Bench-to-bedside review: Resuscitation in the emergency department

Over the past decade the practice of acute resuscitation and its monitoring have undergone significant changes. Utilization of noninvasive mechanical ventilation, goal-directed therapy, restricted fluid volume, blood transfusion and minimally invasive technology for monitoring tissue oxygenation have changed the practice of acute resuscitation. Early diagnosis and definitive treatment of the underlying cause of shock remains the mainstay for survival after successful resuscitation. Patient-centered outcome end-points, in addition to survival, are being utilized to appraise the effectiveness of treatment. Application of medical ethics to the ever changing practice of acute resuscitation has also become a societal expectation.     

Resuscitation in shock associated with burns. Tradition or evidence-based medicine?

OBJECTIVE: To summarize the present standards and guidelines for fluid treatment of shock associated with burns, and to evaluate their scientific support in the literature. DESIGN: Nonsystematic, critical review of the literature regarding the indications for crystalloid and colloid fluid treatment, invasive monitoring and the use of resuscitation end points in shock associated with burns. SUMMARY POINTS: Crystalloid fluid resuscitation of patients with burns is traditionally managed using empirical resuscitation formulae, with the efficacy monitored by vital signs and urinary output The value of these end points has been questioned by recent studies, which have suggested that such noninvasive parameters may be inadequate for detecting malperfusion. No consensus exists regarding appropriate assessment of adequate resuscitation, and the impact on survival of invasive measures has still to be proven in controlled randomized trials. Generally, a significantly higher fluid requirement has been demonstrated when resuscitation is based on invasive cardiorespiratory monitoring. Colloid resuscitation in burns patients is controversial. Published reports suggest that colloid infusion should be started between 6 and 36 h following thermal injury. A recent meta-analysis highlighted the shortcomings of albumin in patients with burns, and this, together with restrictions for the use of plasma products, has obscured the choice of colloid solution. The effect of colloid resuscitation on survival remains to be proven in burned patients. CONCLUSION: The current standards for monitoring fluid therapy in patients with large burns are not supported by scientific data. Further randomized, controlled trials are indicated, and should help establish general guidelines regarding monitoring and treatment end points in these patients.     

Cardiopulmonary and cerebral resuscitation

The future of cardiopulmonary resuscitation lies in new technologies for monitoring and generating vital organ perfusion during cardiac arrest and the post-resuscitation phase and in pharmacologic agents that will enhance ROSC and reverse ischemia-reperfusion injury. ROSC is the first step toward survival, so interventions that improve ROSC deserve further investigation. Long-term survival with good neurologic recovery is the critical endpoint. Interventions recommended for clinical practice must therefore demonstrate improved long-term survival. The resources required to provide many of the interventions discussed in this article, principally invasive perfusion technologies, cannot be justified unless there is clear benefit. The allocation of such resources to provide intensive resuscitation and post-resuscitation support will need to be addressed from medical and societal viewpoints.     

Defibrillation by general practitioners

OBJECTIVE: To investigate the mode of cardiac arrest in patients with acute myocardial infarction attended by general practitioners, and the effectiveness of early defibrillation. DESIGN: Retrospective observational study. SETTING: British general practice. PARTICIPANTS: General practitioners equipped with defibrillators by the British Heart Foundation. MAIN OUTCOME MEASURES: Cardiac rhythm when first monitored, response to defibrillation assessed by survival to reach hospital alive and survival to hospital discharge. INTERVENTIONS: Defibrillation and standard cardiopulmonary resuscitation in patients with cardiac arrest complicating acute myocardial infarction attended by British general practitioners. RESULTS: When a doctor equipped with a defibrillator witnessed an arrest or was able to initiate resuscitation within 4 min of the patient collapsing, 90% of patients were found to have developed a rhythm likely to respond to a defibrillatory shock. Defibrillation under these circumstances was very successful with more than 70% of patients subsequently admitted to hospital alive and approximately 60% surviving to be discharged alive. When the doctor commenced resuscitation later, fewer patients were found to have rhythms likely to be responsive to a DC shock. A greater proportion was in asystole and resuscitation was less frequently successful under these circumstances. When the arrest occurred in the doctor's surgery, 85% of patients were admitted to hospital alive and three quarters survived to hospital discharge. CONCLUSIONS: All those who provide the initial care for this vulnerable group of patients should be equipped with defibrillators. The more widespread deployment of defibrillators in the community may be a successful strategy for reducing unnecessary deaths from coronary heart disease.     

