Early selective trans-nasal cooling during CPR improves success of resuscitation in a porcine model of prolonged pulseless electrical activity cardiac arrest.

Aim Of Study: In the present study, we investigated trans-nasal cooling in settings of pulseless electrical activity (PEA). We hypothesized that early trans-nasal cooling during CPR improves outcomes when cardiac arrest is associated with PEA.

Methods: Ventricular fibrillation (VF) was electrically induced in 16 domestic male pigs weighing 40±3 kg.

Clinical correlates of arterial lactate levels in STEMI patients.

Increases in blood lactate reflect decreases in systemic blood flows associated with low blood flow states characteristic of circulatory shock. Accordingly, the report by Vermeulen and colleagues documents the use of the blood lactate measurement as a prognostic indicator in settings of ST elevation myocardial infarction. That lactate value therefore identified high-risk patients as a complication, often with clinical signs of cardiogenic shock of corresponding severities.

An algorithm used for ventricular fibrillation detection without interrupting chest compression.

Ventricular fibrillation (VF) is the primary arrhythmic event in the majority of patients suffering from sudden cardiac arrest. Attention has been focused on this particular rhythm since it is recognized that prompt therapy, especially electrical defibrillation, may lead to a successful outcome. However, current versions of automated external defibrillators (AEDs) mandate repetitive interruptions of chest compression for rhythm analyses since artifacts produced by chest compression during cardiopulmonary resuscitation (CPR) preclude reliable electrocardiographic (ECG) rhythm analysis.

From intensive care to critical care medicine: a historical perspective.

The evolution of Critical Care Medicine is traced in relationship to its predecessors, namely Intensive Care and Intensive Therapy. This commentary documents the initial physical care rendered by professional nurses in hospitals of the 19th century in locations close to the nursing stations. The development of incubators for newborns and life-support devices to support ventilation and renal function or to reverse fatal arrhythmias characterized Intensive Therapy of the early 20th century.

Effect of therapeutic hypothermia vs δ-opioid receptor agonist on post resuscitation myocardial function in a rat model of CPR.

Aim: This study is to compare the effect of the δ-opioid receptor agonist, D-Ala(2)-D-Leu(5) enkephalin (DADLE) with normothermic control and therapeutic hypothermia on post resuscitation myocardial function and 72-h survival in a rat model of cardiac arrest and resuscitation.

Methods: Ventricular fibrillation (VF) was induced in 15 male Sprague-Dawley rats. After 8 min of untreated VF, cardiopulmonary resuscitation was performed for 8 min before defibrillation.

Pharmacologically induced hypothermia with cannabinoid receptor agonist WIN55, 212-2 after cardiopulmonary resuscitation.

Objective: To investigate whether hypothermia could be induced pharmacologically after resuscitation with the cannabinoid CB1/CB2 receptor agonist in a rat model and its effects on outcomes of cardiopulmonary resuscitation.

Design: Prospective, randomized, placebo-controlled experimental study.

Setting: University-affiliated animal research laboratory.

The effects of epinephrine on outcomes of normothermic and therapeutic hypothermic cardiopulmonary resuscitation.

Objective: To investigate the effects of epinephrine when administered during either normothermic or therapeutic hypothermic cardiopulmonary resuscitation on postresuscitation myocardial and cerebral function and survival.

Design: Prospective, randomized, placebo-controlled experimental study.

Setting: University-affiliated animal research laboratory.

Hypothermia improves ventricular myocyte contractility under conditions of normal perfusion and after an interval of ischemia.

Aim: Recent investigations have reported improved myocardial function during hypothermia following resuscitation from cardiac arrest. The effects of hypothermia on myocyte contractility were investigated under conditions of normal perfusion and after a 10min interval of ischemia.

Methods: Ventricular myocytes were obtained from 10 male Sprague-Dawley rats weighing 400+/-50g.

The optimal phasic relationship between synchronized shock and mechanical chest compressions.

