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Robert A Berg

Publications and source records attributed to Robert A Berg.

At least 37 records · Page 2Linked to original sources

Effect of one-rescuer compression/ventilation ratios on cardiopulmonary resuscitation in infant, pediatric, and adult manikins.

OBJECTIVE: Optimal chest compression to ventilation ratio (C:V) for one-rescuer cardiopulmonary resuscitation (CPR) is not known, with current American Heart Association recommendations 3:1 for newborns, 5:1 for children, and 15:2 for adults. C:V ratios influence effectiveness of CPR, but memorizing different ratios is educationally cumbersome. We hypothesized that a 10:2 ratio might provide adequate universal application for all age arrest victims. DESIGN: Clinical study. SETTING: Tertiary care children's hospital. SUBJECTS: Thirty-five health care providers. INTERVENTIONS: Thirty-five health care providers performed 5-min epochs of one-rescuer CPR at C:V ratios of 3:1, 5:1, 10:2, and 15:2 in random order on infant, pediatric, and adult manikins. Compressions were paced at 100/min by metronome. The number of effective compressions and ventilations delivered per minute was recorded by a trained basic life support instructor. Subjective assessments of fatigue (self-report) and exertion (change in rescuer pulse rate compared with baseline) were assessed. Analysis was by repeated measures analysis of variance and paired Student's t-test. MEASUREMENTS AND MAIN RESULTS: Effective infant compressions per minute did not differ by C:V ratio, but ventilations per minute were greater at 3:1 vs. 5:1, 10:2, and 15:2 (p < .05). Effective pediatric compressions per minute were less at 3:1 vs. 5:1, 10:2, and 15:2 (p < .05) and not different between 5:1, 10:2, and 15:2 ratios. Effective pediatric ventilations per minute were greater at 3:1 than all other ratios and both 5:1 and 10:2 were >15:2 (p < .05). Effective adult compressions per minute were progressively greater with 3:1 vs. 5:1 vs. 10:2 vs. 15:2 (p < .05). Self-efficacy was assessed, and rescuers always subjectively rated 10:2 and 15:2 ratios as easier than 5:1 or 3:1 ratios for all manikins. Rescuer pulse change (exertion) was greater after pediatric and adult vs. infant CPR (p < .05), with no significant difference by C:V ratio. CONCLUSIONS: C:V ratio and manikin size have a significant influence on the number of effective compressions and ventilations delivered during ideal, metronome-paced, one-rescuer CPR. Low ratios of 3:1, 5:1, and 10:2 favor ventilation, and high ratios of 15:2 favor compression, especially in adult manikins. Rescuers subjectively preferred C:V ratios of 10:2 and 15:2 over 3:1 or 5:1. Infant CPR caused less exertion and subjective fatigue than pediatric or adult CPR technique, without significant difference by C:V ratio. We speculate that a universal 10:2 C:V ratio for one-rescuer layperson CPR is physiologically reasonable but warrants further study with particular attention to educational value and technique retention.

Adult↗

Cardiac arrest and cardiopulmonary resuscitation outcome reports: update and simplification of the Utstein templates for resuscitation registries: a statement for healthcare professionals from a task force of the International Liaison Committee on Resuscitation (American Heart Association, European Resuscitation Council, Australian Resuscitation Council, New Zealand Resuscitation Council, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Councils of Southern Africa).

Outcome after cardiac arrest and cardiopulmonary resuscitation is dependent on critical interventions, particularly early defibrillation, effective chest compressions, and advanced life support. Utstein-style definitions and reporting templates have been used extensively in published studies of cardiac arrest, which has led to greater understanding of the elements of resuscitation practice and progress toward international consensus on science and resuscitation guidelines. Despite the development of Utstein templates to standardize research reports of cardiac arrest, international registries have yet to be developed. In April 2002, a task force of the International Liaison Committee on Resuscitation (ILCOR) met in Melbourne, Australia, to review worldwide experience with the Utstein definitions and reporting templates. The task force revised the core reporting template and definitions by consensus. Care was taken to build on previous definitions, changing data elements and operational definitions only on the basis of published data and experience derived from those registries that have used Utstein-style reporting. Attention was focused on decreasing the complexity of the existing templates and addressing logistical difficulties in collecting specific core and supplementary (ie, essential and desirable) data elements recommended by previous Utstein consensus conferences. Inconsistencies in terminology between in-hospital and out-of-hospital Utstein templates were also addressed. The task force produced a reporting tool for essential data that can be used for both quality improvement (registries) and research reports and that should be applicable to both adults and children. The revised and simplified template includes practical and succinct operational definitions. It is anticipated that the revised template will enable better and more accurate completion of all reports of cardiac arrest and resuscitation attempts. Problems with data definition, collection, linkage, confidentiality, management, and registry implementation are acknowledged and potential solutions offered. Uniform collection and tracking of registry data should enable better continuous quality improvement within every hospital, emergency medical services system, and community.

