Cardiocerebral Resuscitation: An Approach to Improving Survival of Patients With Primary Cardiac Arrest.

Out-of-hospital cardiac arrest (OHCA) is a major public health problem. In the United States, OHCA accounts for more premature deaths than any other cause. For over a half-century, the national "Guidelines" for resuscitation have recommended the same initial treatment of primary and secondary cardiac arrests. Using this approach, the overall survival of patients with OHCA, while quite variable, was generally very poor. One reason is that the etiologies of cardiac arrests are not all the same. The vast majority of nontraumatic OHCA in adults are due to a "primary" cardiac arrest, rather than secondary to respiratory arrest. Decades of research and ongoing reviews of the literature led the University of Arizona Sarver Heart Center Resuscitation Research Group to conclude in 2003 that the national guidelines for patients with primary cardiac arrest were not optimal. Therefore, we instituted a new, nonguidelines approach to the therapy of primary cardiac arrest that dramatically improved survival. We called this approach cardiocerebral resuscitation (CCR), as it is the heart and the brain that are the most vulnerable and therefore need to be the focus of resuscitation efforts for these patients. In contrast, cardiopulmonary resuscitation should be reserved for respiratory arrests. Cardiocerebral resuscitation evolved into 3 components: the community, with emphasis for lay individuals to "Check, Call, Compress" and use an automated external defibrillator if available; the Emergency Medical Services, that emphasizes delayed intubation in favor of passive ventilation, urgent and near continuous chest compressions before and immediately after a single indicated shock, and the early administration of epinephrine; and the third component, added in 2007, the designations of hospitals in Arizona that request this designation and agree to receive patients with return of spontaneous circulation following OHCA and to institute state-of-the-art postresuscitation care that includes urgent therapeutic mild hypothermia and cardiac catheterization as a Cardiac Receiving Center. Each component of CCR is critical for optimal survival of patients with primary OHCA. In each city, county, and state where CCR was instituted, the result was a marked increase in survival of the subgroup of patients with OHCA most likely to survive, for example, those with a shockable rhythm. The purpose of this invited article on CCR is to review this alternative approach to resuscitation of patients with primary cardiac arrest and to encourage its adoption worldwide so that more lives can be saved.

Statewide regionalization of postarrest care for out-of-hospital cardiac arrest: association with survival and neurologic outcome.

STUDY OBJECTIVE: For out-of-hospital cardiac arrest, authoritative, evidence-based recommendations have been made for regionalization of postarrest care. However, system-wide implementation of these guidelines has not been evaluated. Our hypothesis is that statewide regionalization of postarrest interventions, combined with emergency medical services (EMS) triage bypass, is associated with improved survival and neurologic outcome. METHODS: This was a prospective before-after observational study comparing patients admitted to cardiac receiving centers before implementation of the interventions ("before") versus those admitted after ("after"). In December 2007, the Arizona Department of Health Services began officially recognizing cardiac receiving centers according to commitment to provide specified postarrest care. Subsequently, the State EMS Council approved protocols allowing preferential EMS transport to these centers. Participants were adults (≥ 18 years) experiencing out-of-hospital cardiac arrest of presumed cardiac cause who were transported to a cardiac receiving center. Interventions included (1) implementation of postarrest care at cardiac receiving centers focusing on provision of therapeutic hypothermia and coronary angiography or percutaneous coronary interventions (catheterization/PCI); and (2) implementation of EMS bypass triage protocols. Main outcomes included discharged alive from the hospital and cerebral performance category score at discharge. RESULTS: During the study (December 1, 2007, to December 31, 2010), 31 hospitals were recognized as cardiac receiving centers statewide. Four hundred forty patients were transported to cardiac receiving centers before and 1,737 after. Provision of therapeutic hypothermia among patients with return of spontaneous circulation increased from 0% (before: 0/145; 95% confidence interval [CI] 0% to 2.5%) to 44.0% (after: 300/682; 95% CI 40.2, 47.8). The post return of spontaneous circulation catheterization PCI rate increased from 11.7% (17/145; 95% CI 7.0, 18.1) before to 30.7% (210/684; 95% CI 27.3, 34.3) after. All-rhythm survival increased from 8.9% (39/440) to 14.4% (250/1,734; adjusted odds ratio [aOR] = 2.22; 95% CI 1.47 to 3.34). Survival with favorable neurologic outcome (cerebral performance category score = 1 or 2) increased from 5.9% (26/439) to 8.9% (153/1,727; aOR = 2.26 [95% CI 1.37, 3.73]). For witnessed shockable rhythms, survival increased from 21.4% (21/98) to 39.2% (115/293; aOR = 2.96 [95% CI 1.63, 5.38]) and cerebral performance category score = 1 or 2 increased from 19.4% (19/98) to 29.8% (87/292; aOR = 2.12 [95% CI 1.14, 3.93]). CONCLUSION: Implementation of a statewide system of cardiac receiving centers and EMS bypass was independently associated with increased overall survival and favorable neurologic outcome. In addition, these outcomes improved among patients with witnessed shockable rhythms.