Objective: Pauses for shock delivery in chest compressions are detrimental to the success of resuscitation and may be eliminated with the use of mechanical chest compressors. However, the optimal phasic relationship between mechanical chest compression and defibrillation is still unknown. We therefore undertook a study to assess the effects of timing of defibrillation in the mechanical chest compression cycle on the defibrillation threshold (DFT) using a porcine model of cardiac arrest.

Apoptosis is not involved in the mechanism of myocardial dysfunction after resuscitation in a rat model of cardiac arrest and cardiopulmonary resuscitation.

Objective: To investigate the presence of apoptosis after the global myocardial ischemia of cardiopulmonary resuscitation and the regional myocardial ischemia after left anterior descending coronary artery occlusion and relate it to the severity of postresuscitation myocardial dysfunction.

Design: Prospective animal study.

Setting: University-affiliated animal research laboratory.

Opioid receptor agonist reduces myocardial ischemic injury when administered during early phase of myocardial ischemia.

Aim Of The Study: Postresuscitation myocardial dysfunction is one of the leading causes of early death after initial success of resuscitation, the mechanisms of postresuscitation myocardial dysfunction remain controversial. We hypothesize that ischemia injury, rather than reperfusion injury is the major cause of postresuscitation myocardial dysfunction. We proposed to investigate the separate effects of ischemia and reperfusion injury on postresuscitation myocardial dysfunction.

Intra-arrest selective brain cooling improves success of resuscitation in a porcine model of prolonged cardiac arrest.

Aims Of Study: We have previously demonstrated that early intra-nasal cooling improved post-resuscitation neurological outcomes. The present study utilizing a porcine model of prolonged cardiac arrest investigated the effects of intra-nasal cooling initiated at the start of cardiopulmonary resuscitation (CPR) on resuscitation success. Our hypothesis was that rapid nasal cooling initiated during "low-flow" improves return of spontaneous resuscitation (ROSC).

Survival and neurological outcomes after nasopharyngeal cooling or peripheral vein cold saline infusion initiated during cardiopulmonary resuscitation in a porcine model of prolonged cardiac arrest.

Objective: We have previously demonstrated that nasopharyngeal cooling initiated during cardiopulmonary resuscitation improves the success of resuscitation. In this study, we compared the effects of nasopharyngeal cooling with cold saline infusion initiated during cardiopulmonary resuscitation on resuscitation outcome in a porcine model of prolonged cardiac arrest. We hypothesized that nasopharyngeal cooling initiated during cardiopulmonary resuscitation would yield better resuscitation outcome when compared with cold saline infusion.

The cerebral microcirculation is protected during experimental hemorrhagic shock.

Objective: Decreases in buccal microcirculation are indicative of the severity of hemorrhage, but incidental observations suggest that this may not apply to the cerebral microcirculation. We therefore hypothesized that the cerebral microcirculation may be preserved in hemorrhagic shock in which systemic and buccal microcirculatory flow are reduced. We propose to relate changes in the macrocirculation to the buccal and cerebral microcirculations during hemorrhage and after fluid resuscitation.

Defibrillation delivered during the upstroke phase of manual chest compression improves shock success.

Objective: The current standard of manual chest compression during cardiopulmonary resuscitation requires pauses for rhythm analysis and shock delivery. However, interruptions of chest compression greatly decrease the likelihood of successful defibrillations, and significantly better outcomes are reported if this interruption is avoided. We therefore undertook a prospective randomized controlled animal study in an electrically induced ventricular fibrillation pig model to assess the effects of timing of defibrillation on the manual chest compression cycle on the defibrillation threshold.

Biomarkers of myocardial injury after cardiac arrest or myocardial ischemia.

Outcomes of victims of cardiac arrest or acute myocardial ischemic events have improved with advances in medical therapy. Heart failure, however, remains a leading cause of morbidity and mortality after these conditions have occurred. Clinical features may be useful for predicting patients who are at risk of developing such complications, but they lack of sensitivity and specificity.