Capnography as a predictor of the return of spontaneous circulation

EtCO2 monitoring is a valuable tool for clinical management of patients in cardiac arrest, near-arrest and post-arrest. During cardiac arrest, EtCO2 levels fall abruptly at the onset of cardiac arrest, increase after the onset of effective CPR and return to normal at return of spontaneous circulation (ROSC). During effective CPR, end-tidal CO2 has been shown to correlate with cardiac output, coronary perfusion pressure, efficacy of cardiac compression, ROSC and even survival. Colorimetric detectors (shown to correlate with infrared capnometry) have been shown to have prognostic value in both adult and pediatric CPR. The higher the initial value of EtCO2, the greater was short-term survival. EtCO2 is a useful tool during patient resuscitation for evaluating the current and potential effects of treatment, and could be potentially useful in determining when to terminate resuscitation efforts.     

An overview of the new resuscitation guidelines

New resuscitation guidelines contain significant changes intended to improve resuscitation practice and survival from cardiac arrest. The guidelines also include helpful new sections with guidance on in-hospital resuscitation. This article provides an overview of the key changes and discusses their practice implications for nurses.     

Colloids versus crystalloids for emergency patients

Emergency as well as critical care nurses are often responsible for the administration and regulation of fluid resuscitation for their patients. A serious and potentially fatal decline in vital organ performance can often occur as a result of inappropriate volume management. However, emergency and/or critically ill patients who require fluid resuscitation often receive concurrent therapy and monitoring that may have equal or greater impact on the survival and therapeutic end points than does the type of fluid received. These variables have made historical comparisons of crystalloid versus colloid resuscitation difficult. The purpose of this article is to critique three articles that examine crystalloid and colloid resuscitation for patients with various disease processes.     

护理干预对重症急性胰腺炎病人液体复苏的影响

介绍了液体复苏的相关概念、液体复苏与重症急性胰腺炎（SAP）早期并发症之间的关系、护理干预措施对SAP病人液体复苏的影响。重点阐述了液体复苏的监护、参考指标的选择、监护记录表的改良、液体复苏的时间及顺序、液体复苏单位时间量。     

Lactate profiles as a resuscitation assessment tool in a rat model of battlefield hemorrhage resuscitation

Time profiles of arterial lactate concentrations have been proposed as markers for both the degree of physiological derangement during shock and effectiveness of clinical resuscitation, but have not been evaluated for use in short-term experimental protocols. We developed two quantitative mixed models of sequential arterial lactate concentrations to evaluate competing low-volume (<4 mL/kg) battlefield resuscitation therapies in a rat model of acute severe hemorrhagic shock: a simple linear additive model and a nonlinear mechanistic model that described lactate profiles in a continuous trajectory with a defined turning point. Data were obtained during a study evaluating a novel hemoglobin polymer (OxyVita) in a cocktail of hypertonic saline and Hextend as an alternative to standard Hextend. Fluids were either infused by titration to a mean systolic pressure of 60 mmHg or as a single bolus. Parameter estimates derived from both models were assessed for evidence of treatment efficacy and as indicators of short-term survival. A cocktail of hypertonic saline and Hextend was superior to standard Hextend in enhancing survival; however, lactate profiles did not differ between treatments. Regardless of resuscitation regimen, animals surviving to at least 60 min posthemorrhage can be discriminated from nonsurvivors by significantly lower peak lactates (a difference of at least 3 mM; P < 0.001), and all survivors exhibited a decline in lactate with resuscitation. Sequential measurements of lactate over relatively short time frames during resuscitation are of value in assessing both response to resuscitation and short-term mortality.     

