Benjamin S. Abella

Chest compression rates during cardiopulmonary resuscitation are suboptimal: a prospective study during in-hospital cardiac arrest.

Background—Recent data highlight a vital link between well-performed cardiopulmonary resuscitation (CPR) and survival after cardiac arrest; however, the quality of CPR as actually performed by trained healthcare providers is largely unknown. We sought to measure in-hospital chest compression rates and to determine compliance with published international guidelines. Methods and Results—We developed and validated a handheld recording device to measure chest compression rate as a surrogate for CPR quality. A prospective observational study of adult cardiac arrests was performed at 3 hospitals from April 2002 to October 2003. Resuscitations were witnessed by trained observers using a customized personal digital assistant programmed to store the exact time of each chest compression, allowing offline calculation of compression rates at serial time points. In 97 arrests, data from 813 minutes during which chest compressions were delivered were analyzed in 30-second time segments. In 36.9% of the total number of segments, compression rates were <80 compressions per minute (cpm), and 21.7% had rates <70 cpm. Higher chest compression rates were significantly correlated with initial return of spontaneous circulation (mean chest compression rates for initial survivors and nonsurvivors, 90±17 and 79±18 cpm, respectively; P=0.0033). Conclusions—In-hospital chest compression rates were below published resuscitation recommendations, and suboptimal compression rates in our study correlated with poor return of spontaneous circulation. CPR quality is likely a critical determinant of survival after cardiac arrest, suggesting the need for routine measurement, monitoring, and feedback systems during actual resuscitation.

Paclitaxel Stent Coating Inhibits Neointimal Hyperplasia at 4 Weeks in a Porcine Model of Coronary Restenosis

BackgroundDespite limiting elastic recoil and late vascular remodeling after angioplasty, coronary stents remain vulnerable to restenosis, caused primarily by neointimal hyperplasia. Paclitaxel, a microtubule-stabilizing drug, has been shown to inhibit vascular smooth muscle cell migration and proliferation contributing to neointimal hyperplasia. We tested whether paclitaxel-coated coronary stents are effective at preventing neointimal proliferation in a porcine model of restenosis. Methods and ResultsPalmaz-Schatz stents were dip-coated with paclitaxel (0, 0.2, 15, or 187 &mgr;g/stent) by immersion in ethanolic paclitaxel and evaporation of the solvent. Stents were deployed with mild oversizing in the left anterior descending coronary artery (LAD) of 41 minipigs. The treatment effect was assessed 4 weeks after stent implantation. The angiographic late loss index (mean luminal diameter) decreased with increasing paclitaxel dose (P <0.0028 by ANOVA), declining by 84.3% (from 0.352 to 0.055, P <0.05) at the highest level tested (187 &mgr;g/stent versus control). Accompanying this change, the neointimal area decreased (by 39.5%, high-dose versus control;P <0.05) with increasing dose (P <0.040 by ANOVA), whereas the luminal area increased (by 90.4%, high-dose versus control;P <0.05) with escalating dose (P <0.0004 by ANOVA). Inflammatory cells were seen infrequently, and there were no cases of aneurysm or thrombosis. ConclusionsPaclitaxel-coated coronary stents produced a significant dose-dependent inhibition of neointimal hyperplasia and luminal encroachment in the pig LAD 28 days after implantation; later effects require further study. These results demonstrate the potential therapeutic benefit of paclitaxel-coated coronary stents in the prevention and treatment of human coronary restenosis.

Improving In-Hospital Cardiac Arrest Process and Outcomes With Performance Debriefing

BACKGROUND Recent investigations have documented poor cardiopulmonary resuscitation (CPR) performance in clinical practice. We hypothesized that a debriefing intervention using CPR quality data from actual in-hospital cardiac arrests (resuscitation with actual performance integrated debriefing [RAPID]) would improve CPR performance and initial patient survival. METHODS Internal medicine residents at a university hospital attended weekly debriefing sessions of the prior weeks resuscitations, between March 2006 and February 2007, reviewing CPR performance transcripts obtained from a CPR-sensing and feedback-enabled defibrillator. Objective metrics of CPR performance and initial return of spontaneous circulation were compared with a historical cohort in which a similar feedback-delivering defibrillator was used but without RAPID. RESULTS Cardiopulmonary resuscitation quality and outcome data from 123 patients resuscitated during the intervention period were compared with 101 patients in the baseline cohort. Compared with the control period, the mean (SD) ventilation rate decreased (13 [7]/min vs 18 [8]/min; P < .001) and compression depth increased (50 [10] vs 44 [10] mm; P = .001), among other CPR improvements. These changes correlated with an increase in the rate of return of spontaneous circulation in the RAPID group (59.4% vs 44.6%; P = .03) but no change in survival to discharge (7.4% vs 8.9%; P = .69). CONCLUSIONS The combination of RAPID and real-time audiovisual feedback improved CPR quality compared with the use of feedback alone and was associated with an increased rate of return of spontaneous circulation. Cardiopulmonary resuscitation sensing and recording devices allow for methods of debriefing that were previously available only for simulation-based education; such methods have the potential to fundamentally alter resuscitation training and improve patient outcomes. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00228293.