Advancing resuscitation science.

PURPOSE OF REVIEW: To describe an alternative approach for improving survival of patients with out-of-hospital cardiac arrest (OHCA). The survival of patients with OHCA has been poor and relatively unchanged for decades in spite of recurrent national and international guidelines. Although there are exceptions, many thought and continue to think that any change in the guidelines for cardiopulmonary resuscitation should be based on randomized controlled trials in humans. However, many factors, including the need for informed consent, the marked variability of patients, and the variability of the type and quality of bystander and advanced resuscitation efforts, all make such studies problematic. Thus, potentially life-saving procedures are often withheld for decades, resulting in unnecessary loss of life. RECENT FINDINGS: Many improvements in public health conditions have been made using models of continuous quality improvement. When applied to resuscitation science, once baseline data are obtained, changes based on reliable experimental findings are instituted and outcomes measured. This approach has now been shown to result in significant improvement in neurologically intact survival of patients with OHCA. SUMMARY: Following this model, we found significant improvement in survival of patients with a witnessed OHCA primary cardiac arrest.

Mild hypothermia delays the development of stone heart from untreated sustained ventricular fibrillation--a cardiovascular magnetic resonance study.

BACKGROUND: 'Stone heart' resulting from ischemic contracture of the myocardium, precludes successful resuscitation from ventricular fibrillation (VF). We hypothesized that mild hypothermia might slow the progression to stone heart. METHODS: Fourteen swine (27 ± 1 kg) were randomized to normothermia (group I; n=6) or hypothermia groups (group II; n=8). Mild hypothermia (34 ± 2 °C) was induced with ice packs prior to VF induction. The LV and right ventricular (RV) cross-sectional areas were followed by cardiovascular magnetic resonance until the development of stone heart. A commercial 1.5T GE Signa NV-CV/i scanner was used. Complete anatomic coverage of the heart was acquired using a steady-state free precession (SSFP) pulse sequence gated at baseline prior to VF onset. Un-gated SSFP images were obtained serially after VF induction. The ventricular endocardium was manually traced and LV and RV volumes were calculated at each time point. RESULTS: In group I, the LV was dilated compared to baseline at 5 minutes after VF and this remained for 20 minutes. Stone heart, arbitrarily defined as LV volume <1/3 of baseline at the onset of VF, occurred at 29 ± 3 minutes. In group II, there was less early dilation of the LV (p<0.05) and the development of stone heart was delayed to 52 ± 4 minutes after onset of VF (P<0.001). CONCLUSIONS: In this closed-chest swine model of prolonged untreated VF, hypothermia reduced the early LV dilatation and importantly, delayed the onset of stone heart thereby extending a known, morphologic limit of resuscitability.

Epinephrine improves 24-hour survival in a swine model of prolonged ventricular fibrillation demonstrating that early intraosseous is superior to delayed intravenous administration.