The problem with and benefit of ventilations: should our approach be the same in cardiac and respiratory arrest?

PURPOSE OF REVIEW: Recent advances in cardiopulmonary resuscitation have led to greater understanding of cardio-cerebral-pulmonary interactions during the process. The purpose of this discussion is to update the physiologic understanding of these interactions during cardiopulmonary resuscitation, review the detrimental and beneficial effects of ventilation, and identify implications for clinical practice. RECENT FINDINGS: There is an inversely proportional relationship between mean intrathoracic pressure, coronary perfusion pressure, and survival from cardiac arrest. Increased ventilation rates and increased ventilation duration impede venous blood return to the heart, decreasing hemodynamics and coronary perfusion pressure during cardiopulmonary resuscitation. It has also been shown that there is a direct and immediate transfer of the increase in intrathoracic pressure to the cranial cavity with each positive pressure ventilation, also reducing cerebral perfusion pressure. The reduced amount of blood flowing through the pulmonary bed during cardiopulmonary resuscitation tends to be overventilated, compromising hemodynamics to both the heart and brain and resulting in ventilation/perfusion mismatch. SUMMARY: The fundamental hemodynamic principle of intrathoracic pressure defines cardio-cerebral-pulmonary interactions during cardiopulmonary resuscitation. Further research is essential to optimize these interactions during treatment of profound shock.     

延迟复苏治疗活动性失血性休克临床探讨

目的：探讨延迟复苏策略治疗重症活动性失血性休克在临床的应用实践。方法：延迟复苏组（A组）,限制输晶体液和胶体液量,扩容更多地依赖输血及血浆,控制目标血压以收缩压80~90 mm Hg（1 mm Hg=0.133 kPa）为允许性低血压;传统复苏组（B组）,不限制输晶体液和胶体液量,快速进行液体复苏。输液以晶体液和胶体液为主,输血及血浆为辅助,不有意控制血压上限。结果：A组抢救成活率显著高于B组。结论：在重症加强护理病房（ICU）临床上认识重症活动性失血性休克特殊性以及治疗的特殊性。应用延迟复苏方法,有望提高该类危重患者的治愈率。     

PICCO监测在创伤性急性呼吸窘迫综合征治疗中的应用研究

目的：探讨PICCO在指导创伤急性肺损伤（ALI）/急性呼吸窘迫综合症（ARDS）患者液体容量管理治疗及判断预后的意义,为创伤性ARDS治疗提供新的监测手段。方法：为前瞻性观察研究,对已诊断创伤性ARDS的患者进行随机分为实验组与对照组,两组患者均给予常规监护及一般治疗。实验组应用PiCCO对血流动力学的变化进行监测并进行早期积极的液体容量管理,对照组给予经验性液体治疗管理。采用统计学软件SPSS 17.0进行数据处理及分析。结果：与对照组比较PICCO组APPACHⅡ评分在24h和72h时明显降低（P〈0.05）;实验组肺泡-动脉氧分压差的变化72h后明显好于对照组（P〈0.01）;机械通气时间和入住EICU时间明显缩短（P〈0.01）。但对创伤性ARDS患者的死亡率并无明显影响（P〉0.05）。PICCO组中,EVLWI在存活组明显低于死亡组。结论：应用PICCO监测指导创伤性ARDS早期液体治疗,能有效缩短创伤性ARDS患者机械通气时间和入住EICU时间,EVLWI可有效评估创伤性ARDS患者预后。     

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.     

Monitoring during resuscitation

Use of many different types of monitors during resuscitation has been described in the literature. These monitors differ in their usefulness, technical feasibility, initial costs, and long-term costs (Table 4). There have been many published reports of CPR success rates in the hospital and in the pre-hospital setting. In spite of considerable advances in technology over the past 30 years, survival from CPR has changed little over that time. Although numerous types of monitoring during resuscitation are possible, and sometimes useful, the impact of expensive technology on ultimate outcome (survival) must be critically evaluated.     