Adult↗

A comparison of high-dose and standard-dose epinephrine in children with cardiac arrest.

BACKGROUND: When efforts to resuscitate a child after cardiac arrest are unsuccessful despite the administration of an initial dose of epinephrine, it is unclear whether the next dose of epinephrine (i.e., the rescue dose) should be the same (standard) dose or a higher dose. METHODS: We performed a prospective, randomized, double-blind trial to compare high-dose epinephrine (0.1 mg per kilogram of body weight) with standard-dose epinephrine (0.01 mg per kilogram) as rescue therapy for in-hospital cardiac arrest in children after failure of an initial, standard dose of epinephrine. The trial included 68 children, and Utstein-style reporting guidelines were used. The primary outcome measure was survival 24 hours after the arrest. RESULTS: The rate of survival at 24 hours was lower in the group assigned to a high dose of epinephrine as rescue therapy than in the group assigned to a standard dose: 1 of the 34 patients in the high-dose group survived for 24 hours, as compared with 7 of the 34 patients in the standard-dose group (unadjusted odds ratio for death with the high dose, 8.6; 97.5 percent confidence interval, 1.0 to 397.0; P=0.05). After adjustment by multiple logistic-regression analysis for differences in the groups at the time of arrest, the high-dose group tended to have a lower 24-hour survival rate (odds ratio for death, 7.9; 97.5 percent confidence interval, 0.9 to 72.5; P=0.08). The two treatment groups did not differ significantly in terms of the rate of return of spontaneous circulation (which occurred in 20 patients in the high-dose group and 21 of those in the standard-dose group; odds ratio, 1.1; 97.5 percent confidence interval, 0.4 to 3.0). None of the patients in the high-dose group, as compared with four of those in the standard-dose group, survived to hospital discharge. Among the 30 patients whose cardiac arrest was precipitated by asphyxia, none of the 12 who were assigned to high-dose epinephrine were alive at 24 hours, as compared with 7 of the 18 who were assigned to a standard dose (P=0.02). CONCLUSIONS: We did not find any benefit of high-dose epinephrine rescue therapy for in-hospital cardiac arrest in children after failure of an initial standard dose of epinephrine. The data suggest that high-dose therapy may be worse than standard-dose therapy.

Asphyxia↗

Attenuated adult biphasic shocks compared with weight-based monophasic shocks in a swine model of prolonged pediatric ventricular fibrillation.

AIM: To compare the safety and efficacy of attenuated adult biphasic shocks with standard monophasic weight-based shocks in a piglet model of prolonged prehospital ventricular fibrillation (VF). BACKGROUND: If attenuated adult shocks are safe and effective for prehospital pediatric VF, automated external defibrillators (AEDs) can be easily adapted for pediatric use. METHODS: After 7 min of untreated VF, piglets were randomized to treatment with attenuated adult biphasic shocks or weight-based monophasic shocks. The attenuated adult biphasic group received 200/300/360 J shocks, attenuated by specialized pediatric electrodes to 51/78/81 J and the monophasic weight-based control group received 2/4/4 J/kg shocks. Forty-eight female piglets were studied, 16 in each of three weight categories: 4 kg (neonatal), 14 kg (younger child) and 24 kg (older child). The primary outcome measures of efficacy and safety were 24h survival with good neurological outcome and post-resuscitation left ventricular ejection fraction (LVEF), respectively. RESULTS: For the 24 kg piglets, attenuated adult biphasic shocks resulted in superior 24 h survival with good neurological outcome (6/8 versus 0/8, P < 0.001) and greater LVEF 4 h post-resuscitation (34 +/- 4% versus 18 +/- 5%, P < 0.05). For the 14 and 4 kg piglets, 24 h survival with good neurological outcome occurred in 7/8 versus 5/8 and 7/8 versus 3/8, respectively, and LVEF 4 h post-resuscitation was 30 +/- 3% versus 36 +/- 6% and 30 +/- 3% versus 22 +/- 4%, respectively. CONCLUSIONS: The escalating attenuated adult biphasic dosage strategy was at least as safe and effective as the standard weight-based monophasic dose over a wide range of weights in this piglet model of prehospital VF. This work supports the concept of using an attenuated adult biphasic dosage in children.

