by a well-defined protocol, a designated support assistant charged with carefully explaining the resuscitative efforts and prior training of medical staff. Future studies should aim to improve our understanding of why the presence of family members during CPR may reduce their suffering and in what kind of health system such an approach could be implemented in practice in a safe and cost-effective manner.     

Survival from out-of-hospital cardiac arrest. A multivariate analysis

A recursive estimation model is used to investigate the roles of cardiopulmonary resuscitation (CPR) and advanced life support in improving survival from out-of-hospital cardiac arrest. The importance of life support measures is clearly evidenced in the analysis: Fewer elapsed minutes between the cardiac arrest and the start of CPR increase the probabilities of both a favorable cardiac rhythm and defibrillation and the probability of survival. Similarly, a shorter elapsed time between the start of CPR and defibrillation is significantly related to a higher probability of survival of the cardiac arrest. Personal characteristics also contribute to survival, but primarily via their association with a favorable initial postarrest cardiac rhythm and the probability of defibrillation. The initial postarrest cardiac rhythm is shown to be an indicator of the heart's condition, but when other factors associated with survival are included in the analysis, it does not independently influence an individual's probability of survival.     

Lactic acidosis as a predictor of downtime during cardiopulmonary arrest in dogs

Studies have shown that over 50% of cardiovascular deaths occur before hospitalization. A major factor associated with survival in cases of out-of-hospital cardiac arrest is the time from cardiovascular collapse to the initiation of cardiopulmonary resuscitation (CPR) or "downtime." The purpose of this study was to determine whether blood lactate levels could be used to predict downtime in the canine cardiac arrest model. Femoral arterial and Swan-Ganz catheters were placed in 22 mongrel dogs, and ventricular fibrillation was electrically induced. The dogs remained in ventricular fibrillation without ventilation for 5, 10, 15, 30, or 60 minutes. After the predetermined fibrillation time, a left anterolateral thoracotomy was performed, and open-chest cardiac massage was begun. Arterial and mixed venous lactate levels were determined for every 5 minutes during 30 minutes of cardiopulmonary resuscitation. The correlation coefficient between the mixed venous and arterial lactate levels was 0.96 or greater during all stages of resuscitation. Peak serum lactate level increased linearly in relation to downtime. The increase in lactate level was not evident until after CPR was begun, and it remained at peak levels or decreased insignificantly, despite optimal open-chest CPR. Linear regression analysis revealed that 84% of the variability in serum lactate levels could be explained by downtime differences. In this model, blood lactate level is a reliable and objective measure of downtime and may be a useful indicator of the adequacy of CPR if levels decrease or remain stable. The clinical implications of this study lie with the use of blood lactate levels in the emergency department to guide the aggressiveness of resuscitative efforts.     

Termination of Resuscitative Efforts for Out-of-hospital Cardiac Arrests

OBJECTIVE: To determine the rate of termination of resuscitative efforts for out-of-hospital cardiac arrest patients and whether variability exists among different base hospitals providing online medical control (OLMC). METHODS: This was an observational one-year study that included all adult patients in the city of Los Angeles with nontraumatic, out-of-hospital cardiac arrests with attempted resuscitative efforts by paramedics. OLMC was provided by 13 base hospitals. The main outcome measure was the incidence of termination of resuscitative efforts on scene as directed by OLMC. RESULTS: Of 1,700 patients, 151 (9%) had resuscitative efforts terminated on scene via direction by OLMC. Patients pronounced on scene were statistically more likely to be older, be found in an extended care facility, have an unwitnessed arrest, and present in asystole. Two base hospitals were more likely to terminate resuscitative efforts via OLMC than all others. Incidence at base hospital A was 37% (odds ratio, 18.6; 95% confidence interval = 11.7 to 30.0; p < 0.0001); incidence at base hospital B was 14% (odds ratio, 3.3; 95% confidence interval = 1.9 to 5.5; p < 0.0001), and incidence at all other base hospitals was 5%. Cardiac arrest patients handled by base hospital A were more likely to be found in ventricular fibrillation; those patients handled by base hospital B had shorter emergency medical services response times and were more likely to be found in an extended care facility. All other characteristics of cardiac arrest patients were not significantly different among the base hospitals. CONCLUSIONS: There is significant variability in Los Angeles, depending on the particular base hospital that provides OLMC, in pronouncement of death and termination of resuscitative efforts for medical cardiac arrest in the field. Given potential ethical, logistical, and economic concerns, efforts to assure consistency in the practice of discontinuing resuscitative efforts in the field is warranted.     

