2,833 publications from this institution
Electromechanical dissociation (EMD) is the most frequent cause of unsuccessful cardiac resuscitation in critically ill patients. In a clinical study of cardiac arrest, including 54 episodes in 50 fully monitored patients, 14 episodes of ventricular fibrillation were observed and seven were reversed. In the remaining 40 instances, 36 cases of EMD were initially observed. Four patients had asystole. None of the patients with EMD or asystole were successfully resuscitated. For objective study of EMD and its treatment, we developed an experimental model in which ventricular fibrillation was induced in mechanically ventilated dogs. EMD was predictably observed when, after an interval of 120 seconds, ventricular fibrillation was reversed with an external countershock. Neither metabolic acidosis nor metabolic alkalosis modified the incidence of EMD. A few dogs were pretreated with glucose-insulin-potassium or pharmacologic doses of methylprednisolone, but this did not clearly reduce the incidence of EMD. However, the onset of EMD was delayed when the body temperature of the animal was spontaneously reduced.
info:eu-repo/semantics/published
This observational study does not support the view that blood transfusions are associated with increased mortality rates in acutely ill patients.
SCOPUS: le.j
SCOPUS: ed.j
Nobody will argue with the observation that a positive fluid balance is associated with increased mortality rates (1-3). Indeed, this finding is not surprising, because patients who are more severely ill are more likely to develop edema whether or not they have renal failure. Therefore, studies investigating the impact of fluid balance on outcomes must use multivariable or propensity-matched analyses that include many variables in order to determine whether fluid balance is independently associated with outcome. This has been done in several recent studies. In a study conducted in our Department of Intensive Care in Brussels, fluid balance was more positive in non-surviving than in surviving patients with sepsis, and these factors remained related even after adjustment for many variables (2). The monocentric nature of the study may be seen as a weakness, but it is also a strength because it means that variability in patient management was limited. Larger observational studies conducted in Europe (3) and worldwide (1) have shown similar results. These two studies included many variables, enabling quite extensive multivariable analyses to be conducted. In the SOAP study (3), a positive fluid balance had an impressively high prognostic value, just below that of the SAPS II score. In the recent analysis of the ICON database, the effects of a positive fluid balance, again significantly associated with outcome, were particularly important after the first 24 hours (1).
Summary: Calcium-entry blockers were administered in an attempt to protect myocardium during cardiac arrest due to ventricular fibrillation in mechanically ventilated dogs. An intravenous injection of verapamil, nifedipine, or lidoflazine was administered prior to successively prolonged episodes of ventricular fibrillation, during which no thoracic compression was performed. It is of interest that ventricular defibrillation was more easily obtained after treatment with the three drugs. As previously observed in this model, nine control dogs developed electromechanical dissociation (EMD) after 120 seconds of ventricular fibrillation. In contrast, six of the 11 dogs treated with 0.3 mg/kg of verapamil recovered mechanical systole after 120 seconds of ventricular fibrillation (p < 0.05). Nifedipine administration also postponed the onset of EMD in three of four dogs. However, lidoflazine postponed the onset of EMD in only one of the eight dogs. The later onset of EMD after administration of verapamil or nifedipine in this model was attributed to myocardial protection by calcium-entry blockers during ventricular fibrillation. Decreased energy utilization during cardiac arrest was considered to be the principal protective mechanism. These observations indicate calcium-entry blockers, and especially verapamil and nifedipine, can be valuable drugs during cardiac resuscitation for ventricular fibrillation.