Animals↗

Optimal dosing of dobutamine for treating post-resuscitation left ventricular dysfunction.

OBJECTIVES: This study was designed to determine the optimal dose of dobutamine in the treatment of post-resuscitation left ventricular dysfunction. BACKGROUND: Global left ventricular dysfunction following successful resuscitation from prolonged, ventricular fibrillation cardiac arrest, negatively impacts long-term survival. Dobutamine can overcome this global myocardial stunning. Previous data indicate a dose of 10 mcg/kgmin improves systolic and diastolic function, but markedly increases the heart rate. METHODS: Twenty swine (24 +/- 0.4 kg) were randomized to one of four doses (0, 2, 5, and 7.5 mcg/kgmin) of dobutamine for the treatment of post-resuscitation myocardial dysfunction following 12.5 min of untreated ventricular fibrillation cardiac arrest. Cardiac function was measured at pre-arrest baseline and serially for 6 h post-resuscitation. Left ventricular function was evaluated by contrast ventriculograms, left ventricular pressures, +dP/dt, Tau, -dP/dt, and cardiac output. Myocardial oxygen consumption and myocardial blood flow were measured to assess the functional significance of any dobutamine-mediated heart rate responses. RESULTS: Left ventricular dysfunction was evident at 25 min and peaked 4 h post-resuscitation. Significant (P < 0.05) improvements in ventricular systolic (EF, CO) and diastolic (LVEDP, Tau) function were evident within minutes of dobutamine initiation and persisted at 6h for the 5 and 7.5 mcg/kgmin groups. Tachycardia manifested with all dobutamine doses, but only affected myocardial oxygen consumption significantly (P < 0.05) at the highest dose (7.5 mcg/kgmin). CONCLUSIONS: Dobutamine at 5 mcg/kgmin appears optimal for restoring systolic and diastolic function post-resuscitation without adversely affecting myocardial oxygen consumption.

Analysis of Variance↗

Uninterrupted chest compression CPR is easier to perform and remember than standard CPR.

INTRODUCTION: It has long been observed that CPR skills rapidly decline regardless of the modality used for teaching or criteria used for testing. Uninterrupted chest compression CPR (UCC-CPR) is a proposed alternative to standard single rescuer CPR (STD-CPR) for laypersons in witnessed unexpected cardiac arrest in adults. It delivers substantially more compressions per minute and may be easier to remember and perform than standard CPR. METHODS: In this prospective study, 28 medical students were taught STD-CPR and UCC-CPR and then were tested on each method at baseline (0), 6, and 18 months after training. The students' performance for at least 90 s of CPR was evaluated based on video and Laerdal Skillreporter Resusci Anne recordings. RESULTS: The mean number of correct chest compressions delivered per minute trended down over time in STD-CPR (23 +/- 3, 19 +/- 4 , and 15 +/- 3; P = 0.09) but stayed the same in UCC-CPR (43 +/- 9, 38 +/- 7, and 37 +/- 7 = 0.91) at 0, 6, and 18 months, respectively. The mean percentage of chest compressions delivered correctly fell over time in STD-CPR (54 +/- 6%, 35 +/- 6%, and 32 +/- 6%; P = 0.02) but stayed the same in UCC-CPR (34 +/- 5%, 41 +/- 7%, and 38 +/- 8%) at 0, 6, and 18 months, respectively. The number of chest compressions delivered per minute was higher in UCC-CPR at 0, 6, and 18 months (113 versus 44, P < 0.0001; 94 versus 47, P < 0.0001; and 92 versus 44, P < 0.001). The greater number of chest compressions was due to a mean ventilaroty pause of 13-14 s during STD-CPR at all three time points. CONCLUSIONS: Chest compression performance during STD-CPR declined in repeated testing over 18 months whereas there was minimal decline in chest compressions performance on repeated testing of UCC-CPR. In addition, substantially more chest compressions were delivered during UCC-CPR compared to STD-CPR at all time points primarily because of long pauses accompanying rescue breathing.

Adult↗

Ventricular fibrillation frequency characteristics and time evolution in piglets: a developmental study.