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.     

Successful extracorporeal life support in cardiac arrest with recurrent ventricular fibrillation unresponsive to standard cardiopulmonary resuscitation

Extracorporeal life support has been used as an extension of conventional cardiopulmonary resuscitation (CPR). However, the appropriate indications for extracorporeal CPR (ECPR) including the duration of CPR are unknown. We present a case of a male, 37-year-old out-of-hospital cardiac arrest patient who received prolonged CPR followed by ECPR. Despite advanced cardiac life support, he did not regain a sustained spontaneous circulation and had recurrent ventricular fibrillation (VF) during the prolonged CPR. VF was unresponsive to CPR, defibrillation, adrenaline (epinephrine), and antiarrhythmics. The CPR time before ECPR was approximately 2h. During extracorporeal life support, the VF did not recur and percutaneous coronary angioplasty was achieved. Ultimately, the patient was discharged without neurological complications. Although cardiac arrest occurred out-of-hospital and CPR was performed for a long time, a patient might be a candidate for ECPR if perfusing rhythms are restored transiently but not successfully maintained due to recurrent VF. ECPR may be used for VF unresponsive to standard CPR techniques.     

Clinical review: Reappraising the concept of immediate defibrillatory attempts for out-of-hospital ventricular fibrillation

Despite well developed emergency medical services with rapid response advanced life support capabilities, survival rates following out-of-hospital ventricular fibrillation (VF) have remained bleak in many venues. Generally, these poor resuscitation rates are attributed to delays in the performance of basic cardiopulmonary resuscitation by bystanders or delays in defibrillation, but recent laboratory data suggest that the current standard of immediately providing a countershock as the first therapeutic intervention may be detrimental when VF is prolonged beyond several minutes. Several studies now suggest that when myocardial energy supplies begin to dwindle following more prolonged periods of VF, improvements in coronary artery perfusion must first be achieved in order to prime the heart for successful return of spontaneous circulation after defibrillation. Therefore, before countershocks, certain pharmacologic and/or mechanical interventions might take precedence during resuscitative efforts. This evolving concept has been substantiated recently by clinical studies, including a controlled clinical trial, demonstrating a significant improvement in survival when basic cardiopulmonary resuscitation is provided for several minutes before the initial countershock. Although this evolving concept differs from current standards and may pose a potential problem for automated defibrillator initiatives (e.g. public access defibrillation), successful defibrillation and return of spontaneous circulation have been rendered more predictable by evolving technologies that can score the VF waveform signal and differentiate between those who can be shocked immediately and those who should receive other interventions first.     

Clinical review: Reappraising the concept of immediate defibrillatory attempts for out-of-hospital ventricular fibrillation

Despite well developed emergency medical services with rapid response advanced life support capabilities, survival rates following out-of-hospital ventricular fibrillation (VF) have remained bleak in many venues. Generally, these poor resuscitation rates are attributed to delays in the performance of basic cardiopulmonary resuscitation by bystanders or delays in defibrillation, but recent laboratory data suggest that the current standard of immediately providing a countershock as the first therapeutic intervention may be detrimental when VF is prolonged beyond several minutes. Several studies now suggest that when myocardial energy supplies begin to dwindle following more prolonged periods of VF, improvements in coronary artery perfusion must first be achieved in order to prime the heart for successful return of spontaneous circulation after defibrillation. Therefore, before countershocks, certain pharmacologic and/or mechanical interventions might take precedence during resuscitative efforts. This evolving concept has been substantiated recently by clinical studies, including a controlled clinical trial, demonstrating a significant improvement in survival when basic cardiopulmonary resuscitation is provided for several minutes before the initial countershock. Although this evolving concept differs from current standards and may pose a potential problem for automated defibrillator initiatives (e.g. public access defibrillation), successful defibrillation and return of spontaneous circulation have been rendered more predictable by evolving technologies that can score the VF waveform signal and differentiate between those who can be shocked immediately and those who should receive other interventions first.     