BACKGROUND: Vasopressors administered IV late during resuscitation efforts fail to improve survival. Intraosseous (IO) access can provide a route for earlier administration. We hypothesized that IO epinephrine after 1 minute of cardiopulmonary resuscitation (CPR) (an "optimal" IO scenario) after 10 minutes of untreated ventricular fibrillation (VF) cardiac arrest would improve outcome in comparison with either IV epinephrine after 8 minutes of CPR (a "realistic" IV scenario) or placebo controls with no epinephrine. METHODS: Thirty swine were randomized to IO epinephrine, IV epinephrine, or placebo. Important outcomes included return of spontaneous circulation (ROSC), 24-hour survival, and 24-hour survival with good neurological outcome (cerebral performance category 1). RESULTS: ROSC after 10 minutes of untreated VF was uncommon without administration of epinephrine (1 of 10), whereas ROSC was nearly universal with IO epinephrine or delayed IV epinephrine (10 of 10 and 9 of 10, respectively; P = 0.001 for either versus placebo). Twenty-four hour survival was substantially more likely after IO epinephrine than after delayed IV epinephrine (10 of 10 vs. 4 of 10, P = 0.001). None of the placebo group survived at 24 hours. Survival with good neurological outcome was more likely after IO epinephrine than after placebo (6 of 10 vs. 0 of 10, P = 0.011), and only 3 of 10 survived with good neurological outcome in the delayed IV epinephrine group (not significant versus either IO or placebo). CONCLUSION: In this swine model of prolonged VF cardiac arrest, epinephrine administration during CPR improved outcomes. In addition, early IO epinephrine improved outcomes in comparison with delayed IV epinephrine.

Continued breathing followed by gasping or apnea in a swine model of ventricular fibrillation cardiac arrest.

BACKGROUND: Continued breathing following ventricular fibrillation has here-to-fore not been described. METHODS: We analyzed the spontaneous ventilatory activity during the first several minutes of ventricular fibrillation (VF) in our isoflurane anesthesized swine model of out-of-hospital cardiac arrest. The frequency and type of ventilatory activity was monitored by pneumotachometer and main stream infrared capnometer and analyzed in 61 swine during the first 3 to 6 minutes of untreated VF. RESULTS: During the first minute of VF, the air flow pattern in all 61 swine was similar to those recorded during regular spontaneous breathing during anesthesia and was clearly different from the patterns of gasping. The average rate of continued breathing during the first minute of untreated VF was 10 breaths per minute. During the second minute of untreated VF, spontaneous breathing activity either stopped or became typical of gasping. During minutes 2 to 5 of untreated VF, most animals exhibited very slow spontaneous ventilatory activity with a pattern typical of gasping; and the pattern of gasping was crescendo-decrescendo, as has been previously reported. In the absence of therapy, all ventilatory activity stopped 6 minutes after VF cardiac arrest. CONCLUSION: In our swine model of VF cardiac arrest, we documented that normal breathing continued for the first minute following cardiac arrest.

Chest compression-only CPR by lay rescuers and survival from out-of-hospital cardiac arrest.