BACKGROUND: Derived variables of ventricular fibrillation, such as the frequency distribution by fast Fourier transformation and its evolution over time, have been used to determine the optimum timing for defibrillation. We hypothesized that these frequency variables would differ among neonatal, young child and older child populations due to cardiac developmental and size differences. Such differences may have important implications for developing defibrillation algorithms for pediatric patients and for extrapolating adult defibrillation algorithms to children in VF. METHODS: Ventricular fibrillation was induced and recorded for 6 min in 4 kg (n = 11), 14 kg (n = 10), and 24 kg (n = 16) piglets, corresponding to neonatal, young child and older children. Mean, median, and dominant frequencies were computed in 30 s intervals and compared among weight classes. RESULTS: All frequency variables in all weight groups showed first a decline at 1.25-1.75 min, followed by a gradual rise and plateau. There were significant differences for mean, median and dominant frequencies among weight classes. Specifically, 14 kg piglets showed higher frequency variables overall with a time evolution that was different from that of 4 and 24 kg piglets. Mean frequency showed the most stable time evolution with the least moment-to-moment variability. CONCLUSION: The frequency waveform characteristics and time course are somewhat different in 14 kg piglets compared with 4 and 24 kg piglets. If similar differences are demonstrable among children of different weights and ages, AEDs designed to determine optimal timing of defibrillation shocks in adults by frequency waveform characteristics may require modification for use in children with VF.

Animals↗

Single-rescuer cardiopulmonary resuscitation: 'two quick breaths'--an oxymoron.

The Guidelines 2000 for CPR and ECC recommend for single lay-rescuers performing basic life support, "two quick breaths followed by 15 chest compressions", repeated until professional help arrives. It is uncertain that this can actually be accomplished by the majority of lay rescuers. We evaluated 53 first-year medical students after completing BLS CPR training to determine if they could deliver the goal of 80 compressions per minute when following this AHA BLS recommendation. Alternatively, a simplified technique of uninterrupted chest compression (UCC) BLS CPR was also taught and compared with standard BLS CPR (STD). The mean number of chest compressions/minute delivered with AHA BLS CPR was only 43 +/- 1 immediately after initial training and 49 +/- 2 when tested 6 months later. Uninterrupted chest compression BLS resulted in 113 +/- 2 compressions/min delivered immediately after training and 91 +/- 4 six months later (STD versus UCC; P < 0.0001). The mean length of time needed to provide the two breaths during STD-CPR was 14 +/- 1 and 12 +/- 1s (immediately after first training and six months after training). For STD-CPR, the mean minute ventilation was poor immediately after initial training (3.3 +/- 0.3 l/min) and further declined (1.9 +/- 0.4 l/min) at 6 months (P = 0.003). For single rescuer basic cardiopulmonary resuscitation, motivated BLS CPR-trained medical students take nearly as long as previously reported for middle-aged lay individuals to deliver these "two quick breaths". The "Guidelines 2000" recommendation for "two quick breaths" is an oxymoron, as it averages more than 13s. New recommendations for single-rescuer CPR should be considered that emphasize uninterrupted chest compressions.

Adult↗

Cardiac arrest and cardiopulmonary resuscitation outcome reports: update and simplification of the Utstein templates for resuscitation registries. A statement for healthcare professionals from a task force of the international liaison committee on resuscitation (American Heart Association, European Resuscitation Council, Australian Resuscitation Council, New Zealand Resuscitation Council, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Southern Africa).

Outcome following cardiac arrest and cardiopulmonary resuscitation is dependent on critical interventions, particularly early defibrillation, effective chest compressions, and advanced life support. Utstein-style definitions and reporting templates have been used extensively in published studies of cardiac arrest, which has led to greater understanding of the elements of resuscitation practice and progress toward international consensus on science and resuscitation guidelines. Despite the development of Utstein templates to standardize research reports of cardiac arrest, international registries have yet to be developed. In April 2002 a task force of ILCOR met in Melbourne, Australia, to review worldwide experience with the Utstein definitions and reporting templates. The task force revised the core reporting template and definitions by consensus. Care was taken to build on previous definitions, changing data elements and operational definitions only on the basis of published data and experience derived from those registries that have used Utstein-style reporting. Attention was focused on decreasing the complexity of the existing templates and addressing logistical difficulties in collecting specific core and supplementary (i.e., essential and desirable) data elements recommended by previous Utstein consensus conference. Inconsistencies in terminology between in-hospital and out-of-hospital Utstein templates were also addressed. The task force produced a reporting tool for essential data that can be used for both quality improvement (registries) and research reports and that should be applicable to both adults and children. The revised and simplified template includes practical and succinct operational definitions. It is anticipated that the revised template will enable better and more accurate completion of all reports of cardiac arrest and resuscitation attempts. Problems with data definition, collection, linkage, confidentiality, management, and registry implementation are acknowledged and potential solutions offered. Uniform collection and tracking of registry data should enable better continuous quality improvement within every hospital, EMS system, and community.