Intra-Arrest Cooling Improves Outcomes in a Murine Cardiac Arrest Model

Background—Recent clinical studies have demonstrated that hypothermia to 32° to 34°C provides significant clinical benefit when induced after resuscitation from cardiac arrest. However, cooling during the postresuscitation period was slow, requiring 4 to 8 hours to achieve target temperatures after return of spontaneous circulation (ROSC). Whether more rapid cooling would further improve survival remains unclear. We sought to determine whether cooling during cardiac arrest before ROSC (ie, “intra-arrest” hypothermia) has survival benefit over more delayed post-ROSC cooling, using a murine cardiac arrest model. Methods and Results—A model of potassium-induced cardiac arrest was established in C57BL/6 mice. After 8 minutes of untreated cardiac arrest, resuscitation was attempted with chest compression, ventilation, and intravenous fluid. Mice were randomized to 3 treatment groups (n=10 each): an intra-arrest hypothermia group, in which mice were cooled to 30°C just before attempted resuscitation, and then rewarmed after 1 hour; a post-ROSC hypothermia group, in which mice were kept at 37°C for 20 minutes after successful ROSC and then were cooled to 30°C for 1 hour; and a normothermic control group, in which mice were kept at 37°C. The intra-arrest hypothermia group demonstrated better 72-hour survival than delayed hypothermia and normothermia groups (6/10 versus 1/10 and 1/10 survivors, respectively, P <0.05), with similar differences seen at 6-hour survival and on neurological scoring. Conclusions—Timing of hypothermia is a crucial determinant of survival in the murine arrest model. Early intra-arrest cooling appears to be significantly better than delayed post-ROSC cooling or normothermic resuscitation.

Regional Systems of Care for Out-of-Hospital Cardiac Arrest. A Policy Statement From the American Heart Association

Out-of-hospital cardiac arrest continues to be an important public health problem, with large and important regional variations in outcomes. Survival rates vary widely among patients treated with out-of-hospital cardiac arrest by emergency medical services and among patients transported to the hospital after return of spontaneous circulation. Most regions lack a well-coordinated approach to post-cardiac arrest care. Effective hospital-based interventions for out-of-hospital cardiac arrest exist but are used infrequently. Barriers to implementation of these interventions include lack of knowledge, experience, personnel, resources, and infrastructure. A well-defined relationship between an increased volume of patients or procedures and better outcomes among individual providers and hospitals has been observed for several other clinical disorders. Regional systems of care have improved provider experience and patient outcomes for those with ST-elevation myocardial infarction and life-threatening traumatic injury. This statement describes the rationale for regional systems of care for patients resuscitated from cardiac arrest and the preliminary recommended elements of such systems. Many more people could potentially survive out-of-hospital cardiac arrest if regional systems of cardiac resuscitation were established. A national process is necessary to develop and implement evidence-based guidelines for such systems that must include standards for the categorization, verification, and designation of components of such systems. The time to do so is now.

Early goal-directed hemodynamic optimization combined with therapeutic hypothermia in comatose survivors of out-of-hospital cardiac arrest