CONTEXT: Chest compression-only bystander cardiopulmonary resuscitation (CPR) may be as effective as conventional CPR with rescue breathing for out-of-hospital cardiac arrest. OBJECTIVE: To investigate the survival of patients with out-of-hospital cardiac arrest using compression-only CPR (COCPR) compared with conventional CPR. DESIGN, SETTING, AND PATIENTS: A 5-year prospective observational cohort study of survival in patients at least 18 years old with out-of-hospital cardiac arrest between January 1, 2005, and December 31, 2009, in Arizona. The relationship between layperson bystander CPR and survival to hospital discharge was evaluated using multivariable logistic regression. MAIN OUTCOME MEASURE: Survival to hospital discharge. RESULTS: Among 5272 adults with out-of-hospital cardiac arrest of cardiac etiology not observed by responding emergency medical personnel, 779 were excluded because bystander CPR was provided by a health care professional or the arrest occurred in a medical facility. A total of 4415 met all inclusion criteria for analysis, including 2900 who received no bystander CPR, 666 who received conventional CPR, and 849 who received COCPR. Rates of survival to hospital discharge were 5.2% (95% confidence interval [CI], 4.4%-6.0%) for the no bystander CPR group, 7.8% (95% CI, 5.8%-9.8%) for conventional CPR, and 13.3% (95% CI, 11.0%-15.6%) for COCPR. The adjusted odds ratio (AOR) for survival for conventional CPR vs no CPR was 0.99 (95% CI, 0.69-1.43), for COCPR vs no CPR, 1.59 (95% CI, 1.18-2.13), and for COCPR vs conventional CPR, 1.60 (95% CI, 1.08-2.35). From 2005 to 2009, lay rescuer CPR increased from 28.2% (95% CI, 24.6%-31.8%) to 39.9% (95% CI, 36.8%-42.9%; P < .001); the proportion of CPR that was COCPR increased from 19.6% (95% CI, 13.6%-25.7%) to 75.9% (95% CI, 71.7%-80.1%; P < .001). Overall survival increased from 3.7% (95% CI, 2.2%-5.2%) to 9.8% (95% CI, 8.0%-11.6%; P < .001). CONCLUSION: Among patients with out-of-hospital cardiac arrest, layperson compression-only CPR was associated with increased survival compared with conventional CPR and no bystander CPR in this setting with public endorsement of chest compression-only CPR.

Gasping during cardiac arrest in humans is frequent and associated with improved survival.

BACKGROUND: The incidence and significance of gasping after cardiac arrest in humans are controversial. METHODS AND RESULTS: Two approaches were used. The first was a retrospective analysis of consecutive confirmed out-of-hospital cardiac arrests from the Phoenix Fire Department Regional Dispatch Center text files to determine the presence of gasping soon after collapse. The second was a retrospective analysis of 1218 patients with out-of-hospital cardiac arrests in Arizona documented by emergency medical system (EMS) first-care reports to determine the incidence of gasping after arrest in relation to the various EMS arrival times. The primary outcome measure was survival to hospital discharge. An analysis of the Phoenix Fire Department Regional Dispatch Center records of witnessed and unwitnessed out-of-hospital cardiac arrests with attempted resuscitation found that 44 of 113 (39%) of all arrested patients had gasping. An analysis of 1218 EMS-attended, witnessed, out-of-hospital cardiac arrests demonstrated that the presence or absence of gasping correlated with EMS arrival time. Gasping was present in 39 of 119 patients (33%) who arrested after EMS arrival, in 73 of 363 (20%) when EMS arrival was <7 minutes, in 50 of 360 (14%) when EMS arrival time was 7 to 9 minutes, and in 25 of 338 (7%) when EMS arrival time was >9 minutes. Survival to hospital discharge occurred in 54 of 191 patients (28%) who gasped and in 80 of 1027 (8%) who did not (adjusted odds ratio, 3.4; 95% confidence interval, 2.2 to 5.2). Among the 481 patients who received bystander cardiopulmonary resuscitation, survival to hospital discharge occurred among 30 of 77 patients who gasped (39%) versus only 38 of 404 among those who did not gasp (9%) (adjusted odds ratio, 5.1; 95% confidence interval, 2.7 to 9.4). CONCLUSIONS: Gasping or abnormal breathing is common after cardiac arrest but decreases rapidly with time. Gasping is associated with increased survival. These results suggest that the recognition and importance of gasping should be taught to bystanders and emergency medical dispatchers so as not to dissuade them from initiating prompt resuscitation efforts when appropriate.

New insights into effective CPR: cardiocerebral resuscitation for primary cardiac arrest.