Adult↗

Precountershock cardiopulmonary resuscitation improves initial response to defibrillation from prolonged ventricular fibrillation: a randomized, controlled swine study.

OBJECTIVES: To compare immediate countershocks (defibrillation 1st) with precountershock cardiopulmonary resuscitation (CPR 1st) for prolonged ventricular fibrillation (VF). DESIGN: Randomized, controlled trial. SETTING: University animal laboratory. SUBJECTS: Thirty swine (27 +/- 1 kg). INTERVENTIONS: After 8 mins of untreated ventricular fibrillation, swine were randomly assigned to receive either immediate countershocks or CPR for 90 secs followed by countershocks. MEASUREMENTS AND MAIN RESULTS: After the first set of shocks, nine of 15 CPR 1st animals attained return of spontaneous circulation vs. 0 of 15 defibrillation 1st animals (p <.001), and pulseless electrical activity occurred in only one of 15 CPR 1st animals vs. ten of 15 defibrillation 1st animals (p <.01). The ultimate outcomes in the two groups were not different: Return of spontaneous circulation and 24-hr survival occurred in 15 of 15 CPR 1st and 13 of 15 defibrillation 1st animals. Good neurologic outcome at 24 hrs occurred in 12 of 15 CPR 1st and nine of 15 defibrillation 1st animals. None of the animals was successfully resuscitated with defibrillation alone; all successfully resuscitated animals were provided with chest compressions during the resuscitation. The ventricular fibrillation median frequency by fast Fourier transformation decreased during the untreated ventricular fibrillation interval in both groups (9.7 +/- 0.3 Hz and 10.1 +/- 0.2 Hz after 1 min vs. 8.8 +/- 0.3 Hz and 8.9 +/- 0.5 Hz at 8 mins, respectively). Because the ventricular fibrillation median frequency substantially increased after CPR 1st, it was much higher in the CPR 1st group before the first shock (15.1 +/- 0.9 Hz vs. 8.9 +/- 0.5 Hz, p <.001). The ventricular fibrillation median frequency before the first countershock was much higher in the animals that attained return of spontaneous circulation after the first set of shocks vs. those that did not (16.1 +/- 1.3 Hz vs. 10.0 +/- 0.6 Hz, p <.0001) CONCLUSIONS: Precountershock CPR can result in substantial physiologic benefits and superior response to initial defibrillation attempts compared with immediate defibrillation in the setting of prolonged ventricular fibrillation.

Animals↗

Attenuated adult biphasic shocks for prolonged pediatric ventricular fibrillation: support for pediatric automated defibrillators.

OBJECTIVE: To evaluate published data regarding the treatment of prolonged pediatric defibrillation, with special emphasis on the use of attenuated adult biphasic shocks for pediatric defibrillation. DESIGN: Review relevant human and animal literature. RESULTS: Rhythm analysis algorithms from two manufacturers of automated external defibrillators can accurately distinguish shockable from nonshockable rhythms in children. Theoretical considerations and transthoracic impedance data from animals and children suggest that pediatric defibrillation doses should not necessarily vary in a simple weight-based manner. Two piglet studies have established that an attenuated adult biphasic dosage can be successfully used for 3.5- to 24-kg animals in ventricular fibrillation. One study established that the attenuated adult biphasic dosage was at least as safe and effective as the standard monophasic weight-based dosing. CONCLUSION: This review supports the American Heart Association's new guidelines for pediatric automated external defibrillator usage: "Automated external defibrillators may be used for children 1 to 8 yrs of age who have no signs of circulation. Ideally the device should deliver a pediatric dose. The arrhythmia detection system used in the device should demonstrate high specificity for pediatric shockable rhythms, i.e., it will not recommend delivery of a shock for nonshockable rhythms."

Adult↗

Effect of vasopressin on postresuscitation ventricular function: unknown consequences of the recent Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.