BACKGROUND Comatose survivors of out-of-hospital cardiac arrest (OHCA) have high in-hospital mortality due to a complex pathophysiology that includes cardiovascular dysfunction, inflammation, coagulopathy, brain injury and persistence of the precipitating pathology. Therapeutic hypothermia (TH) is the only intervention that has been shown to improve outcomes in this patient population. Due to the similarities between the post-cardiac arrest state and severe sepsis, it has been postulated that early goal-directed hemodyamic optimization (EGDHO) combined with TH would improve outcome of comatose cardiac arrest survivors. OBJECTIVE We examined the feasibility of establishing an integrated post-cardiac arrest resuscitation (PCAR) algorithm combining TH and EGDHO within 6h of emergency department (ED) presentation. METHODS In May, 2005 we began prospectively identifying comatose (Glasgow Motor Score<6) survivors of OHCA treated with our PCAR protocol. The PCAR patients were compared to matched historic controls from a cardiac arrest database maintained at our institution. RESULTS Between May, 2005 and January, 2008, 18/20 (90%) eligible patients were enrolled in the PCAR protocol. They were compared to historic controls from 2001 to 2005, during which time 18 patients met inclusion criteria for the PCAR protocol. Mean time from initiation of TH to target temperature (33 degrees C) was 2.8h (range 0.8-23.2; SD=h); 78% (14/18) had interventions based upon EGDHO parameters; 72% (13/18) of patients achieved their EGDHO goals within 6h of return of spontaneous circulation (ROSC). Mortality for historic controls who qualified for the PCAR protocol was 78% (14/18); mortality for those treated with the PCAR protocol was 50% (9/18) (p=0.15). CONCLUSIONS In patients with ROSC after OHCA, EGDHO and TH can be implemented simultaneously.

Therapeutic hypothermia utilization among physicians after resuscitation from cardiac arrest

Objective:We sought to evaluate current physician use of therapeutic hypothermia after cardiac arrest, to ascertain reasons for nonadoption of this treatment, and to determine current cooling techniques employed. Design:Web-based survey. Setting:International physician cohort in the United States, UK, and Finland. Subjects:Physicians (MD or DO) caring for resuscitated cardiac arrest patients. Interventions:An anonymous Web-based survey was distributed to physicians identified through United States–based critical care, cardiology, and emergency medicine directories and critical care networks in the UK and Finland. Recipients were queried regarding use of postresuscitation therapeutic hypothermia. Measurements and Main Results:Of the final 13,272 surveys actually distributed to physicians, 2,248 (17%) were completed. Most respondents were attending physicians (82%) at teaching hospitals (76%) who practiced critical care (35%), cardiology (20%), or emergency medicine (22%). Of all replies, 74% of United States respondents and 64% of non–United States respondents had never used therapeutic hypothermia. United States emergency medicine physician adoption of cooling was significantly less than that of United States intensivists (16% vs. 34%, p < .05). The most often cited reasons for nonuse by respondents were “not enough data,” “not part of Advanced Cardiac Life Support guidelines,” and “too technically difficult to use.” Factors associated with increased use included non–United States residence, critical care specialty, and larger hospital size. Conclusions:Physician utilization of cooling after cardiac arrest remains low. For improved adoption of therapeutic hypothermia, our data suggest that development of better cooling methodology and recent incorporation into resuscitation guidelines may improve use.

Incidence of treated cardiac arrest in hospitalized patients in the United States.

Objective:The incidence and incidence over time of cardiac arrest in hospitalized patients is unknown. We sought to estimate the event rate and temporal trends of adult inhospital cardiac arrest treated with a resuscitation response. Design:Three approaches were used to estimate the inhospital cardiac arrest event rate. First approach: calculate the inhospital cardiac arrest event rate at hospitals (n = 433) in the Get With The Guidelines-Resuscitation registry, years 2003–2007, and multiply this by U.S. annual bed days. Second approach: use the Get With The Guidelines-Resuscitation inhospital cardiac arrest event rate to develop a regression model (including hospital demographic, geographic, and organizational factors), and use the model coefficients to calculate predicted event rates for acute care hospitals (n = 5445) responding to the American Hospital Association survey. Third approach: classify acute care hospitals into groups based on academic, urban, and bed size characteristics, and determine the average event rate for Get With The Guidelines-Resuscitation hospitals in each group, and use weighted averages to calculate the national inhospital cardiac arrest rate. Annual event rates were calculated to estimate temporal trends. Setting:Get With The Guidelines-Resuscitation registry. Patients:Adult inhospital cardiac arrest with a resuscitation response. Measurements and Main Results:The mean adult treated inhospital cardiac arrest event rate at Get With The Guidelines-Resuscitation hospitals was 0.92/1000 bed days (interquartile range 0.58 to 1.2/1000). In hospitals (n = 150) contributing data for all years of the study period, the event rate increased from 2003 to 2007. With 2.09 million annual U.S. bed days, we estimated 192,000 inhospital cardiac arrests throughout the United States annually. Based on the regression model, extrapolating Get With The Guidelines-Resuscitation hospitals to hospitals participating in the American Hospital Association survey projected 211,000 annual inhospital cardiac arrests. Using weighted averages projected 209,000 annual U.S. inhospital cardiac arrests. Conclusions:There are approximately 200,000 treated cardiac arrests among U.S. hospitalized patients annually, and this rate may be increasing. This is important for understanding the burden of inhospital cardiac arrest and developing strategies to improve care for hospitalized patients.