Prompt Advanced Life Support Improves Survival from Ventricular Fibrillation

Objective. To determine whether the interval between the arrival of basic life support (BLS) providers and the arrival of advanced life support (ALS) providers is associated with patient outcome after cardiac arrest. Methods. We conducted a retrospective cohort study of all witnessed, out-of-hospital ventricular fibrillation (VF) cardiac arrests between January 1, 1991, and December 31, 2007. Eligible patients (n = 1,781) received full resuscitation efforts from both BLS and ALS providers. Results. The BLS-to-ALS arrival interval was a significant predictor of survival to hospital discharge (odds ratio [OR] 0.96, 95% confidence interval [CI] 0.93–0.99); the likelihood of survival decreased by 4% for every minute that ALS arrival was delayed following BLS arrival. Other significant predictors of survival were whether the arrest occurred in public (OR 1.48, 95% CI 1.19–1.85), whether a bystander administered cardiopulmonary resuscitation (CPR) (OR 1.34, 95% CI 1.07–1.68), and the interval between the 9-1-1 call and BLS arrival (OR 0.78, 95% CI 0.73–0.83). Conclusions. We found that a shorter BLS-to-ALS arrival interval increased the likelihood of survival to hospital discharge after a witnessed, out-of-hospital VF cardiac arrest. We conclude that ALS interventions may provide additional benefits over BLS interventions alone when utilized in a well-established, two-tiered emergency medical services (EMS) system already optimized for rapid defibrillation. The highest priorities in any EMS system should still be early CPR and early defibrillation, but timely ALS services can supplement these crucial interventions.     

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

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

Evaluation of out-of-hospital cardiopulmonary resuscitation with resuscitative drugs: a prospective comparative study in Japan

OBJECTIVE: This study aimed at evaluating two emergency medical service systems, one in which emergency life-saving technicians (ELSTs) are allowed to administer epinephrine (adrenaline) to patients with out-of-hospital cardiac arrest and one in which ELSTs are allowed to administer epinephrine, lidocaine, and atropine. METHODS: A modified, prospective community health trial was conducted from April 1 to October 31, 2003. Areas served by physician-manned ambulances, where out-of-hospital cardiopulmonary resuscitation (CPR) was performed with resuscitative drugs (experimental areas), were compared to areas served by ELST-manned ambulances, where resuscitative drugs were not administered outside the hospital (reference areas). The sequence of emergency procedures performed in the experimental areas was divided into three phases. Phase I included administration of epinephrine, which simulated administration of epinephrine by ELSTs. Phase II started with the use of lidocaine or atropine. Phases I and II simulated administration of epinephrine, lidocaine, and atropine by ELSTs. Phase III began with administration of another drug. Outcomes, resuscitation rates and 1-month survival rates were determined, and differences between the two types of areas were analyzed. RESULTS: For non-traumatic cardiac arrest, outcomes through phase II in the experimental areas were significantly better than those in the reference areas. Phase I-only outcomes in the experimental areas were better, but not significantly better, than those in the reference areas. CONCLUSION: Use of resuscitative drugs for non-traumatic prehospital CPR appears to be effective in terms of resuscitation rates and 1-month survival rates.     

Hemodynamic-directed cardiopulmonary resuscitation during in-hospital cardiac arrest

Cardiopulmonary resuscitation (CPR) guidelines assume that cardiac arrest victims can be treated with a uniform chest compression (CC) depth and a standardized interval administration of vasopressor drugs. This non-personalized approach does not incorporate a patient's individualized response into ongoing resuscitative efforts. In previously reported porcine models of hypoxic and normoxic ventricular fibrillation (VF), a hemodynamic-directed resuscitation improved short-term survival compared to current practice guidelines. Skilled in-hospital rescuers should be trained to tailor resuscitation efforts to the individual patient's physiology. Such a strategy would be a major paradigm shift in the treatment of in-hospital cardiac arrest victims.