Cardiocerebral resuscitation is a new approach to patients with primary cardiac arrest that has been shown to dramatically increase survival. The term cardiocerebral is used to stress that the issue is immediate and effective support of the central circulation. Cardiocerebral resuscitation consists of continuous chest compressions--without mouth-to-mouth ventilations--administered by bystanders, and a new algorithm for emergency medical services that consists of sets of 200 chest compressions before and immediately after electrocardiographic analysis and, if indicated, a single shock. Ventilation is initially provided by passive oxygen insufflation rather than with intubation or bag-mask ventilation. Early establishment of intravenous or intraosseous access for epinephrine is emphasized. Postresuscitation care for comatose patients includes early coronary intervention and 24 hours of mild hypothermia. Studies show marked improvement in prehospital cardiac arrest patients with return of spontaneous circulation who subsequently received specialized postresuscitation care.

Gasping during cardiac arrest.

PURPOSE OF REVIEW: The purpose of this study is to review the prevalence and significance of gasping in patients experiencing cardiac arrest. RECENT FINDINGS: In a recent study by Bobrow et al., gasping was identified in 33% of patients who arrested after the arrival of emergency medical services (EMS). Patients who arrested previous to EMS arrival experienced a decreasing incidence of gasping with increasing duration of cardiac arrest: 20% if EMS arrived within 7 min, 14% if EMS arrival was between 7 and 9 min, and 7% if EMS arrived after 9 min. There was a positive association between the presence of gasping and survival: 28% of those who gasped survived compared with 8% of those who did not gasp (odds ratio, 3.4, 95% confidence interval, 2.2-5.2). Among the 481 patients who received bystander cardiopulmonary resuscitation, survival to hospital discharge occurred among 39% of patients who gasped versus 9% among those who did not gasp (adjusted odds ratio, 5.1, 95% confidence interval, 2.7-9.4). SUMMARY: Gasping frequently occurs during cardiac arrest. Public and emergency medical dispatchers must be more aware of its presence and significance.

Ventilation during resuscitation efforts for out-of-hospital primary cardiac arrest.

PURPOSE OF REVIEW: To discuss recent findings surrounding the role of ventilation during cardiopulmonary resuscitation for individuals with out-of-hospital primary cardiac arrest. RECENT FINDINGS: Active assisted ventilation during primary cardiac arrest may not always be beneficial and, in some circumstances, may lead to worse outcomes. By interrupting chest compressions and thereby decreasing vital organ perfusion, rescue breathing may be deleterious. In addition to the time required to administer breaths, the delay due to the insertion of advanced airways, even by well trained individuals, is often extensive. Furthermore, once intubation is completed, excessive hyperventilation occurs frequently, even by recently trained medical providers. Although most experts agree that excessive ventilation is harmful during out-of-hospital cardiac resuscitation, the optimal rate, tidal volume, timing, and technique of ventilation is still unknown. There is increasing evidence that, in patients with witnessed arrests and a shockable rhythm, the optimal form of ventilation is passive oxygen insufflation. SUMMARY: Assisted ventilation during the initial provision of cardiopulmonary resuscitation is less important than previously believed. It is hypothesized that, by training prehospital medical providers to utilize passive oxygen insufflation for individuals with primary cardiac arrest, critical organ perfusion will increase and, therefore, survival after out-of-hospital cardiac arrest will improve.

Passive oxygen insufflation is superior to bag-valve-mask ventilation for witnessed ventricular fibrillation out-of-hospital cardiac arrest.