OBJECTIVE: To compare the effect on postresuscitation left ventricular function of vasopressin vs. epinephrine used during cardiopulmonary resuscitation in a swine model of prolonged prehospital ventricular fibrillation. DESIGN: Prospective, randomized experimental study. SETTING: University large animal resuscitation research laboratory. SUBJECTS: Forty-eight swine (29 +/- 1 kg). INTERVENTIONS: Resuscitation after 12.5 mins of untreated ventricular fibrillation, randomizing animals during cardiopulmonary resuscitation to treatment with epinephrine, vasopressin, or vasopressin followed by a vasopressin antagonist administered in the postresuscitation period. MEASUREMENTS AND MAIN RESULTS: Serial measurements of left ventricular systolic and diastolic function (prearrest, postresuscitation at 30 mins and 6 hrs) and 24-hr survival. Animals receiving vasopressin had more postresuscitation left ventricular dysfunction than those receiving epinephrine (p < .05). The vasopressin antagonist produced vasodilation and improved early postresuscitation left ventricular systolic and diastolic function but did not have a lasting effect on such postresuscitation ventricular function and decreased 24-hr survival compared with the use of vasopressin alone (3/16 vs. 10/16 survivors; p < .05). CONCLUSIONS: Vasopressin use during cardiopulmonary resuscitation results in worse postresuscitation left ventricular function early but did not compromise 24-hr outcome. Reversal of vasopressin's effect with a specific V-1 antagonist in the postresuscitation period did not improve survival.

Animals↗

Effect of amiodarone on haemodynamics during cardiopulmonary resuscitation in a canine model of resistant ventricular fibrillation.

OBJECTIVE: Amiodarone has been shown to be superior to both placebo and lidocaine in improving survival to hospital admission for victims of out-of-hospital refractory ventricular fibrillation. Concern had been expressed about the known vasodilatatory effects of amiodarone if given without precedent vasoconstrictive medications. The haemodynamic effects of intravenous amiodarone administered during ongoing CPR have not been systemically investigated. Our intention was to verify if amiodarone alone produced significantly lower resuscitation haemodynamics than did either adrenaline (epinephrine) alone or the combination of amiodarone and adrenaline. DESIGN: Prospective, randomized, comparative study. SETTING: Research laboratory of a medical school. SUBJECTS: Thirty mongrel dogs. INTERVENTIONS: After 8 min of untreated VF, defibrillation was attempted once at 3 J/kg and external chest compressions and ventilation started. Those animals resistant to the defibrillation attempt were randomized, ten to an adrenaline (0.02 mg/kg) group, ten to an amiodarone (5 mg/kg) group, and ten to a group receiving a combination of both drugs. MEASUREMENTS AND MAIN RESULTS: Aortic systolic and diastolic, and coronary perfusion pressures were all significantly lower in the group receiving amiodarone alone than in the other two groups. Amiodarone combined with adrenaline produced pressures during CPR similar to adrenaline alone. CONCLUSION: Amiodarone can be safely administered simultaneously in combination with adrenaline and such a combination results in similar haemodynamic support as adrenaline alone. Amiodarone administered alone produces significantly lower coronary perfusion pressure than when combined with adrenaline.

Amiodarone↗

Cardiopulmonary resuscitation of adults in the hospital: a report of 14720 cardiac arrests from the National Registry of Cardiopulmonary Resuscitation.

The National Registry of Cardiopulmonary Resuscitation (NRCPR) is an American Heart Association (AHA)-sponsored, prospective, multisite, observational study of in-hospital resuscitation. The NRCPR is currently the largest registry of its kind. The purpose of this article is to describe the NRCPR and to provide the first comprehensive, Utstein-based, standardized characterization of in-hospital resuscitation in the United States. All adult (>/=18 years of age) and pediatric (<18 years of age) patients, visitors, employees, and staff within a facility (including ambulatory care areas) who experience a resuscitation event are eligible for inclusion in the NRCPR database. Between January 1, 2000, and June 30, 2002, 14720 cardiac arrests that met inclusion criteria occurred in adults at the 207 participating hospitals. An organized emergency team is available 24 h a day, 7 days a week in 86% of participating institutions. The three most common reasons for cardiac arrest in adults were (1) cardiac arrhythmia, (2) acute respiratory insufficiency, and (3) hypotension. Overall, 44% of adult in-hospital cardiac arrest victims had a return of spontaneous circulation (ROSC); 17% survived to hospital discharge. Despite the fact that a primary arrhythmia was one of the precipitating events in nearly one half of adult cardiac arrests, ventricular fibrillation (VF) was the initial pulseless rhythm in only 16% of in-hospital cardiac arrest victims. ROSC occurred in 58% of VF cases, yielding a survival-to-hospital discharge rate of 34% in this subset of patients. An automated external defibrillator was used to provide initial defibrillation in only 1.4% of patients whose initial cardiac arrest rhythm was VF. Neurological outcome in discharged survivors was generally good. Eighty-six percent of patients with Cerebral Performance Category-1 (CPC-1) at the time of hospital admission had a postarrest CPC-1 at the time of hospital discharge.