A MIODARONE AND R URAL E MERGENCY M EDICAL S ERVICES C ARDIAC A RREST P ATIENTS : A C OST A NALYSIS

Objective: Recent American Heart Association guidelines suggest amiodarone as an antiarrhythmic in refractory ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). The authors sought to assess the impact of amiodarone use on outcomes and cost associated with this practice in a rural emergency medical services (EMS) state. Methods: Statewide EMS records were reviewed for the calendar year 1999. Data reviewed included prehospital diagnosis, medications given by prehospital providers to patients with cardiac arrest, and procedures performed, including cardiopulmonary resuscitation (CPR) and defibrillation. Cost-benefit analysis assumed the cost of amiodarone treatment to be $137.65 per patient encounter. Absolute risk reduction (ARR) and number needed to treat (NNT) analysis utilized resuscitation rates published in the ARREST and ALIVE trials. Results: During the study period, EMS providers diagnosed 2,189 patients as having cardiac arrest. Five hundred thirty-five (24.4%) cardiac arrest patients were defibrillated. One hundred sixty patients (7.3%), including 15 who did not receive defibrillation, were given lidocaine during resuscitation efforts. The annual cost increase from current practice for a statewide amiodarone VF/VT protocol was $21,822.40 (10,572.87%). The initial cost to stock EMS vehicles for this protocol would be $50,115.52. The cost-benefit analysis yielded a potential for one additional patient survival to hospital discharge in Maine per 3.125 years of system-wide practice at a cost of $68,840.00. Conclusion: Based on current data, instituting amiodarone treatment for refractory VF and pulseless VT in a rural EMS setting requires the investment of substantial resources, relative to current treatment strategies, for any potential survival benefit.     

Amiodarone and rural emergency medical services cardiac arrest patients: A cost analysis

Objective: Recent American Heart Association guidelines suggest amiodarone as an antiarrhythmic in refractory ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). The authors sought to assess the impact of amiodarone use on outcomes and cost associated with this practice in a rural emergency medical services (EMS) state. Methods: Statewide EMS records were reviewed for the calendar year 1999. Data reviewed included prehospital diagnosis, medications given by prehospital providers to patients with cardiac arrest, and procedures performed, including cardiopulmonary resuscitation (CPR) and defibrillation. Cost-benefit analysis assumed the cost of amiodarone treatment to be $137.65 per patient encounter. Absolute risk reduction (ARR) and number needed to treat (NNT) analysis utilized resuscitation rates published in the ARREST and ALIVE trials. Results: During the study period, EMS providers diagnosed 2,189 patients as having cardiac arrest. Five hundred thirty-five (24.4%) cardiac arrest patients were defibrillated. One hundred sixty patients (7.3%), including 15 who did not receive defibrillation, were given lidocaine during resuscitation efforts. The annual cost increase from current practice for a statewide amiodarone VF/VT protocol was $21,822.40 (10,572.87%). The initial cost to stock EMS vehicles for this protocol would be $50,115.52. The cost-benefit analysis yielded a potential for one additional patient survival to hospital discharge in Maine per 3.125 years of system-wide practice at a cost of $68,840.00. Conclusion: Based on current data, instituting amiodarone treatment for refractory VF and pulseless VT in a rural EMS setting requires the investment of substantial resources, relative to current treatment strategies, for any potential survival benefit. PREHOSPITAL EMERGENCY CARE 2002;6:291-294     

急性心肌梗死心肺复苏后溶栓治疗临床价值探讨

目的:探讨急性心肌梗死心肺复苏后溶栓治疗的安全性及临床价值。方法:选择7例急性心肌梗死并心肺复苏后溶栓治疗的患者,分析其冠脉再通率、自主循环恢复率、急性期死亡率、出院生存率、重要脏器出血的发生率、脑复苏的成功率等。结果:对于急性心肌梗死并心肺复苏后的患者,在排除急性心包填塞、胸腹腔出血、继发性颅内出血后给予及时溶栓开通冠脉,能提高患者的自主循环恢复率、出院生存率、降低急性期死亡率,重要脏器出血的发生率无明显提高;对于发病年龄较轻、心肺复苏时间10 min的患者,脑复苏的成功率较高。结论:急性心肌梗死心肺复苏后溶栓治疗是安全有效的。     