STUDY OBJECTIVE: Assisted ventilation may adversely affect out-of-hospital cardiac arrest outcomes. Passive ventilation offers an alternate method of oxygen delivery for these patients. We compare the adjusted neurologically intact survival of out-of-hospital cardiac arrest patients receiving initial passive ventilation with those receiving initial bag-valve-mask ventilation. METHODS: The authors performed a retrospective analysis of statewide out-of-hospital cardiac arrests between January 1, 2005, and September 28, 2008. The analysis included consecutive adult out-of-hospital cardiac arrest patients receiving resuscitation with minimally interrupted cardiopulmonary resuscitation (CPR) consisting of uninterrupted preshock and postshock chest compressions, initial noninvasive airway maneuvers, and early epinephrine. Paramedics selected the method of initial noninvasive ventilation, consisting of either passive ventilation (oropharyngeal airway insertion and high-flow oxygen by nonrebreather facemask, without assisted ventilation) or bag-valve-mask ventilation (by paramedics at 8 breaths/min). The authors determined adjusted neurologically intact survival from hospital and public records and by telephone interview and mail questionnaire. The authors compared adjusted neurologically intact survival between ventilation techniques by using generalized estimating equations. RESULTS: Among the 1,019 adult out-of-hospital cardiac arrest patients in the analysis, 459 received passive ventilation and 560 received bag-valve-mask ventilation. Adjusted neurologically intact survival after witnessed ventricular fibrillation/ventricular tachycardia out-of-hospital cardiac arrest was higher for passive ventilation (39/102; 38.2%) than bag-valve-mask ventilation (31/120; 25.8%) (adjusted odds ratio [OR] 2.5; 95% confidence interval [CI] 1.3 to 4.6). Survival between passive ventilation and bag-valve-mask ventilation was similar after unwitnessed ventricular fibrillation/ventricular tachycardia (7.3% versus 13.8%; adjusted OR 0.5; 95% CI 0.2 to 1.6) and nonshockable rhythms (1.3% versus 3.7%; adjusted OR 0.3; 95% CI 0.1 to 1.0). CONCLUSION: Among adult, witnessed, ventricular fibrillation/ventricular tachycardia, out-of-hospital cardiac arrest resuscitated with minimally interrupted cardiac resuscitation, adjusted neurologically intact survival to hospital discharge was higher for individuals receiving initial passive ventilation than those receiving initial bag-valve-mask ventilation.

Improved neurological outcome with continuous chest compressions compared with 30:2 compressions-to-ventilations cardiopulmonary resuscitation in a realistic swine model of out-of-hospital cardiac arrest.

BACKGROUND: The 2005 Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care changed the previous ventilations-to-chest-compression algorithm for bystander cardiopulmonary resuscitation (CPR) from 2 ventilations before each 15 chest compressions (2:15 CPR) to 30 chest compressions before 2 ventilations (30:2 CPR). It was acknowledged in the guidelines that the change was based on a consensus rather than clear evidence. This study was designed to compare 24-hour neurologically normal survival between the initial applications of continuous chest compressions without assisted ventilations with 30:2 CPR in a swine model of witnessed out-of-hospital ventricular fibrillation cardiac arrest. METHODS AND RESULTS: Sixty-four animals underwent 12 minutes of ventricular fibrillation before defibrillation attempts. They were divided into 4 groups, each with increasing durations (3, 4, 5, and 6 minutes, respectively) of untreated ventricular fibrillation before the initiation of bystander resuscitation consisting of either continuous chest compression or 30:2 CPR. After the various untreated ventricular durations plus bystander resuscitation durations, all animals were given the first defibrillation attempt 12 minutes after the induction of ventricular fibrillation, followed by the 2005 guideline-recommended advanced cardiac life support. Neurologically normal survival at 24 hours after resuscitation was observed in 23 of 33 (70%) of the animals in the continuous chest compression groups but in only 13 of 31 (42%) of the 30:2 CPR groups (P=0.025). CONCLUSIONS: In a realistic model of out-of-hospital ventricular fibrillation cardiac arrest, initial bystander administration of continuous chest compressions without assisted ventilations resulted in significantly better 24-hour postresuscitation neurologically normal survival than did the initial bystander administration of 2005 guideline-recommended 30:2 CPR.

Myocardial microcirculatory dysfunction after prolonged ventricular fibrillation and resuscitation.

