Resuscitation
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Comparative Study
Comparison of ease of use of three automated external defibrillators by untrained lay people.
The use of automated external defibrillators (AED) by lay people has the potential to markedly increase survival from community cardiac arrest. Wider public use of AEDs requires units that can be operated safely and effectively by people with minimal or no training. This study compares the use of three AEDs by untrained lay people regarding ease-of-use, safety, pad positioning and time to defibrillation. 24 subjects with no prior exposure to the use of AEDs were asked to perform simulated defibrillation on a manikin using three defibrillators: Zoll AEDPlus, Medtronic Physio-Control LifePak CR Plus and Philips/Laerdal HeartStart OnSite Defibrillator. ⋯ The majority of subjects safely and effectively delivered defibrillating shocks without any prior training and within quite acceptable times. Untrained subjects find the Physio-Control and Laerdal Defibrillator easier to use than the Zoll device. Features of AED design that improved ease of use are discussed.
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Guidelines for the management of suspected spinal injury patients from the scene of their accident to the emergency department were published in September 1998. This study was commissioned on behalf of the Faculty of Pre-hospital Care at the Royal College of Surgeons of Edinburgh, to examine the handling of patients on spinal boards on arrival in the emergency department. ⋯ It is suggested that as the spine board is such a widely used piece of equipment, there should be some guidelines to standardise its use at the emergency department interface with pre-hospital care. We recommend that spinal board removal should be part of the completion of the primary survey.
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Randomized Controlled Trial Clinical Trial
Hypoxia and hypercapnia during respiration into an artificial air pocket in snow: implications for avalanche survival.
Snow avalanche case reports have documented the survival of skiers apparently without permanent hypoxic sequelae, after prolonged complete burial despite there being only a small air pocket on extrication. We investigated the underlying pathophysiological changes in a prospective, randomised 2 x 2 crossover study in 12 volunteers (28 tests) breathing into an artificial air pocket (1- or 2-l volume) in snow. Peripheral SpO(2), ETCO(2), arterialised capillary blood variables, air pocket O(2) and CO(2), snow density, and snow conditions at the inner surface of the air pocket were determined. ⋯ We conclude that the degree of hypoxia following avalanche burial is dependent on air pocket volume, snow density and unknown individual personal characteristics, yet long-term survival is possible with only a small air pocket. Hence, the definition of an air pocket, "any space surrounding mouth and nose with the proviso of free air passages" is validated as the main criterion for triage and management of avalanche victims. Our experimental model will facilitate evaluating the interrelation between volume and inner surface area of an air pocket for survival of avalanche victims, whilst the present findings have laid the basis for future investigation of possible interactions between hypoxia, hypercapnia, and hypothermia (triple H syndrome) in snow burial.
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Meta Analysis
Biphasic and monophasic shocks for transthoracic defibrillation: a meta analysis of randomised controlled trials.
Biphasic waveforms are routinely used for implantable defibrillators. These waveforms have been less readily adopted for external defibrillation. This study was performed in order to evaluate the efficacy and harms of biphasic waveforms over monophasic waveforms for the transthoracic defibrillation of patients in ventricular fibrillation (VF) or haemodynamically unstable ventricular tachycardia. ⋯ Biphasic waveforms defibrillate with similar efficacy at lower energies than standard 200 J monophasic waveforms, and greater efficacy than monophasic shocks of the same energy. Available data suggests that lower delivered energy and voltage result in less post-shock myocardial injury.
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Programs for research and practice in resuscitation have focused on identification and reversal of ventricular fibrillation (VF). While substantial progress has been achieved, evidence is accumulating that clinical death is less likely to be caused by fibrillation now than in the 1960s and 1970s. Pulseless electrical activity (PEA) has emerged as the most common rhythm found in arrests in the hospital and is rapidly rising in pre-hospital reports. ⋯ VF is a manifestation of severe, undiagnosed coronary artery disease (CAD). Rates of death from CAD increased from rare in 1930 to become the most common cause of death in the US. CAD death rates peaked in the early 1960s and had declined over 50% by the late 1990s. Primary and secondary prevention, early diagnosis and aggressive, successful treatment have contributed to this decline. PEA is a brief phase in clinical death that occurs after losses in consciousness, ventilatory drive and circulation but before decay to asystole; survival rates are poor. PEA is a common stage in clinical death from any of a variety of tissue hypoxic/anoxic insults. Research on PEA is needed; 50 years of attention to CAD and VF have resulted in improved survival and changed the disease spectrum. Similar attention to animal and clinical research on PEA may have the potential to improve survival.