Short-term health system costs of paediatric in-hospital acute life-threatening events including cardiac arrest

ObjectivesAcute life-threatening events in children are medical emergencies requiring immediate intervention. They can be due to cardiac arrest, respiratory arrest or another cause of sudden compromise for example, choking. Internationally, hospital systems are being introduced to reduce preventable acute life-threatening events and, despite having significant resource implications, have not yet been subject to economic analysis. This study presents the additional short-term health service costs of in-hospital acute life-threatening events to inform a cost-effectiveness analysis of prevention strategies.MethodologyPatient level costs (GB pounds, price year 2005), in excess of baseline costs, were collected from a short-term NHS perspective. The cost per survivor to hospital discharge included the cost of the cardiopulmonary resuscitation attempt, resuscitation preparedness, and the cost of in-hospital post-resuscitation care. Acute life-threatening events calls were classified into two groups: cardiac arrest, and respiratory arrest and other acute life threatening events. Outcomes from these groups were compared to a similar group of unplanned Paediatric Intensive Care (PIC) admissions. All survival and length of stay outcomes were calculated for the first episode.ResultsThe survival to hospital discharge was 64.4% (65/101), (95% Confidence Intervals 55.02, 73.70) for all acute life-threatening event calls, and 41.3% (12/29), (95% Confidence Intervals 23.45, 59.31) for cardiac arrest. The mean cost of the resuscitation attempt was £3664 for all acute life-threatening event calls, and £3884 for cardiac arrest. The annual cost of cardiopulmonary resuscitation preparedness was £181,565.The mean cost of the post-event length of stay in hospital was £22,562 for cardiac arrest, £26,335 for other acute life-threatening events, and £26,138 for urgent PIC admissions. The cost per survivor to hospital discharge was £53,289.ConclusionThe short-term costs of paediatric in-hospital acute life-threatening events, including cardiac arrest, from an NHS perspective, are more expensive than those reported for adults, but similar to other life saving treatments. This new information will serve to improve efficiency in the current resuscitation programme and contribute to cost-effectiveness analysis of prevention strategies.     

Monitoring during cardiac arrest: are we there yet?

Advancements in electronic data acquisition have translated into improved monitoring of victims of cardiac arrest, but initial techniques remain direct observation of pulses and respirations. The most essential monitor continues to be the electrocardiogram. However, monitoring diastolic blood pressure, myocardial perfusion pressure, and end-tidal carbon dioxide are extremely useful. Most of the current research on monitoring during cardiopulmonary resuscitation focuses on methods for analyzing ventricular fibrillation waveforms. By analyzing the waveform, defibrillation shocks may be delivered at the time when the chance of success is optimal. Low-amplitude and low-frequency fibrillation waveforms are associated with increased rates of asystole and pulseless electrical activity after defibrillation. Methods of analyzing the ventricular fibrillation waveform include measuring the amplitude and frequency and combining the contributions of amplitude and frequency by various methods to improve discrimination. Other types of monitoring being studied for their usefulness during cardiac arrests include sonography, Bispectral Index monitoring, tissue carbon dioxide monitors, and pupil observation. The test of these monitoring techniques is ultimately their ability to improve patient survival to hospital discharge, which is a major challenge for resuscitation researchers.     

Microdialysis shows metabolic effects in skin during fluid resuscitation in burn-injured patients

Introduction  

Established fluid treatment formulas for burn injuries have been challenged as studies have shown the presence of tissue hypoxia during standard resuscitation. Such findings suggest monitoring at the tissue level. This study was performed in patients with major burn injuries to evaluate the microdialysis technique for the continuous assessment of skin metabolic changes during fluid resuscitation and up to four days postburn.