OBJECTIVE: The etiology of postresuscitation myocardial stunning is unknown but is thought to be related to either ischemia occurring during cardiac arrest and resuscitation efforts and/or reperfusion injury after restoration of circulation. A potential common pathway for postischemia/reperfusion end-organ dysfunction is microvascular injury. We hypothesized that myocardial microcirculatory function is markedly abnormal in the postresuscitation period. DESIGN: In vivo study of myocardial microvascular function. SETTING: University animal laboratory. SUBJECTS: Five swine (25 +/- 2 kg). INTERVENTIONS: Measurements before and after cardiac arrest and resuscitation. MEASUREMENTS AND MAIN RESULTS: Baseline data were not different among the five subjects. Left ventricular ejection fraction was significantly lower at all postresuscitation time periods (p < .05), reaching a nadir of 19% at 1 hr postresuscitation. Cardiac output declined following fibrillation and resuscitation and was significantly lower than baseline at 1 and 4 hrs postresuscitation (p < .05). Prearrest coronary flow reserve, a ratio of normal to maximal intracoronary flow velocity, was 3.4 ("normal" ratio is 2:4), but was below normal (<2) throughout the 4-hr post resuscitation period (p < .05). CONCLUSION: This in vivo study showed that normal myocardial microcirculatory function is quickly lost after prolonged ventricular fibrillation and resuscitation. As early as 30 min postresuscitation the myocardial microcirculatory function is less than 50% of its prearrest baseline level. This dysfunction persists for at least 4 hrs. During the postresuscitation period, both left ventricular ejection fraction and cardiac output decline from their prearrest levels. No cause and effect relationship was proven, but a parallel decline in left ventricular function and coronary flow reserve is evident.

Cardiocerebral resuscitation: a better approach to cardiac arrest.

PURPOSE OF REVIEW: To present a new approach to patients with cardiac arrest that improves neurologically normal survival. It is called cardiocerebral resuscitation (CCR), rather than cardiopulmonary resuscitation, as the major goal in cardiac arrest is to resuscitate the heart and the brain. CCR has three components: continuous chest compressions cardiopulmonary resuscitation for bystanders; a different Advanced Cardiac Life Support (ACLS) algorithm for Emergency Medical System; and a recently added aggressive postresuscitation care for resuscitated but comatose patients that includes therapeutic hypothermia and early catheterization/intervention. RECENT FINDINGS: Kellum et al. instituted the first two components of CCR in rural Wisconsin in 2004. In the subgroup of patients with a witnessed cardiac arrest and a shockable rhythm they found that neurological intact survival at hospital discharge was 15% the preceding 3 years, when the 2000 Guidelines were being followed, but 40% for the 3 years during CCR. Bobrow et al. instituted CCR for out-of-hospital cardiac arrest in metropolitan areas of Arizona and found a greater than 300% improvement (4.7-17.6%) in survival to hospital discharge of this subgroup of patients. SUMMARY: CCR improves survival of patients with cardiac arrest.

Cardiocerebral resuscitation improves neurologically intact survival of patients with out-of-hospital cardiac arrest.

STUDY OBJECTIVE: In an effort to improve neurologically normal survival of victims of cardiac arrest, a new out-of-hospital protocol was implemented by the emergency medical system medical directors in 2 south-central rural Wisconsin counties. The project was undertaken because the existing guidelines for care of such patients, despite their international scope and periodic updates, had not substantially improved survival rates for such patients during nearly 4 decades. METHODS: The neurologic status at or shortly after discharge was documented for adult patients with a witnessed collapse and an initially shockable rhythm. Patients during two 3-year periods were compared. During the 2001 through 2003 period, in which the 2000 American Heart Association guidelines were used, data were collected retrospectively. During the mid-2004 through mid-2007 period, patients were treated according to the principles of cardiocerebral resuscitation. Data for these patients were collected prospectively. Cerebral performance category scores were used to define the neurologic status of survivors, and a score of 1 was considered as "intact" survival. RESULTS: In the 3 years preceding the change in protocol, there were 92 witnessed arrests with an initially shockable rhythm. Eighteen patients survived (20%) and 14 (15%) were neurologically intact. During the 3 years after implementation of the new protocol, there were 89 such patients. Forty-two (47%) survived and 35 (39%) were neurologically intact. CONCLUSION: In adult patients with a witnessed cardiac arrest and an initially shockable rhythm, implementation of an out-of-hospital treatment protocol based on the principles of cardiocerebral resuscitation was associated with a dramatic improvement in neurologically intact survival.