Therapeutic hypothermia after cardiac arrest: Unintentional overcooling is common using ice packs and conventional cooling blankets

Objectives:Although therapeutic hypothermia for cardiac arrest survivors has been shown to improve neurologically intact survival, optimal methods to ensure controlled induction and maintenance of cooling are not clearly established. Precise temperature control is important to evaluate because unintentional overcooling below the consensus target range of 32–34°C may place the patient at risk for serious complications. We sought to measure the prevalence of overcooling (<32°C) in postarrest survivors receiving primarily noninvasive cooling. Design:Retrospective chart review of postarrest patients. Setting:Three large teaching hospitals. Patients:Cardiac arrest survivors receiving therapeutic hypothermia. Interventions:Charts were reviewed if primarily surface cooling was used with a target temperature goal between 32°C and 34°C. Measurements and Main Results:Of the 32 cases reviewed, overcooling lasting for >1 hr was identified as follows: 20 of 32 patients (63%) reached temperatures of <32°C, 9 of 32 (28%) reached temperatures of <31°C, and 4 of 32 (13%) reached temperatures of <30°C. Of those with overcooling of <32°C, 6 of 20 (30%) survived to hospital discharge, whereas of those without overcooling, 7 of 12 (58%) survived to hospital discharge (p = not significant). Conclusions:The majority of the cases reviewed demonstrated unintentional overcooling below target temperature. Improved mechanisms for temperature control are required to prevent potentially deleterious complications of more profound hypothermia.

Primary Outcomes for Resuscitation Science Studies A Consensus Statement From the American Heart Association

Background and Purpose— The guidelines presented in this consensus statement are intended to serve researchers, clinicians, reviewers, and regulators in the selection of the most appropriate primary outcome for a clinical trial of cardiac arrest therapies. The American Heart Association guidelines for the treatment of cardiac arrest depend on high-quality clinical trials, which depend on the selection of a meaningful primary outcome. Because this selection process has been the subject of much controversy, a consensus conference was convened with national and international experts, the National Institutes of Health, and the US Food and Drug Administration. Methods— The Research Working Group of the American Heart Association Emergency Cardiovascular Care Committee nominated subject leaders, conference attendees, and writing group members on the basis of their expertise in clinical trials and a diverse perspective of cardiovascular and neurological outcomes (see the online-only Data Supplement). Approval was obtained from the Emergency Cardiovascular Care Committee and the American Heart Association Manuscript Oversight Committee. Preconference position papers were circulated for review; the conference was held; and postconference consensus documents were circulated for review and comments were invited from experts, conference attendees, and writing group members. Discussions focused on (1) when after cardiac arrest the measurement time point should occur; (2) what cardiovascular, neurological, and other physiology should be assessed; and (3) the costs associated with various end points. The final document underwent extensive revision and peer review by the Emergency Cardiovascular Care Committee, the American Heart Association Science Advisory and Coordinating Committee, and oversight committees. Results— There was consensus that no single primary outcome is appropriate for all studies of cardiac arrest. The best outcome measure is the pairing of a time point and physiological condition that will best answer the question under study. Conference participants were asked to assign an outcome to each of 4 hypothetical cases; however, there was not complete agreement on an ideal outcome measure even after extensive discussion and debate. There was general consensus that it is appropriate for earlier studies to enroll fewer patients and to use earlier time points such as return of spontaneous circulation, simple “alive versus dead,” hospital mortality, or a hemodynamic parameter. For larger studies, a longer time point after arrest should be considered because neurological assessments fluctuate for at least 90 days after arrest. For large trials designed to have a major impact on public health policy, longer-term end points such as 90 days coupled with neurocognitive and quality-of-life assessments should be considered, as should the additional costs of this approach. For studies that will require regulatory oversight, early discussions with regulatory agencies are strongly advised. For neurological assessment of post–cardiac arrest patients, researchers may wish to use the Cerebral Performance Categories or modified Rankin Scale for global outcomes. Conclusions— Although there is no single recommended outcome measure for trials of cardiac arrest care, the simple Cerebral Performance Categories or modified Rankin Scale after 90 days provides a reasonable outcome parameter for many trials. The lack of an easy-to-administer neurological functional outcome measure that is well validated in post–cardiac arrest patients is a major limitation to the field and should be a high priority for future development.