Adolescent↗

Comparison of standard CPR versus diffuse and stacked hand position interposed abdominal compression-CPR in a swine model.

Interposed abdominal compression cardiopulmonary resuscitation (IAC-CPR) is an innovative basic life support technique requiring no mechanical adjuncts. Optimizing its performance remains a challenge. Hand-position technique over the abdomen during interposed abdominal compression (IAC) may be important. The purpose of this study was to determine if there is a difference in efficacy depending on the type of abdominal hand-position used. Two different hand positions were studied: open hands, placed side by side, resulting in diffuse abdominal compression and stacked hands, with one on top of the other, producing a more focal compression of the abdomen. Thirty swine were cannulated with micromanometer-tipped pressure transducers in the ascending aorta (Ao) and right atrium (RA), and Millar Doppler-tipped catheters in the descending aorta and inferior vena cava (IVC) to determine flow patterns during cardiopulmonary resuscitation (CPR), During CPR there were no differences in aortic systolic or right atrial systolic pressures. Both forms of IAC-CPR produced greater aortic diastolic and right atrial diastolic pressures then standard CPR (STD-CPR) (P<0.05). Coronary perfusion pressures (CPP), however, were not different. Blood flow directions and velocity patterns showed that STD-CPR chest compressions produce caudally directed blood flow in both the descending aorta and the IVC, and that such flows reverse (becoming cranially directed) during the relaxation phase of chest compression. IAC-CPR produced similar blood flow patterns in the aorta and IVC, as seen with STD-CPR. There were no differences in blood flow patterns between the different forms of IAC-CPR. No CPR-produced trauma difference was found. Abdominal hand position (diffuse or stacked) did not affect blood flow in either the aorta or IVC or resuscitation success in this experimental model. There was a trend towards better outcomes with stacked hands IAC-CPR with 90 versus 70% survival with STD-CPR.

Abdomen↗

Automated external defibrillation versus manual defibrillation for prolonged ventricular fibrillation: lethal delays of chest compressions before and after countershocks.

STUDY OBJECTIVE: We sought to determine whether the delays in chest compressions and defibrillation associated with an automated external defibrillator would adversely affect outcome compared with manual defibrillation in a swine model of out-of-hospital prolonged ventricular fibrillation. METHODS: After 8 minutes of untreated ventricular fibrillation, 16 swine (33+/-4 kg) were randomly assigned to automated external defibrillator defibrillation or manual defibrillation with the same biphasic truncated exponential waveform 150-J shock through the same type of pads. Defibrillation with the automated external defibrillator was performed as recommended by the manufacturer, and manual defibrillation was provided per American Heart Association Guidelines. The primary outcome measure was 24-hour survival with good neurologic outcome. Data are described as means+/-SD. RESULTS: None of 8 animals in the automated external defibrillator group survived for 24 hours, whereas 5 of 8 animals in the manual defibrillation group survived 24 hours, all with good neurologic outcome (P=.027). The time interval from simulated defibrillator arrival to first compressions was 98+/-18 seconds in the automated external defibrillator group versus 68+/-15 seconds in the manual defibrillation group. In particular, the interval from first shock to first chest compressions was 46+/-18 seconds versus 22+/-16 seconds, respectively. The mean percentage of time that chest compressions were performed in the first minute after the first countershock was 15%+/-13% versus 40%+/-15%, respectively. As a result, return of spontaneous circulation within 5 minutes of simulated defibrillator arrival occurred in only 1 of 8 animals in the automated external defibrillator group versus 6 of 8 animals in the manual defibrillation group. CONCLUSION: The longer delays in chest compressions with automated external defibrillator defibrillation versus manual defibrillation can worsen the outcome from prolonged ventricular fibrillation.

Animals↗