Minimally interrupted cardiac resuscitation by emergency medical services for out-of-hospital cardiac arrest.

CONTEXT: Out-of-hospital cardiac arrest is a major public health problem. OBJECTIVE: To investigate whether the survival of patients with out-of-hospital cardiac arrest would improve with minimally interrupted cardiac resuscitation (MICR), an alternate emergency medical services (EMS) protocol. DESIGN, SETTING, AND PATIENTS: A prospective study of survival-to-hospital discharge between January 1, 2005, and November 22, 2007. Patients with out-of-hospital cardiac arrests in 2 metropolitan cities in Arizona before and after MICR training of fire department emergency medical personnel were assessed. In a second analysis of protocol compliance, patients from the 2 metropolitan cities and 60 additional fire departments in Arizona who actually received MICR were compared with patients who did not receive MICR but received standard advanced life support. INTERVENTION: Instruction for EMS personnel in MICR, an approach that includes an initial series of 200 uninterrupted chest compressions, rhythm analysis with a single shock, 200 immediate postshock chest compressions before pulse check or rhythm reanalysis, early administration of epinephrine, and delayed endotracheal intubation. MAIN OUTCOME MEASURE: Survival-to-hospital discharge. RESULTS: Among the 886 patients in the 2 metropolitan cities, survival-to-hospital discharge increased from 1.8% (4/218) before MICR training to 5.4% (36/668) after MICR training (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.1-8.9). In the subgroup of 174 patients with witnessed cardiac arrest and ventricular fibrillation, survival increased from 4.7% (2/43) before MICR training to 17.6% (23/131) after MICR training (OR, 8.6; 95% CI, 1.8-42.0). In the analysis of MICR protocol compliance involving 2460 patients with cardiac arrest, survival was significantly better among patients who received MICR than those who did not (9.1% [60/661] vs 3.8% [69/1799]; OR, 2.7; 95% CI, 1.9-4.1), as well as patients with witnessed ventricular fibrillation (28.4% [40/141] vs 11.9% [46/387]; OR, 3.4; 95% CI, 2.0-5.8). CONCLUSIONS: Survival-to-hospital discharge of patients with out-of-hospital cardiac arrest increased after implementation of MICR as an alternate EMS protocol. These results need to be confirmed in a randomized trial.

The mechanism of blood flow during chest compressions for cardiac arrest is probably influenced by the patient's chest configuration.

AIM: Mechanical assist devices are sometimes needed during resuscitation efforts of patients with prolonged cardiac arrest. Two such devices, the AutoPulse and the LUCAS, have different mechanisms of action. We propose that the effectiveness of mechanical assist devices is somewhat dependent on the configuration and compliance of the patient's chest wall. METHODS: A previous study of patients with out-of-hospital cardiac arrest in Arizona reported that survivors were younger and many were observed to have narrow anterior-posterior chest diameters. These observations suggest that the predominant mechanism of blood flow during cardiopulmonary resuscitation of individuals with primary cardiac arrest is influenced by the patient's anterior-posterior chest diameter and compliance. It is proposed that in older individuals with an increased anterior-posterior chest diameter and decreased chest compliance that the AutoPulse, which works by increasing intrathoracic pressures, may be more effective. In contrast, the LUCAS device, which works predominately by compression of the sternum, is probably more effective in patients with narrower anterior-posterior diameters and a more compliant chest. RESULTS: These hypotheses need to be confirmed by researchers who not only have access to the lateral chest roentgenograms of patients with cardiac arrest, to determine their anterior-posterior chest diameter, but also to the type of mechanical device that was used during resuscitation efforts and their patient's survival. If the observations herein proposed are confirmed, hospitals and paramedics may ideally need to have one of each type of mechanical chest compression unit and select the one to use depending on the patient's age and anterior-posterior chest diameter. CONCLUSIONS: The mechanism of blood flow in patients with cardiac arrest is predominantly secondary to cardiac compression in younger patients with narrow anterior chest diameters and predominately secondary to the thoracic pump mechanism in older patients with emphysema.