The resuscitation blanket: a useful tool for "hands-on" defibrillation.

Aim Of Study: We investigated the safety, feasibility and efficacy of a resuscitation blanket designed with the intent to protecting the rescuer from the risk of receiving electrical current during defibrillation which, would allow for uninterrupted chest compressions.

Methods: Fifteen pigs weighing between 22 and 40 kg were investigated with an established model of cardiac arrest and CPR. CPR was performed with the interposition of the blanket between the rescuer's hands and the chest of the animal.

The effects of phase duration on defibrillation success of dual time constant biphasic waveforms.

Aim Of Study: The effects of first and second phase duration of biphasic waveforms on defibrillation success were evaluated in a guinea pig model of ventricular fibrillation (VF). We hypothesized that waveform duration, and especially the first phase duration, played a main role on defibrillation efficacy in comparison to energy, current and voltage, when a dual time constant biphasic shock was employed.

Methods: VF was induced and untreated for 5s in 30 male guinea pigs, prior to attempting a single defibrillatory shock with one of 5 defibrillation waveforms which had different durations of the first and second phase.

A comparison of defibrillation efficacy between different impedance compensation techniques in high impedance porcine model.

Aim Of Study: Impedance compensation methods differ markedly among manufacturers and can play an important role in defibrillation success. In this study we compared the efficacy of two different commercial defibrillators based on defibrillation success in a high impedance porcine model of cardiac arrest. The first defibrillator (A) compensates high impedance by controlling current with fixed shock duration, while the second defibrillator (B) by prolonging the shock duration.

Challenging the rationale of routine vasopressor therapy for management of hypotension.

There is persuasive evidence, including the present report by Dubin and colleagues, of a dissociation between increases in arterial pressure produced by vasopressor agents and improvement in microvascular perfusion and delivery of vital substrates. Especially in settings of septic shock, the current routine administration of adrenergic vasopressor therapy therefore may fail to reverse the primary defect.

Comparison of efficacy of pulsed biphasic waveform and rectilinear biphasic waveform in a short ventricular fibrillation pig model.

Aim Of Study: The waveform designs and their relative defibrillation efficacy of external biphasic waveforms may differ remarkably among manufacturers. In this study, we compared pulsed biphasic waveform (PBW) with rectilinear biphasic waveform (RBW) and their effects on terminating ventricular fibrillation (VF).

Methods: VF was electrically induced and untreated for 10s in 6 domestic pigs weighing between 56 and 70 kg.

Individual effect of components of defibrillation waveform on the contractile function and intracellular calcium dynamics of cardiomyocytes.

Objectives: Although electrical shock is a unique and effective treatment for fatal arrhythmia, it produces myocardial dysfunction closely related to the intensity of shock delivered. The isolated contribution of defibrillator components to postshock contractile impairment is not yet securely established. We sought to evaluate contractile function in cardiomyocytes following electrical shocks with different peak currents, energies, and durations.

Preserved cerebral microcirculation during cardiogenic shock.

Objective: To hypothesize that in severe states of cardiogenic shock with profound decreases in buccal microcirculation, the cerebral microcirculation may be selectively protected. Decreases in buccal microcirculatory flow are closely associated with the severity and outcomes of circulatory shock.

Design: We investigated the concurrent changes in cerebral and buccal microcirculation, in a rat model of cardiogenic shock caused by left ventricular failure.

Coronary blood flow produced by muscle contractions induced by intracardiac electrical CPR during ventricular fibrillation.

Unlabelled: It has been reported that transthoracic electrical cardiopulmonary resuscitation (ECPR) generates coronary perfusion pressures (CPP) similar to manual chest compressions (MCC). We hypothesized that intracardiac ECPR produces similar CPP.

Methods: ECPR pulse train protocols were applied for 20 seconds in a porcine model following 10 seconds of ventricular fibrillation (VF), using a defibrillator housing electrode and a right ventricular coil (IC-ECPR).